Colon Cancer: Know the Warning Signs

No one likes to talk about colon cancer. And that’s OK, as long as you take action. After all, colon cancer is the second leading cause of cancer deaths in the United States. You can take steps to protect yourself.

March is Colorectal Cancer Awareness Month,  a good time to have a preventive screening.

You don’t have to wait until March, though. You can do it any time of the year. Talk with your doctor about when you should be screened and how often. Your age and family history will play a role in deciding what’s best for you.

Why is Screening Important?

Small growths, called polyps, can grow along the colon lining. Some of these polyps can be cancerous or become cancerous if left untreated. A colonoscopy can help find these growths and possible cancers early. Early detection offers a better chance for successful treatment and recovery.

Are There Warning Signs?

Before it has grown or spread, colon cancer often doesn’t have any symptoms. There may be warning signs, though. Pay attention if you notice any:

• Change in bowel habits or stool shape that lasts more than a few days and isn’t caused by a change in diet
• Cramping or stomach pain
• Unexplained weight loss
• Fatigue, shortness of breath or weakness due to anemia
• Rectal bleeding
• Blood in the stool or toilet after a bowel movement
• Dark or black stools
• An urge to go even though the bowel is empty

Your doctor may recommend a colon screening if you have one or more symptoms.

When and How Should I Be Screened?

While the U.S. Preventive Services Task Force (USPSTF) recommends adults 45-75 be screened, talk about the risks and benefits with your health care provider. Ask when and how often you should be screened.*

If you have a family history of colon cancer or other health issues that put you at higher risk, your doctor may advise earlier or more frequent screening.

Today, there are simple noninvasive screening choices, too. Talk to your health care provider (doctor, nurse practitioner, physician assistant, etc.) about which ones may be right for you. Each has advantages and disadvantages. The test you and your health care provider choose may depend on your preferences and medical condition. 

The most common screening option is colonoscopy. Using a flexible, lighted tube equipped with a small camera, your doctor can look at the whole rectum and colon for signs of cancer. Precancerous polyps may even be removed during the test.

Some people avoid a colonoscopy because they worry it might be painful. But the test is quick and painless. You are asleep during the test, and it takes less than an hour.

Other screening options include:

Fecal occult blood test: This lab test scans a stool sample for blood, a possible sign of cancer. Fecal immunochemical testing (FIT) uses antibodies to spot blood in the stool. Fecal immunochemical testing (FIT)-DNA combines FIT with a test that finds changes in the DNA of stool.

Sigmoidoscopy: This method looks only at the rectum and the lower colon.

Virtual colonoscopy: A CT scan gives detailed images of the colon.

Are There Ways to Prevent Colon Cancer?

While there is no sure way to stop colon cancer from developing, you can take steps to help lower your risk.

• Eat a diet that’s high in fruits, vegetables and fiber.
• Stay away from red, grilled and processed meat.
• Avoid smoking, heavy use of alcohol and inactive lifestyles.
• Exercise
• Keep your weight in check.

Learn more about colon cancer and other recommended health screenings in our Adult Wellness Guidelines. As always, check to make sure your care and testing providers are in network. Show your insurance ID card so providers can check if they are part of your health plan network.

For details about your benefits coverage, log in to your Blue Access for Members^SM.

* Recommendations may vary. Discuss screening options with your health care provider, especially if you are at increased risk.

Sources: Colorectal Cancer,  Centers for Disease Control and Prevention, 2023; Colorectal Cancer: Screening,  U.S. Preventive Services Task Force 2021

Originally published 2/25/2019; Revised 2022, 2024