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

Polyps of the colon and rectum are usually benign and produce no symptoms, but they may cause painless rectal bleeding. There may be single or multiple polyps and they become more common as people age. Over time, certain types of polyps, called adenomatous polyps, may develop into cancer. Another common type of polyp found in the colon is called a hyperplastic polyp, which is generally not at risk for developing into colon cancer.

Polyps greater than one centimeter have a greater cancer risk associated with them than polyps under one centimeter. Risk factors include advancing age or a family history of colon cancer or polyps.

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

• Gardner's syndrome
• Peutz-Jeghers syndrome
• Juvenile polyposis
• Familial adenomatous polyposis
• Lynch syndrome (HNPCC)

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

• Rectal bleeding
• Bloody stools
• Fatigue associated with anemia
• Abdominal pain (rare)

A rectal examination may reveal a polyp that can be felt by the physician. However, the physical exam is usually normal.

Tests that show polyps:

• Sigmoidoscopy
• Colonoscopy
• Virtual colonoscopy
• Barium enema

Over time, adenomatous colorectal polyps can develop into cancer and should be removed. In most cases, the polyps may be removed at the same time a colonoscopy is performed. For patients with polyps, follow-up colonoscopy should be performed within 3 to 5 years to see if the polyps have returned.

Rarely, for polyps with a high potential of becoming cancerous, a colectomy (removal of a part of the colon) may be recommended.

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

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

Call your health care provider if rectal bleeding occurs.

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

People over 50 should have a colonoscopy screening, which makes earlier diagnosis and treatment possible. This may reduce the odds of developing colon cancer, or at least helps catch it in its most treatable stage. Those with a family history of colon cancer or colon polpys may need to be screened at an earlier age.

Colonoscopy prevents colon cancer by removing polyps before they can become cancer.