Symptomatology, pathophysiology, diagnostic work-up, and treatment of Hirschsprung disease in infancy and childhood.

In the majority of infants and children with constipation, no obvious cause can be identified. A rare cause of constipation is Hirschsprung disease (HD). HD is characterized by the absence of ganglion cells from the anorectum for a variable length up to the duodenum. The extent of the aganglionic segment varies, but in most patients the lesion does not extend beyond the rectum and sigmoid colon. This review focuses on the passage of meconium, the recognition of HD, and new insights in its pathophysiology and genetics. The authors also provide a summary of the diagnostic evaluation and treatment of HD in infancy and childhood.