Renal Colic 🪨
Renal colic and suspected renal stone in adults, based on IAEM v2.0 (2025): POCUS for AAA over 50, CT KUB within 24 hours, NSAID first, stone size plan, admission and discharge criteria.
🚨 Over 50: Exclude AAA
- Especially men over 50 with a first episode.
- Bedside POCUS for AAA.
- Abnormal or AAA suspected: urgent vascular review ± CT aortogram.
- Normal POCUS: continue renal colic workup.
🚨 Obstructed Kidney + Infection or Anuria
- Urological emergency: call urology immediately.
- Screen for and treat sepsis.
- Fever: infected obstructed kidney, or another infective or inflammatory cause.
⚠️ Outside This Pathway (IAEM)
- Under 18, pregnant, known AAA or underlying renal disease.
🧾 History & Exam
- Loin pain ± radiation to groin, vomiting, fever.
- Haematuria in about 82%.
- Personal or family history of stones.
- Structural renal tract abnormality.
- Gout, hyperparathyroidism, RTA, osteoporosis, recurrent UTI.
- Loop diuretics, antibiotics.
- Full abdomino-pelvic exam.
- A stone does not exclude another urgent diagnosis.
🧪 Investigations
- Urine dipstick: blood, leucocytes, nitrites, pH.
- Urine culture if dipstick abnormal.
- Urine βhCG if of childbearing age.
- FBC, U&E, creatinine, CRP.
- Urate and bone profile if no normal result in past year.
- Consider coagulation if intervention likely.
📷 Imaging
- Bedside US looks for hydronephrosis. It often misses ureteric stones.
- Bedside US by trained operators only. Never delay analgesia for it.
Suspected stone
- Imaging
- Low-dose NCCT (CT KUB) within 24 h
Fever, solitary kidney, diagnosis unclear
- Imaging
- Immediate bedside US, plus NCCT
Pregnant
- Imaging
- US, then MRI, then low-dose CT
No stone seen
- Imaging
- Find the cause of pain
| Situation | Imaging |
|---|---|
| Suspected stone | Low-dose NCCT (CT KUB) within 24 h |
| Fever, solitary kidney, diagnosis unclear | Immediate bedside US, plus NCCT |
| Pregnant | US, then MRI, then low-dose CT |
| No stone seen | Find the cause of pain |
💊 Analgesia (IAEM)
- First line: NSAID (ibuprofen, diclofenac).
- Alternative: paracetamol.
- PR NSAID may control pain better.
- No NSAID in heart failure (NYHA II to IV), IHD, PAD or cerebrovascular disease.
- CKD: NSAID with caution, short course only.
- Second line: opioid, if NSAID contraindicated or pain uncontrolled.
- Combine opioid with paracetamol and NSAID to spare opioid.
🎯 Stone Size (IAEM)
- New stone under 10 mm, no removal needed: inpatient observation is an option. Discuss with urology.
- Alpha blocker: consider for distal ureteric stones over 5 mm.
- Off-label, and trial evidence is mixed.
- A 2 to 4 mm stone takes about 40 days to pass.
Under 4 mm
- Plan
- Up to 80% pass alone
Under 5 mm, low risk
- Plan
- Urology OPD follow-up
Over 5 mm
- Plan
- Discuss with urology ± admit
Over 8 mm
- Plan
- Unlikely to pass alone
Over 10 mm
- Plan
- Active removal usually indicated
| Stone | Plan |
|---|---|
| Under 4 mm | Up to 80% pass alone |
| Under 5 mm, low risk | Urology OPD follow-up |
| Over 5 mm | Discuss with urology ± admit |
| Over 8 mm | Unlikely to pass alone |
| Over 10 mm | Active removal usually indicated |
🔧 Active Removal Usually Indicated (IAEM)
- Stone over 10 mm.
- Pain not controlled.
- Obstruction with infection.
- Risk of pyonephrosis or urosepsis.
- Single kidney with obstruction.
- Bilateral obstruction.
🚩 Admit (Even If Under 4 mm)
- Shock, fever or systemic infection.
- Renal impairment or risk to renal function.
- Bilateral obstructing stones.
- Pain uncontrolled or severe pain recurs.
- Vomiting, cannot take oral fluids.
🏠 Discharge
- After imaging, stone under 5 mm: no obstruction, no sepsis, pain controlled, passing urine, normal renal function. Urology OPD.
- Before imaging, low risk, NCCT not available now. All of:
- Stone the likely diagnosis.
- No AAA concern: under 50, or negative POCUS.
- No sepsis, pain controlled, passing urine.
- Imaging available next day.
- Social situation allows return next day.
- Clear return pathway in place.
- Advice: 2.5 to 3 L fluid a day, mostly water.
Based on
Related NICE guidance
NICENICE NG118 — Renal and ureteric stones: assessment and management (Jan 2019)
Full guidance on nice.org.uk. BetterCall is not endorsed by NICE.
Educational reference only. Medical disclaimer