**Core Concept**
The Duhamel procedure is a surgical intervention used to treat Hirschsprung's disease, a congenital condition characterized by the absence of ganglion cells in the distal colon, leading to functional obstruction and chronic constipation.

**Why the Correct Answer is Right**
The Duhamel procedure involves the resection of the aganglionic segment of the distal colon and anastomosis of the proximal colon to the rectum, followed by a segmental resection of the affected bowel. It is specifically indicated in Hirschsprung's disease when the aganglionic segment is located in the distal colon. This procedure helps restore normal bowel motility and prevents obstruction by removing the non-responsive segment.

**Why Each Wrong Option is Incorrect**
Option B: HPSS (Hirschsprung's, Polyps, Sigmoid, Sclerosis) is not a recognized entity; it is a distractor. HPSS is not a surgical condition and has no association with the Duhamel procedure.
Option C: Meckels diverticulum is a congenital anomaly typically managed with resection, but not via the Duhamel procedure. It presents with bleeding or obstruction, not aganglionosis.
Option D: Volvulus involves twisting of the bowel, leading to ischemia and obstruction, and is treated with decompression and resection, not the Duhamel procedure.

**Clinical Pearl / High-Yield Fact**
In Hirschsprung's disease, the Duhamel procedure is performed in patients with a short-segment disease, where the aganglionic segment is distal to the rectum. It is less commonly used today due to the preference for more effective procedures like the Swenson or Soave operations, but remains a valid option in selected cases.

✓ Correct Answer: A. Hirschsprung's disease