Well I am out to lunch on that one. The pain of kidney stones is because the ureter is trying to work the stone down into the bladder and is using peristaltic action, just like the gut. It is muscle spasming of the ureter that causes the pain. Yep cannabis will reduce the spasming.....I am not so sure that is a good thing. The spasming is trying to get the stone out.

Not only that, they can do sonic destruction of the stones, even in the kidney before they get into the urinary tract. Find a better urologist dude, I would want the stones lithotripsied in the kidney before it gets into the ureter.

I did not find relief from renal calculi with cannabis, just maybe a better tolerance.