Fistula-in-ano: an unusual presentation of chronic schistosomiasis.

A 30 year old Ethiopian man presented with recurrent perianal abscess and fistula-in-ano. Ova of Schistosoma mansoni were found on fecal microscopy, and were subsequently identified in fibrous tissue excised from the fistula tract. Chronic schistosomiasis should be recognized as a rare cause of fistula-in-ano. Treatment of schistosomiasis with praziquantel may prevent further complications of this condition.