this was not "mild" pain.  This was a fully blocked ureter. The pain isn't from the stone passing, it is caused by fluids building up and causing swelling in the kidney.  It started like a gas pain, then gradually got worse and worse, until I was throwing up and was unable to even stand. I just curled up in a ball.  I've heard that this is the worst pain known to human beings, including childbirth, but it's hard to compare.  I can swear that it was mind-numbing. The nicest words I ever heard in the world were "This is morphine, it will stop the pain".  

I've had a few smaller stondes, and had a bit of mild discomfort with them.  Nothing serious.  I drink a ton of water every day.  Preventative. I'm never going through that again.