This information is approved and/or reviewed by U-M Health System providers but it is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition.| Complete disclaimer


What is a colonoscopy?

A colonoscopy is an examination of the lining of the colon with a lighted, flexible tube about the thickness of your finger. The doctor will insert the tube through your rectum and up through your colon, checking for abnormalities. Often during the colonoscopy, your doctor may perform other minor procedures such as a polyp removal. In addition, if necessary, a small piece of tissue (a biopsy) can be taken for examination in the lab. Please note that biopsies are taken for many reasons and do not necessarily imply cancer.

Prep Links

U-M Health System Related Sites:

Department of Internal Medicine Division of Gastroenterology

Other Related Web Sites:

NIDDK - Diagnostic Tests - Colonoscopy
Your Digestive System and How it Works
Screening for Colorectal Cancer - see the colonoscopy educational video produced by the American Society for Gastrointestinal Endoscopy

Michigan Medicine • Medical Procedures Unit • MPU/MPC staff • Last revised 04/2017.