Anorectal supralevator abscess-fistula in ano.

Small percentages of anorectal abscesses and of chronic fistula in ano are supralevator, resulting from a high intermuscular abscess caused by infected anal glands or chronic ulcer of the anus. The disease is not to be confused with a pelvic abscess caused by other factors. The recommended treatment is internal sphincterotomy to permit drainage at the site of perforation in the longitudinal muscle into the rectum. On rare occasions, in critically ill patients, additional drainage of the pelvic abscess may be necessary through the fossa ischiorectalis or by a lumbar-retroperitoneal space approach.