Chinese herbals
Depending where you are based, a visit to the Chinese herbalist can help. I know two people that got rid of painful kidney stones that way. One used the standard brown bag of bundled herbs that needed boiling with water. It tasted disgusting, but worked very well, with the urine coming out with a milky colouring. Four years later no repeat of the condition, this with no dietary changes. The other person used herbal tablets, very cheap, bought over the counter, that worked well also.