ABSTRACT
Hirschsprung disease (HD) results from the failure of migration in the enteric nervous system in the distal bowel during fetal development. It is characterized by an absence of ganglion cells in the myenteric and submucosal plexus of the affected bowel and extends proximally in variable lengths from the internal anal sphincter. Hypoganglionosis is a rare entity within the group of disorders resulting from congenital innervation defects in the colon. The isolated form of hypoganglionosis has two presentations: the first, a severe neonatal form with small bowel involvement and which has a poor prognosis despite surgical intervention. Second, a milder childhood form with a shorter segment of affected bowel which has a good prognosis with conservative management or surgical intervention. Hypoganglionsosis is also associated with HD and occurs in the portion of bowel proximal to the aganglionic segment. If it involves a long segment of bowel, there may by residual dysmotility after corrective surgery.
