What could be causing a 3-year-old child to vomit multiple times a week without any other symptoms?

Recurrent Vomiting in a 3-Year-Old Without Other Symptoms

The most likely diagnosis in a 3-year-old with isolated recurrent vomiting (multiple times weekly) without other symptoms is cyclic vomiting syndrome or an unrecognized gastrointestinal disorder, though you must systematically exclude serious anatomic and metabolic causes before settling on a functional diagnosis. 1, 2

Critical Red Flags to Exclude First

Before considering benign causes, you must actively rule out the following:

• Bilious (green) vomiting – This is a surgical emergency at any age and indicates obstruction distal to the ampulla of Vater, requiring immediate imaging and surgical consultation 1, 3
• Blood in vomitus or "currant jelly" stools – Suggests mucosal damage from intussusception or other serious pathology 1, 3
• Poor weight gain or weight loss – Elevates concern from benign reflux to GERD disease or other pathology requiring aggressive intervention 4, 2
• Abdominal distension or severe abdominal pain – May indicate obstruction or other surgical conditions 1, 2
• Altered mental status or neurological symptoms – Consider increased intracranial pressure, metabolic disorders, or toxic ingestions 2, 5

Age-Specific Considerations

At 3 years old, this child is beyond the typical age range for most common infant causes of vomiting:

• Gastroesophageal reflux (GER) typically resolves by 12 months of age in 95% of infants 6
• Hypertrophic pyloric stenosis presents between 3-6 weeks of age, not at 3 years 1, 4
• Viral gastroenteritis causes acute (not chronic weekly) vomiting with diarrhea, most common under 2 years 1, 7

Diagnostic Approach for Chronic Isolated Vomiting

History Details to Elicit:

• Timing and pattern: Relation to meals, time of day, episodic vs continuous 2, 5
• Character: Projectile, forceful, or effortless; bilious vs non-bilious 1, 4
• Associated symptoms: Even subtle ones like irritability, back arching (suggesting reflux pain), feeding difficulties, or sleep disturbances 4, 6
• Growth parameters: Review growth chart for weight gain trajectory 4, 2
• Dietary history: Consider cow's milk protein allergy, which overlaps with GERD in 42-58% of cases 6
• Family history: Migraines (associated with cyclic vomiting syndrome) 2

Physical Examination Priorities:

• Vital signs and hydration status: Assess for chronic dehydration 2, 5
• Abdominal examination: Palpate for masses, distension, tenderness; check hernial orifices and genitalia 2, 5
• Neurological examination: Fundoscopy for papilledema, assess for encephalopathy 2, 5
• Blood pressure measurement: Essential to exclude hypertension from renal or other causes 5

When to Image

The yield of upper GI series in otherwise healthy children with chronic vomiting (no hematemesis, no bilious vomiting, no dysphagia, no respiratory symptoms, normal growth) is extremely low at 0.6% 8. However:

• Obtain abdominal X-ray immediately if any concern for obstruction (bilious vomiting, distension, severe pain) 1, 3
• Consider upper GI series if there are red flags like poor weight gain, forceful vomiting suggesting anatomic abnormality, or failure to respond to conservative management 4, 8
• Ultrasound has no role unless specific concern for pyloric stenosis (wrong age) or intussusception (would have other symptoms) 4, 3

Laboratory Evaluation

Not routinely needed for uncomplicated chronic vomiting, but consider:

• Serum electrolytes, renal function, liver function if dehydration present or red flags identified 2
• Trial elimination of cow's milk protein for 2-4 weeks before extensive testing, given high overlap with GERD 6

Management Strategy

For Uncomplicated Chronic Vomiting:

• Parental reassurance and education are usually sufficient for non-complicated cases 4, 6
• Lifestyle modifications: Smaller, more frequent meals; avoid trigger foods 4
• Consider 2-4 week trial of cow's milk protein elimination given 42-58% overlap with GERD 6

Pharmacotherapy Considerations:

• Antiemetics are NOT routinely indicated for chronic vomiting without specific indication 4, 2
• Ondansetron (0.2 mg/kg oral, max 4 mg) may be used for cyclic vomiting syndrome episodes or when persistent vomiting prevents oral intake 4, 2
• Acid suppression therapy (e.g., esomeprazole) only if GERD with erosive esophagitis is documented, not for empiric trial 6
• Prokinetics lack sufficient evidence for routine use per NASPGHAN/ESPGHAN guidelines 6

Common Pitfalls to Avoid

• Do not dismiss bilious vomiting as "just gastroenteritis" – it requires urgent surgical evaluation 1
• Do not perform routine imaging in well-appearing children with normal growth and no red flags 8
• Do not use antidiarrheal or antimotility agents – they are ineffective and potentially dangerous 4
• Do not start acid suppression empirically without documented pathology 6
• Do not overlook cow's milk protein allergy as a treatable cause that mimics GERD 6

When to Refer or Escalate

• Immediate surgical consultation: Any bilious vomiting, signs of obstruction, or acute abdomen 1, 3
• Gastroenterology referral: Poor weight gain despite conservative measures, suspected GERD disease requiring endoscopy, or diagnostic uncertainty 4, 6
• Observation/admission: If cause not apparent after initial assessment or if unable to maintain hydration 5