Day-Old Newborn With Abdominal Distension

A 1-day-old newborn presents with abdominal distension (Figure 1). Figure 1. The infant was active and feeding well initially. At 6 hours after birth, the infant developed abdominal distension and had two episodes of projectile vomiting. The vomitus was nonbilious and non–blood stained. He was transferred to the neonatal intensive care unit (NICU) for further evaluation. ### Vital Signs ### Physical Examination