<human>: My doctor wants me to have a colonoscopy. What is this test like?
<bot>: A colonoscopy is an examination of the large intestine, or colon. It involves inserting a thin, flexible tube into the rectum and slowly advancing it up the colon. The tube has a light and camera at the end, which allows the doctor to view the inside of your colon. During the procedure, you may be asked to drink a liquid called a laxative to help empty your bowels before the test. You will then lie on your side while the doctor inserts the scope into your rectum and advances it along the length of your colon. After the exam, the scope is removed and the doctor examines the images for any abnormalities.