Colorectal cancer is cancer that starts in the colon or rectum. It’s the 3rd most common cancer diagnosed in both men and women in the U.S. (not counting skin cancers).
But it’s also one of the most preventable—and treatable—when caught early. Regular screening can find cancer before symptoms develop. And in some cases, it can even prevent cancer by finding and removing precancerous growths called polyps.
That’s why it’s so important to understand your options and stay up to date with recommended screenings.
Choosing the screening option that’s right for you
Adults at average risk should begin regular screening at age 45. There are several effective screening options available. Each has its own advantages.
Colonoscopy
A colonoscopy allows your doctor to look at the entire colon using a thin, flexible camera. Polyps can be removed right away, preventing them from becoming cancer. The procedure:
- Takes about 30 minutes
- Is done under sedation for comfort
- Is typically only needed every 10 years if results are normal
Because it both detects and removes polyps, a colonoscopy is the gold standard for screening. But it does require some not-so-fun prep, including drinking a special solution to clean out your bowels and sticking to a clear liquid diet the day before the procedure.
At-home screening tests
At-home stool tests (like Cologuard) are a valuable option for many people. “They’re convenient, noninvasive, and easy to complete,” says Mark Ringold, MD, with Carilion Clinic Gastroenterology. “They’re a good screening tool for people at average risk.”
With at-home tests, you collect a small stool sample and mail it to a lab for analysis. These tests can detect hidden blood or abnormal DNA that may be signs of cancer. If results are abnormal, a colonoscopy is recommended as a follow-up.
At-home tests:
- Are easy to complete at home (no prep drinks or limited diet required!)
- Don’t require sedation
- Have no downtime or recovery
For many people, these tests are a great way to begin regular screening. But they do come with the risk of false positives or negatives and need to be completed more often (every 1 – 3 years depending on the test).
CT colonography (“virtual colonoscopy”)
CT colonography uses a CT scan to create detailed pictures of the colon. Sometimes called a “virtual colonoscopy,” this type of test is:
- Noninvasive, with no sedation required
- Quick—usually about 10 – 15 minutes
- Recommended every 5 years for patients at average risk
“This can be a good place to start if you don’t want to undergo a traditional colonoscopy or can’t for medical reasons and want a more thorough screening than at-home testing,” says Dr. Ringold. CT colonography does require some prep, similar to a colonoscopy. If polyps are found, a standard colonoscopy is needed to remove them.
Flexible sigmoidoscopy
Flexible sigmoidoscopy is similar to a colonoscopy but only looks at the lower part of the colon. This procedure:
- Is shorter and requires less prep than a colonoscopy
- Usually doesn’t require sedation
- Is recommended every 5 years for those at average risk
While it doesn’t examine the entire colon, it can still help find cancer and polyps in the lower portion.
Protecting your colorectal health
In addition to screening, you can lower your risk by:
- Eating fruits, vegetables, and whole grains
- Limiting red and processed meats
- Exercising regularly
- Maintaining a healthy weight
- Quitting smoking
- Limiting alcohol
Talk with your family doctor about which screening method is best for you. Early detection saves lives—and screening is the first step!
