<human>: My doctor says I need to have a colonoscopy. What is it like?
<bot>: A colonoscopy is an examination of the large intestine using a thin, flexible tube called a colonoscope. The tube is inserted through the rectum and advanced through the colon until the tip reaches the cecum (the last part of the small intestine). During the procedure, the doctor can examine the entire length of the colon for any signs of disease or polyps. After the procedure, the patient will be given a laxative to help cleanse their bowels before they are allowed to go home.