Anal fissures and fistulas.

Thorough understanding of the pathophysiology of anal fissures and fistulas is essential for the physician treating these conditions. An acute fissure often heals in a month with conservative management; long-standing disease is relieved by lateral internal sphincterotomy. An acute fistulous abscess must be drained by unroofing the abscess rather than by simple incision, which fosters recurrence. Chronic fistula in ano requires fistulotomy, which can be done with a local anesthetic. Fistulas with multiple external orifices should be treated by a specialist in rectal surgery.