Colon Cancer and Poop: What to Watch For, According to a Colorectal Surgeon

Updated: Jun. 13, 2024

With colon cancer rates on the rise, it's important to know the subtle warning signs. Experts say a look in your toilet bowl could provide crucial clues at every stage of the disease.

According to the American Cancer Society’s 2024 report, colorectal cancer has surged to the forefront of health concerns, now ranking as the number one cause of cancer deaths among men under 50 and second for women in the same demographic. This rise from its previous fourth-place standing two decades ago highlights a critical need for heightened awareness and early detection—a key factor that can profoundly impact survival rates and treatment success. Colon cancer poop can be an important early sign.

Leading health experts are pointing to our bowel movements as a potential warning system for colon cancer. It turns out the characteristics of our poop—ranging from changes in bowel habits to alterations in stool appearance—carry necessary signals worth heeding. Keep reading to learn what you should know about signs of colon cancer in poop and what to look out for during your next bathroom visit, all based on the expertise and research of medical professionals.

Early signs of colon cancer in poop

Under normal circumstances, poop presents itself in a soft, brown form, smoothly making its way through the digestive tract. However, the early stages of colon cancer might introduce noticeable changes in this routine, serving as critical alerts. Although these signs don’t directly confirm cancer’s presence, as other digestive issues can present with these symptoms, they’re significant enough to merit a conversation with your healthcare provider. Colon cancer poop changes might include:

  • Blood in stool: Spotting blood in your poop, whether as red streaks or in a darker, tar-like form, is a warning sign. Arielle Kanters, MD, a colorectal cancer surgeon from the Cleveland Clinic, shares in their Health Essentials blog: “The most common thing that we see people coming to us with is with blood in their stool. A lot of people are very quick to brush that off as being hemorrhoids, but it’s important to pay attention to it, and if it’s persisting, then you see a doctor about it.”
  • Change in consistency: Look for shifts toward either looser, watery stools or stools that are harder and resemble pebbles, making them tough to pass.
  • Persistent changes in bowel habits: Unexpected diarrhea, constipation, or a noticeable alteration in your stool’s shape—such as it appearing pencil-thin or ribbon-like—could suggest a blockage within the colon and shouldn’t be overlooked.
  • Mucus in stool: While finding some mucus in your stool can be expected, an excess is a red flag, particularly if it’s alongside other symptoms.

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Poop changes in stage 3 colon cancer

As colon cancer progresses to stage 3, it means the cancer has spread to nearby lymph nodes but not to distant organs. At this stage, changes in bowel habits and the appearance of poop may become more pronounced, like an increase of blood in stool and experiencing abdominal pain or discomfort.

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Poop changes in stage 4 colon cancer

Stage 4 colon cancer indicates that the cancer has spread to distant organs and tissues. At this point, the symptoms related to poop can reflect more systemic issues. It’s also essential to look out for unexplained weight loss and fatigue. Dr. Kanters shares, “[This] can be true of any cancer, but if you’re having those experiences along with changes in bowel patterns and/or blood in your stool, absolutely talk to your doctor about that.”

It’s important to remember that for some people, symptoms of colon cancer may not appear at all. This is why individuals with a family history of colorectal cancer need to have a conversation with their doctor about early screening options, such as getting a colonoscopy before the age of 45.

And if you’re unsure whether your symptoms warrant a visit to the doctor, consider the words of Vikram Reddy, MD, PhD, MBA, a surgeon at Yale Medicine. In a 2024 article from Yale, Dr. Reddy offers this valuable guidance: “If anyone has any change in their bowel habits, if they have any bleeding—even if they think it’s a hemorrhoid, and it doesn’t go away—just get a colonoscopy.”

While it may seem uncomfortable to discuss bowel movements, being informed about the signs and symptoms of colon cancer poop can be life-saving. Your health is worth the conversation.

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