Procedure guide · 7 min read

Flexible ureteroscopy and laser for kidney stones

Last updated: 4 May 2026 · Reviewed by Mr Sanjay Rajpal, Consultant Urological Surgeon · GMC 6106646

Flexible ureteroscopy with laser fragmentation is one of the most effective ways to treat stones in the ureter and kidney. It uses the body's natural channels — no skin incisions — and is normally a day-case procedure performed under general anaesthetic.

Key point: The aim is not just to remove the stone, but to leave the drainage channel healthy and the patient confident in a prevention plan. A small temporary stent is often used for a short period afterwards.

How the procedure works

A thin, flexible telescope is passed through the urethra, into the bladder, and up the ureter to reach the stone. A holmium or thulium laser fibre is then used to break the stone into small fragments or fine dust. Fragments are removed with a basket or left to flush out naturally. A double-J stent — a thin internal tube — is often left in place for one to two weeks to keep the kidney draining as the ureter heals.

Who it suits

Stones in the ureter that are not passing on their own.
Kidney stones up to around 2 cm.
Stones causing infection, severe pain, or kidney drainage problems.
Pilots, professional drivers and others who cannot tolerate unpredictable colic.

Alternatives

Smaller, low-position stones may pass with hydration, painkillers and sometimes medical expulsive therapy. Shockwave lithotripsy is a non-invasive option for selected stones, but success rates are lower for harder stones or those in the lower kidney pole. Larger or complex stones are better treated with mini-PCNL.

What happens on the day

You will be admitted on the day, fasted and reviewed by the anaesthetist. The procedure itself typically takes 30–90 minutes. Most patients go home the same day. You will leave with instructions about hydration, painkillers and stent care if a stent has been placed.

Recovery

First 48 hours: mild burning, urgency and traces of blood are normal — drink well.
First week: bladder discomfort or flank twinges with full bladder are typical with a stent.
Stent removal: usually 1–2 weeks later under local anaesthetic in clinic.
Six weeks: imaging and a metabolic plan to reduce future stone risk.

Risks and side-effects

Most patients recover quickly. Possible issues include urinary tract infection, occasional blood in the urine, stent-related discomfort, ureteric injury, and the need for a second procedure if a stone is large or hard. Sepsis is uncommon but is the reason urine is checked and treated before surgery. Long-term ureteric narrowing is rare in experienced hands.

When to seek help

Fever, shaking chills, or worsening pain.
Inability to pass urine.
Heavy bleeding or large clots in the urine.
New severe flank pain that does not settle with painkillers.

Preventing the next stone

Once the stone is gone, the work shifts to prevention: fluid intake of around 2.5–3 litres a day, modest dietary changes based on the stone's chemistry, and where appropriate a metabolic stone clinic with 24-hour urine testing and tailored medication.