Lower and mid ureteral calculi, accounting for approximately 70% of ureteral calculi, has a high chance of successful treatment thanks to ureteroscopic lithotripsy or extracorporeal shock wave lithotripsy (ESWL)1-3), but at the same time have problems of postprocedural complications and high expenses4). A lower ureteral calculus, which measures 5 millimeters and less, may be easily expelled by symptomatic therapy. Actually, it has about a 50% chance of successful expulsion5). However, a complication such as urinary tract infection or hydronephrosis or persistent pain may occur before it is expelled. Thus, it is imperative to minimize the occurrence of complications in the process of expectant treatment and also to reduce the time required to expel calculi.