🤢 Chapter 12: Vomiting and Regurgitation

Nelson's Pediatric Symptom-Based Diagnosis | GERD · Pyloric Stenosis · Malrotation · Cyclic Vomiting · Metabolic Emergencies · Bilious Emesis

🔍 Vomiting & Regurgitation in Children: Key Concepts

📊 Definitions
Regurgitation: effortless, reflux of gastric contents. Vomiting: forceful expulsion with retching/nausea. Projectile vomiting suggests obstruction (pyloric stenosis, increased ICP). Bilious vomiting = obstruction distal to ampulla of Vater until proven otherwise.
🔄 Gastroesophageal Reflux (GER)
Physiologic in infants; peaks 4 months, resolves by 12-18 months. GERD if complications (FTT, esophagitis, respiratory symptoms). Treatment: thickened feeds, positioning, trial of hypoallergenic formula, PPI if severe.
⚠️ Pyloric Stenosis
Age 2-6 weeks, progressive projectile nonbilious vomiting, palpable olive, hypochloremic metabolic alkalosis. Ultrasound diagnostic. Pyloromyotomy curative.
💧 Malrotation & Volvulus (Surgical Emergency)
Bilious vomiting in any age (especially first weeks). Upper GI shows abnormal duodenal position. Midgut volvulus: vascular compromise, bowel necrosis. Emergent surgery.
🧬 Cyclic Vomiting Syndrome (CVS)
Stereotypical episodes of intense vomiting separated by symptom-free intervals. Often migrainous. Triggers: infection, stress, fasting. Treat: ondansetron, amitriptyline prophylaxis.
🚩 Red Flags (Emergencies)
Bilious vomiting, hematemesis, lethargy/coma, bulging fontanel, hepatomegaly, acidosis, hyperammonemia, hypoglycemia, abdominal distention/rigidity, shock.

💡 Key Takeaway: Bilious vomiting in an infant is a surgical emergency until malrotation/volvulus is excluded. Pyloric stenosis presents with nonbilious projectile vomiting. GER is common but red flags warrant investigation.

🩺 Clinical Approach to Vomiting: Step-by-Step Algorithm

🔹 Step 1: Determine if bilious (green) vomiting
• Bilious emesis in neonate/infant → obstruction distal to ampulla of Vater (malrotation with volvulus, duodenal atresia, jejunal atresia).
• EMERGENCY: URGENT surgical consult and upper GI series. Do not delay.
🔹 Step 2: Distinguish regurgitation (GER) from vomiting
• Regurgitation: effortless, after feeds, infant otherwise well, no FTT.
• Vomiting: forceful, may have retching, concerning for organic cause.
🔹 Step 3: Age-based differential
• Neonate (0-4wk): malrotation/volvulus, duodenal atresia, NEC, Hirschsprung, metabolic (galactosemia, CAH, urea cycle).
• Infant (1-12mo): GER (common), pyloric stenosis (2-6wk), intussusception, gastroenteritis, metabolic.
• Child/Adolescent: gastroenteritis, appendicitis, cyclic vomiting, pregnancy, DKA, increased ICP.
🔹 Step 4: Red flags for serious cause
• Hematemesis, bilious emesis, abdominal distention/rigidity, lethargy/coma, bulging fontanel, hepatomegaly, acidosis, hyperammonemia, hypoglycemia.
🔹 Step 5: Diagnostic workup
• Bilious vomiting: upper GI series (malrotation, volvulus).
• Suspected pyloric stenosis: ultrasound.
• Metabolic: glucose, electrolytes, ammonia, lactate, blood gas.
• Increased ICP: CT/MRI head, fundoscopic exam.
• GER: trial of therapy; UGI if no improvement or red flags.