It appears that a disproportionate number of Hmong patients suffer from kidney stones. A St. Paul urologist has found that more than half of his Hmong patients have stones while only 11-percent of his patients who are not Hmong have them. Dr. Andrew Portis says the Hmong also frequently have more severe kidney damage. Portis found that up to 8-percent have had to have a kidney removed. He says that's because many Hmong are refusing conventional medical treatment until they have reached a crisis.