Diagnosis and treatment of fistula-in-ano.

The operative treatment for anal fistula in 51 patients began with an intra-anal procedure to detect the internal opening. It was located in all cases by operative inspection and the use of a hooked probe. Pre-operatively, the internal opening was identified by digital examination in 98%. All internal openings were located at the dentate line; 68.9% were found in the posterior quadrant. In 14 cases a high extension was found; horseshoeing occurred in 9 cases. The recurrence rate was 4%: in two cases a high extension was missed, but both were cured by a second operation. Anal control was slightly impaired in 10%.