7 Early Warning Signs of Colon Cancer You Can't Afford to Ignore

Early detection saves nine out of 10 patients. It's time you knew the symptoms.

In tragic news, it was announced this morning that Chadwick Boseman, who rose to fame as the star of Black Panther, died on Friday evening after a four-year battle with colon cancer. As fans grieve the loss of this iconic actor, also known for playing pivotal black figures like Jackie Robinson, Thurgood Marshall, and James Brown, what particularly stings is the unfairness of his young age: Boseman was just 43.

A statement released via the actor's Instagram account shared that Boseman learned in 2016 that he had Stage III colon cancer—a diagnosis with a daunting 40 percent survival rate. Despite "countless surgeries and chemotherapy," the statement explains that his cancer progressed to Stage IV over the following four years.

Boseman's sad and untimely death is a wakeup call to many for whom colorectal cancer is at best an afterthought, and at worst a taboo. That's why we're sharing the seven signs of colon cancer you should never ignore: knowing the symptoms and seeing a doctor for routine screening are your two best tools for avoiding a late-stage cancer diagnosis. And for more health red flags, check out these 30 Signs of Deadly Health Conditions Hiding in Plain Sight.

A persistent change in your bowel habits

Flushing toilet

Though changes in your bowel habits could be the result of dietary or lifestyle changes, you'll want to take notice if they persist over time. According to the Mayo Clinic, "Constipation or diarrhea that lasts longer than a week may indicate the presence of a large colon polyp," which can develop into cancer on the inner lining of the colon.

Abdominal discomfort, such as cramps, gas or pain

young man with stomach pain
Shutterstock/Aaron Amat

You may experience cramps or gas after eating something that doesn't agree with you, but if the pain is severe and persistent, your body could be trying to alert you to something far more dangerous. Many colon cancer patients also experience bloating and discomfort brought on by eating. And for more on abdominal symptoms, This Is Everything Your Stomach Is Trying to Tell You About Your Health.

Rectal bleeding or bright red blood in your stool

woman talking to her doctor in the waiting room with forms

If you notice blood in your stool, this could be a telltale sign of colon cancer. According to the American Cancer Society (ACS), "Colorectal cancers can often bleed into the digestive tract. Sometimes the blood can be seen in the stool or make it look darker, but often the stool looks normal." If you notice this symptom, ACS recommends having a blood test, which can reveal a low red blood cell count in early stages of the cancer's development.

A feeling that your bowel doesn't empty completely

Woman with stomach pain

If you regularly feel that the need to empty your bowels isn't relieved by actually going, this could be a sign of colon cancer. Some patients describe feeling as though their bowels don't empty completely, and note that it takes longer for them to go. And for more on early detection of cancer, here are the 4 Signs of Pancreatic Cancer Alex Trebek Wished He'd Known Sooner.

Weakness or fatigue


Polyps can cause internal bleeding in the colon, which can ultimately lead to fatigue and weakness, according to the American Cancer Society. As WebMD points out, "Cancer-related fatigue is one of the most common side effects of colorectal cancer and its treatment. It is not predictable by tumor type, treatment, or stage of illness. Usually, it comes on suddenly, does not result from activity or exertion, and is not relieved by rest or sleep." If you notice weakness or fatigue paired with any other symptoms on this list, ask your doctor about having a screening.

Unexplained weight loss

Man going on the scale looking at his weight

Unexpected and unexplained weight loss can be a sign of various types of cancer. In particular, this symptom may point to colon cancer because polyps can affect the way your body metabolizes food, making it harder to keep weight on. Blockages in the colon can also interfere with digestion, and the resulting discomfort may lead to a decrease in food intake. And for more on surprising symptoms, These Are The 51 Most Common COVID Symptoms You Could Have.

Changes in stool color or consistency

Concerned patient

OK, so it's unpleasant to talk about, but knowing these signs could literally save your life! Those with colon cancer often notice changes in their stool, including darkened color (usually the result of blood entering the digestive tract), softened consistency, or a more "narrow" shape. If you notice any prolonged changes, be sure to talk to your doctor about screening for colon cancer.

Lauren Gray
Lauren Gray is a New York-based writer, editor, and consultant. Read more
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