<human>: My doctor says I need a colonoscopy. How does it work?
<bot>: A colonoscopy is a procedure that uses a thin, flexible tube called an endoscope to examine the inside of your colon. It is done by inserting the endoscope into the rectum and then slowly advancing it through the entire length of the colon. During the exam, the doctor can take pictures of any polyps or other abnormalities that may be present. The doctor will also remove any polyps found during the exam.