Question

A newborn baby is brought to the hospital with a complaint of persistent bilious vomiting soon after birth. The baby has passed meconium. The abdomen shows minimal distension and there is no palpable lump. The most probable diagnosis is

• A. Esophageal atresia
• B. Infantile pyloric stenosis
• C. Duodenal atresia
• D. Ileal atresia

Hint:

Match how early the vomiting starts and how little the abdomen is distended to how high up the obstruction must be.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
A newborn has persistent bilious vomiting starting soon after birth, has passed meconium, shows only minimal abdominal distension, and has no palpable lump. The question asks for the most probable diagnosis based on this pattern.

Step 2: Key Concept or Approach:
Bilious vomiting in a neonate points to an obstruction distal to the ampulla of Vater. The level of obstruction can be judged from the degree of abdominal distension: a very proximal, high obstruction produces early bilious vomiting with only minimal distension because little bowel lies proximal to the block, while a more distal obstruction produces greater distension as more bowel fills before the block is reached.

Step 3: Working Through the Options:
Esophageal atresia presents with drooling, choking, and inability to pass a feeding tube, and vomiting is typically non-bilious since the obstruction is above the ampulla; it does not fit this picture. Infantile pyloric stenosis presents later, around three to six weeks of age, with classic non-bilious projectile vomiting, since the obstruction is proximal to the bile duct opening. Ileal atresia is a distal small bowel obstruction and would cause marked abdominal distension with delayed or absent meconium passage, which does not match the minimal distension described here. Duodenal atresia is a high, proximal obstruction, so it produces bilious vomiting very soon after birth with only minimal distension, no palpable lump, and meconium can still be passed since its formation does not depend on postnatal oral intake.

Step 4: Conclusion:
The correct answer is Duodenal atresia.