Complications after ineffective medical management are indications for surgical treatment in Crohn's disease and ulcerative colitis. Immediate intervention is necessary in perforation, bleeding and intestinal obstruction, but abscess, fistulation, chronic bowel obstruction and an inflammatory tumor need also surgery without longer delay. Acute ileitis terminalis imitating acute appendicitis is an exceptional case of Crohn's disease. Local recurrence, severe abdominal pain, diarrhoea, retardation of growth and development, and risk of malignant change may be reasons for elective surgery. As development of recurrence after operation is frequent and the results of colectomy and proctocolectomy with ileostomy are not always satisfactory some caution to surgery in ulcerative colitis and Crohn's disease in childhood is advisable.