Hypoganglionosis.

Only a few reports of intestinal hypoganglionosis (H) have been reported, mainly because of diagnostic difficulties. Persistent stool retention since birth and increasing distension of the colon are common to Hirschsprung's disease. It is extremely difficult to establish the diagnosis histochemically unless full-thickness biopsies are performed. Morphometric examination is essential for objective confirmation of the diagnosis. In H, the number of ganglion cells per longitudinal centimeter is decreased by a factor of 2, and the development of nerve fibers is scarce. Manometric findings are inconsistent, and barium studies of the colon and rectum may not provide answers regarding the underlying condition. Treatment of localized disease consists of resection followed by a Soave-type pull-through procedure. The etiology of H is still unknown, but an inborn hypoplasia of the parasympathetic myenteric plexus may be responsible. Among 353 rectal biopsies, 15 cases of H were detected. In seven children, it occurred as an isolated form, in four it was combined with distal aganglionosis, and in four it involved proximal intestinal neuronal dysplasia as well. After proper bowel preparation and resection of the hypoganglionic segment, the outcome was good for all patients. Secondary operations consisted of temporary colostomy in one patient due to anastomotic complications. One patient had an adhesive small bowel obstruction. In two patients with disseminated H of the small bowel and colon, resection was not indicated. Both are dependent on partial parenteral feeding since ages 9 and 3 years. It is expected that more cases of H will be diagnosed in the future, especially if diagnostic measures are improved. The diagnosis is likely in cases of persistent stool retention despite resection of an aganglionic segment.