paeds526

A 10-year-old boy presents with a bloating sensation with crampy abdominal pain and diarrhoea, passing stools for up to 5 times a day. Following his return from a recent holiday in Egypt, he had been to the local pool a few days ago. He recalls that the stool floats in the toilet water and that he has not passed any blood in his stools. What is the most likely cause for his symptoms?