Diseases of the anus and perineum (proctology)

The anal canal is the terminal part of the digestive system.

The anal canal is approximately 2.5 to 5 cm long. It begins where the puborectal muscle grips the rectum and ends at the anus where its lining meets the skin. It constitutes the distal anatomical part of the rectum.

The anal canal is surrounded by the internal and external sphincters, which control continence and the evacuation of stool.