Bleeding may occur form the site of biopsy or polyp removal. Rarely, transfusions or surgery may be required. Localized irritation of the vein may occur at the site of medication injection. A tender lump develops which may remain for several weeks to several months but goes away eventually. Other risks include drug reactions and complications for unrelated diseases such as heart attack or stroke.
Death is extremely rare, but remains a remote possibility.
Colonoscopy is a valuable tool for the prevention, diagnosis and treatment of many diseases of the large intestine, including colon cancer. Abnormalities suspected by x-ray can be confirmed and studied in detail. Even when x-rays are negative, the cause of symptoms such as rectal bleeding or change in bowel habits may be found by colonoscopy. It is useful for the diagnosis and follow-up of patients with inflammatory bowel disease as well. Colonoscopy's greatest impact is probably in its contribution to the control of colon cancer by polyp removal.