About 80% of stones are calcium oxalate. Struvite is Magnesium Ammonium Phosphate and is the most common urinary stone in dogs (and occasionally occurs in humans which is a bit ruff.)

It is estimated at about 15% which means dont exclude renal colic just because the urine is clear on urine analysis.

At 0-3mm about 95%+ pass. At 4mm about 80% pass. At 5mm 60%. At 6mm only a third pass.

It acts to relax the smooth muscle of the ureter and bladder to potentially allow stone passage. It has gone out of favour with many urologists.

He sold it to GoldenPalace.com--an online casino. Mr Shatner donated the money to the charity "Habitat for Humanity".

The back pressure from the stone has dilated the ureter and pushed fluid out through the kidney capsule.

Sometimes the stone looks like it has entered the bladder. But be careful because the distal ureter invaginates into the bladder and so a stone can look like it has entered the bladder but is in fact still stuck in the VUJ.(Vesicoureteric junction).

It is pretty common and it is said that between 4 and 8% of the population suffer from kidney stones at any 1 time. Sounds high.

Colour doppler was put on this lodged VUJ stone. This effect tends to be seen with stones who have a rough surface.

It was removed in 2009 in Budapest. Good door stop.