Viewing the lower digestive tract
Colonoscopy is a test to view the inside of your lower digestive tract (colon and rectum). Sometimes it can show the last part of the small intestine (ileum). During the test, small pieces of tissue may be removed for testing. This is called a biopsy. Small growths, such as polyps, may also be removed.
Why is colonoscopy done?
Colorectal cancer screenings to detect polyps in the colon should begin at age 50, or earlier if there is a personal or family history of colorectal polyps or a family history of colorectal cancer. The goal is to detect polyps before they develop into cancer or while they're still in the early stages.
Colorectal cancer screenings can be done either with an annual fecal occult blood testing or colonoscopy every 10 years. A colonoscopy may be needed once a year, depending on factors such as your: