Anorectal problems usually bring up the rear in polite conversation, but they can turn your priorities upside down. Symptoms range from itching to bleeding, to pain, or even leakage of stool (fecal incontinence). In most cases, the causes are mild disorders that you can manage on your own. But you should know when to call your doctor, what tests and treatments are available, and when to expect referral to a specialist.
The normal structures
It may not be a top priority for students of anatomy, but the lower end of the gastrointestinal tract is actually a busy little world of its own (see figure). The anus is the final portion of the tract; it is a mere inch and a half long, whereas the rectum above it occupies the final 6""8 inches of the colon, the large intestine. The rectum is lined by the same type of mucous membrane as the rest of the colon, whereas the anus is covered by skinlike tissue.
A look inside
Hemorrhoids develop when the channels that carry blood away from the anus and rectum become dilated (widened). They are classified according to their location. External hemorrhoids develop in the anus, internal hemorrhoids in the rectum. Many people have both.