For some reason, I'm prone to kidney stones.
The doc asked me to save one for them to analyse.
Never got back to the doc.
I've got quite a collection of stones in a jar to gross out friends with.
That, in a nutshell, is todays information you never needed to know.

Seriously:
I end up passing 2 or 3 a year. I've found a few things help:
Hoard narcotic painkillers. Once it starts to hurt, it'll take too long to get a new prescription, go to pharmacy, etc. Much quicker to just pop a percocet before the pain gets too bad.
Lie on side in dark room.
Mine usually make the trip to the bladder in a few hours - thats the only intense part of the pain. The doc 'splained it to me as the fact that the kidney really does not like having urine back up, and this is the painful part.
Passing them from the bladder doesn't really hurt me - but having the stone sit in your bladder is irritating as all get out. The trick is to drink loads of water - fast. Try to hold it as long as possible. The more pressure and flow you create the quicker the stone passes.
The 'stutter' that occurs in the stream when the stupid stone finally passes has never failed to give me the creeps, tho.