Growth failure often complicates Crohn's disease in pediatric patients and is principally due to inadequate caloric intake. To assess whether intermittent courses of an elemental diet could reestablish growth, 8 children (aged 9.8-14.2 yr) with Crohn's disease and growth failure entered into a prospective trial. Each patient was studied during an observation year on standard therapy, then for an experimental year during which they received enteral elemental diet 1 out of 4 mo. An age- and disease-matched control group of 4 patients was treated by conventional medical therapy during both years. Elemental diet therapy was administered nocturnally, at home, by continuous nasogastric infusion and increased the daily caloric intake by 25% (p less than 0.01). Anthropometric measurements demonstrated significant height and weight gains in the elemental diet group vs. controls (p less than 0.01). Crohn's disease activity index and prednisone intake decreased significantly in patients receiving elemental diet therapy when compared with themselves and with controls on conventional medical therapy (p less than 0.05). In contrast, the rate of pubertal development was similar in both groups irrespective of the treatment modality. This study demonstrates that chronic intermittent elemental diet effectively reverses growth arrest, while decreasing prednisone requirements and Crohn's disease activity index in pediatric Crohn's disease patients prior to puberty.