Synopsis
Assess vomiting by physiology and timing, correct dehydration and electrolyte danger, recognise obstruction and extra-abdominal emergencies, and investigate persistent gastric retention without premature prokinetic treatment.
- Clarify whether material is gastric, bilious, bloody, coffee-ground or faeculent and whether nausea precedes it; effortless regurgitation and rumination have different mechanisms from forceful vomiting.
- Early morning headache or neurological change, chest pain, pregnancy, drugs, cannabis, alcohol withdrawal, sepsis and metabolic disease must remain in the differential even when abdominal symptoms dominate.
- Postprandial fullness, early satiation and late vomiting of recognisable food suggest impaired gastric emptying or outlet obstruction, but structural narrowing must be excluded before diagnosing gastroparesis.
Key red flags
Progressive early satiation, epigastric fullness, weight loss, dehydration and large-volume late postprandial vomiting suggest retention proximal to the pylorus or duodenum. Malignancy must be excluded promptly, particularly with short progressive history.
Investigation priorities
Identify diabetic ketoacidosis, starvation ketosis, hypoglycaemia and acid-base consequences of vomiting.
Management branches
Vomiting is persistent, severe or associated with physiological abnormality.
- Assess airway and aspiration risk, breathing, circulation, mental state and abdominal signs; obtain venous access, bedside glucose and ketones and relevant bloods.
- Provide monitored crystalloid and electrolyte replacement based on losses and comorbidity, keep nil by mouth when obstruction or procedure is plausible, and measure urine output.
Key medicines
Mechanism-selected antiemeticChoose one current BNF and locally approved agent and route, adjusting for pregnancy, renal or hepatic impairment, QT interval and likely central or gastric mechanism.
Parenteral thiamine for deficiency riskGive the local high-risk thiamine regimen before carbohydrate or dextrose administration in prolonged vomiting, severe restriction, alcohol dependence or refeeding risk.