Colonoscopy is a medical term that has two parts - colono which refers to the colon, or large intestine, and scopy which means "looking into." Therefore, colonoscopy is a test that enables your doctor to look inside your colon. The instrument used to perform this test is the colonoscope: a long, flexible tube about the width of your index finger. Within the end of this tube is a miniaturized color-TV camera with a wide-angle lens. After passing this "scope" through the rectum and into your colon, your doctor then directly examines the lining of your lower digestive tract on a television monitor. In this manner, it is possible to evaluate intestinal inflammation, ulceration, bleeding, diverticulitis, colitis, colon polyps, tumors, etc.