General Overview

  • Symptoms
    • Renal colic, hematuria, abdominal/flank pain waves or paroxysms, nausea, urinary symmptoms
      • Struvite with UTI, flank pain, urine pH<7
  • Stones
    • Calcium (oxalate>phosphate) stones (80%), uric acid, struvite (magnesium ammonium phosphate), cystine
  • Risk
    • History of prior nephrolithiasis (50% recurrence at 10y)
    • Family history (2xRR)
    • Hypertension (2xRR)
    • Enhanced enteric oxalate absorption (gastric bypass, bariatric surgery, short bowel syndrome)
    • Proteus/Klebsiella UTI for Struvite
  • Complications
    • Renal obstruction/damage (eg. Staghorn calculi)
    • Do not miss pyelonephritis, diverticular abscess

Red Flags

  • Concurrent UTI (risk of pyonephrosis, bacteremia)
  • Single kidney
  • Bilateral obstruction
  • Premorbid renal failure or anuria


  • Non-contrast CT scan (88% sensitivity)
    • Ureteral dilatation or stranding without a stone likely recent passage of stone
  • Ultrasound (54% sensitivity)
    • First-line in pregnancy
  • Other: KUB (abdominal plain film)


  • UA + Urine culture
  • Serum electrolytes (Na, K, Cl, HCO3, Ca, Creat)
  • Stone analysis

Additional investigations for risk (<18yo, multiple or recurrent stones, non-calcium stones - uric acid or cystine, complication - AKI, sepsis, hospitalization)

  • Albumin, uric acid, bicarbonate
  • PTH if serum calcium is high normal or high
  • Vitamin D if serum calcium low normal or elevated PTH
  • 24h urine collection x2
    • Volume, creatinine, Ca, Na, K, Oxalate, Citrate, uric acid, magnesium
    • Cystine if suspect cystine stone (or if stone analysis cystine)
  • Spot urine: pH, UA, Specific gravity


  • Pain control: NSAID + Opioid
    • Ketorolac 15mg IV or indomethacin 100mg PR + morphine 5mg IV
  • Hydration (Target 2.5L daily urine output)
  • Consider Tamsulosin 0.4mg PO daily (or nifedipine)
    • Recent studies do not show a significant benefit
  • Urology consultation
    • Inpatient if urosepsis, acute kidney injury, anuria, N/V (unable to tolerate oral)
    • Outpatient if >10mm (unlikely to pass)
  • Strain urine to analyse stone
  • Diet
    • High in fiber, fruits, vegetables
    • Calcium 1000-1200mg/day
      • Calcium stone - aim for sodium intake of 1500mg (<2300mg daily)
    • Avoid Vitamin C