Colonoscopy allows a doctor to look inside the colon for bleeding, cancer, and polyps.
Polyps are small growths that can become cancerous.
A colonoscope is a long, slender, flexible, hollow, lighted tube that is roughly the thickness of a finger. The scope, inserted through the rectum and into the colon, is connected to a video camera and a video display. A gentle sedative is given before the procedure, which takes 30 minutes to an hour to perform. Virtual colonoscopy is a new test that is being considered as a different way to see the colon. During a CT scan, a person lies still on a table and passes through an X-ray machine that looks like a doughnut.