Evaluation of acute anal sepsis, and anterior horseshoe fistula.

A technique is described for examining patients with perianal sepsis in the acute stage in which with an anal retractor in place the abscess is pressed to watch for pus coming out of the anal canal. The fistulous tract if present can be diagnosed and satisfactorily treated. As a result of these and other studies a number of anterior horseshoe fistulae have been found both in acute and non acute patients. Anterior horseshoe fistulae should be suspected to exist if a patient with an opening of the fistula anterior to the line drawn coronally through anal canal has such an opening more than 2.5 cm away from the anal verge or if there are multiple openings. In recurrent apparently straight forward anterior fistulae, anterior horseshoe fistula should be suspected to exist.