Anal Abscess Overview
A perirectal abscess is a collection of pus in the deep tissues surrounding the anus. By contrast, a perianal abscess is a shallower collection of pus under the skin surrounding the anus; however, both are sometimes described as an anal abscess. Both types of abscesses need immediate medical attention; however, a perirectal abscess usually is the more severe infection. A delay in treatment may cause serious worsening of the condition and unnecessary complications.
Anal Abscess Causes
Perirectal and perianal abscesses are thought to develop from the glands surrounding the anus; on occasion, perianal abscesses may develop from infected skin adjacent to the anus. Glands may plug up, usually leading to bacterial infection. When the glands fill with pus, they may burst inward, releasing their infected contents into the spaces around the rectum and anus. This pus causes an abscess, or pus collection, in the spaces surrounding the rectum or anus. The anal abscess may enlarge, causing pain, fever, and difficulty with bowel movements.