Colon polyps are nodular growths on the lining of the colon. Generally, they produce no symptoms and are only discovered when a colonoscopy (use of a flexible, lighted tube called a colonoscope to examine the colon) is performed.

Polyps are common; two out of every three people over age 60 have them. However, 90 percent of colorectal cancers arise from initially benign polyps, and the larger the polyp, the more likely it is to become cancerous. Thus, early detection and treatment are imperative.

Colon Image - Masterfile

What Causes Colon Polyps?

  • The cause of most colon polyps is unknown.
  • Chronic inflammation of the colon due to ulcerative colitis may lead to the development of polyps.
  • A diet high in fat (especially from red meat) and low in fiber may contribute to polyp formation.
  • Hereditary factors may be involved. One disorder, known as familial colonic polyposis, is characterized by the growth of a large number of polyps (as many as 1,000 or more) in the colon. Gardner’s syndrome, another hereditary disorder, produces multiple colonic and intestinal polyps as well as nonmalignant tumors in the bones and skin.
  • People who have had colon polyps in the past or have a family history of them are at increased risk.

Symptoms of Colon Polyps

  • Rectal bleeding
  • Blood and mucus in the stool
  • Change in bowel movements
  • Abdominal pain
  • Diarrhea or constipation that lasts over one week
  • Blood on toilet paper or on underwear after a bowel movement

Prevention of Colon Polyps

  • Eat a diet low in animal fat and red meat, but high in fiber.
  • Get regular checkups if you have had colon polyps, if members of your family have had colon cancer or polyps, or if you are over age 50. The checkup may include testing of a stool sample for bleeding.
  • Don't smoke and avoid alcohol.
  • Exercise regularly and lose weight if you're overweight.
  • Eat foods high in calcium such as milk, cheese, yogurt and broccoli.
  • Ask your doctor if you should take a low dose of aspirin every day.

Diagnosis of Colon Polyps

  • A small, lighted viewing tube will be passed through the anus to the lower large intestine (sigmoidoscopy) or to the entire large intestine (colonoscopy) to examine the colon.
  • X-rays following a barium enema, which provide a clear image of the colon. This procedure is not as sensitive as a scope in detecting polyps, nor can it differentiate between benign and malignant polyps.
  • Blood and stool samples may be taken. Stool samples are examined for hidden (occult) blood.

How to Treat Colon Polyps

  • Generally, polyps are removed upon detection during the diagnostic colonoscopy. In a few cases, a small incision (laparotomy) may be made in the abdomen to gain access to a portion of the colon. Surgery may involve removing the polyp and possibly a section of the colon and nearby lymph nodes.

When to Call a Doctor

  • Make an appointment with a doctor if you experience symptoms of colon polyps.
  • Children in families with a hereditary predisposition toward colon polyps should be screened for colon disorders by age 12.
  • All adults over 50 should have a colonoscopy to screen for polyps and colorectal cancer.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 29 Aug 2011

Last Modified: 17 Nov 2014