 6. Strengths This study is unique in that it randomizes patients at low to moderate risk of postoperative infection and it uses the most updated definition of sepsis as the primary outcome. The limitations of previous studies have been lack of randomization, exclusion of patients at moderate-high risk of infection, and less contemporary definitions of sepsis. It aims to answer very important and relevant questions as it pertains both to the surgical management of kidney stone disease and to the prophylactic use of preoperative antibiotics in patients with an increase risk of infection. It will also represent a broad geographic distribution of patients from the US and Canada due to the location of the participating sites. 