Anorectal abscesses typically arise from obstruction of the anal glands and ducts, which communicate with the anal crypts located at the dentate line. The resulting infection begins in the space between the internal and external sphincters and can spread through the perianal spaces, forming pockets of purulent material. Locations of anorectal abscesses include (in order of frequency) (1) perianal, (2) ischioanal, (3) intersphincteric, (4) supralevator  (Figs. 24.1 and 24.2). Patients typically present with pain, palpable mass, fever, urinary retention, or sepsis. Predisposing factors may include diarrhea, trauma, or underlying inflammatory bowel disease. Once identified, usually on physical exam alone, drainage of the abscess cavity must take place as expediently as possible to minimize progressive symptoms and infectious complications. © Springer-Verlag London Limited 2010.