This study is To confirm the efficacy of Naftopidil for reducing discomfort of ureteral stent after urinary stone surgery.

1. Enrollment

   1. patients underwent Double-J ureteral stent indwelling after urological surgery during less than 15 days
   2. patients aged more than 20 years

2. Randomization

   1. naftopidil 75 mg qd or placebo until Double-J stent removal
   2. Standard treatment with pain-killers on demand were also applied.(aceclofenac)

3. Follow-up to the day of Double-J stent removal (Evaluation should be done at stent removal)

Inclusion Criteria:Patients to be undergone double-J stent indwelling

• >= 20 years
• undergoing unilateral retrograde double J (DJ) stent placement planned for 5-15 days indwelling

Exclusion Criteria:

• after percutaneous nephrolithotomy, open or laparoscopic ureterolithotomy presence of ureteral stone
• renal insufficiency (serum Cr > 1.4)
• febrile urinary tract infection (fever > 38.0°C, evidence of urinary infection )
• pregnancy or breast feeding
• solitary kidney
• hypersensitivity to Naftopidil
• current use of any alpha blocker, calcium channel blocker, corticosteroid moderate or sever cardiovascular or cerebrovascular disease
• hepatic dysfunction
• prior history of pelvic surgery or irradiation
• prior history of transurethral resection of bladder tumor or prostate surgery
• significant active medical illness which in the opinion of the investigator would preclude protocol treatment
• genetic disorder such ad galactose intolerance, lapp lactase deficiency, glucose-galactose malabsorption