OSF Medical Group


Colonoscopy is a diagnostic procedure that allows the physician to examine the entire length of the large intestine. A colonoscopy can assist in identifying problems with the colon, such as early signs of cancer, inflamed tissue, ulcers, and bleeding.

A colonoscopy is also used to screen for colorectal cancer, the second leading cause of cancer-related deaths in the US and the fourth most common cancer in men and women. The American Cancer Society recommends a colonoscopy every 10 years, after age 50.

What to Expect

An endoscope, also called a colonoscope, is a long, flexible, lighted tube that is inserted through the rectum and into the colon. In addition to allowing visualization of the internal colon, the colonoscope enables the physician to irrigate, suction, inject air, and access the bowel with surgical instruments. During a colonoscopy, the physician may remove tissue and/or polyps for further examination and possibly treat any problems that are discovered.

Other related procedures that may be used to assess problems of the colon include abdominal X-ray, computed tomography (CT scan) of the abdomen, abdominal ultrasound, barium enema, and sigmoidoscopy.

Preparing for Your Colonoscopy

Preparation for your colonoscopy procedure will vary depending upon which type of scoping procedure you are scheduled for.