As much as I know stone need core to form a stone.
Common core is eggs of the parasite, most commonly ascaris.
These core are rapped by layers of chloestrol and fat and become stones.
Try to eliminate parasites.
Another way is thick fat droplet form stones.
So avoiding high fat intake is essential.
Another theory is slow bile flow.
If bile flows slowly, this stasis enhanced to form stone. So Liver Flush is essential too.