A 3-day-old neonate has not passed meconium and presents with bilious vomiting and abdominal distension. Rectal examination results in explosive passage of gas and liquid stool. Contrast enema shows a transition zone in the sigmoid colon. The definitive diagnosis is confirmed by:

• A CT scan showing megacolon
• B Serum acetylcholinesterase level measurement
• C Barium follow-through to identify the length of aganglionosis
• D Rectal suction biopsy demonstrating absence of ganglion cells (aganglionosis) in the submucosal and myenteric plexuses ✓

Explanation

Hirschsprung's disease (congenital aganglionosis) is definitively diagnosed by rectal suction biopsy demonstrating absence of ganglion cells in the submucosal (Meissner's) and myenteric (Auerbach's) plexuses, along with hypertrophied nerve trunks and elevated acetylcholinesterase staining of the nerve fibres. The transition zone on contrast enema is diagnostic of the site but not the definitive test. CT is not the standard of care. Serum acetylcholinesterase is not a diagnostic tool for Hirschsprung's disease.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.