As a kidney stone sufferer, now on #25 in the past 3 years, I can sympathize with the pain you are having. I am told by a number of urologists and from my own experience that a stone sitting in the kidney usually causes no pain. It is when the stone enters the Ureter that the pain begins. The pain can be of different intensities based on size, shape, composition, movement and other factors. I have had 4mm stones that have hurt terribly and caused problems and 7mm stones that have passed through and I didn't even know it until it came out.
I am now scheduled for my 3rd lithotripsy, this time on an 8mm stone sitting in the kidney. The first 2 were successful. The procedure is pretty quick and the after effects are some back pain and any discomfort you may get from many small pieces of stones passing through the Ureter, bladder and then out. The back pain is from the procedure itself since they send up to 3,000 hits to the stone.
I have to say, again from experience that if I have to weigh the option of dealing with a large stone passing through the system in hopes that it comes out or if it doesn't, the procedure to have it removed against having a lithotripsy done to avoid it coming out in one piece, I would opt certainly for the lithotripsy as I am doing now.
My experiences are so vast and extensive, I am running a blog at KidneyStones.Care . Please stop over and share your experiences.
Whichever direction you decide to go, good luck with the stone.