kidney stones are most often caused by to much calcuim in your kidneys and if their not pasted or removed they many something cause pain...it best to get the proper test done to see what your choices are.
there are different types of stones but one type is made of calcium. And if there not removed can cause severe back ache and blood in urine and damage to kidneys. i have the lithotripsy done to break up the stones and they put you to sleep and they blast the stones. For some people passing the stone can be painful but i never had any problems with it.