A 35 year old man presents with watery diarrhea and nausea for 4 weeks.

During this time, his bowel movements changed from once a day to 4 to 6 times a day with foul smelling, loose, urgent stools associated with a crampy abdominal pain.

He had lost 8 kg of weight during the same time period.

The symptoms started around 1 week after returning from a holiday to Turkey, where he had gone camping and drunk water from a natural spring.

His medical and surgical histories are unremarkable but his family history is significant for a sister with celiac disease.