An anorectal abscess is a collection of pus in the area of the anus and rectum.

Anal abscess; Rectal abscess; Abscess - anorectal

Common causes include:

• Blocked gland in the area
• Infection of an anal fissure
• Sexually transmitted infection

Deep rectal abscesses may be caused by intestinal disorders such as Crohn's disease or diverticulitis.

The following factors increase your risk for an anorectal abscess:

• Anal sex
• Diabetes
• Inflammatory bowel disease (Crohn's disease and ulcerative colitis)
• Weakened immune system

The condition may occur in infants and toddlers who are still in diapers and who have a history of anal fissures.