<human>: My doctor has suggested that I get a colonoscopy. What's a colonoscopy and why do I need one?
<bot>: A colonoscopy is a procedure where the doctor inserts a thin, flexible tube into your rectum and slowly advances it up to your colon. The goal of the test is to examine the lining of your colon for any abnormal growths or polyps. If any are found, they can be removed during the procedure.