Colonoscopy

Why It Is Done

Colonoscopy is done to:

• Find problems or diseases of the anus, rectum, or colon. These tests are often done to because you have had problems such as bleeding from the rectum, ongoing diarrhea or constipation, blood or pus in the stool (feces), or ongoing lower belly pain.
• Check the colon after abnormal results from a barium enema test.
• Check for colorectal cancer or polyps.
  • Most experts, including the Canadian Association of Gastroenterology (CAG) and the Canadian Digestive Health Foundation (CDHF), recommend that people with no risk factors for colorectal cancer start screening tests at age 50.¹ Fecal occult blood testing (FOBT) or a sigmoidoscopy test may be recommended or a colonoscopy or double-contrast barium enema (DCBE) may be used. If results from FOBT or sigmoidoscopy show a problem, a follow-up colonoscopy is recommended.
  • The CAG and CDHF recommend that people with risk factors for colorectal cancer start screening tests at age 40.¹ Tests may include FOBT, sigmoidoscopy, barium enema, or colonoscopy. If you are at increased risk of colon cancer, talk to your doctor about which test is best for you and how often you should do the tests. If you have a family history of colon cancer, you may need a colonoscopy at age 40 or before age 40 in special cases.

Colonoscopy also may be done to:

• Check for colon or rectal cancer that has come back in people who had treatment.
• Watch the growth of polyps that cannot be completely removed.
• See whether treatment of inflammatory bowel disease is working.
• Take out polyps or take tissue samples (biopsy).
• Take out foreign bodies.
• Check for the cause of chronic diarrhea.
• Check for the cause of bleeding inside the colon.

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Author:	Douglas Dana Jan Nissl, RN, BS	Last Updated: October 23, 2006
Medical Review:	Adam Husney, MD - Family Medicine Kathleen Romito, MD - Family Medicine Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology
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