Kidney, ureteral and bladder stones: when it is urgent

Why it hurts so much

When a stone lodges in the ureter — the tube running from the kidney to the bladder — urine stops flowing and the kidney distends. That rise in pressure produces the colic: severe pain in the flank or lower back radiating to the groin, coming in waves, with nausea, vomiting and an inability to find a comfortable position.

There may also be blood in the urine, a constant urge to pass water even when little comes out, and burning at the end of urination as the stone approaches the bladder.

When to seek care immediately

Some situations cannot wait for Monday's appointment. Go to the emergency department if you have:

• Fever or chills together with the pain. This is the most dangerous of all: it means possible infection above an obstruction, and the kidney must be drained without delay. It can become life-threatening within hours.
• Pain that does not settle with painkillers, or vomiting that prevents you keeping fluids down.
• Stopping passing urine, or passing only minimal amounts.
• A single functioning kidney, or a previous kidney transplant.
• Pain in both flanks at the same time.
• Known impairment of kidney function.

Outside those scenarios colic can be managed on a scheduled basis — but scheduled does not mean indefinite.

An obstructed kidney is on the clock

This is the most underestimated point. A kidney that stays obstructed loses function progressively, and beyond a certain time that damage does not recover even if the stone is removed.

As a practical reference: an obstruction should not be left beyond six weeks. After that, the risk of permanent damage rises significantly, and with complete obstruction the deterioration can begin considerably earlier.

That is why "waiting to see if it passes" has a limit, and that limit must be set by imaging, not by the absence of pain. The right question in consultation is not whether it hurts, but whether the kidney is still obstructed.

What determines the treatment

• Size. Small stones may pass on their own; beyond a certain calibre the chance drops sharply.
• Location. A stone in the kidney, the upper ureter or near the bladder is not the same problem.
• Hardness and composition, estimated on CT and confirmed by analysing the stone once removed.
• Your anatomy, and whether there are malformations or previous surgery.
• Whether there is infection, which changes the priorities entirely.

Ureteroscopy with laser

This is the treatment of choice for most ureteral stones and many kidney stones. It is performed through the natural passage, with no incisions: a fine endoscope is advanced until the stone is located, and it is then pulverised with a holmium laser.

Two things determine the result. The first is the power and control of the laser: a high-power generator turns the stone to dust rather than breaking it into large fragments that then have to be chased. The second is the quality of the optics and imaging control, which is what allows safe work inside a channel only a few millimetres wide.

In every procedure I perform I use a high-power, high-quality holmium laser — a 100 W Quanta or Fiberdust — Karl Storz endoscopes and fluoroscopic control throughout the operation. This is not equipment that varies from case to case or with what happens to be available: it is the standard I always work with.

Other options

Not every stone is treated the same way. For large or complex kidney stones, percutaneous surgery allows removal through a direct access of a few millimetres in the flank. In that setting it is the technique that leaves the kidney clear in a single stage, something less invasive alternatives cannot achieve when the stone burden is high.

And with bladder stones, which usually appear when there is outflow obstruction, treatment must also resolve the cause — normally prostate enlargement — or they will form again.

The JJ stent

It is common to leave an internal stent between the kidney and the bladder for a few days or weeks. It has a clear purpose: keeping the passage open and protecting the kidney while the inflammation settles.

It is worth knowing that it causes symptoms: frequent urge to pass urine, some burning, flank discomfort on voiding and sometimes blood. This does not mean something is going wrong; it is the expected behaviour.

Every one of my patients with a stent is given specific treatment for those symptoms, which in most cases reduces them considerably and in some removes them altogether. With that management, the great majority tolerate it without difficulty. And in any case they settle once it is removed, which is a brief procedure.

Stopping it happening again

Anyone who has had a stone is at high risk of another, and that part is almost never addressed. Reducing recurrence depends on three things:

• Analysing the stone once removed. Knowing what it is made of changes prevention entirely.
• Metabolic testing of blood and urine when episodes are repeated, stones are large or there is a family history.
• Sufficient, sustained hydration, plus the dietary adjustments that suit your stone type. There is no single diet for every stone.

What to bring to your appointment

• Your CT or ultrasound if you have already had them, on disc or with digital access. Non-contrast CT is the study that best defines size and location, but having no imaging is not an obstacle: do not wait to obtain it — book an appointment promptly and the appropriate study will be arranged here.
• Previous studies, even from years ago: comparison is what shows whether the kidney is suffering.
• The stone itself, if you managed to retrieve it. It is valuable information.
• Recent blood and urine tests.
• Your current medications and any previous episodes, with their dates.