The colon, or large bowel, is the last portion of the digestive tract.  It is a hollow tube that starts at the end of the small intestine and ends at the rectum and anus. The colon is about 5 feet long, and its main function is to store unabsorbed food waste and absorb water and other body fluids before the waste is eliminated as stool.

A Colonoscopy is used to visually examine the entire colon and rectum for abnormalities.  This is generally considered the procedure of choice for colon cancer screening. During the exam, a long, flexible tube called a colonoscope is inserted into the rectum. A tiny video camera at its tip allows the physician to view the inside of the patient’s colon. 

• A colonoscopy may be conducted for the following reasons:
• identify and remove pre-cancerous growths (polyps) before they become cancer
• diagnose colorectal cancers
• identify and stop the source of lower intestinal bleeding
• investigate causes for changes in bowel habits
• investigate causes of lower abdominal pain