Drink fluids, others
For all types of kidney stones, drinking water is #1 for prevention - drink enough that your urine
looks like clear water with slight yellow color (2 liters/day for avg adult).
When a stone is passed, it can be analyzed in a lab to find what it is made of, to make more specific dietary & med recommendations. See also http://kidney.Niddk.Nih.Gov/kudiseases/pubs/kidneystonediet/index.Aspx.