Review Question - QID 212765

A 3-day-old newborn girl is admitted to the neonatal intensive care unit for emesis. She has been vomiting for the past 6 hours, and the mother reports that the vomitus is green in color. The patient was delivered at 39 weeks 2 days via an uncomplicated delivery. However, the dad reports that she has yet to have a bowel movement. A physical examination demonstrates a newborn baby in moderate distress with abdominal distension, facial findings shown in Figure A, and large passage of stool upon rectal examination. Her vital signs are within normal limits. What is the most likely explanation for this patient’s symptoms?