Many nutritional issues are important in the care of children and adolescents with inflammatory bowel disease. No specific dietary toxin or antigen has been identified to have an etiologic role in either ulcerative colitis or Crohn's disease. A possible modulating effect of omega-3 polyunsaturated fatty acids on intestinal inflammation is being investigated. Most prevalent among the nutritional consequences of inflammatory bowel disease is weight loss, for which inadequate caloric intake is primarily responsible. Impairment of linear growth and associated delay in pubertal development commonly complicate childhood Crohn's disease. The two major etiologic factors are chronic undernutrition and direct effects of inflammatory mediators secreted from the inflamed gut. Recent studies have incriminated interleukin-6. Treatment of intestinal inflammation and provision of adequate nutrition are of paramount importance in preventing or remedying growth impairment. Exclusive enteral nutrition using formulated food is efficacious primary therapy of active Crohn's disease, although the mode of action is poorly understood.