Information about Benign Growths in the Colon and Rectum

Colorectal polyps are small, noncancerous (benign) clumps of cells that grow in the rectum and colon. Over the course of 10 to 15 years, some of these polyps—usually the ones that are larger than a pea—can become cancerous. Fortunately, regular screening for colorectal cancer helps to identify and remove polyps, often before they progress to colon cancer.

Causes of Colorectal Polyps

It is not known why polyps develop, but some people are more prone than others. For instance, the older you get—especially after age 50—the more likely you are to have them. You're also more likely to develop polyps if you've had them before (polyps tend to recur) or if someone in your family has had polyps or cancer of the colon.

Your behavior also influences your risk:

  • Eating a lot of fatty foods,
  • smoking cigarettes,
  • drinking alcohol,
  • not exercising,
  • and being overweight
can all contribute to the formation of polyps.

Symptoms of Colorectal Polyps

Most colorectal polyps don't cause any symptoms. You might not know you have them until your doctor finds one or more during a physical examination or colorectal cancer screening test.

However, some people notice rectal bleeding (especially after a bowel movement), constipation or diarrhea that lasts longer than a week, or blood in their stool (the stool looks black or contains red streaks). In these cases, you should see your doctor for an evaluation.

Diagnosis of Colorectal Polyps

Polyps can be diagnosed by a digital rectal exam, barium enema, sigmoidoscopy, or colonoscopy.

Treatment of Colorectal Polyps

Polyps are removed during a sigmoidoscopy or colonoscopy. The removed polyps are then tested to see if they are cancerous and if any further treatment is needed.

Publication Review By: H. Franklin Herlong, M.D.

Published: 29 Mar 2011

Last Modified: 17 Nov 2014