Vomiting with abdominal pain alone (unrelated to food and no fever)—metabolic causes

This is associated with a wide variety of GI and systemic disorders. It is non-specific.

Some differential diagnoses and typical outline evidence

Drugs overdose e.g. digoxin	Suggested by: drug history.
	Confirmed by: serum drug levels.
	Management: OHCM p830.
Diabetic ketoacidosis	Suggested by: polyuria, dehydration, ±Kussmaul respiration.
	Confirmed by: ↑blood glucose, ↓pH,ketonuria or plasma bicarbonate <15mmol/l.
	Management: OHCM p818.
Hypercalcaemia	Suggested by: lethargy, confusion, constipation, muscle weakness, polydipsia and polyuria.
	Confirmed by: ↑serum Ca2+.
	Management: OHCM p696.
Acute intermittentporphyria	Suggested by: family history, constipation, peripheral neuropathy, hypertension, psychoses, urine darkens on standing.
	Confirmed by: Elevated urinary-aminolevulinic acid and porphobilinogen, plasma porphyrins.
	Management: OHCM p708.
Lead poisoning	Suggested by: anorexia, personality changes, headaches, metallic taste.
	Confirmed by: elevated whole blood lead concentration >2.4µmol/L.
	Management: OHCM pp210, 628.
Vitamin A intoxication	Suggested by: ↑intracranial pressure, headache, irritability.
	Confirmed by: symptoms and signs disappearing within 1–4 weeks after stopping vitamin A ingestion.
Phaeochromocytoma	Suggested by: headache, sweating, palpitations, pallor, nausea, hypertension (intermittent or persistent), tachycardia.
	Confirmed by: 24 hour urinary metanephrines ↑, serum catecholamines ↑↑(adrenaline, noradrenaline), CT abdomen, MRI scan.
	Management: OHCM pp314, 822.