I can't say for sure that what I've passed are stones or where they came from. What I can say is that before my first flush, I was in pain for hours at a time, several times a week. Now, after five flushes, I very very rarely have an attack. When I do, it is minor and lasts only an hour or less. I have more flushes ahead, but I completely avoided the gb surgery that my doctor said I would need!!! So- even if I didn't pass stones (I believe I did) I still did something very good for myself!!!