What causes persistent vomiting?

Causes of Persistent Vomiting

Persistent vomiting is most commonly caused by gastrointestinal obstruction, gastroesophageal reflux, medication side effects, or systemic conditions including infections and metabolic disorders, with the specific etiology varying by age group and requiring targeted evaluation based on presenting symptoms. 1

Age-Specific Etiologies

In Infants

• Non-bilious vomiting

  • Gastroesophageal reflux (GER) - most common cause in infants with normal weight gain 1, 2
  • Overfeeding - particularly in the first weeks of life 1
  • Formula intolerance 1
  • Pylorospasm 1
  • Hypertrophic pyloric stenosis (HPS) - characterized by palpable "olive" of hypertrophied muscle 1

• Bilious or forceful vomiting (surgical emergencies)

  • Malrotation with or without volvulus 1
  • Intestinal atresia (antropyloric region, small bowel, colon) 1
  • Annular pancreas 1
  • Hirschsprung disease 1
  • Meconium ileus 1

• Other causes

  • Systemic infections (sepsis, meningitis) 1, 3
  • Metabolic disorders (phenylketonuria, hyperammonemia, maple syrup urine disease, galactosemia) 1
  • Increased intracranial pressure (hydrocephalus, tumor, trauma) 1
  • Gastroenteritis 1, 3

In Older Children and Adults

• Gastrointestinal causes

  • Gastric outlet obstruction 1
  • Bowel obstruction 1
  • Constipation 1
  • Gastroenteritis 4, 5
  • Appendicitis 6
  • Intussusception 3, 6

• Medication-related

  • Opioid use 1
  • Chemotherapy 1
  • Digoxin, phenytoin, carbamazepine, tricyclic antidepressants 1

• Systemic conditions

  • Hypercalcemia 1
  • Uremia 3
  • Diabetic ketoacidosis 3
  • Migraine headaches 5
  • Vestibular disorders 5

• In cancer patients

  • Chemotherapy/radiation-induced 1
  • Disease-related (tumor burden) 1

Red Flag Symptoms Requiring Urgent Evaluation

• Bilious vomiting - indicates obstruction distal to the ampulla of Vater 1
• Bloody vomiting 3
• Forceful/projectile vomiting - suggests increased intracranial pressure or pyloric stenosis 1
• Altered mental status 3
• Signs of dehydration 3
• Abdominal distention or tenderness 3
• Absence of bowel movements 1
• Weight loss or failure to thrive 1

Diagnostic Approach

1. Clinical assessment

   • Thorough history focusing on:
     • Timing and pattern of vomiting
     • Character of vomitus (bilious, bloody, projectile)
     • Associated symptoms (pain, diarrhea, fever)
     • Medication use
   • Physical examination to identify:
     • Dehydration status
     • Abdominal tenderness/masses
     • Neurological signs

2. Laboratory evaluation (when indicated)

   • Electrolytes and blood gases
   • Renal and liver function tests
   • Blood glucose
   • Complete blood count

3. Imaging studies (based on clinical suspicion)

   • Abdominal radiographs - for obstruction
   • Ultrasound - for pyloric stenosis, intussusception
   • CT scan - for appendicitis, tumors, other causes

Management Considerations

• Treat underlying cause when identified
• Manage dehydration with appropriate fluid replacement
• For non-specific nausea and vomiting: dopamine receptor antagonists (prochlorperazine, haloperidol, metoclopramide, olanzapine) 1
• For persistent symptoms: consider adding 5-HT3 receptor antagonists, anticholinergics, antihistamines, or corticosteroids 1
• For medication-induced vomiting: consider medication adjustment or rotation 1
• For gastroesophageal reflux in infants: positioning, feeding adjustments, reassurance 2

Important Pitfalls to Avoid

1. Missing surgical emergencies - bilious vomiting should always prompt evaluation for intestinal obstruction 1, 6
2. Attributing persistent vomiting to gastroenteritis without considering other causes 6
3. Overlooking medication side effects as potential causes 1, 5
4. Failing to recognize increased intracranial pressure as a cause of vomiting, especially in children 1
5. Inadequate fluid replacement leading to dehydration and electrolyte abnormalities 3

Remember that persistent vomiting can significantly impact quality of life and may indicate serious underlying conditions requiring prompt diagnosis and management 4, 5.