Complex carbohydrate intolerance: diagnostic pitfalls and approach to management.

Complex carbohydrate intolerance occurred in three of 105 patients with protracted diarrhea of infancy. Nosocomial gastroenteritis complicated a primary disorder of carbohydrate absorption (primary glucose galactose malabsorption, two; primary sucrase isomaltase deficiency, one) in all patients. Their course was characterized by protracted diarrhea, variable degrees of villus atrophy on intestinal biopsy tissue, and negative caloric balance requiring intravenous alimentation for periods varying from 6 to 16 weeks. Dietary management required rigid exclusion of all offending carbohydrates from the diet. Delay in the diagnosis of primary carbohydrate intolerance varied from 2 weeks to 6 months. Complex carbohydrate intolerance may be more common than has been reported, and should be considered in all infants with protracted diarrhea of infancy when there is persistent carbohydrate intolerance.