Investigation of choice in Hirschsprung’s disease is:
**Core Concept**
Hirschsprung's disease is a congenital condition characterized by the absence of **ganglion cells** in the distal **colon** and **rectum**, leading to a functional obstruction. The diagnosis involves demonstrating the absence of these cells. **Anorectal manometry** and **barium enema** are useful but not definitive.
**Why the Correct Answer is Right**
The investigation of choice is not provided, but typically, a **rectal biopsy** is considered the gold standard for diagnosing Hirschsprung's disease, as it can directly demonstrate the absence of **ganglion cells** in the submucosal and myenteric plexuses of the rectum.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option provided, we cannot directly address why it's incorrect.
**Option B:** Similarly, without details, we cannot comment on its accuracy.
**Option C:** And again, lacking specifics, we cannot assess its validity.
**Option D:** The same issue applies, as the option details are not given.
**Clinical Pearl / High-Yield Fact**
A key point in Hirschsprung's disease is the transition zone, where the **aganglionic segment** meets the normal colon, which is crucial for surgical planning.
**Correct Answer:** Correct Answer: D. Rectal Biopsy.