What is the appropriate management for a child presenting with bilious vomiting?

Management of Bilious Vomiting in Children

Bilious vomiting in a child is a surgical emergency until proven otherwise and requires immediate evaluation with abdominal radiograph followed by upper GI contrast series to exclude malrotation with midgut volvulus, which can cause intestinal necrosis within hours. 1

Immediate Clinical Actions

Initial Stabilization

• Stop all oral intake immediately and place a nasogastric tube for gastric decompression in any child with bilious vomiting 2
• Assess airway, breathing, circulation, and hydration status 2
• Obtain immediate pediatric surgical consultation—do not delay for imaging if the child appears toxic or has peritoneal signs 1, 3

Critical Pathophysiology to Understand

The presence of bile in vomitus indicates obstruction distal to the ampulla of Vater 1. In neonates within the first 72 hours of life, 20% of bilious vomiting cases represent midgut volvulus 1. This condition causes the mesentery to twist around the superior mesenteric artery, leading to venous congestion, arterial compromise, transmural intestinal ischemia, and potentially catastrophic bowel necrosis requiring massive resection or resulting in death—all within hours 1.

Diagnostic Algorithm

Step 1: Obtain Abdominal Radiograph Immediately

• This is the mandatory first imaging study 3
• Look for:
  • Classic "double bubble" sign (suggests duodenal atresia) 4
  • Multiple dilated bowel loops with absent/decreased distal gas (suggests distal obstruction) 4
  • Few distended loops or normal gas pattern (does NOT exclude malrotation/volvulus) 4

Critical pitfall: Normal abdominal radiographs do not exclude malrotation or volvulus—clinical suspicion based on bilious vomiting alone mandates proceeding to upper GI study regardless of radiograph findings 1.

Step 2: Upper GI Contrast Series (Reference Standard)

• This is the definitive study for bilious vomiting and should be performed urgently 4, 3
• The upper GI series directly images the stomach and small bowel to identify:
  • Abnormal position of the duodenojejunal junction (ligament of Treitz), which indicates malrotation 4
  • Presence of midgut volvulus requiring immediate surgery 4
• Sensitivity is 96% for detecting malrotation, though false-positives (10-15%) and false-negatives (up to 7%) can occur due to redundant duodenum, bowel distension, or jejunal position 4

Step 3: Contrast Enema (Only for Specific Scenarios)

• Do NOT use as initial study for bilious vomiting 3
• Reserved only when radiographs show distal bowel obstruction (multiple dilated loops with no distal gas) 4
• Used to differentiate meconium plug, meconium ileus, ileal atresia, or Hirschsprung disease 4
• Approximately 20% false-negative rate for malrotation, making it inferior to upper GI series 4

Ultrasound Considerations

• Limited role as primary imaging modality 4
• Can evaluate SMV/SMA relationship and duodenal position, but has 21% false-positive and 2-3% false-negative rates for malrotation 4
• Bowel gas obscures visualization in up to 17% of cases 4
• Should not delay upper GI series 4

Age-Specific Differential Diagnosis

Neonates (First 2 Days of Life)

• Malrotation with midgut volvulus (most urgent—requires surgery within hours) 4, 1
• Duodenal atresia (classic double bubble) 4
• Jejunal or ileal atresia 4, 1
• Hirschsprung disease 1, 5
• Meconium ileus or meconium plug 4, 5
• Necrotizing enterocolitis (in premature infants) 6

Older Infants and Children

• Intussusception (look for crampy pain, "currant jelly" stools) 1, 3
• Internal hernia 1
• Appendicitis (older children) 2

Non-Surgical Causes (Diagnosis of Exclusion)

• Sepsis (13/39 cases in one series) 7
• No identifiable cause (20/39 cases in one series with normal upper GI studies) 7
• Neurologic conditions (polymicrogyria) 7
• Metabolic disorders 2

Common Pitfalls to Avoid

1. Never assume normal radiographs exclude surgical pathology—malrotation with incomplete volvulus can have normal bowel gas patterns 4, 1

2. Do not confuse with pyloric stenosis, which presents with non-bilious projectile vomiting in infants 2 weeks to 3 months old 3

3. Do not perform contrast enema as initial study—it is less direct than upper GI series and has higher false-negative rates for malrotation 4, 3

4. Do not delay surgical consultation while awaiting imaging if the child appears septic, has peritoneal signs, or shows signs of vascular compromise 1

5. Meticulous technique is essential for upper GI interpretation to avoid false results from redundant duodenum or bowel distension 4

Management Priorities

• Immediate nasogastric decompression and NPO status 2
• Fluid resuscitation for dehydration 2
• Urgent pediatric surgical consultation upon confirmation of bilious vomiting 3
• Proceed directly to surgery if upper GI series confirms malrotation/volvulus 4, 1
• Antiemetics (ondansetron 0.2 mg/kg oral or 0.15 mg/kg IV, max 4 mg) only after surgical causes excluded 2