The incidence of recurrent abscesses or fistula-in-ano following anorectal suppuration.

To determine whether primary fistulotomy should be performed at the time of incision and drainage of anorectal abscesses, a retrospective study of 117 patients who underwent incision and drainage of anorectal abscesses was conducted to ascertain what percentage of patients would subsequently develop a fistula-in-ano or recurrent abscess. None of the patients treated for intersphincteric abscesses developed recurrences. Of the 83 patients with perianal or ischiorectal abscesses, nine (11 per cent) developed recurrent abscesses and 31 (37 per cent) developed persistent fistula-in-ano for a combined persistence or recurrence rate of 48 per cent. These data support the policy of secondary fistulotomy to avoid division of sphincter muscle in the 52 per cent of patients who would not need it. In addition, the vast majority of perianal and ischiorectal abscesses can be drained under local anesthesia and hence a general anesthetic and hospital admission are obviated.