Procedure prep
Fasting Before Kidney Stone Surgery (Ureteroscopy / Lithotripsy)
Kidney stones are commonly treated by ureteroscopy with a laser (a telescope passed up to the stone) or by shockwave lithotripsy (breaking the stone from outside). The single most important preparation point is making sure there's no untreated urine infection.
Fasting for this procedure
→ Get your exact fasting times with the calculator
Medicines to check
- Blood thinners (aspirin, clopidogrel, warfarin, Eliquis, Xarelto) — important here, as stone surgery can bleed; shockwave lithotripsy in particular usually can't be done on blood thinners. See medications to stop.
- Diabetes medicines & insulin need a fasting-day plan. See diabetes tablets.
- Blood pressure medicines — confirm which to take with a sip of water.
- Finish any antibiotics you've been given for a urine infection, and tell your team.
- Mention any alpha-blocker (tamsulosin) you've been prescribed to help pass the stone.
When this surgery may be delayed
- A urine infection or fever — this must be treated first, because operating through infected urine can cause serious blood infection (sepsis)
- A new cough/cold or chest infection
- Being on blood thinners that haven't been paused (especially for shockwave treatment)
- A positive or unknown pregnancy test
- You ate or drank outside your fasting window
Reports & documents to carry
- Photo ID and your insurance or hospital paperwork
- A current list of all your medicines, doses, and allergies
- Your CT or ultrasound stone scans and any recent urine test results
- Any antibiotics you were given, and details of recent infections
- A ride home, as you'll have had an anesthetic
What to ask your anesthesia team
- Will I have a ureteroscopy with laser, or shockwave treatment?
- Do I need to stop any blood thinners, and when do I restart them?
- Will you place a stent, and how and when is it removed?
- Have my urine tests confirmed there's no infection before surgery?
- What should I expect when passing urine afterward?
Your prep checklist
Tick things off as you sort them — saved on this device only, nothing is sent anywhere.
A general guide — your hospital's own instructions always come first.
Frequently asked questions
Why is a urine infection such a big deal before kidney stone surgery?
Operating on a stone while there's infected urine behind it can release bacteria into the bloodstream and cause sepsis, which is serious. That's why teams check your urine beforehand, treat any infection with antibiotics first, and may postpone surgery until it's clear. Always finish prescribed antibiotics and report any fever.
Will I have a stent after kidney stone surgery?
Often yes, especially after ureteroscopy. A JJ stent is a soft tube that keeps the ureter open and draining while it settles. It can cause some urinary urgency, discomfort or a little blood in the urine, and is removed later in a quick procedure. Your team will explain how long it stays in.
Can I have shockwave lithotripsy if I take blood thinners?
Usually not without pausing them — shockwave treatment can cause bleeding around the kidney, so it's generally avoided while you're on blood thinners. Your team will plan a safe gap if you need it stopped, or may suggest a different treatment. Never stop a blood thinner on your own.