10 Things That Increase Your Colon Cancer Risk

by Andrea Peirce Senior Editor

Anytime you think about your risk for colon cancer, it’s important to consider two factors: things you can change and things you can’t. Case in point: You can’t do much about your age, but you can do a lot about the choices you make. And the good news about colon cancer is that those choices have huge power behind them. We asked experts to share 10 top risk factors, their best advice for keeping them—and colon cancer—in check, plus a few important signs that warrant a call to your doctor.

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You're Over Age 50

Age matters—to some extent. Nearly 90 percent of colon cancer cases occur in people over age 50, according to the American Cancer Society.

What to Do: Schedule a screening test no later than your 50th birthday. The American Cancer Society recently suggested that most adults actually start screenings at age 45 instead of 50, due in part to the increasing numbers of under-50s being diagnosed. You might also qualify for earlier testing if you have a family history or other risk factors (we’ll talk about those next).

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There's Colon Cancer in Your Family

“A family history of colorectal cancer or of polyps is definitely a risk,” says Gowrapopala (G.S.) Ramesh, M.D., a gastroenterologist at the Cancer Center at Memorial Hermann-Texas Medical Center in Houston, TX. (A polyp is a clump of cells in the lining of the colon or rectum that could turn cancerous.)

What to Do: Be vigilant! Start screenings a decade before an affected relative was diagnosed, says Dr. Ramesh, and definitely make sure your doctor knows your full history.

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You've Put Off Screenings

Can’t lie—there’s nothing fun about colonoscopy prep. Also can’t lie about this: When colon cancer is caught early, the cure rate is 90-95 percent, Dr. Ramesh says.

What to Do: Schedule that colonoscopy. (Now. We’ll wait!) Your doctor will sedate you, then use a scope to examine the rectum and colon for abnormal changes. Or get a virtual colonoscopy, which is done via CT scan and doesn’t require sedation. Last choice: Send a sample of your poop to a lab using a Cologuard or FIT Test, which scans for blood and DNA changes.

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You Have an Inflammatory Bowel Disease (IBD)

If you’ve had ulcerative colitis or Crohn's disease (but not irritable bowel syndrome) for eight years or more, you’re at increased risk for colon cancer, says Dr. Ramesh. Experts think this may depend on how much of the colon has been inflamed: One study showed increased risk for patients whose IBD involved at least one-third of their colon.

What to Do: Schedule follow-up screenings like clockwork every one to two years. Also smart: Signing up for alerts from a research organization focused on inflammatory bowel diseases to stay up on the latest findings.

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You're African-American

Screening for colon cancer is extra-important if you’re African-American because your risk for getting—and dying—from this cancer is substantially higher than it is for other Americans. Researchers suspect this might be due to genetic differences that can affect the immune system, as well as an increased chance of developing long-lasting inflammation. African-Americans also more frequently encounter obstacles in getting screenings or medical care.

What to Do: Talk frankly with your doctor about your particular risk level, and be super-proactive about screenings.

You're a Couch Potato

If you sit (or lie down) for hours each day, this means you! And your colon-cancer risk rises the longer you’re inactive, says Dr. Ramesh.

What to Do: At a minimum, stand up and take a walk—a brisk one!—for 30 minutes daily. If you can manage more, even better. Movement that gets your heart beating faster encourages peristalsis, the bowel function that moves waste along and prevents it from “sitting” in the colon, giving it more time to potentially expose the body to toxins.

Your Jeans No Longer Fit

The National Cancer Institute says people who are obese are about 30% more likely to develop colon cancer than folks of normal weight.

What to Do: You know the keys are eating less and exercising more, but we can probably all agree that that’s easier said than done. (And for some people, it’s not enough.) Start small, like getting yourself to eat a healthy snack by stashing an apple in your bag, or walking 10 minutes a day. Build from there. If you’re really struggling, there’s no shame in asking your doctor for help.

You're a Red-Meat Lover

Loading up on foods high in fat, including red meat, increases the risk of colon polyps—and therefore colon cancer. The American Institute for Cancer Research puts the hazard tipping point at 18 ounces a week of red meat (beef, lamb, pork). Also bad: Meat that’s processed (salted, smoked, cured) or injected with preservatives.

What to Do: Make meat-free days a regular part of your week and overall, make meat portions smaller. Lean more toward fish, chicken, and turkey, and add in high-fiber grains, fruits and vegetables that function like colon-scrubbers, such as beans and bran.

You Smoke and/or Drink Regularly

Smoking exposes your body to 70+ chemicals that force cells to repeatedly fix themselves. In this frenzy of repair, DNA can get damaged and become cancer-prone. Moderate or heavy alcohol consumption (it doesn’t matter what type of alcohol) wreaks similar havoc on your digestive system, says the American Cancer Society. Together, they’re a double whammy: Alcohol can fast-track entry of harmful tobacco chemicals into the body, compounding the cycle of cell damage and flawed repair.

What to Do: Limit to two drinks a day if you’re male, one if you’re female. (Smoker? Please, please quit.)

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You're Embarrassed

Yes, it qualifies as a risk factor. When you can’t bring yourself to talk about constipation, the shape of poop, and similar red flags, early colorectal cancer warning signs get missed.

What to Do: Remind yourself that it’s crucial to be frank with your doctor. We don’t do enough screenings, says Dr. Ramesh, who after 30 years has seen plenty of patients grapple with touchy topics. In 2018, medical societies set a lofty goal of screening 80% of eligible folks for colon cancer but only reached 65%—compared to 95% for breast and prostate cancer screenings, he says.

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Your Poop's Changed

OK, it isn't a risk factor, but a warning sign: If a change in your bowel movements—diarrhea, constipation, extra-dark or bloody stools, or weirdly shaped, narrow (pencil-thin or stringy) poo—lasts longer than four weeks, get checked. Same if you keep feeling the need to go but nothing happens.

What to Do: Never ignore symptoms, says Yi-Qian Nancy You, M.D., a colorectal cancer surgeon at MD Anderson Cancer Center in Houston, TX. Call your doc. If she gives you the brush-off because you’re under 50, ask for a rectal exam or stool test. Or a second opinion.

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You've Got Nagging Tummy Troubles or Unexplained Weight Loss

Other potentially significant symptoms: abdominal discomfort (cramps, gas, etc.) that sticks around for longer than you can rationalize as “something I ate”—definitely if it lasts a week or more, says Dr. You. There’s likely a simple explanation, but growths in the colon can cause both sharp and dull pain. And pay attention if you’re eating as usual but dropping pounds; cancer can burn up the body’s energy supply and alter how you absorb nutrients and process energy from food.

What to Do: You know the drill. See your doctor.

  • Colonoscopy Effectiveness: New England Journal of Medicine. (2012). “Colonoscopic Polypectomy and Long-Term Prevention of Colorectal-Cancer Deaths.” pubmed.ncbi.nlm.nih.gov/22356322/

  • Colon Cancer and Inflammatory Bowel Disease: World Journal of Gastroenterology. (2019). “Colorectal cancer surveillance in inflammatory bowel disease: Practice guidelines and recent developments.” wjgnet.com/1007-9327/full/v25/i30/4148.htm

  • Higher Risk for African-Americans: Frontiers in Oncology. (2018) “Clinical and Genetic Factors to Inform Reducing Colorectal Cancer Disparities in African Americans,” frontiersin.org/articles/10.3389/fonc.2018.00531/full

Andrea Peirce
Meet Our Writer
Andrea Peirce

Andrea is Senior Editor of Custom Content for HealthCentral. Previously, she worked as a writer and editor for Memorial Sloan Ketting Cancer Center, and was the Director of Editorial Communications for the Lupus Research Institute and S.L.E. Lupus Foundation.