Health

Early Signs of Colon Cancer Often Ignored

17. Unexplained Fever Unexplained, persistent fever can sometimes signal an underlying health issue, including colon cancer. As tumors grow, they can cause areas of inflammation or… Alina Yasinskaya - July 23, 2025

Colon cancer remains a significant health concern worldwide, with over 153,000 new cases diagnosed in the United States in 2023 alone, and more than 42,000 cases reported in the UK. Survival rates dramatically improve with early detection—over 90% of patients survive five years if diagnosed at an early stage, yet late-stage detection drops survival to about 14% American Cancer Society. The colon, a vital part of the digestive system, helps process waste and absorb nutrients. Unfortunately, subtle early symptoms often go unnoticed, leading to poorer outcomes.

1. Persistent Changes in Bowel Habits

1. Persistent Changes in Bowel Habits
A bathroom scene features a calendar hanging on the wall beside the toilet, marking regular bowel movement days. | Generated by Google Gemini

One of the earliest and most commonly overlooked warning signs of colon cancer is a persistent change in bowel habits. This can include diarrhea, constipation, or a noticeable change in stool consistency. While occasional irregularity is normal, especially with dietary or lifestyle changes, ongoing issues may indicate something more serious. For example, if you regularly experience constipation that lasts for several weeks, or if your stools suddenly become narrower and remain that way, it could be your body signaling an underlying problem.

People often dismiss these symptoms as minor or attribute them to stress, aging, or routine dietary fluctuations. However, experts caution that any significant change in your normal bowel pattern—especially when it persists for more than two to three weeks—warrants medical attention. According to the American Cancer Society, changes in bowel habits are among the most common early symptoms described by patients later diagnosed with colon cancer.

If you notice persistent constipation, ongoing diarrhea, or a sudden, unexplained alteration in your usual bowel movements, it’s important not to ignore these signs. Early intervention significantly increases the chances of successful treatment and recovery.

2. Rectal Bleeding or Blood in Stool

2. Rectal Bleeding or Blood in Stool
A close-up of a toilet bowl with traces of blood, alongside a stool sample container ready for a doctor’s examination. | Generated by Google Gemini

Noticing blood in your stool or on toilet paper can be alarming, yet many people dismiss this symptom as a sign of common issues like hemorrhoids or minor anal irritation. However, rectal bleeding or blood in the stool is also a potential early warning sign of colon cancer. Tumors in the colon or rectum can cause bleeding as they grow, damaging the delicate lining of the digestive tract.

The blood may appear bright red, indicating bleeding closer to the rectum, or darker, resembling tar, which can suggest bleeding higher up in the colon. While hemorrhoids and anal fissures are frequent, benign causes of blood in the stool, it’s essential not to assume the source without medical evaluation. Sometimes, people ignore this symptom for months, attributing it to their diet or minor issues.

The Cancer Research UK emphasizes the importance of prompt investigation for any unexplained rectal bleeding. If you experience blood in your stool, especially when combined with other changes in bowel habits or unexplained weight loss, schedule a visit with your doctor right away. Early diagnosis can make a critical difference in outcomes.

3. Unexplained Weight Loss

3. Unexplained Weight Loss
A concerned individual stands on a weight scale, closely watching the numbers in their weight loss journey. | Generated by Google Gemini

Sudden, unexplained weight loss is a symptom that should never be ignored, especially when it occurs without changes to diet or exercise habits. Colon cancer and other cancers can cause metabolic changes in the body, leading to rapid weight loss. As cancer cells grow and spread, they can alter how the body uses energy and nutrients, sometimes stealing nutrients from healthy tissues and increasing caloric expenditure.

For example, someone who loses 10 pounds in just a few months without trying—especially if their appetite remains the same—should be concerned. This kind of weight loss may be subtle at first but can quickly become noticeable. The underlying reason is often a combination of reduced absorption of nutrients, increased inflammation, and the body’s immune response to the presence of cancer cells.

According to the National Cancer Institute, unintentional weight loss is one of the red flags that should prompt medical evaluation. If you experience a persistent and unexplained drop in weight, it’s crucial to consult your doctor. Detecting the cause early can significantly impact treatment success and long-term health.

4. Abdominal Pain or Discomfort

4. Abdominal Pain or Discomfort
A person clutches their stomach with a pained expression, clearly experiencing discomfort from abdominal cramps and pain. | Generated by Google Gemini

Abdominal pain or discomfort is a symptom that is often easy to overlook, especially since many people experience occasional stomach cramps, bloating, or indigestion from time to time. However, when the pain is persistent or unusual, it may be a sign of something more serious, such as colon cancer. Tumors developing in the colon can create a blockage or irritate the lining of the bowel, leading to cramping, pain, or a sensation of fullness that doesn’t resolve with typical remedies.

Unlike common indigestion—which often has an identifiable cause like eating too quickly, consuming rich foods, or stress—pain related to colon cancer may feel different. It might be dull, sharp, or crampy, and it often doesn’t go away after a bowel movement or with over-the-counter antacids. In some cases, the pain may worsen over time or become associated with other symptoms like changes in bowel habits.

The Centers for Disease Control and Prevention (CDC) recommends paying close attention to recurring or persistent abdominal discomfort. If you experience ongoing pain, especially if it’s unexplained or accompanied by other symptoms, seek medical evaluation to rule out serious underlying conditions.

5. A Feeling That the Bowel Doesn’t Empty Completely

5. A Feeling That the Bowel Doesn't Empty Completely
A person sits thoughtfully on a toilet in a modern bathroom, highlighting the importance of digestive tract health. | Generated by Google Gemini

Another subtle but important symptom of early colon cancer is the persistent sensation that your bowel doesn’t empty completely, even after a normal bowel movement. This feeling, known as “tenesmus,” can be both uncomfortable and frustrating. It may be caused by a tumor obstructing part of the colon or rectum, which can disrupt the normal movement of stool and give a continued urge to go, even when the bowel is already empty.

For instance, imagine someone who finishes using the bathroom but still feels the need to strain or return to the toilet soon after. They may feel as though something is “left behind,” or experience frequent urges with little result. While this can occasionally happen due to dietary issues or constipation, its persistence over several weeks should not be ignored.

The American Cancer Society emphasizes that ongoing sensations of incomplete evacuation warrant further investigation. If you notice this symptom recurring regularly, especially alongside other changes, consult your healthcare provider. Early assessment can help identify or rule out serious causes, including colon cancer.

6. Narrow or Ribbon-Like Stools

6. Narrow or Ribbon-Like Stools
An informative illustration shows different stool shapes in a toilet, alongside a labeled diagram of the human colon. | Generated by Google Gemini

A noticeable and persistent change in the shape of your stool, such as stools that are narrow or ribbon-like, can be an early sign of colon cancer. When a tumor grows inside the colon, it can partially block the passageway, causing stool to become thinner as it squeezes past the obstruction. This physical narrowing can lead to stools that consistently appear pencil-thin or flat.

It’s important to note that stool shape can temporarily change due to factors like diet, dehydration, or minor digestive disturbances. For example, eating less fiber or being mildly constipated might result in occasional narrow stools for a day or two. However, if you observe that your stools remain narrow over several weeks, or if the change is unexplained and persistent, it’s time to take notice.

According to the Mayo Clinic, persistent narrow stools—especially when accompanied by other symptoms—should prompt a visit to your healthcare provider. Monitoring the shape and size of your stool may feel awkward, but it’s a valuable clue for early detection of potentially serious conditions, including colon cancer.

7. Fatigue or Weakness

7. Fatigue or Weakness
A weary individual reclines on a cozy sofa, eyes closed and body relaxed, seeking relief from overwhelming fatigue. | Generated by Google Gemini

Unexplained fatigue or persistent weakness can be a subtle but important early warning sign of colon cancer. As tumors in the colon grow, they may cause slow, chronic blood loss into the stool. Over time, this hidden blood loss can lead to iron-deficiency anemia, reducing the amount of oxygen that red blood cells can carry throughout the body. The result is a lingering sense of tiredness or lack of energy, even after adequate rest.

Imagine someone who feels unusually exhausted at work, struggles to complete routine activities, or finds themselves short of breath after climbing just a few stairs. They may chalk it up to stress, aging, or a busy schedule. However, if fatigue persists for weeks and doesn’t improve with sleep or lifestyle changes, it’s a signal that something deeper may be wrong.

The MD Anderson Cancer Center highlights the link between ongoing fatigue and underlying medical conditions like colon cancer. If you notice persistent tiredness or unexplained weakness, especially when paired with other symptoms, seek medical advice to rule out serious causes.

8. Iron Deficiency Anemia

8. Iron Deficiency Anemia
A healthcare professional carefully examines a blood sample for signs of anemia and iron deficiency in a clinical setting. | Generated by Google Gemini

Iron deficiency anemia is a common yet frequently overlooked early sign of colon cancer. When a tumor in the colon slowly bleeds over time, it can gradually deplete the body’s iron stores, even if the blood loss isn’t obvious in the stool. This ongoing blood loss reduces the body’s ability to produce healthy red blood cells, leading to symptoms such as chronic fatigue, shortness of breath, and pale skin.

People with iron deficiency anemia often feel persistently tired or weak, regardless of how much rest they get. You might notice a lack of energy that interferes with daily activities or recurring headaches and dizziness. Many individuals attribute these symptoms to busy lifestyles, aging, or other health conditions, missing the underlying cause.

According to CDC guidance, unexplained anemia in adults—especially men and postmenopausal women—should always be investigated. If a routine blood test reveals low iron levels or anemia without an obvious cause, it’s important to ask your doctor about further evaluation for gastrointestinal bleeding, including the possibility of colon cancer.

9. Gas and Bloating

9. Gas and Bloating
A person sits clutching their stomach with a pained expression, clearly uncomfortable from bloating and abdominal gas. | Generated by Google Gemini

Persistent gas and bloating are symptoms that most people associate with dietary choices or minor digestive upset. However, when these symptoms become frequent and unrelenting, they might signal a deeper issue such as colon cancer. As a tumor slowly grows within the colon, it can partially block the passage of stool and gas, leading to a sensation of fullness, pressure, or trapped gas within the abdomen.

Unlike the typical bloating that results from eating certain foods or drinking carbonated beverages, cancer-related bloating tends to be ongoing and less responsive to common remedies. People may notice that their abdomen feels distended or uncomfortable much of the time, regardless of what they eat. This can interfere with daily activities and may even be accompanied by visible swelling.

The Cancer Treatment Centers of America explains that persistent gas, bloating, or abdominal discomfort should be taken seriously—especially if these symptoms are new or do not resolve with dietary changes. If you experience chronic bloating or gas, consult a healthcare professional to rule out more serious underlying causes such as colon cancer.

10. Unexplained Nausea or Vomiting

10. Unexplained Nausea or Vomiting
A pale, unwell person clutches their stomach near a bathroom sink, struggling with intense nausea and vomiting. | Generated by Google Gemini

Nausea and vomiting are common symptoms of many mild illnesses, but when they persist without an obvious cause, they may signal a more serious underlying problem such as colon cancer. Tumors in the colon can partially or completely block the passage of food and waste, leading to a backup in the digestive tract. This obstruction can trigger persistent nausea or episodes of vomiting, as the body struggles to move contents through the colon.

Consider the example of someone who experiences ongoing nausea every morning, unrelated to food or motion, or finds themselves vomiting after meals without any clear reason. These symptoms may be accompanied by abdominal pain or bloating, or may occur alone, making them easy to dismiss as a stomach bug or stress.

The American Society of Clinical Oncology advises that ongoing nausea or vomiting, especially when paired with other digestive changes, should prompt a medical evaluation. If these symptoms linger for more than a few days or recur frequently, consult your doctor to rule out serious causes, including potential blockages from colon cancer.

11. Changes in Stool Color

11. Changes in Stool Color
A modern bathroom scene featuring a toilet alongside a detailed stool color chart for easy health reference. | Generated by Google Gemini

A change in the color of your stool can be a valuable clue to what’s happening inside your digestive system. Colon cancer can cause bleeding higher up in the colon, which may not always be visible as bright red. Instead, the blood can darken as it travels through the intestines, resulting in stools that are black, tarry, or maroon in color. This is known as “melena” and often indicates bleeding from the upper or middle parts of the colon.

It’s important to remember that certain foods and medications can also alter stool color. For instance, eating large amounts of beets, licorice, or taking iron supplements can temporarily darken your stool. However, these changes are usually short-lived and easily linked to recent dietary choices.

The Cleveland Clinic recommends taking note if you consistently notice black, tarry, or maroon stools—especially if you cannot connect the change to something you ate or a supplement. Persistent changes in stool color, particularly those suggesting internal bleeding, should be discussed promptly with a healthcare professional.

12. Cramping or Sharp Abdominal Pain

12. Cramping or Sharp Abdominal Pain
A person clutches their abdomen with a pained expression, clearly experiencing intense cramping and discomfort. | Generated by Google Gemini

Frequent cramping or sudden, sharp abdominal pain can be more than just a passing discomfort. When a tumor develops in the colon, it can partially block the flow of waste, causing the muscles of the bowel to contract forcefully in an attempt to move material past the obstruction. This often results in recurring cramps or stabbing pain that may be localized or spread across the lower abdomen.

Unlike the dull ache of indigestion or the cyclical pain of menstrual cramps, pain from a colon blockage can be intense and unpredictable. For example, someone might experience sharp, gripping pains that come and go, sometimes severe enough to interrupt daily activities. These cramps may not respond to common remedies and often become more frequent as the blockage worsens.

According to American Cancer Society experts, persistent or worsening abdominal cramps—especially sharp pain that recurs—should never be ignored. If you routinely experience these symptoms without a clear explanation, seek medical evaluation to rule out colon cancer or other serious gastrointestinal issues.

13. Unusual Urgency to Have a Bowel Movement

13. Unusual Urgency to Have a Bowel Movement
A man dashes toward a brightly lit bathroom, clutching his stomach with an urgent expression on his face. | Generated by Google Gemini

A sudden or persistent urgency to have a bowel movement—sometimes with little or no actual result—can be an early indicator of colon cancer. Tumors located in the lower colon or rectum can irritate the lining of the bowel, creating a sense of pressure or urgency even if the bowel is not full. This feeling can be unsettling, with some people rushing to the restroom only to find minimal or no stool.

This type of urgency is different from what’s typically experienced with irritable bowel syndrome (IBS), which is often linked to stress or certain foods. With IBS, urgency tends to come and go, and is usually relieved by a bowel movement. In the case of colon cancer, the urge may be persistent, unpredictable, and not always associated with relief after using the toilet.

According to the Bowel Cancer UK, it’s important to take note if you begin experiencing new or unexplained urgency, especially if it’s accompanied by other bowel changes. Monitoring and reporting these changes to your healthcare provider can help identify potential problems early, when treatment is most effective.

14. Loss of Appetite

14. Loss of Appetite
A worried individual sits at a table, staring at a plate of untouched food, clearly struggling with loss of appetite. | Generated by Google Gemini

A sudden or gradual loss of appetite is another early warning sign of colon cancer that is often dismissed. Cancer can interfere with hormones and chemical signals that regulate hunger, making food seem less appealing or causing a feeling of fullness after eating only a small amount. Tumors may also cause inflammation or blockages in the digestive tract, contributing to discomfort and reduced interest in meals.

Picture someone who usually enjoys dinner with family but suddenly finds themselves pushing their plate away night after night. They might start skipping meals or feel nauseated at the thought of eating, even when they haven’t changed their diet or routine. This unexpected and persistent decline in appetite should prompt closer attention, as it can quickly lead to unintentional weight loss and nutritional deficiencies.

According to the American Society of Clinical Oncology, unexplained loss of appetite—especially when accompanied by other symptoms—should be evaluated by a healthcare provider. If you notice a significant or ongoing decrease in appetite, don’t ignore it; early medical attention can help uncover the cause and improve outcomes.

15. Frequent Feeling of Fullness

15. Frequent Feeling of Fullness
A detailed illustration shows the digestive tract, highlighting a comfortably full stomach after a satisfying meal. | Generated by Google Gemini

A frequent or ongoing sensation of fullness, even after eating only a small portion of food, can be an early indicator of colon cancer. Tumors in the colon may partially obstruct the bowel, causing waste and gas to build up behind the blockage. This leads to a lingering feeling of fullness or bloating that doesn’t resolve with normal digestion.

Consider the story of a patient who found themselves unable to finish even modest meals. They noticed that their stomach felt distended and uncomfortable, regardless of how much or how little they ate. Family members might comment on their smaller portions, or they may begin to lose interest in food altogether because of the persistent sensation of being “stuffed.”

The Cancer Treatment Centers of America note that ongoing fullness—especially when combined with other digestive changes—should always be investigated. If you consistently feel full very quickly or struggle with ongoing bloating, consult your healthcare provider to rule out potential obstructions or other serious causes like colon cancer.

16. Lower Back Pain

16. Lower Back Pain
A detailed illustration highlights the human spine, with a vivid red glow emphasizing the source of lower back pain. | Generated by Google Gemini

While lower back pain is commonly attributed to muscle strain or injuries, it can sometimes be a sign of more serious conditions like colon cancer. As tumors grow, especially in the advanced stages, they may extend into nearby tissues or press on nerves in the pelvic and lower back region. This pressure can produce a dull, persistent ache or even sharp pain in the lower back that doesn’t improve with rest or physical therapy.

Unlike typical muscular back pain—which is often linked to specific movements, heavy lifting, or poor posture—cancer-related back pain tends to be constant and may worsen over time. For example, someone might notice the pain is unaffected by changing positions or using common remedies like heat packs and over-the-counter medications. The pain might also be accompanied by other digestive symptoms or unexplained weight loss.

According to the Cancer Treatment Centers of America, persistent lower back pain, particularly when combined with bowel changes or abdominal discomfort, should not be ignored. Always consider the location and duration of your symptoms, and seek medical evaluation for prolonged, unexplained lower back pain.

17. Unexplained Fever

17. Unexplained Fever
A worried person checks their temperature with a digital thermometer, their flushed cheeks hinting at a persistent fever. | Generated by Google Gemini

Unexplained, persistent fever can sometimes signal an underlying health issue, including colon cancer. As tumors grow, they can cause areas of inflammation or even lead to infections within the colon. This process may result in a low-grade fever that lingers for days or weeks without a clear source, such as a respiratory or urinary infection.

Unlike the high fevers that typically accompany viral illnesses or the brief spikes seen with minor infections, cancer-related fevers are often subtle. A person may experience a mild elevation in body temperature, chills, or night sweats, sometimes mistaken for a passing virus or simply attributed to stress. This type of fever may come and go but often returns and persists despite over-the-counter medications.

The American Society of Clinical Oncology recommends seeking medical advice if you have a persistent low-grade fever without an obvious cause. Persistent fever should always be investigated, especially when accompanied by other symptoms such as weight loss, fatigue, or digestive changes.

18. Pelvic Pain

18. Pelvic Pain
A woman gently holds her lower abdomen, highlighting the area commonly affected by pelvic pain and discomfort. | Generated by Google Gemini

Pelvic pain that is new, persistent, or unexplained can sometimes be a sign of advanced colon cancer. As tumors grow, they may begin to invade nearby pelvic tissues, nerves, or organs, causing a deep, aching, or pressure-like pain in the lower abdomen or pelvis. This pain may radiate to the hips, lower back, or thighs, and often doesn’t respond to usual home remedies.

Unlike menstrual pain, which is usually cyclical and related to the menstrual cycle, cancer-related pelvic pain tends to be constant, intensifying over time, and not tied to a specific time of month. For example, someone who never experienced pelvic discomfort may suddenly find themselves dealing with ongoing, dull pain that interferes with walking, sitting, or even sleeping.

The Cancer Treatment Centers of America highlight that new and persistent pelvic pain—especially if it’s associated with changes in bowel habits, bleeding, or weight loss—should not be ignored. If you notice these symptoms, schedule a medical evaluation to determine the cause and ensure timely treatment.

19. Mucus in Stool

19. Mucus in Stool
A close-up of a stool sample reveals visible mucus, highlighting potential concerns within the digestive tract. | Generated by Google Gemini

A noticeable increase in mucus within your stool can be an early signal of colon cancer. The colon naturally produces a small amount of mucus to lubricate and protect its lining, but when a tumor develops, it may irritate the bowel wall or trigger excess mucus production. As a result, you might observe a gelatinous, clear, or whitish substance mixed with your stool or coating it.

While some mucus in stool is normal, especially if you have irritable bowel syndrome (IBS), cancer-related mucus changes tend to be more pronounced and persistent. With IBS, mucus usually appears intermittently and is often accompanied by cramping or changes in bowel habits that fluctuate with stress or diet. In contrast, mucus associated with colon cancer may increase steadily, become more noticeable, and not resolve with typical IBS management strategies.

According to American Cancer Society guidance, any new or unusual mucus in your stool that persists should be discussed with your doctor. Pay attention to changes in your bowel movements, and don’t ignore signs that are out of the ordinary.

20. Unexplained Night Sweats

20. Unexplained Night Sweats
A restless person lies in bed at night, visibly sweating and tangled in damp sheets from night sweats. | Generated by Google Gemini

Night sweats are episodes of excessive sweating that soak your pajamas or sheets while you sleep. While many associate them with hormonal changes or infections, they can also be a response to cancer-driven inflammation. Tumors, including those in the colon, can disrupt the body’s normal temperature regulation by releasing chemicals called cytokines, which trigger fever and sweating, particularly during the night.

Imagine someone who wakes up repeatedly drenched in sweat, despite keeping the room cool and using lightweight bedding. If these episodes are new and unrelated to menopause, medication, or recent illness, they may be a sign of an underlying health issue. With colon cancer, night sweats may accompany other symptoms like unexplained weight loss, fever, or fatigue.

The Cancer Treatment Centers of America recommend tracking the onset and frequency of night sweats, especially if they are persistent or appear alongside other concerning changes. If you experience new, unexplained night sweats, consult your healthcare provider for a thorough evaluation.

21. Pain During Bowel Movements

21. Pain During Bowel Movements
A concerned individual sits on a bathroom toilet, visibly uncomfortable and clutching their stomach during a painful bowel movement. | Generated by Google Gemini

Experiencing pain during bowel movements is an often-overlooked symptom that can be linked to colon cancer, especially if tumors are located near the rectum. As these tumors grow, they may narrow the passageway or irritate the sensitive lining of the rectum, resulting in sharp, aching, or burning pain while passing stool. The discomfort might be brief or linger after a bowel movement.

While hemorrhoids are a common cause of pain during defecation, the pain from hemorrhoids usually presents as soreness or itching and is often linked with visible bleeding. In contrast, pain caused by a tumor is typically deeper, more persistent, and may not improve with over-the-counter treatments. If pain is accompanied by other symptoms—such as blood in the stool, changes in stool shape, or a feeling of incomplete evacuation—it warrants particular attention.

According to the American Cancer Society, persistent pain during bowel movements should be evaluated by a healthcare professional, especially if it’s a new development. Don’t dismiss ongoing discomfort as merely hemorrhoids—seeking help early can lead to timely diagnosis and better outcomes.

22. Unintentional Flatulence

22. Unintentional Flatulence
A humorous cartoon shows a person clutching their stomach as bubbles of gas travel through their digestive tract. | Generated by Google Gemini

While passing gas is a normal part of digestion, a sudden increase in unintentional flatulence can be more than just a dietary quirk. Tumors in the colon can partially block the passage of stool, leading to the buildup of gas behind the obstruction. This trapped gas often escapes unexpectedly, resulting in more frequent or uncontrollable flatulence, which can be both uncomfortable and socially embarrassing.

For example, someone who rarely had issues with gas may begin to notice a pattern of increased flatulence, even when they haven’t changed their diet or routine. They might avoid social situations or feel anxious about public embarrassment. This change is often subtle at first but can become more pronounced over time, especially if accompanied by other digestive symptoms.

The Cancer Treatment Centers of America highlight that new patterns of flatulence—especially if they are persistent and unexplained—should be discussed with a healthcare provider. Paying attention to digestive changes, even those that seem minor, can be key to early detection of colon cancer.

23. Difficulty Passing Stool

23. Difficulty Passing Stool
A person sits on a toilet, clutching their stomach in discomfort, highlighting the struggle with digestive tract issues. | Generated by Google Gemini

Difficulty passing stool, or the sensation of straining to have a bowel movement, can be an early warning sign of colon cancer. When a tumor develops in the colon, it can gradually narrow the passageway, making it harder for stool to move through. This may result in a persistent feeling of blockage or the need to exert more effort than usual to complete a bowel movement.

Consider a patient who previously had regular, effortless bowel movements but begins to notice increased straining, even when consuming plenty of fiber and water. Over time, this difficulty may worsen, and the person might feel as though there is a physical obstruction preventing the normal passage of stool. Such symptoms are often mistakenly attributed to constipation, stress, or dehydration but can indicate a more serious underlying problem if new or persistent.

According to the American Cancer Society, new or unexplained difficulty passing stool should always prompt a visit to your healthcare provider. Early evaluation is crucial, as timely diagnosis can dramatically improve outcomes and treatment options.

24. Swelling in the Abdomen

24. Swelling in the Abdomen
A close-up view of a person’s abdomen shows noticeable swelling and bloating, highlighting abdominal discomfort. | Generated by Google Gemini

Swelling in the abdomen, also called abdominal distension, can be an important clue to underlying health issues such as colon cancer. As a tumor grows, it may block the normal movement of digestive contents or cause fluid (ascites) to accumulate in the abdominal cavity. This swelling often presents as a visible or palpable increase in abdominal girth—not just a feeling of fullness, but a physical expansion that is difficult to ignore.

Unlike typical bloating after a large meal or from gas-producing foods, swelling from colon cancer tends to be persistent and does not resolve with dietary changes. For example, someone might notice that their pants no longer fit around the waist or that their abdomen appears rounded even first thing in the morning. The swelling may be accompanied by discomfort or pressure, but sometimes it is painless.

The Cancer Treatment Centers of America recommend paying attention to any ongoing or unexplained abdominal swelling. If you notice persistent distension that doesn’t go away with typical remedies, consult your healthcare provider for a proper evaluation.

25. Visible Lump in the Abdomen

25. Visible Lump in the Abdomen
A doctor carefully palpates a patient’s abdomen to examine a noticeable lump during a clinical evaluation. | Generated by Google Gemini

While rare, some individuals with colon cancer may notice a visible or palpable lump in their abdomen. This lump is often the result of a tumor growing large enough to be felt through the abdominal wall or becoming noticeable during routine self-examinations. The lump may be firm, irregular, or fixed in place, and it might not cause pain initially.

For instance, a person might discover a mass while showering or getting dressed, or a partner may notice a new bulge that wasn’t there before. Unlike the soft, moveable lumps that can occur with benign conditions like lipomas or cysts, a cancerous mass is typically more solid and less mobile.

The Cancer Treatment Centers of America emphasize the importance of promptly evaluating any new lump or mass in the abdomen. If you detect a new lump, especially if it grows or is accompanied by other symptoms, seek medical attention right away for proper diagnosis and peace of mind.

26. Loss of Taste for Favorite Foods

26. Loss of Taste for Favorite Foods
A half-eaten plate of food sits untouched, hinting at taste loss and growing aversion to once-loved meals. | Generated by Google Gemini

A sudden or gradual loss of taste for favorite foods can sometimes signal an underlying health problem, including colon cancer. Cancer can alter metabolism and disrupt the body’s chemical signals, affecting appetite and the way flavors are perceived. Inflammation and certain substances released by tumors may change how the brain and taste buds interpret food, leading to a decreased enjoyment or even aversion to previously loved meals.

Imagine someone who once delighted in chocolate or their favorite comfort dish but now finds these foods bland, unappealing, or even off-putting. This change can be subtle at first, but over time, it may contribute to reduced calorie intake, unintentional weight loss, and general apathy toward eating.

According to the American Society of Clinical Oncology, changes in taste—particularly if they persist and are not explained by medications or other illnesses—should be discussed with a healthcare provider. If you or a loved one notices a shift in food preferences or taste, especially when combined with other symptoms, it’s important to seek medical advice.

27. Breathlessness

27. Breathlessness
A woman pauses on a park bench, her hand on her chest, visibly breathless and fatigued from anemia. | Generated by Google Gemini

Shortness of breath, or breathlessness, can sometimes be an early sign of colon cancer, particularly when it results from anemia due to chronic internal blood loss. As colon tumors bleed slowly over time, the body’s red blood cell count drops, leading to less oxygen being transported throughout the body. This lack of oxygen can cause individuals to feel winded or out of breath even during routine, non-strenuous activities.

This type of breathlessness is different from the shortness of breath experienced after intense exercise or physical exertion. For example, someone may notice they are suddenly short of breath while walking up a single flight of stairs, carrying groceries, or even at rest. There may be no accompanying chest pain, but a sense of fatigue and weakness often goes hand-in-hand with the symptom.

According to the Cancer Treatment Centers of America, new or unexplained breathlessness—especially in combination with fatigue or pale skin—should prompt a medical evaluation. If you experience persistent shortness of breath without an obvious cause, consult your healthcare provider to rule out anemia or other serious conditions.

28. Swelling in the Legs

28. Swelling in the Legs
Swollen legs with visible edema, showing pronounced puffiness and stretched skin along the lower limbs. | Generated by Google Gemini

Swelling in the legs, also known as peripheral edema, can sometimes be a sign of advanced colon cancer. As tumors grow, they may press on or invade veins in the abdomen or pelvis, impeding the normal return of blood from the lower limbs to the heart. This blockage can cause fluid to build up in the feet, ankles, and legs, resulting in visible and sometimes uncomfortable swelling.

Unlike the temporary puffiness that can occur after a long day of sitting or standing, cancer-related leg swelling is more persistent and may be accompanied by other symptoms such as abdominal swelling, fatigue, or unexplained weight changes. The swelling may not improve with elevation or rest and can even worsen over time.

The Cancer Treatment Centers of America advise that unexplained or persistent swelling in the legs should never be ignored, especially if it appears suddenly or is associated with other concerning signs. If you notice new or ongoing swelling in your legs, consult your healthcare provider promptly to determine the cause and receive appropriate care.

29. Dizziness or Lightheadedness

29. Dizziness or Lightheadedness
A person sits down with their hand on their forehead, pausing to steady themselves after feeling dizzy and lightheaded. | Generated by Google Gemini

Dizziness or lightheadedness can be a subtle but significant symptom of colon cancer, especially when caused by chronic blood loss and resulting anemia. As the number of healthy red blood cells drops, less oxygen reaches the brain and other vital organs, leading to episodes of feeling faint, woozy, or unsteady. These sensations may be especially noticeable when standing up quickly, climbing stairs, or engaging in everyday activities.

Imagine someone who suddenly feels dizzy while shopping or experiences a spinning sensation upon rising from a chair. While occasional lightheadedness can be related to dehydration or skipped meals, persistent or worsening symptoms may indicate a more serious cause, such as iron deficiency anemia from ongoing internal bleeding.

According to the Cancer Treatment Centers of America, ongoing dizziness or recurrent episodes of feeling faint should prompt a medical evaluation. If you or someone you know experiences persistent lightheadedness—especially in combination with fatigue, pale skin, or shortness of breath—consult a healthcare provider to uncover the underlying cause.

30. Skin Pallor

30. Skin Pallor
A young woman with noticeably pale skin gazes thoughtfully out a window, her delicate complexion hinting at anemia. | Generated by Google Gemini

A noticeable paleness of the skin, or skin pallor, is a classic sign of anemia—a condition that frequently arises from the chronic blood loss associated with colon cancer. When there aren’t enough healthy red blood cells to circulate oxygen, the skin may lose its usual rosy or warm tone and appear unusually pale, especially on the face, palms, or inside the lower eyelids.

It’s important to distinguish this kind of pallor from the temporary lightness that can occur after spending time indoors or during colder months. Cancer-related pallor is persistent and often accompanied by other symptoms like fatigue, dizziness, or shortness of breath. Family members or friends are sometimes the first to notice a change in someone’s complexion, especially if it develops gradually.

According to the Cancer Treatment Centers of America, any new or unexplained paleness of the skin should be evaluated by a healthcare professional. If you observe persistent paleness in yourself or a loved one—especially alongside other signs of anemia—seek medical attention for further assessment.

31. Unusual Bruising

31. Unusual Bruising
Faint purple bruises scatter across pale skin, their irregular shapes hinting at recent bumps or minor injuries. | Generated by Google Gemini

Unusual bruising can sometimes be linked to underlying health problems, including colon cancer. Cancer and chronic blood loss can disrupt the body’s normal blood clotting mechanisms, making it easier for bruises to form even after minor bumps or without clear explanation. This happens because the body may have fewer platelets or essential clotting factors, or because the liver is affected by cancer’s spread.

Picture someone who starts noticing dark purple or blue patches on their arms or legs, even if they don’t remember getting hurt. These bruises may appear more frequently or take longer to heal than normal. Some individuals might also see small red or purple spots (petechiae) on the skin, which are another sign of bleeding under the surface.

The Cancer Treatment Centers of America advise paying close attention to new or unexplained bruising, especially if it’s accompanied by other symptoms such as fatigue or bleeding. If you notice unusual bruises or changes in how your skin reacts to minor injuries, consult your healthcare provider for a thorough evaluation.

32. Persistent Itchiness

32. Persistent Itchiness
A person gently scratching their arm, revealing red, irritated skin as they try to relieve persistent itching. | Generated by Google Gemini

Persistent itchiness, or pruritus, can be a lesser-known symptom of colon cancer, particularly when the liver becomes involved. If colon cancer spreads to the liver, it may interfere with the normal processing and elimination of bile salts, leading to their buildup in the bloodstream. This accumulation can cause widespread, unrelenting itching, often without visible rash or irritation.

Unlike the temporary itchiness caused by dry skin, weather changes, or minor allergies, cancer-related itchiness tends to be persistent and difficult to relieve with lotions or antihistamines. People may notice the urge to scratch at all hours, sometimes even disrupting sleep or daily activities. The itching can affect any part of the body and may seem unrelated to external factors.

According to the Cancer Treatment Centers of America, ongoing or unexplained itchiness—especially if accompanied by jaundice (yellowing of the skin or eyes) or other systemic symptoms—warrants prompt medical attention. If you experience persistent itchiness that does not improve with standard remedies, consult your doctor for further evaluation.

33. Jaundice (Yellowing Skin/Eyes)

33. Jaundice (Yellowing Skin/Eyes)
A close-up of a person’s face reveals strikingly yellow eyes, a common sign of liver-related jaundice. | Generated by Google Gemini

Jaundice, or the yellowing of the skin and whites of the eyes, can be a sign that colon cancer has spread to the liver—a common site for advanced disease. As tumors invade or compress the liver and its bile ducts, they can block the normal flow of bile. This causes a buildup of bilirubin, a yellow pigment, in the bloodstream, resulting in the distinct discoloration known as jaundice.

While jaundice can be caused by other conditions, such as hepatitis, gallstones, or certain blood disorders, it is always a symptom that deserves urgent attention. People may also notice dark urine, pale stools, and persistent itchiness accompanying the yellowing, which are further signs of liver dysfunction.

The Cancer Treatment Centers of America stress that any new or unexplained yellowing of the skin or eyes should prompt immediate medical evaluation. If you or someone you know develops jaundice—especially with a history of digestive symptoms—seek care promptly to determine the underlying cause and receive appropriate treatment.

34. Dark Urine

34. Dark Urine
A clear plastic cup filled with dark urine sits on a bathroom countertop, highlighting a possible health concern. | Generated by Google Gemini

Dark urine can be a symptom of colon cancer that has affected the liver or bile ducts. When tumors block the normal drainage of bile, bilirubin—normally processed and excreted by the liver—begins to accumulate in the bloodstream and is excreted in the urine, giving it a dark yellow or brownish color. This change is typically more pronounced in the morning or after periods of dehydration, but with liver involvement, it may persist regardless of fluid intake.

Imagine someone who suddenly notices their urine is consistently darker than usual, despite drinking plenty of water. They may initially attribute it to dietary changes, medication, or a lack of hydration, but when the dark color continues day after day, it could indicate a more serious underlying issue.

The Cancer Treatment Centers of America recommend discussing any persistent changes in urine color with your healthcare provider, particularly if accompanied by jaundice or other digestive symptoms. Monitoring the color of your urine can provide important clues about your overall health and help catch liver involvement early.

35. Difficulty Sleeping

35. Difficulty Sleeping
A restless person lies awake in bed, eyes fixed on a glowing alarm clock as sleeplessness lingers. | Generated by Google Gemini

Difficulty sleeping, or insomnia, can become a problem for people with undiagnosed colon cancer. Many of the early and advanced symptoms—such as abdominal pain, bloating, night sweats, or the urgent need to use the bathroom—can repeatedly disrupt sleep. These interruptions may cause restless nights, frequent awakenings, or trouble falling back asleep, leading to chronic fatigue and daytime sleepiness.

While stress or anxiety often plays a role in sleep disturbances, cancer-related insomnia is typically driven by persistent physical discomfort or systemic symptoms. For instance, someone might wake multiple times due to abdominal cramps, nausea, or the urge to have a bowel movement, even if they normally sleep well. Over time, the lack of restorative sleep can also worsen other symptoms and affect overall well-being.

According to the Cancer Treatment Centers of America, new or worsening sleep problems—especially when accompanied by other digestive or systemic changes—should be brought to a healthcare provider’s attention. Tracking the onset and duration of sleep issues can help your doctor evaluate whether further investigation is needed.

36. Mood Changes

36. Mood Changes
A concerned person sits alone by a window, their expression reflecting the weight of mood swings and emotional health struggles. | Generated by Google Gemini

Mood changes are an often-overlooked aspect of the early warning signs of colon cancer. The persistent discomfort, fatigue, and physical symptoms that accompany colon cancer can have a significant psychological impact, even before a diagnosis. Chronic pain, sleep disturbances, and unexplained health changes may lead to increased irritability, anxiety, or feelings of depression.

For example, someone may find themselves snapping at loved ones, feeling overwhelmed by minor frustrations, or struggling with inexplicable sadness or worry. These emotional shifts can arise because the body’s stress response is constantly activated, and underlying inflammation may even affect brain chemistry. Unlike mood swings tied directly to external stressors, these changes often seem to come out of nowhere or persist despite positive life events.

The Cancer Treatment Centers of America recommend taking mental and emotional health seriously alongside physical symptoms. If you or someone you care about experiences new, persistent mood changes—especially in combination with unexplained physical symptoms—consider discussing both physical and emotional well-being with a healthcare provider.

37. Decreased Ability to Exercise

37. Decreased Ability to Exercise
A tired individual pauses mid-workout, their expression reflecting the fatigue and frustration of exercise intolerance. | Generated by Google Gemini

A reduced ability to exercise or tolerate physical activity can be an early but subtle sign of colon cancer. Chronic fatigue and anemia—both common consequences of slow internal bleeding or the body’s immune response to cancer—can sap stamina and make even routine activities feel challenging. As the body’s oxygen-carrying capacity drops, muscles tire more quickly, and recovery after exertion takes longer than usual.

For instance, someone who used to enjoy daily walks or regular gym sessions may suddenly find themselves out of breath or exhausted after only a short period of activity. They may skip workouts, cut exercise routines short, or feel discouraged by a noticeable drop in endurance. These changes can develop gradually, making it easy to attribute them to aging, stress, or being out of shape.

The Cancer Treatment Centers of America advise paying attention to any unexplained decline in your ability to exercise or perform physical tasks. If you notice a persistent decrease in stamina, especially alongside other symptoms, consult your healthcare provider to explore the underlying cause.

38. Increased Susceptibility to Infections

38. Increased Susceptibility to Infections
A weary person wrapped in a blanket rests in bed while animated immune cells fight off invading germs nearby. | Generated by Google Gemini

Cancer, including colon cancer, can weaken the immune system and make the body more prone to infections. Tumors may produce substances that suppress immune cell function or divert resources away from fighting off germs. In addition, chronic blood loss and malnutrition from cancer can further compromise the body’s natural defenses, leaving individuals at heightened risk for bacterial, viral, or fungal infections.

Unlike the occasional cold or seasonal flu, increased susceptibility to infections might look like frequent or lingering illnesses that are difficult to shake. For example, someone might develop repeated respiratory infections, urinary tract infections, or even unusual skin infections within a short time frame. This pattern is different from the typical few colds a year most adults experience, and it should not be ignored.

The Cancer Treatment Centers of America recommend monitoring for patterns of recurrent or severe infections, particularly when they are accompanied by other unexplained symptoms. If you find yourself getting sick more often than usual, or infections seem unusually difficult to recover from, seek medical advice to determine if there is an underlying cause.

39. Loss of Interest in Usual Activities

39. Loss of Interest in Usual Activities
A lonely figure sits on the couch, surrounded by neglected art supplies and musical instruments, staring wistfully into space. | Generated by Google Gemini

Chronic illnesses like colon cancer can profoundly affect a person’s motivation and emotional engagement with life. Fatigue, pain, and the stress of ongoing physical symptoms can sap the energy and enthusiasm once reserved for hobbies, social events, or even daily routines. Over time, this can develop into a persistent loss of interest in activities that used to bring joy or satisfaction.

For example, someone who previously looked forward to gardening, book clubs, or family gatherings may begin skipping these activities, citing tiredness or simply a lack of desire. Friends and relatives might notice the individual withdrawing or becoming less communicative. This disinterest is different from occasional boredom or the need for rest; it lingers and often coincides with other symptoms of chronic illness or depression.

The Cancer Treatment Centers of America point out that changes in emotional well-being are significant and should not be disregarded. If you or a loved one experiences a sustained loss of motivation or enjoyment in life—especially alongside physical symptoms—consider discussing these changes with a healthcare provider.

40. Numbness or Tingling in Extremities

40. Numbness or Tingling in Extremities
A close-up of hands and feet gently touching, highlighting areas of tingling and numbness with soft, glowing accents. | Generated by Google Gemini

Numbness or tingling in the hands or feet can sometimes be traced back to advanced colon cancer. When cancer spreads to other parts of the body, it can affect nerves directly through compression or indirectly by causing nutritional deficiencies, such as low levels of vitamin B12 or folate due to poor absorption. This can lead to a sensation of “pins and needles,” burning, or even loss of sensation in the extremities.

Unlike the temporary numbness you might feel after crossing your legs for too long or sleeping in an awkward position, cancer-related neuropathy tends to persist and may worsen over time. For instance, someone may notice their fingers feel tingly throughout the day or that they have difficulty with fine motor tasks. This symptom is concerning when it’s new, ongoing, and not related to posture or external pressure.

The Cancer Treatment Centers of America emphasize the importance of reporting persistent numbness or tingling to a healthcare provider. If you experience ongoing changes in sensation, it’s crucial to seek evaluation to determine the cause and prevent further nerve damage.

41. Trouble Concentrating

41. Trouble Concentrating
A person sits at their desk, head in hand, struggling to concentrate as brain fog clouds their thoughts. | Generated by Google Gemini

Trouble concentrating, or “brain fog,” is a symptom that can arise from the fatigue and anemia commonly associated with colon cancer. When the body is low on healthy red blood cells and oxygen delivery to the brain is reduced, mental clarity and focus can suffer. This cognitive effect may be subtle at first, but can progress to interfere with work, conversations, and day-to-day decision-making.

For example, someone who once managed complex tasks with ease may find themselves struggling to recall details, losing track of conversations, or feeling mentally “sluggish.” They might need to reread information several times or have difficulty staying organized. While everyone occasionally experiences lapses in concentration due to stress or poor sleep, persistent or worsening cognitive issues—especially when paired with physical symptoms—deserve attention.

The Cancer Treatment Centers of America recommend monitoring for new or ongoing trouble with memory, focus, or mental sharpness. If you notice significant changes in your ability to concentrate, discuss these symptoms with your healthcare provider to determine if an underlying health issue may be responsible.

42. Sudden, Severe Constipation

42. Sudden, Severe Constipation
A person sits on a toilet, clutching their stomach in discomfort, highlighting struggles with digestive tract issues and constipation. | Generated by Google Gemini

A sudden and severe bout of constipation can indicate more than just a minor dietary issue—it may be a sign of a serious blockage caused by a colon tumor. When a mass grows large enough to significantly obstruct the colon, stool passage can be abruptly and completely halted, leaving a person unable to have a bowel movement for several days. This type of constipation is often accompanied by abdominal pain, bloating, and a feeling of fullness or pressure.

Unlike typical constipation, which is usually mild and resolves with increased fiber, fluids, or over-the-counter laxatives, cancer-related constipation is more intense and doesn’t respond to usual remedies. For example, someone might suddenly go from regular bowel movements to complete stoppage, with increasing discomfort and no relief, despite efforts to address the issue at home.

The Cancer Treatment Centers of America stress that any sudden, severe, or worsening constipation—especially if new and unlike previous experiences—requires prompt medical evaluation. Do not ignore abrupt changes in your bowel habits, as early intervention can prevent serious complications and improve outcomes.

43. Persistent Diarrhea

43. Persistent Diarrhea
A person clutching their stomach hurries into a bathroom, showing the urgent effects of digestive tract distress. | Generated by Google Gemini

Persistent diarrhea—loose, watery stools that last for several weeks—can be a sign of irritation or inflammation in the colon caused by cancer. Tumors can disrupt the normal functioning of the bowel lining, making it more difficult for the colon to absorb water or nutrients. This leads to frequent episodes of diarrhea, sometimes accompanied by urgency, abdominal cramping, or even mucus in the stool.

Unlike the brief episodes of diarrhea associated with stomach bugs or food poisoning, which typically resolve within a few days, cancer-related diarrhea is ongoing and does not improve with typical home remedies. For example, someone may notice loose stools daily for weeks, regardless of dietary changes or over-the-counter medications. They may begin to feel dehydrated, weak, or develop unintended weight loss as a result.

The Cancer Treatment Centers of America recommend seeking medical advice if you experience ongoing diarrhea without a clear explanation. Persistent changes in your bowel habits—especially if accompanied by other symptoms—should always be discussed with your healthcare provider.

44. Unexplained Dehydration

44. Unexplained Dehydration
A close-up of a hand with visibly dry skin reaches for a refreshing glass of water to combat dehydration. | Generated by Google Gemini

Unexplained dehydration can occur when chronic diarrhea or persistent vomiting—both potential symptoms of colon cancer—cause the body to lose more fluids than it takes in. When the colon is unable to absorb water efficiently due to irritation or tumor-related changes, or when vomiting becomes frequent, vital fluids and electrolytes are lost. This can quickly lead to symptoms such as extreme thirst, dry mouth, reduced urination, dizziness, and even confusion.

Imagine someone who starts experiencing ongoing loose stools or vomiting and finds themselves constantly thirsty, with dry, cracked lips and headaches that don’t subside with water intake. They may notice their urine becomes darker and less frequent, or that they feel weak and lightheaded during simple activities. These signs point to significant fluid loss that should not be ignored.

The Cancer Treatment Centers of America highlight the importance of recognizing and addressing dehydration promptly, especially when the cause isn’t obvious. If you notice symptoms of dehydration that persist despite increased fluid intake, or if it is accompanied by other digestive complaints, seek medical attention right away.

45. Bad Breath (Halitosis)

45. Bad Breath (Halitosis)
A person covers their mouth with their hand, looking embarrassed and concerned about having bad breath. | Generated by Google Gemini

Persistent bad breath, or halitosis, is sometimes an overlooked symptom of digestive issues, including colon cancer. When tumors partially block the colon and disrupt normal digestion, waste can accumulate and ferment, producing foul-smelling gases that may be released through the breath. This can result in a lingering, unpleasant odor that is resistant to regular oral hygiene routines.

For instance, a person may notice that their breath smells sour or putrid even after brushing, flossing, and using mouthwash. Friends or colleagues might comment on the change, or the individual may become self-conscious about speaking closely with others. While bad breath is often attributed to dental problems, sinus infections, or certain foods, when it is persistent and not linked to these common causes, it could signal an underlying issue in the digestive tract.

The Cancer Treatment Centers of America advise noting any new or ongoing halitosis, especially if it does not improve with good oral care or dietary adjustments. If you experience persistent bad breath along with other digestive symptoms, consult a healthcare provider for a comprehensive evaluation.

46. Unexplained Body Aches

46. Unexplained Body Aches
A person clutches their shoulder and winces, clearly struggling with body aches and persistent muscle pain. | Generated by Google Gemini

Unexplained body aches can arise when colon cancer triggers inflammation in the body or spreads (metastasizes) to bones, muscles, or other organs. The immune system’s response to cancer often involves releasing inflammatory chemicals called cytokines, which can cause generalized discomfort, soreness, or deep, persistent aches. When cancer reaches bones or nerves, pain may become more localized and severe.

Unlike the fleeting aches and pains that accompany a bout of the flu or a strenuous workout, cancer-related body aches tend to be ongoing and do not improve with rest, hydration, or over-the-counter pain relievers. For example, someone might notice soreness in the hips, back, or limbs that lingers for weeks, gradually interfering with daily activities or sleep.

The Cancer Treatment Centers of America caution that persistent or unexplained body aches—especially if they are new and not linked to physical exertion or illness—should be brought to a healthcare provider’s attention. Ongoing pain is never normal and warrants further investigation to determine its source.

47. Unexplained Coughing or Hoarseness

47. Unexplained Coughing or Hoarseness
A person with a hoarse voice is shown coughing, with a detailed illustration of lungs highlighting respiratory discomfort. | Generated by Google Gemini

Although rare, colon cancer can sometimes metastasize to the lungs, leading to symptoms such as persistent coughing or hoarseness. When cancer cells travel through the bloodstream or lymphatic system and settle in the lungs or airways, they may cause irritation, inflammation, or even small tumors that trigger a chronic cough. This cough is typically dry, does not respond to usual remedies, and can sometimes be accompanied by shortness of breath or chest discomfort.

For example, someone who has never had respiratory issues may suddenly develop a nagging cough that lasts for weeks, or a hoarse voice that doesn’t improve despite rest or vocal care. Unlike coughs from colds, allergies, or smoking, this symptom is persistent and lacks an obvious explanation. In some cases, coughing may be worse at night or after lying down.

According to the Cancer Treatment Centers of America, ongoing cough or hoarseness—especially when it cannot be linked to infection or environmental factors—should prompt medical evaluation. If you notice a new cough or voice change that persists, consult your healthcare provider to rule out serious underlying causes.

48. Difficulty Swallowing

48. Difficulty Swallowing
A woman pauses with concern while holding her throat at the dinner table, struggling to swallow a bite of food. | Generated by Google Gemini

Difficulty swallowing, or dysphagia, is a rare but possible symptom in advanced colon cancer, particularly if the disease has spread to the chest, lymph nodes, or esophagus. Tumor growth or metastatic lesions can press on or invade structures involved in swallowing, making it hard to move food or liquids from the mouth to the stomach. This can lead to sensations of food “sticking,” pain while swallowing, or even choking episodes.

Most cases of difficulty swallowing are related to more common causes such as acid reflux, throat infections, or neurological conditions. However, when swallowing problems are new, persistent, and not explained by these usual culprits, they should not be ignored. For example, someone may suddenly find it hard to eat solid foods or may begin to avoid meals due to discomfort or fear of choking.

According to the Cancer Treatment Centers of America, any new or unexplained difficulty swallowing should be evaluated promptly by a healthcare professional. Early assessment is crucial to identify the underlying cause and to ensure appropriate treatment, especially in the context of other concerning symptoms.

49. Visual Changes or Eye Problems

49. Visual Changes or Eye Problems
A concerned woman discusses recent vision changes with her optometrist during a thorough eye exam in a bright clinic. | Generated by Google Gemini

Visual changes or eye problems are rare but possible symptoms related to colon cancer, especially in advanced cases. Cancer can indirectly affect vision if it metastasizes to the brain or eye structures, or if severe anemia reduces the amount of oxygen delivered to the optic nerves and retina. Symptoms may include blurred vision, double vision, sudden loss of sight, or seeing floaters and flashes of light.

For example, someone with chronic anemia from ongoing blood loss might notice that they feel dizzy when standing, and their vision becomes momentarily blurred or dim. In rare cases, metastatic lesions can cause more persistent or dramatic changes, such as partial vision loss or difficulty focusing.

The Cancer Treatment Centers of America recommend seeking prompt medical attention for any new, unexplained changes in vision or eye health. If you develop persistent visual disturbances, especially if accompanied by other neurological or systemic symptoms, consult your healthcare provider to determine the underlying cause.

50. Family History and Genetic Risk

50. Family History and Genetic Risk
A multigenerational family gathers around a detailed family tree chart, exploring their shared genetics and rich history together. | Generated by Google Gemini

A strong family history of colon cancer or known hereditary syndromes such as Lynch syndrome or familial adenomatous polyposis (FAP) can significantly increase a person’s risk of developing the disease. Individuals with a parent, sibling, or child diagnosed with colon cancer—especially at a young age—are at much higher risk than those with no family history. Hereditary syndromes can also be linked to other cancers, making genetic risk assessment even more critical.

For instance, someone whose parent was diagnosed with colon cancer at age 45 is advised to start screening much earlier than the general population. In contrast, a person with no known family history and no genetic risk factors might begin regular screening at age 45 or 50, as recommended by most guidelines.

According to the American Cancer Society, knowing your family history and discussing it with your healthcare provider is essential. If you have a family history or genetic predisposition, talk to your doctor about starting colon cancer screening sooner and possibly considering genetic counseling.

Conclusion

Conclusion
A doctor discusses the importance of timely colon screening with a patient, as a clock ticks in the background. | Generated by Google Gemini

Recognizing the early warning signs of colon cancer is crucial for improving survival rates and patient outcomes. Many symptoms—such as changes in bowel habits, unexplained weight loss, and persistent fatigue—are often overlooked or attributed to less serious causes. However, timely action can make all the difference. If you experience any persistent or unexplained symptoms, don’t hesitate to speak with your healthcare provider. Routine screening, especially for those with family history or genetic risk, remains one of the most effective tools for early detection. Staying vigilant, informed, and proactive can save lives. For more information and resources, visit the American Cancer Society or consult your local healthcare professional.

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