Colonoscopy is a test that allows your doctor to look at the inner lining of your large intestine. A colonoscopy helps find ulcers, colon polyps, tumors, and areas of inflammation or bleeding. During a colonoscopy, tissue samples can be collected and abnormal growths can be taken out. Colonoscopy can also be used as a screening test to check for cancer or precancerous growths in the colon or rectum.

The colonoscope is a thin, flexible tube that ranges from 48 in. to 72 in. long. A small video camera is attached to the colonoscope so that your doctor can take pictures or video of the large intestine. The colonoscope can be used to look at the whole colon and the lower part of the small intestine. 


Your doctor may recommend a colonoscopy for a number of reasons, for example:

  • To look for early signs of cancer in the colon and rectum
  • To look for causes of unexplained changes in bowel habits
  • To evaluate symptoms like abdominal pain, rectal bleeding, and weight loss