A term newborn fails to pass meconium by 48 hours and develops abdominal distension with bilious vomiting. Contrast enema shows a transition zone between a narrow distal segment and dilated proximal colon. Which investigation confirms the definitive diagnosis?
- A Rectal suction biopsy showing absence of ganglion cells in the submucosal plexus ✓
- B Anorectal manometry showing absence of the rectoanal inhibitory reflex
- C Full-thickness surgical biopsy of the dilated proximal colon
- D Serum acetylcholinesterase level
Correct answer: A. Rectal suction biopsy showing absence of ganglion cells in the submucosal plexus
Explanation
Hirschsprung disease is confirmed histologically by rectal suction biopsy demonstrating absence of ganglion cells in Meissner and Auerbach plexuses with hypertrophied nerve trunks, highlighted by acetylcholinesterase staining. Manometry supports screening in older children but cannot confirm the diagnosis in neonates because the reflex may be physiologically immature. Biopsy must come from the aganglionic distal segment, not the dilated proximal colon.
Reference: Schwartz Principles of Surgery, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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