MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Rectum and Anus

By

Atenodoro R. Ruiz, Jr.

, MD, The Medical City, Pasig City, Philippines

Last full review/revision Oct 2019| Content last modified Oct 2019
Click here for the Professional Version
GET THE QUICK FACTS
Topic Resources

The rectum is a chamber that begins at the end of the large intestine, immediately following the sigmoid colon, and ends at the anus (see also Overview of the Anus and Rectum). Ordinarily, the rectum is empty because stool is stored higher in the descending colon. Eventually, the descending colon becomes full, and stool passes into the rectum, causing an urge to move the bowels (defecate). Adults and older children can withstand this urge until they reach a bathroom. Infants and young children lack the muscle control necessary to delay bowel movement.

The anus is the opening at the far end of the digestive tract through which stool leaves the body. The anus is formed partly from the surface layers of the body, including the skin, and partly from the intestine. The anus is lined with a continuation of the external skin. A muscular ring (anal sphincter) keeps the anus closed until the person has a bowel movement.

Locating the Rectum and Anus

Locating the Rectum and Anus
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Test your knowledge

Effects of Aging on the Digestive System
Although aging does not affect the digestive system as much as it affects other organ systems, it can be a factor in several digestive system disorders. However, aging has only minor effects on the structure of which of the following parts of the digestive system?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP