 Ureteral stent placement is one of the most common procedures performed within urology. The stents are generally placed for relief of obstruction or to prevent obstruction following a urological procedure. Most patients with ureteral stents will eventually form stent encrustations. However, patients form these encrustations at dramatically different degrees and rates ranging from no encrustation at 1 year of stenting to severe encrustation in just a few weeks. The purpose of this study is to determine if the degree of encrustation on a stent for any given patient can be predicted based on 24 hour urine parameters prior to stent placement, with the stent in place and after stent removal. 