5 Colon Cancer Symptoms You May Be Ignoring, According to Doctors


One of the scariest things about colon cancer is how easy it is to miss some of the symptoms. But early diagnosis is key to combating the disease. "Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in the United States," reports the American Cancer Society (ACS)—which notes that "The rate of people being diagnosed with colon or rectal cancer each year has dropped overall since the mid-1980s, mainly because more people are getting screened and changing their lifestyle-related risk factors."

In addition to screening and preventative measures, knowing what symptoms to look for is also a vital contributing factor to an early diagnosis. When colorectal cancer is found before it spreads, the ACS says, it has a five-year survival rate of around 90 percent.

Read on to find out about five easy-to-miss colon cancer symptoms you might be ignoring.

READ THIS NEXT: If You Notice This in the Bathroom, Get Checked for Cancer.

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Constipation is common, and has many potential causes. It might stem from a medication you're taking, or a diet that's low in fiber. But it can also be a sign of serious conditions, some of which don't even seem like they'd be linked to the colon, such as dementia or Parkinson's disease. It may also indicate colon cancer.

"Constipation can sometimes be a symptom if the lesion is obstructing the pathway of the stool through the bowel," warns Jessica DeLuise, physician's assistant and founder of The Wellness Kitchenista. "It may also interrupt the nerves and muscles that cause contraction/peristalsis."


Another common condition with numerous possible causes, fatigue is a cancer symptom that can be easy to ignore. However, "Fatigue is the most common and least definitive of symptoms associated with colon cancer," according to Tri-City Medical Center.

"Fatigue can happen if polyps or tumors bleed into the digestive tract, leading to a loss of iron over time and possibly iron-deficiency anemia." The site warns that if you're feeling more tired than usual, and especially if it's something that keeps going away and coming back, you should talk to your medical provider about testing your blood cell count. If your count is low, "This may prompt your doctor to order a full screening for colon cancer."

Incomplete evacuation
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"Incomplete evacuation is the sensation that a bowel movement has not been complete even if it has," explains Verywell Health. "This is not an uncommon symptom affecting people with chronic (frequent or persistent) constipation or chronic diarrhea."

However, incomplete evacuation, also known as tenesmus, can also be an early symptom of colon cancer when there are tumors located low in the rectum, says Medscape.

Other changes in the bathroom

Constipation or tenesmus aren't the only changes in your bowel movements that can signal colon cancer. The American Cancer Society lists other bathroom changes that could be caused by conditions such as hemorrhoids or irritable bowel syndrome—but which may also be a sign of colon cancer.

These include include diarrhea or narrowing of the stool "that lasts more than a few days," rectal bleeding with bright red blood, or "blood in the stool, which might make it look dark brown or black."

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No symptoms at all

Colon cancer can sometimes be asymptomatic, cautions DeLuise—another reason that screenings are so important. In a study conducted over the course of 20 years and published by the National Library of Medicine (NLM), "96 of 1,046 cases of colorectal cancer were asymptomatic and detected by screening."

According to the Centers for Disease Control and Prevention, "adults age 45 to 75 should be screened for colorectal cancer, and " People at an increased risk of getting colorectal cancer should talk to their doctor about when to begin screening, which test is right for them, and how often to get tested."