Apple juice. An unappreciated cause of chronic diarrhea.

Chronic nonspecific diarrhea (CNSD) remains a common pediatric problem. Previous reports have suggested disordered small intestinal motility, food intolerances, dietary fat restriction, and excessive fluid consumption as possible contributory factors. We have recently encountered a subset of children with CNSD in whom nonexcessive apple juice intake seemed to cause their diarrhea. In five subjects, ingestion of 240 mL of apple juice disclosed evidence of significant carbohydrate malabsorption by breath-hydrogen testing and resulted in diarrhea. Withdrawal of apple juice from the diets of these subjects was curative in all cases. Before embarking on an expensive and time-consuming evaluation for CNSD in otherwise healthy children, a brief restriction of apple juice intake may be warranted.