Lateral subcutaneous sphincterotomy versus anal dilatation in the treatment of fissure in ano in outpatients: a prospective randomised study.

Fifty eight patients with idiopathic chronic anal fissure were included in a randomised prospective trial of lateral subcutaneous sphincterotomy versus simple anal dilatation carried out as outpatient procedures. Operations were performed under local anaesthesia and the patients reviewed 10-30 months later (median follow up time 18 months). Altogether 30 patients were treated by lateral subcutaneous sphincterotomy and 28 by anal dilatation. No serious complications were observed in either group. One recurrence was observed in the group treated by sphincterotomy, whereas eight occurred in the other group (p less than 0.05). Functional results with respect to impaired control of flatus and soiling of underwear were significantly better after sphincterotomy (p less than 0.002). It is concluded that lateral subcutaneous sphincterotomy is the treatment of choice for idiopathic chronic anal fissure resistant to conservative measures.