An infant born 2 days ago has not passed a meconium stool and begins to vomit bilious secretions. Which action should the nurse take first?

A. Monitor strict urinary output: Monitoring urine output helps assess hydration but does not address the acute gastrointestinal issue causing bilious vomiting and absence of meconium, which could indicate a bowel obstruction. B. Gather supplies for an IV infusion: IV access may be needed later for fluids or decompression support, but the nurse must first perform an assessment to identify the extent of abdominal distention and obstruction before initiating interventions. C. Measure abdominal circumference: Bilious vomiting and lack of meconium within 48 hours suggest a possible intestinal obstruction, such as Hirschsprung disease or meconium ileus. Measuring abdominal girth helps assess distention and progression, making it the first and most immediate nursing action. D. Prepare for anorectal manometry: Anorectal manometry confirms Hirschsprung disease but is a diagnostic procedure performed later. The nurse must first assess and monitor the infant’s condition to provide essential data for the healthcare provider.