Vomiting, Fever, Yellow Urine: Differential Includes Infections, Biliary Disease, Appendicitis, UTI, Medication Toxicity, Pancreatitis

This symptom cluster (vomiting, fever, dark urine) suggests several diagnostic categories requiring urgent evaluation:

1. Infectious

• Gastroenteritis (viral/bacterial) → dehydration → concentrated urine.
• Influenza/COVID-19: systemic + GI symptoms.
• Foodborne illness (Salmonella, Campylobacter, E. coli).

2. Hepatobiliary

• Acute cholecystitis/cholangitis: RUQ pain, fever, vomiting, jaundice → dark urine (bilirubinuria).
• Acute hepatitis (viral A/B/E, alcoholic, autoimmune): nausea, vomiting, dark urine, elevated transaminases.

3. Surgical Abdomen

• Appendicitis: periumbilical → RLQ pain, anorexia, vomiting, low-grade fever.
• Pancreatitis: epigastric pain radiating to back, vomiting, fever; gallstones/alcohol common causes.

4. Urinary

• Pyelonephritis: flank pain, fever, vomiting, dysuria; urine shows WBC, bacteria.

5. Toxic/Metabolic

• Medication adverse effects (antibiotics, chemo, opioids).
• Diabetic ketoacidosis: vomiting, polyuria, ketonuria.

Action

Seek immediate medical attention. Workup: CBC, CMP, LFTs, lipase, urinalysis/culture, β-hCG (women), imaging (US/CT) as indicated. Do not self-diagnose.