[Delayed diagnosis of congenital membranous stenosis of the duodenum (author's transl)].

A 12 year old boy with Down's syndrome is described who had a congenital membranous duodenal stenosis. Although the boy had been vomiting from birth and normal feeding was impossible, the diagnosis was made only at the age of 6 years when radiographs were taken because he had swallowed foreign bodies. The malformation was not suspected and no treatment undertaken. Because vomiting increased he was admitted at the age of 12 years to a department for surgical pediatrics. At operation stenosis of the duodenum was confirmed, some coins were removed which had settled proximal to it, the membrane was excised and the duodenum, plit longitudinally, sutured transversely. The postoperative course was smooth and now the boy is very fit.