Prognosis of Crohn's disease with onset in childhood or adolescence.
A long-term follow-up study of 522 patients (1955-1974) with onset of Crohn's disease under age 21 was conducted. Follow-up information was obtained for 513 (98.4%) of the patients. The mean follow-up for the entire series was 7.7 years with a greater than five-year follow-up for 67% of patients. Nearly 60% of the patients were ages 16--20 at onset of disease. Operation had been performed for 69% of the patients and 13 (2.4%) had died. Among the survivors 67% considered themselves to be in suboptimal health. Although clinical features and complications varied considerably with anatomic disease location, colonic disease generally caused more disability than small intestine location of disease. Age at onset did not correlate with clinical severity except for presence of growth retardation. Thus, this long-term follow-up study demonstrated the chronic nature of Crohn's disease with onset under age 21. It also emphasized that the disease more commonly affected adolescents than children, that operation was required in about two thirds of the patients, and that, while mortality was low, morbidity from the disease continued for many years.