Review Question - QID 109241

A 3-day-old boy is evaluated in the hospital nursery for the delayed passage of meconium. The patient is breastfed, has been feeding well every 2 hours, and is urinating over 8 times per day. He was born at 35 weeks gestation to a 27-year-old G4P4 mother. The patient is of Ashkenazi Jewish descent and the patient’s parents refused all prenatal genetic testing. The pregnancy was uncomplicated until the patient’s mother had a spontaneous rupture of membranes at 35 weeks of gestation. The patient’s 3 older siblings are all healthy. The patient’s temperature is 98.2°F (36.8°C), blood pressure is 48/32 mmHg, pulse is 164/min, and respirations are 48/min. On physical exam, he appears to be in moderate distress. He has no dysmorphic features, and his abdomen is distended and non-tender. Bowel sounds are absent. Which of the following is the most appropriate next step in management?