Colorectal polyps

A colorectal polyp is a growth that sticks out of the lining of the colon or rectum.

Causes

Polyps of the colon and rectum are usually benign, meaning they are not cancer and they do not spread. There may be one or many polyps, and they become more common as people age.

Common polyps include:

  • Adenomatous polyps may develop into colon cancer over time.
  • Hyperplastic polyp usually do not develop into colon cancer.

Polyps bigger than 1 centimeter have a greater cancer risk than polyps under 1 centimeter. Risk factors include:

  • Age
  • Family history of colon cancer or polyps
  • A type of polyp called villous adenoma

Polyps may also be associated with some inherited disorders, including:

Symptoms

There are usually no symptoms. However, the following symptoms may occur:

Exams and Tests

The health care provider will perform a physical exam. Usually, polyps cannot be felt. However, if one is large enough, it may be felt during a rectal exam.

Most polyps are found with the following tests:

Treatment

Because colorectal polyps can develop into cancer, they should be removed. In most cases, the polyps may be removed while a colonoscopy is being performed. Colonoscopy prevents colon cancer by removing polyps before they can become cancer.

People over age 50 should consider having a colonoscopy or other screening test. Those with a family history of colon cancer or colon polyps may need to be screened at an earlier age.

For patients with adenomatous polyps, new polyps can appear in the future. Follow-up colonoscopy is usually recommended 1 to 10 years later, depending on the:

  • Patient's age and general health
  • Number of polyps
  • Size and characteristics of the polyps

Rarely, for polyps that are very likely to become cancerous, the health care provider may recommend a colectomy (removing part of the colon).

Outlook (Prognosis)

The outlook for patients with colorectal polyps is excellent if the polyps are removed. Polyps that are left behind can develop into cancer over time.

Possible Complications

Polyps can cause bleeding, and over time, can develop into cancers.

When to Contact a Medical Professional

Call your health care provider if you have

  • Blood during a bowel movement
  • Change in bowel habits

Prevention

The following is recommended to reduce the risk of developing polyps:

  • Eat a diet low in fat and high in fruits, vegetables, and fiber
  • Avoid smoking and excessive alcohol intake
  • Maintain a normal body weight

Colonoscopy prevents colon cancer by removing polyps before they can become cancer. People over age 50 should consider having a colonoscopy or other screening test, which makes earlier diagnosis and treatment possible. This may reduce the odds of developing colon cancer, or at least help catch it in its most treatable stage. Those with a family history of colon cancer or colon polyps may need to be screened at an earlier age.

Taking aspirin or similar medicines may help reduce your risk for new polpys. However, such medicines can have serious side effects if you take them for a long time. Side effects include bleeding from your stomach or colon and heart disease. Talk with your doctor before taking these medicines.

See: Physical exam frequency for further recommendations about having a screening test.

Alternative Names

Intestinal polyps; Polyps - colorectal; Adenomatous polyps; Hyperplastic polyps; Villous adenomas

References

Burt RW, Barthel JS, Dunn KB, et al. NCCN clinical practice guidelines in oncology. Colorectal cancer screening. J Natl Compr Canc Netw. 2010 Jan;8(1):8-61.

Cooper K, Squires H, Carroll C, et al. Chemoprevention of colorectal cancer: systematic review and economic evaluation. Health Technol Assess. 2010 Jun;14(32):1-206.

Updated: 4/16/2012

Reviewed by: George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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