What are the initial management and differential diagnoses for a patient presenting with recurrent vomiting?

Differential Diagnoses for Recurrent Vomiting

The differential diagnosis for recurrent vomiting is extensive and must be systematically approached by first distinguishing between acute versus chronic patterns, then categorizing by organ system involvement, with particular attention to life-threatening causes that require immediate intervention. 1, 2

Critical Initial Distinction: Bilious vs Non-Bilious Vomiting

Bilious vomiting is a surgical emergency until proven otherwise and strongly suggests obstruction distal to the ampulla of Vater, requiring urgent fluoroscopy upper GI series. 2 In neonates, this represents midgut volvulus in 20% of cases. 2

Pattern-Based Classification

Acute Vomiting (≤7 days)

The most common causes include: 3, 4

Gastrointestinal causes:

• Acute gastroenteritis (most common cause in children and adults) 3, 5
• Foodborne illness 4
• Acute gastritis 3
• Appendicitis (older children and adults) 3

Neurologic causes:

• Acute migraine headaches 4
• Increased intracranial pressure/intracranial mass lesions 3
• Meningitis or encephalitis 3

Metabolic/Endocrine causes:

• Diabetic ketoacidosis 3
• Uremia 3
• Symptomatic hypoglycemia 3

Other causes:

• Medication adverse effects 6, 4
• Toxic ingestions 3
• Vestibular disturbances 4
• Early pregnancy 4

Chronic/Recurrent Vomiting (≥4 weeks or episodic pattern)

Cyclic Vomiting Syndrome (CVS): This is a critical diagnosis to recognize, affecting approximately 2% of the US population. 7 CVS is characterized by: 1

• Stereotypical episodes of acute-onset vomiting lasting <7 days 1, 7
• At least 3 discrete episodes per year, with 2 in the prior 6 months 1, 7
• Episodes separated by at least 1 week of baseline health 1, 7
• Prodromal symptoms (65% of patients) including impending sense of doom, panic, and inability to communicate 1
• Associated constitutional symptoms: fatigue, mental fog, anxiety, abdominal pain, diaphoresis 1
• Strong association with migraine (personal or family history is supportive) 1, 7
• Mood disorders present in 50-60% of patients 7

Food Protein-Induced Enterocolitis Syndrome (FPIES): Particularly important in infants and young children: 1

• Acute FPIES: repetitive vomiting 1-4 hours after suspect food ingestion 1
• Absence of classic IgE-mediated allergic symptoms (no urticaria, wheezing) 1
• May present with extreme lethargy, marked pallor, hypotension, hypothermia 1
• Diarrhea typically follows in 5-10 hours 1
• Often misdiagnosed as viral gastroenteritis or sepsis 1
• Chronic FPIES: intermittent progressive vomiting and diarrhea with poor weight gain when trigger food consumed regularly 1

Gastroparesis:

• Diagnosed by gastric emptying scintigraphy performed for at least 2-4 hours after radiolabeled solid meal 2
• 13C breath testing is an alternative non-radioactive option 2

Structural/Obstructive causes in infants:

• Congenital intestinal obstruction/atresia 3
• Malrotation with volvulus 1, 2, 3
• Pyloric stenosis 3
• Intussusception 3

Other chronic causes:

• Gastroesophageal reflux disease 2
• Chronic medication adverse effects 6, 4
• Metabolic disorders (inborn errors of metabolism in infants) 3
• Psychogenic disorders 6
• Cannabinoid hyperemesis syndrome (though hot water bathing occurs in 48% of CVS patients without cannabis use) 7

Red Flag Signs Requiring Urgent Evaluation

The following mandate immediate investigation: 3

• Bilious or bloody vomiting 3
• Altered sensorium 3
• Toxic/septic/apprehensive appearance 3
• Inconsolable cry or excessive irritability 3
• Severe dehydration 3
• Severe wasting 3
• Bent-over posture 3

Age-Specific Considerations

Infants (<3 months): 3 Life-threatening causes include necrotizing enterocolitis, congenital adrenal hypoplasia, obstructive uropathy, sepsis, hydrocephalus, and shaken baby syndrome. 3

Older children and adults: 3 Consider appendicitis, intracranial mass lesions, Reye's syndrome, and uremia. 3

Initial Management Approach

For acute presentations with red flags: 3

• Assess airway, breathing, circulation 3
• Stop oral intake and decompress stomach with nasogastric tube if bilious vomiting 3
• Obtain serum electrolytes, blood gases, renal/liver function 3
• Fluoroscopy upper GI series for bilious vomiting 2

For suspected CVS: 1, 2

• Diagnosis is primarily clinical based on Rome IV criteria 2
• Limited testing to exclude mimics 2
• Early intervention during prodromal phase with sumatriptan combined with antiemetics (ondansetron) 2, 7

Common pitfall: Failing to recognize that approximately 15% of CVS patients have episodes lasting >7 days, and some develop "coalescent CVS" with progressively fewer symptom-free days, which can be misdiagnosed as chronic nausea vomiting syndrome. 1, 7 A careful history revealing years of prior episodic pattern is key. 1