An unusual complication of a usually 'innocent' parasitic worm.

worm was captured while entering the abscess cavity ( fig. 2 ). The patient was treated with oral metronidazole and mebendazole. He quickly recovered and a repeat colonoscopy 20 days later was entirely normal. , s i arrme E.vu l c i the most common intestinal parasite in the developed world, is usually of little clinical signifi-cance. It is acquired by the feco-oral route. Ingested eggs hatch in the duodenum. The majority of infested individu-als experience pruritus ani and disturbed sleep [1] . How-ever, ectopic pinworm migration can lead to a number of unusual clinical presentations. Pelvic pain, eosinophilic il-eocolitis [2, 3] , perineal nodules [4] , perianal and ischio-anal abscesses as well as urinary tract infections [5] have been described in association with pinworm infection. A 3 5-year-old man presented with fever, rigors, watery diarrhea and tenesmus associated with vague abdominal pain. There was no personal or family history of bowel disease.On ex amination he had tenderness in the left iliac fos-sa, and digital rectal examination revealed a palpable mass at 7 cm from the anal verge. His white cell count (WCC) was 13.3 ! 10