A 3-week-old infant is diagnosed with pyloric stenosis. When taking a health history from the parent, which symptom would the nurse expect to hear described?

Choice A rationale Refusal to feed is generally not the expected symptom in an infant with pyloric stenosis in the early stages, as the infant is often hungry and avidly seeks to feed due to the rapid, forceful loss of nutrition from vomiting. Feeding refusal is a nonspecific symptom that may indicate systemic illness, but the classic presentation involves hunger coupled with characteristic vomiting after feeding. Choice B rationale The emesis associated with pyloric stenosis classically occurs immediately or shortly after a feeding, not two hours later. The thickened pyloric muscle creates an obstruction that prevents gastric contents from passing through the stomach outlet (pylorus) into the small intestine, leading to the forceful expulsion of the meal as soon as the stomach becomes full or tries to empty. Choice C rationale Abdominal distention is not a characteristic feature of pyloric stenosis. The obstruction is at the pylorus, and while the stomach may be distended briefly before the vomiting episode, the subsequent projectile vomiting often leaves the abdomen flat, or a palpable olive-shaped mass (the hypertrophied pylorus) may be felt in the right upper quadrant. Distention is more typical of lower intestinal obstruction. Choice D rationale Projectile vomiting, described as non-bilious emesis immediately or very soon after a feeding, is the cardinal and expected symptom of pyloric stenosis. The obstruction caused by the hypertrophied pyloric muscle prevents the stomach from emptying, and as the stomach fills, its contents are forcefully ejected over a distance, signifying the increased pressure and blockage at the pylorus.