Vomiting is non-specific. Categorize by bile content, age, and associated features. Bilious vomiting at any age requires urgent surgical evaluation. Forceful, projectile, non-bilious in 3–8 wk old → pyloric stenosis. Always screen for ↑ICP, DKA, sepsis, ingestion, NAT.
🚩 Red-flag clues (must not miss)
- •Bilious vomiting (any age) = malrotation/volvulus until UGI excludes it
- •Projectile non-bilious in 3–8 wk → pyloric stenosis (palpable olive)
- •Vomiting + AMS + hypoglycemia → IEM / Reye syndrome / toxic ingestion
- •Vomiting + AM headache + papilledema → ↑ICP / posterior fossa tumor
- •Vomiting + DKA (Kussmaul, fruity breath) — check glucose + VBG
History
- Bile / blood / feculent content; force; relationship to feeds
- Fever, headache, abdominal pain, diarrhea
- Trauma, ingestion, medication use
- Diabetes, FTT, recurrent episodes (cyclic vomiting)
Exam
- Hydration, vitals, fontanelle, abdomen (mass, distention, tenderness)
- Hernia exam, scrotum (torsion), DRE if obstruction
- Neuro for ↑ICP
Labs
- BMP, glucose, VBG (DKA, IEM)
- UA + cx in younger child without obvious source
- If bilious: type/screen, coags, surgical consult
Imaging
- KUB if obstruction
- UGI series for malrotation
- US for intussusception, pyloric stenosis
- Head CT (without contrast) if neuro signs / trauma
Differential & next step
| Diagnosis | Clue | Next step |
|---|---|---|
| Acute viral gastroenteritis | Diarrhea, contacts | ORT, ondansetron |
| Malrotation / volvulus | Bilious vomiting | EMERGENT UGI, surgery |
| Pyloric stenosis | 3–8 wk, projectile, olive, hypoCl alkalosis | Correct lytes, US, pyloromyotomy |
| Intussusception | Episodic, currant-jelly stool, sausage mass | US → air-contrast enema |
| Appendicitis | Pain → vomiting → fever, RLQ | US/CT, surgery |
| DKA | Polyuria, fruity breath, Kussmaul | DKA protocol (see /dka-peds) |
| ↑ ICP | Morning HA, papilledema, focal deficit | Imaging, neurosurgery |
| UTI / pyelonephritis | Dysuria older, occult in young | UA + cx, abx |
| Toxic ingestion | Access to meds/cleaners | Tox screen, poison control |
| IEM / metabolic | AMS + acidosis + hyperammonemia | Metabolic team, dextrose, ammonia scavengers |
| Cyclic vomiting syndrome | Stereotyped recurrent episodes, family hx migraine | Hydration + ondansetron; abortive triptan in older |
| Pregnancy (adolescent) | Always check βhCG | OB referral |
Management / next steps
- Assess hydration; ondansetron PO if no surgical concern
- ORT trial; IV fluids for moderate–severe dehydration
- Bilious vomiting → NPO, NG, surgical consult, UGI
- Admit if dehydration not corrected, surgical, or unclear etiology