Endoscopy is visual examination of the interior of a hollow body organ by use of an endoscope. Endoscopy is a medical procedure that uses an instrument called an endoscope. The endoscope is put into the body to look inside, and is sometimes used for certain kinds of surgery. It is a non-surgical procedure used to examine a persons digestive tract. Using an endoscope, a flexible tube with a light and camera attached to it, your doctor can view pictures of your digestive tract on a color TV monitor. Endoscopes can be passed into the large intestine (colon) through the rectum to examine this area of the intestine. This procedure is called sigmoidoscopy or colonoscopy depending on how far up the colon is examined.