Which term describes a condition causing projectile vomiting due to pyloric stenosis?

• A. Intussusception
• B. RSV
• C. SIDS
• D. Pyloric Stenosis

Answer: (D)

Projectile vomiting caused by an obstruction at the stomach’s outlet points to pyloric stenosis. This condition is from hypertrophy of the pyloric sphincter, so gastric contents cannot pass into the duodenum, producing forceful, nonbilious vomiting after feeds. In infants, this often appears in the first weeks of life with dehydration and poor weight gain. A classic finding is a palpable olive-shaped mass in the epigastrium or right upper quadrant and visible peristaltic waves after feeding. Metabolic effects from ongoing vomiting commonly include a hypochloremic, hypokalemic metabolic alkalosis.

Other options describe different problems: intussusception is a telescoping of the intestine with episodic abdominal pain and sometimes bilious vomiting, plus a sausage-shaped mass; RSV is a respiratory infection; SIDS is unexpected sudden death in infancy. The term that best fits a condition causing projectile vomiting due to pyloric obstruction is pyloric stenosis.