These muscles are stimulated to contract by nerve bundles, called ganglia, located between the muscle layers. Segments in which there is no peristalsis will not pass any digested matter beyond that point. The end result is that the bowel can not push material through and is effectively obstructed.
Intestinal contents accumulate behind the obstruction causing distention of the bowel and abdomen.
If the condition is severe, symptoms may occur in the newborn with failure to pass meconium , failure to pass stool, abdominal distention , and vomiting . Milder cases may not be diagnosed until a later age. In older children they may be characterized by chronic constipation , abdominal distention, and decreased growth rate. Hirschsprung's disease causes one fourth of all newborn intestinal obstruction , but the condition may not be detected until later in infancy or childhood. It occurs 5 times more often in males than in females.