The nurse is caring for an infant with suspected pyloric stenosis. Which clinical manifestation would indicate pyloric stenosis?

Abdominal rigidity and pain on palpation are not typical signs of pyloric stenosis. Pyloric stenosis usually presents with non-bilious projectile vomiting, a palpable olive-shaped mass in the upper abdomen, and signs of dehydration. A rounded abdomen and hypoactive bowel sounds are characteristic signs of pyloric stenosis. The hypertrophied pyloric muscle obstructs the passage of food from the stomach to the duodenum, leading to gastric distention, visible peristalsis, and vomiting. The infant may appear hungry after vomiting and will continue to feed, leading to weight loss. Visible peristalsis and weight loss are consistent with pyloric stenosis. The visible peristalsis occurs as the infant tries to force the stomach contents through the narrowed pyloric sphincter. Weight loss is a result of poor feeding and vomiting. Distention of the lower abdomen and constipation are not typical findings in pyloric stenosis. Constipation suggests a lower gastrointestinal issue, while pyloric stenosis primarily affects the upper gastrointestinal tract.