Summary In children with granulomatous enterocolitis, growth failure and maturation arrest are found with alarming frequency. Nine patients without physical retardation were managed medically and did well. Thirteen patients with developmental standstill were treated by resection. All 13 experienced a striking growth spurt and 1 yr later had a mean weight gain of 40% of preoperative weight. Pubertal changes were rapidly completed in all. Growth retardation is the most important complication of regional enteritis of childhood, and represents advanced disease. Patients developmentally mature may be treated medically safely. Once growth and maturation have been arrested, the child is beyond the help of medical therapy. Resection of the diseased bowel is required for restoration of normal physical and sexual development, and is remarkably effective.