The funny thing is, it says to take calcium to stop the calcium-based stones from forming, but if you take in too much calcium, it forms them! Ugh! LOL I do drink too many sodas, not enough water and not enough calcium, so I'd say it's something in there that I need to fix. I brought in a stone once to get analyzed and they lost it! I don't have a family doctor right now since we moved here 6 months ago, but as soon as I get one, I'll be bringing in my most current stone (I keep all the ones I find). They are usually dark brown so I think those are calcium-oxalate ones.
ETA: It's grapefruit juice you need to stay away from, not orange juice.
The first kidney stone I had was as bad as being in labor, but since then it hasn't been as bad. Still hurts like a bugger, but not doubled over in pain screaming "get it out!!" LOL