A 3-week-old male infant with projectile vomiting and constant hunger is likely suffering from which condition if an olive-sized mass is palpated in the abdomen?

The scenario describes a 3-week-old male infant displaying projectile vomiting and constant hunger, alongside the presence of an olive-sized abdominal mass. These clinical signs are characteristic of pyloric stenosis, a condition where the pylorus (the opening from the stomach to the small intestine) becomes narrowed, leading to gastric outlet obstruction.

The projectile vomiting occurs due to the delayed gastric emptying, as the stomach contents cannot pass through the narrowed pyloric channel. Additionally, infants often exhibit signs of increased hunger since they are unable to retain food effectively and may continue to seek nourishment shortly after vomiting. The palpable olive-shaped mass commonly located in the right upper quadrant of the abdomen corresponds to the hypertrophied pylorus, which is a classic finding in pyloric stenosis.

This condition typically presents in infants between 3 and 12 weeks of age and is more common in males, which aligns with the demographic details provided. Recognizing the distinct combination of symptoms—projectile vomiting, constant hunger, and the characteristic abdominal mass—is key to correctly diagnosing pyloric stenosis in this infant.