 1. Study Design or Overview This study will be a multi-institutional randomized, controlled clinical trial of a course of a 1 week course of preoperative nitrofurantoin monohydratemacrocrystalline capsules 100 milligrams twice daily leading up to PCNL. The control group will be no preoperative oral antibiotics. The participating institutions are academic medical centers in the United States and Canada that are part of the EDGE Endourologic Disease Group of Excellence research consortium, a research collaborative that has the goal of producing high quality, multi-institutional studies of nephrolithiasis. Separate IRB approvals will be obtained at each institution. UCSD will be the coordinating institution. Member institutions of EDGE maintain frequent email contact with one another and hold a monthly teleconference to discuss safety updates, interim results, issues with accrual, and modifications to research protocols and consents if necessary. 