Crohn's disease and ulcerative colitis are chronic inflammatory diseases of the bowel often associated with significant malnutrition, particularly in children because of increased nutrient demands due to growth. We discuss the increasingly prominent role of nutritional support in inflammatory bowel disease (IBD). Issues that are addressed include the etiology of malnutrition in IBD, assessment and monitoring of patient nutritional status and the use of nutrition in the management of growth failure and as primary medical therapy.