 A colonoscopy is a procedure to detect changes or abnormalities in the large intestine, colon and rectum. Pre-procedure, you must have a low-fibre diet and take medication as advised by your doctor. A coloprep preparation is given to you just before the procedure, which ensures your bowels are completely cleared. During the procedure, you are given a gown to change into and settled comfortably in a private area. You need to remove your eyeglasses, contact lenses and dentures if any. The doctor will pass the colonoscope through the anus into the rectum and advance it through the colon. You may experience some abdominal cramping and bloating, but this is normal and will pass quickly. This procedure takes about 15 to 20 minutes and if you were given a sedative, a companion must be available to accompany you back home.