Hirschsprung's disease (congenital megacolon) is a congenital malformation of the pelvic parasympathetic system consisting of absence of ganglion cells in Auerbach's plexus in a variable portion of the distal colon that is supplied by the pelvic nerve. The length of colon involved in this ganglionic deficit varies but always includes the internal sphincter, the rectum, and rectosigmoid.1 The lesion may extend more proximally, but rarely beyond the sigmoid. In some instances longer portions of colon may be involved, but rarely the whole colon; and in these situations a congenital malformation exists in the vagal fibers that supply the colon to some point in the sigmoid, as well as the pelvic parasympathetic nerve that supplies the remainder of the colon.
The detection of the congenital lesion in the intestine wall can be made on histological sections stained with hematoxylin, eosin, or other routine tissue stain. That special stains are required
Swenson O. MODERN TREATMENT OF HIRSCHSPRUNG'S DISEASE. JAMA. 1954;154(8):651-653. doi:10.1001/jama.1954.02940420013004