A colonoscopy is a procedure that lets your health care provider check the inside of your entire colon (large intestine).
The procedure is done using a long, flexible tube called a colonoscope. The tube has a light and a tiny camera on one end. It is put in your rectum and moved into your colon.
In addition to letting your provider see the inside of your colon, the tube can be used to:
During a colonoscopy, your provider may remove tissue or polyps (abnormal growths) for further examination. He or she may also be able to treat problems that are found.