The purpose of this research study is to test whether administering one dose of an antibiotic before a routine shock wave lithotripsy procedure is more effective at avoiding any urinary infections compared to not taking an antibiotic. This is an important topic to study because urinary tract infections are one of the most common complications after this procedure and there is no clear standard of care regarding the use of pre-procedure antibiotics. Our study results will benefit future patients either by decreasing the rate of infections or decreasing the use of unnecessary antibiotics.