A colonoscopy is an exam of the large intestine that uses a thin, flexible tube called a “colonoscope.” While under conscious sedation, the tube is passed into the rectum and transmits images to a TV screen. This test allows the doctor to look inside the large intestine from the lowest part (the rectum) all the way to the opening to the small intestine.
A sigmoidoscopy is an exam of the sigmoid colon (or pelvic colon, the part of the large intestine that is closest to the rectum and anus) with a shorter flexible tube. This procedure is less invasive than the colonoscopy.
An Upper endoscopy is an exam of the upper gastrointestinal system (the esophagus, stomach and upper intestines). While under conscious sedation, a scope is passed through the esophagus (throat) and transmits images to a TV screen.