Oxazyme in Patients With Hyperoxaluria

Inclusion Criteria: * Roux-en-Y gastric bypass hyperoxaluric Calcium oxalate (CaOx) stone subjects or Idiopathic hyperoxaluric CaOx stone subjects * Patients must have or had radio-opaque stones present on x-ray, or a history consistent with the passage of a stone or stone surgery or Extracorporeal Shock Wave Lithotripsy (ESWL) in the last 5 years. * Hyperoxaluria Ox/Cr ratio ≥36 mg/g * The patient must be able to provide written informed consent * Patients must be able to urinate reliably into a collection vessel to measure urine volume. * Patients may be taking drugs for the prevention of stone disease, including pyridoxine, thiazides, citrate supplements and allopurinol, as long as there have been no changes in these medications for at least 3 months Exclusion Criteria: * Primary hyperoxaluria patients * Use of Oxadrop, Oxabsorb, or other therapies affecting oxalate absorption from the gut, other than stable doses of calcium. * Subjects who are pregnant. Women of childbearing potential must have a negative pregnancy test prior to enrollment and must practice some form of birth control during the trial. * Patients on an unstable dose of any other drugs for the prevention of stone disease (i.e., pyridoxine, citrate supplements. etc.). Patients should have been on a stable dose for at least 3 months prior to randomization.