What is the most appropriate next step for a newborn with abdominal distention, tenderness upon palpation, absent bowel sounds, and no meconium passage for 48 hours?

Most Appropriate Next Step: Refer to Pediatric Surgery

The most appropriate next step is B - refer to pediatric surgery immediately, as this newborn presents with peritoneal signs (tenderness and absent bowel sounds) indicating potential bowel compromise or perforation, which constitutes a surgical emergency requiring urgent evaluation before any diagnostic imaging. 1

Clinical Reasoning

This newborn presents with the classic tetrad of neonatal intestinal obstruction:

• Abdominal distention 2
• Failure to pass meconium beyond 48 hours 1, 2
• Absent bowel sounds 1
• Abdominal tenderness upon palpation 1

The critical distinguishing feature here is the combination of absent bowel sounds with abdominal tenderness, which suggests peritonitis or bowel compromise and mandates immediate surgical evaluation before any diagnostic imaging. 1

Why Surgery First, Not Imaging

Immediate Surgical Consultation is Mandatory

• The American College of Radiology explicitly recommends immediate pediatric surgical consultation for newborns with suspected intestinal obstruction, as 20% of neonates with bilious vomiting in the first 72 hours have midgut volvulus requiring urgent surgery 1
• Never delay surgical consultation for imaging studies in a neonate with peritoneal signs, as this can lead to significant morbidity and mortality 1
• The presence of tenderness and absent bowel sounds indicates potential bowel ischemia, perforation, or necrotizing enterocolitis—all conditions where delayed intervention increases mortality 1

Why Barium Enema is NOT the Next Step

While contrast enema is the diagnostic imaging procedure of choice for suspected distal obstruction 3, 1, it should only be performed after surgical consultation and stabilization, not as the immediate next step in a neonate with peritoneal signs 1

• Barium enema would be appropriate for stable neonates with distal obstruction patterns (meconium plug, Hirschsprung disease, ileal atresia) who lack peritoneal signs 3
• In this case, the clinical presentation suggests potential bowel compromise that requires surgical assessment first 1

Differential Diagnosis Requiring Urgent Surgery

The clinical presentation is consistent with several surgical emergencies:

• Midgut volvulus: Can present identically with obstruction and peritoneal signs, requires urgent surgery 1
• Intestinal atresia (jejunal or ileal): Presents with failure to pass meconium and distention 4
• Necrotizing enterocolitis: Tenderness and absent bowel sounds are concerning features 5
• Intestinal perforation: Peritoneal signs mandate immediate surgical evaluation 1

Appropriate Diagnostic Algorithm (After Surgical Consultation)

Once the surgical team is involved, the typical workup proceeds as follows:

1. Plain abdominal radiographs as the first imaging study to identify dilated bowel loops, air-fluid levels, and presence/absence of distal gas 1, 6
2. Contrast enema if radiographs show distal obstruction pattern (multiple dilated loops with absent distal gas) and the patient is stable without peritoneal signs 3, 1
3. Upper GI series if there is concern for malrotation/midgut volvulus based on clinical presentation or radiographic findings 3, 6

Critical Pitfall to Avoid

The most dangerous error would be ordering a barium enema study first and delaying surgical consultation, as this could result in catastrophic outcomes if the patient has midgut volvulus, perforation, or necrotizing enterocolitis. 1 Time to surgical intervention directly impacts morbidity and mortality in neonatal bowel emergencies, with volvulus potentially causing bowel necrosis within hours 6