Anorectal abscess

[Lizzy Liz]

An anorectal abscess is a pus-filled cavity caused by bacteria invading a mucus-secreting gland in the anus and rectum.

Bacteria infect a blocked gland in the anus or rectum and create an abscess.
The infection produces pus and causes pain and swelling.
The diagnosis is based on an examination and the results of imaging tests if needed.
Cutting and draining the abscess is the best form of treatment.

The rectum is the section of the digestive tract above the anus where stool is held before it passes out of the body through the anus. The anus is the opening at the end of the digestive tract where stool leaves the body. (See also Overview of the Anus and Rectum.)
An abscess may be deep in the rectum or close to the opening of the anus. An abscess develops when a mucus-secreting gland in the anus or rectum is blocked, and bacteria grow and multiply. Although the anus is an area that is rich in bacteria, infection generally does not occur because blood flow to the area is rich. When infection does occur, it usually is caused by a combination of different types of bacteria.
An abscess can cause substantial damage to nearby tissues and may rarely lead to loss of bowel control (fecal incontinence). People who have Crohn disease are at particular risk of abscesses. Sometimes, abscesses are a complication of diverticulitis or pelvic inflammatory disease.