A close relation between different forms of dysganglionosis such as intestinal neuronal dysplasia (IND) type B and aganglionosis has been established. No systematic analysis of other malformations and diseases accompanying IND has been made as yet. Congenital malformations and perinatal morbidity were analyzed in 109 patients with IND seen at the Department of Pediatric Surgery in Mainz from 1977 to 1996. IND was associated with Hirschsprung's disease in 47 cases; 22 children with IND had other abdominal malformations, including anal atresia, rectal stenosis, sigmoidal stenosis, ileal atresia, pyloric stenosis, and esophageal atresia. A cystic bowel duplication, a choledochal cyst, and a persisting urachus were also found. Extra-abdominal malformations such as Down's syndrome, congenital diaphragmatic hernia, aortic stenosis, and malformations of vertebral bodies were seen. Twin siblings of children with IND were either healthy (n=3) or died in utero (n=1). Seventeen children with IND developed severe intra-abdominal complications during the perinatal period such as necrotizing enterocolitis (NEC), meconium ileus, or bowel perforations. NEC was frequently associated with preterm birth. Bowel perforations were seen in mature and preterm newborns with IND. Taken together, IND is found in a variety of obstructive bowel diseases. This may support the hypothesis that IND is a secondary phenomenon or that congenital atresias and stenoses of the digestive tract have a pathogenesis similar to that of intestinal innervation disturbances. IND may also be a part of complex malformation patterns since it occurs with a number of extraintestinal and non-obstructive intestinal malformations.