Human: My doctor wants me to have a colonoscopy, what is a colonoscopy? Assistant: 
A colonoscopy is a procedure that involves inserting a long, flexible tube into the rectum and colon. The tube has a camera on the end of it that allows the doctor to look at the inside of your digestive system. During the procedure, the doctor will also use instruments called biopsy forceps to remove tissue samples from the lining of the colon for further examination. The entire procedure usually takes about 30 minutes.