Screening for Rectal Cancer

Our experts can usually cure rectal cancer if they find it early enough. But the more rectal cancer grows, the more difficult it can be to treat. In average-risk people with no symptoms, our doctors recommend regular screening tests for rectal cancer starting at age 50.

Because more people are getting screened for rectal cancer, we’re detecting the disease earlier and more often. As many as 90 percent of patients live five years or more after treatment if the cancer is found and removed at an early stage.

If you have a hereditary rectal cancer syndrome, two factors determine our recommendation for how often you should have screening tests: the particular condition you have and the number and makeup of your polyps. Your treatment team can explain the benefits and risks of managing the disease with colonoscopies. They can also discuss medications that may help shrink existing polyps or prevent new ones.

Our screening guidelines for rectal cancer consider factors specific to you, including your age, family medical history, and genetics.

Colonoscopy & Other Screening Tests

Routine colonoscopies can find rectal cancer in its early stages. This screening procedure allows your treatment team to carefully examine your rectum for signs of polyps (abnormal growths on the inside surface of the rectum).

Your treatment team may recommend one of the following rectal cancer screening tests.


A colonoscopy is a test in which a thin, flexible tube with a light and a video camera on its tip is placed in your rectum to search for polyps. It’s the most effective way to detect them. Your treatment team will prescribe a clear-liquid diet and medication to clear out your bowel during the 24 hours before the procedure. You’ll also be sedated during the exam. Your doctor can usually remove any polyps that are detected, which then go to a pathologist (a doctor who specializes in diagnosing disease) for examination and analysis.

Flexible Sigmoidoscopy

A flexible sigmoidoscopy is similar to a colonoscopy. The main difference is that your doctor uses a shorter tube to examine your rectum and the lower part of your colon.

Virtual Colonoscopy

A virtual colonoscopy, or VC, is an alterative option performed in some patients by a radiologist. This study uses CT scan technology to create 2-D and 3-D images of your large bowel. It does not require sedation. VC has limitations, however. For example, it requires the same preparation as conventional colonoscopy — a clear-liquid diet and medication to clear out your bowel. In addition, if the study detects a polyp or other abnormality, then you may need to undergo a colonoscopy for further management.

Fecal Occult Blood Test

Because colon or rectal bleeding can be a possible sign of rectal cancer, a fecal (stool) occult blood test may be used to detect small amounts of blood in your stool that are not otherwise visible. The test works like this: For three consecutive days, you’ll place small stool samples on chemically treated cards. You’ll send those cards to a lab for testing. During this time, you’ll have to follow a special diet to ensure accurate test results.

Fecal Immunochemical Test

A fecal immunochemical test (FIT) also screens for rectal cancer by detecting blood in the stool. Unlike more traditional fecal occult blood testing, you don’t have to follow a special diet before the test. FIT reacts to a part of the hemoglobin molecule (a protein found in red blood cells). This test is also called immunochemical fecal occult blood test.