An anal fissure is an ulcer of the anal canal which may extend from the anal verge to the dentate line. It is usually exquisitely painful, so the best treatment is that which is the most expedient but also provides negligible recurrence and minimal disability of anal function. Lateral subcutaneous internal anal sphincterotomy best fulfills these criteria and we strongly recommend it as the primary operation for anal fissure.

Technique

Using caudal or local anesthesia, with the patient in the prone jack-knife position, the perianal region is prepared. The fissure is assessed by inspection and palpation. Special note is taken of any large sentinel tag or hypertrophied anal papilla, as they will be dealt with also.

An intersphincteric abscess underlying the fissure is a contraindication to the operation and, if present, a dorsal sphincterotomy is done. This is not common. An anal retractor is inserted. The lower edge of the internal sphincter becomes easily palpable as a prominent band and is also often visible.