Renal Colic

Renal colic presents as severe loin-to-groin colicky pain ± haematuria. Diclofenac 75mg IM is first-line analgesia. Non-contrast CT KUB is the gold standard imaging modality. An infected obstructed kidney is a surgical emergency requiring same-day…

EAU Urolithiasis Guidelines / NICE CG160

The pathway

1 · Analgesia first

Diclofenac 75mg IM or PR: first-line (prostaglandin inhibition reduces ureteric spasm)
IV morphine 5–10mg: if vomiting, NSAID contraindicated (eGFR <30, peptic ulcer, AKI), or inadequate analgesia
Contraindications to NSAIDs: AKI, eGFR <30, active peptic ulcer, anticoagulation
Reassess pain at 30 minutes

2 · Urine dip and MSU

Haematuria: expected in >80% of renal colic (microscopic or visible)
Nitrites + leucocytes: raises concern for infected stone — key emergency differentiator
Send MSU for culture if any evidence of infection
Absence of haematuria does not exclude renal colic

3 · Baseline bloods

U&E and eGFR: AKI with obstruction changes management urgently
FBC: raised WBC suggests infection
CRP: elevated in infected stone
Clotting and group & save: if intervention likely
Calcium, urate: metabolic stone work-up

4 · Non-contrast CT KUB

Gold standard: detects >97% of stones, identifies size, position, and degree of obstruction
Avoid in pregnancy: use USS (lower sensitivity but no radiation)
Hydronephrosis on USS: assess degree of obstruction if CT unavailable

5 · Stone size and management

<5mm: 80–90% pass spontaneously — conservative management with hydration and analgesia
5–10mm: medical expulsive therapy (MET) with tamsulosin 400mcg OD + urology review; 50% pass
>10mm: urological intervention (ureteroscopy ± laser lithotripsy or ESWL) — refer urology

6 · Infected obstructed kidney — EMERGENCY

Fever + positive urine nitrites/WBC + obstruction on imaging = surgical emergency
Do NOT discharge or delay
Same-day urology referral: ureteric stent (JJ stent) or percutaneous nephrostomy under radiology
IV antibiotics: gentamicin 5mg/kg IV (single dose, check eGFR) + amoxicillin 500mg IV TDS
Sepsis management if systemically unwell

7 · Outpatient follow-up

Stone <5mm with no infection: discharge with analgesia, urine strainer, safety-net advice
Return if: fever, worsening pain, vomiting preventing PO medication
Urology follow-up for all stones not passed or requiring intervention
Metabolic stone work-up at 4 weeks if recurrent (24h urine calcium, oxalate, urate)

Drugs

Drug	Dose	Route	Notes
Diclofenac	75mg	IM or PR	First-line analgesia. Avoid if eGFR <30, AKI, active peptic ulcer, or anticoagulation.
Morphine	5–10mg	IV	If NSAID contraindicated or inadequate analgesia. Titrate IV.
Tamsulosin	400mcg OD	PO	Medical expulsive therapy for 5–10mm stones. Alpha-blocker reduces ureteric spasm.
Gentamicin	5mg/kg	IV	Single dose for infected stone. Check eGFR first. Monitor levels if repeat dosing.

When to escalate

Fever + obstruction = infected stone = surgical emergency — same-day urology/radiology,Solitary kidney + any obstruction — urgent urology referral,Bilateral obstruction with AKI — emergency decompression,Stone >10mm — urology referral for intervention (ureteroscopy/ESWL),Pain not controlled with IV morphine + NSAID — senior review, consider urology admission

Reference: EAU Urolithiasis Guidelines 2023 / NICE CG160 Renal and Ureteric Stones

This page is the reference half

The app adds what a web page cannot: a VINDICATE differential builder, worked on-call scenarios with full A–E findings, recall practice, and all of it offline.