Hirschsprung disease is characterized by the absence of particular nerve cells (ganglions) in a segment of the bowel in an infant. The absence of ganglion cells causes the muscles in the bowels to lose their ability to move stool through the intestine (peristalsis).Watch this video to learn more about this disease. 0:28 Definition 0:40 Pathogenesis 2:45 Genetics and associations 3:33 Clinical presentation 4:17 Associated enterocolitis 4:56 Management