<human>: My doctor says that I need to get a colonoscopy done. What is a colonoscopy?
<bot>: A colonoscopy is a medical procedure used to examine the inside of the large intestine (colon) and rectum. It is performed by inserting a flexible tube with a camera down the rectum into the colon. The tube is then moved along the inside of the colon, allowing the doctor to view the lining of the colon and any polyps or other abnormalities.