unless they block the flow of urine. The urine back up causes your kidneys to swell and that hurts like crazy. That is why if they are small enough to pass they don't hurt once they get to the bladder. The key is to get on top of the pain when it is just starting. I'm not a doctor, so run this past yours, but what I have found works the best is when you first feel pain in your lower back or side, then take 800 milligrams of ibuprofen. My doctor prescribed 800 milligram pills to me along with flomax and oxycodene I think. The Ibuprofen worked better than the narcotic, because I believe it is an anti inflammatory and the pain comes from swelling. Anyway, that is my advice. If you are lucky it will do most of its moving at once and you will be done. But they can take a month or more to pass. The weirdest thing about kidney stones is that you will feel like you are going to die one moment, then as soon as it passes, it's like nothing happened. My wife is always surprised as I am in terrible pain, and then totally fine.