Proctoscopy is a common medical procedure in which an instrument called a proctoscope (also known as a rectoscope) is used to examine the anal cavity, rectum or sigmoid colon. A proctoscope is a short (10in or 25 cm long), straight, rigid, hollow metal tube, and usually has a small light bulb mounted at the end. During proctoscopy, the proctoscope is lubricated and inserted into the rectum, and then the obturator is removed, allowing an unobstructed view of the interior of the rectal cavity. Th… (More on Proctoscopy)