**Question:** True about Hirschsprung's disease:

a) Pathology of myenteric plexus of Auerbach
b) Blood in stool
c) May involve small intestine rarely
d) Involved segment of intestine is dilated
e) Present only in infants and children

**Correct Answer:** .

**Core Concept:** Hirschsprung's disease is a congenital disorder characterized by the absence or dysfunction of ganglion cells in the myenteric (Auerbach's) plexus of the intestinal wall. This leads to impaired motility and eventually obstructive symptoms in the affected segment of intestine.

**Why the Correct Answer is Right:**

Hirschsprung's disease is caused by the absence or dysfunction of ganglion cells in the myenteric plexus of Auerbach, specifically affecting the enteric nervous system (ENS) within the intestinal wall. This disruption in the ENS causes impaired intestinal motility in the involved segment of the intestine.

**Why Each Wrong Option is Incorrect:**

a) Pathology of myenteric plexus of Auerbach (True) - The core concept of Hirschsprung's disease revolves around the pathology of the myenteric plexus, which is correct in this case.

b) Blood in stool (False) - The presence of blood in stool is not a core feature of Hirschsprung's disease but may occur as a complication, such as rectal bleeding or hemorrhoids.

c) May involve small intestine rarely (False) - Hirschsprung's disease primarily affects the colon and rectum, rarely extending to the small intestine.

d) Involved segment of intestine is dilated (True) - In Hirschsprung's disease, the affected segment of intestine becomes dilated due to impaired motility and lack of peristalsis.

e) Present only in infants and children (False) - While Hirschsprung's disease is more common in infants and children, it can also affect adults. Therefore, this statement is not entirely accurate.

**Clinical Pearl:** Hirschsprung's disease is a congenital disorder affecting the enteric nervous system (ENS) in the colon and rectum. The affected segment becomes dilated due to impaired motility and lack of peristalsis. This disease often presents in infants and children, but can also affect adults.