The nurse is caring for an infant admitted with dehydration, irritability, signs of extreme hunger, and a palpable olive-like mass in the upper right abdominal quadrant. When feeding the infant, the nurse should monitor for which development?

Choice A rationale Projectile vomiting in an infant with an olive-like mass in the abdomen suggests pyloric stenosis. This condition causes severe vomiting due to gastric obstruction. It's a hallmark symptom and requires monitoring and surgical intervention. Choice B rationale While arching the back can occur in various conditions, it is not specifically indicative of pyloric stenosis. It could be a sign of discomfort or other neurological issues but not directly related to the gastrointestinal obstruction seen in pyloric stenosis. Choice C rationale Frequent pauses during feeding are common in many infant conditions and are not specific to pyloric stenosis. They indicate general feeding difficulties but are not diagnostic of this particular condition. Choice D rationale Coffee-ground emesis indicates bleeding in the gastrointestinal tract but is not typical of pyloric stenosis. The hallmark sign is non-bloody, forceful vomiting due to gastric outlet obstruction.