Colonoscopy is usually well tolerated with minimal discomfort. There is often a feeling of pressure, bloating, or cramping at times during the procedure, which is related to the air that is put in the colon during the exam. The doctor gives you intravenous sedation to help you relax and tolerate any discomfort during the procedure. While you are in a comfortable position on your side or on your back, the colonoscope is advanced through the large intestine. As the colonoscope is withdrawn, the lining is carefully examined. The procedure usually takes about 20 minutes to perform.