Rectum - Definition

August 2017


Definition

The rectum is the last section of the digestive tube. It constitutes the extension of the sigmoid, or pelvic, colon, joining with the anal canal. On average, the rectum is 12 centimeters long, 5 cm of which is the rectal ampulla that can dilate to contain nearly 400 milliliters of matter before excretion. When a large quantity of excrement is held in the rectal ampulla, they exert pressure on the internal sphincter, which relaxes, then immediately force the contraction of the external sphincter, in order to keep the excrement contained. By releasing this external sphincter, bowel movement is then made possible. Rectoscopy is a medical procedure that allows the interior of the rectum to be visualized, performed by a proctologist or gastroenterologist.

Schema

Related

Original article published by . Translated by Jeff. Latest update on October 26, 2016 at 08:57 AM by MarziaChiriatti.
This document, titled "Rectum - Definition," is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM Health (health.ccm.net).