Does zonal aganglionosis really exist? Report of a rare variety of Hirschsprung's disease and review of the literature.

The aganglionic segment of intestine in Hirschsprung's disease begins at the anus and extends proximally for a distance that varies from case to case. Occasional reports describe patients in whom the aganglionosis is segmental, with normal distal innervation or a skip area of normal innervation within an area of aganglionosis. This paper describes 4 patients with Hirschsprung's disease wherein a segment of normally innervated colon was found in an otherwise aganglionic colon. Two of these patients were siblings with different fathers. Problems encountered in the management of these patients are detailed. In a critical review of the literature, 2 additional male patients with well-documented zonal aganglionosis were identified. Although variations from the usual morphology or Hirschsprung's disease do exist, they are so rare that they merit clinical consideration only when the anatomic record and the clinical course are in obvious disagreement. Rectal biopsy remains the best method for the diagnosis of Hirschsprung's disease.