Find an ACG member gastroenterologist with a specialized interest in liver disease. The rectum refers to the last four or five inches of the digestive tract. The rectal outlet or opening is called the anal canal or anus. Problems in this area are common, but many adults are too shy or embarrassed to ask their doctor about them.
The anus is that part of the intestinal tract that passes through the muscular canal of the pelvis and anal sphincters. It is the final orifice through which stool passes out of the body. In adults, the anus is 4 to 5 centimeters long. The lower half of the anal canal has sensitive nerve endings.
Your doctor will likely ask about your medical history and perform a physical exam, including a gentle inspection of the anal region. Often the tear is visible. Usually this exam is all that's needed to diagnose an anal fissure. An acute anal fissure looks like a fresh tear, somewhat like a paper cut.