A 10-day-old preterm infant develops abdominal distention, lethargy, temperature instability (35°C/95°F), and guaiac-positive stools. Laboratory data shows acidosis, neutropenia, and thrombocytopenia. What is the next most important imaging test?
A well-appearing day-2 term infant develops jaundice starting at 36 hours, peaking at 11 mg/dL on day 4, and resolving by day 7. What type of jaundice is this?
A neonate fails to pass meconium, and a contrast enema reveals a microcolon and filling defects. After enema, the infant passes a tenacious stool. Which is the most appropriate next step?
