Compatibility of such signs, as not differentiated connective tissue dysplasia and chronic gastroduodenitis is considered. 170 patients of school age with the confirmed diagnosis chronic gastroduodenitis are surveyed with the purpose of revealing signs of connective tissue dysplasia. It is shown, that symptoms of connective tissue dysplasia meet more often at children with chronic gastroduodenitis, than at children without inflammatory gastroduodenal disease. Following features of connective tissue dysplasia are most typical for children with gastroduodenal diseases: external (wrong bearing, flat-foot, a thin skin and others) and internal (a vegetative dysfunction, a biliary dyskinesia and others). Those features have the high informative importance for prognosis of inflammatory gastroduodenal disease in children.