Inborn errors of colorectal innervation can be classified in four different forms: 1. Aganglionosis (including total aganglionosis of the colon, Hirschsprung's disease, ultrashort Hirschsprung's segment and neurogenic sphincter achalasia) 2. Hypoganglionosis 3. Congenital malformation of sympathetic innervation of the colon (Neuronal Intestinal Dysplasia Typ A or NID A) 4. Congenital malformation of the submucous plexus (Neuronal Intestional Dysplasia Typ B or NID B). We find in 52.2% of our biopsies with a characteristic malformation of the colorectal innervation an aganglionosis. 40.6% are malformations of the submucous plexus (NID B). Half of the cases with Hirschsprung's disease are combined with NID B. 5.0% of the classified colorectal malformations of the innervation are a hypoganglionosis and 2.2% a NID A. An additional half of our biopsies cannot be introduced into the above given classification due to moderate malformations of the colorectal innervation (mild dysganglionosis, hypogenetic nerve cells of the submucous plexus, heterotopic nerve cells of the submucous and myenteric plexus).