Hirschsprung's disease or aganglionic megacolon is an anomaly caused by the absence of ganglion cells in the myenteric plexus of the distal colon. It produces intestinal obstruction or lethal enterocolitis in the neonatal period and constipation of varying degree in the older child. The diagnosis can be made by history alone and confirmed by physical findings, barium enema, motility studies, and rectal biopsy. Colostomy may be a life saving measure in the newborn, to be followed by a definitive pull-through procedure before the age of 1 year. Operative correction consists of various techniques all of which aim for excision of the aganglionic segment with preservation of the internal anal sphincter. The major pitfall of these procedures is a too perfectly preserved sphincter which remains spastic and still produces obstruction. Some damage to this muscle must be accomplished either during the procedure or postoperatively by bouginage in order to obtain a satisfactory result.