Human: My doctor says I need a colonoscopy. What does that involve? Assistant: 
A colonoscopy is a procedure in which a doctor uses a thin, flexible tube called an endoscope to examine the inside of your colon. The doctor will insert the endoscope into your rectum and move it up through your colon. During the exam, the doctor can take pictures of any polyps or other abnormalities he finds. He may also remove any polyps found during the exam.