1. The patient must have been diagnosed as having post prandial diarrhea for at least 5 years by his/her primary care physician or gastroenterologist and is believed to have no other medical condition that would cause this medical problem. Each person must be over 18 years old and have negative testing for Celiac Disease, a normal colonoscopy within 5 years of enrollment, and a normal Hgb and sedimentation rate within 6 months of enrollment in the trial.