A term neonate develops bilious vomiting on day 1 of life. Abdominal X-ray shows a 'double bubble' sign with no distal gas. Maternal history notes polyhydramnios and trisomy 21. The most likely diagnosis is:

• A Ileal atresia
• B Malrotation with volvulus
• C Hirschsprung's disease
• D Duodenal atresia ✓

Explanation

The double bubble sign (dilated stomach and proximal duodenum) with absent distal gas is pathognomonic of complete duodenal obstruction — most commonly duodenal atresia in a neonate with trisomy 21 (associated in 20–30% of cases) and maternal polyhydramnios. Malrotation can also cause duodenal obstruction but typically presents with bilious vomiting and distress within days in a previously well infant, with partial obstruction. Ileal atresia shows multiple air-fluid levels.

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.