Hi, Thanks for writing in. It is important to know the exact location of the stone. If the stone is causing obstruction to the flow of urine from kidney to bladder and is stuck in the ureter then attempts must be made to clear it from its present location. If it is a small stone less than 6 mm then it can come down by itself following drinking of large amounts of fluids. If it is more than 7 mm then it may have to be broken into smaller parts and then flushed down the ureter. Even if it is a small stone, while passing down the ureter it an cause severe pain and vomiting. He must continue taking fluids and trying to flush the stone.