Blastocystis hominis--an emerging and imitating cause of acute abdomen in children.

Two children aged 12 and 11 years with a similar history of abdominal pain, nausea, vomiting and fever with abdominal tenderness, and muscle guarding at the right lower quadrant for few days were admitted to our hospital. They subsequently developed diarrhea but without clinical relief. Just before the decision of laparotomy, both patients were diagnosed as having Blastocystis hominis infection with light microscopic examination of the stools and were treated uneventfully with the appropriate antibiotics.