Stay in the bladder?

That doesn't seem very likely. The ureter (from kidney to bladder) is smaller diameter than the urethra (from bladder to outside) so once the stone makes it to the bladder it pretty well always comes out. There could be a minor amount of pain when it leaves, but certainly nothing like the pain when it's descending through the ureter. In any case, it could take several days or more to make it from your kidney to your bladder. Drink a LOT of water to help flush it out. Remember that if the pain goes away and nothing comes out that's a BAD sign, not a good one. It likely means that the stone is stuck and may be blocking the exit of one kidney, which can eventually fail under such circumstances.* If such happens, get them to refer you to a urologist (not an ER doctor) who should arrange for an IVP to locate the stone. The IVP uses a X-ray opaque dye which is injected into a vein along with plenty of saline. This moves quite quickly (a few minutes) into the kidneys and out the ureters. As it flows around the stone, the location of the stone can be seen on X-rays. If the stone is completely blocking the passage, the dye won't flow and they won't be able to actually locate the stone (though they will know that there is one). In such a case ultrasound will help to locate the stone (but it's so damned blurry they often have trouble finding it that way too). By the way, the reason for the filtering isn't to see if a stone comes out (you'll know when that happens, believe me) but to catch the stone for chemical analysis so they'll know what preventative measures will be effective. Different treatments apply to different types of stone, the primary kinds being oxalate, calcium and uric acid. Good luck. Somersault * I once, by a horrible coincidence, had stones block both kidneys completely, at the same time. That's BAD news, and I was very sick. Fortunately, I wasn't alone, and I was taken to hospital by ambulance. They were preparing for emergency surgery (I would have died in a few hours) but one of the stones passed about an hour after I arrived. Amazingly, it only takes a few minutes for the blood to clean up once at least one kidney is working, and I was feeling fine again in a short time, so I was released and went home the next morning. The other stone passed a few days later. Was pretty scary, though, my companion was terrified that he was losing me.