IS Case 605: Hirschprung's disease
Imaging Sciences URMC 2010
Publication Date: 2011-11-17
Single contrast barium enema demonstrated distention of the large bowel with an abnormal recto-sigmoid ratio and an apparent transition point at the distal sigmoid colon / proximal rectum. Meconium is noted throughout the colon. Findings were suggestive of Hirschprung’s disease versus meconium plug syndrome.
Normally, 90% of babies pass their first meconium within 24 hours, and 99% within 48 hours. When a baby fails to pass meconium within the first 24-48 hours a distal obstructive process is anticipated. “Common causes of distal obstructive processes in pediatric patients include Hirschprung’s disease, meconium plug syndrome, ileal atresia, meconium ileus and anal atresia/anorectal malformations. Abdominal radiographs of patients with a distal obstruction will reveal dilation of multiple bowel loops” .
The radiographic study of choice for further evaluation is a single contrast barium enema. The differential diagnosis can be reduced by determining if there is a microcolon (ileal pathology), or no microcolon (colonic pathology). Hirschprung’s disease and meconium plug syndrome are colonic obstructive processes that can be distinguished by looking for a transition point between the colon and rectum and a decreased rectosigmoid ratio which are classic findings of Hirschprung’s disease.
“Hirschprung’s disease is the result of absence of the ganglion cells in the distal colon, resulting in abnormal peristalsis. The rectum is always involved but the extent of the proximal involvement varies and is involved in contiguous fashion. Definitive diagnosis is obtained by a rectal biopsy, and patients are treated surgically by resection of the denervated segment” .
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