Kidney stones are forming very frequently. 1 and 1\2 year back I got stones in kidney and gall bladder. Again I got stones now. Both times surgery was done to remove them . I am getting stones of size upto 20mm and they are blocking urination. So there is no option to remove stones except surgery. I am not able to know stones are forming until it becomes serious back pain or blocking of urine. So please suggest why this is happening and how to avoid. Also please how to know that stones are forming earlier.