pediatrics
Hirschsprung Disease
Hirschsprung Enterocolitis (Toxic Megacolon)
Hirschsprung enterocolitis is a life-threatening complication of Hirschsprung Disease resulting in a grossly enlarged colon, often followed by sepsis and shock. The etiology of Hirschsprung enterocolitis seems to be marked proximal dilation secondary to obstruction, with thinning of the colonic wall, bacterial overgrowth, and translocation of gut bacteria. Sepsis or shock can develop (more often when the entire colon is affected by Hirschsprung), and death can follow rapidly; mortality rate is about 1%. Close monitoring of infants with Hirschsprung disease is therefore essential. Hirschsprung enterocolitis occurs most commonly in the first several months of life before surgical correction but can occur postoperatively, typically in the first year after surgery. Infants with Down syndrome are at increased risk of developing this complication postoperatively. Infants present with fever, abdominal distention, diarrhea (which may be bloody), and, subsequently, obstipation. A barium enema should not be done in patients suspected of having Hirschsprung enterocolitis because of the risk of perforation. Initial treatment of Hirschsprung enterocolitis is supportive with fluid resuscitation, decompression with a nasogastric and rectal tube, and broad-spectrum antibiotics to include anaerobic coverage (eg, a combination ofampicillin,gentamicin, andmetronidazole;meropenemalone; orpiperacillin/tazobactam). Some experts advocate saline enemas in infants who are not critically ill to clean out the colon, but this must be done carefully so as not to increase colonic pressure and cause perforation. Surgery is the definitive treatment for infants who have not yet undergone surgical repair, as well as for those with perforation or necrotic gut. For infants who can be stabilized, definitive surgical therapy can be done instead of the previous standard approach of a diverting ileostomy or colostomy. The previous standard approach should be done in those with severe disease. 