Post Marketing Study to Evaluate the Efficacy and Safety of Solifenacin in Patients With OAB (Overactive Bladder) After TURP (Trans-urethral Resection of Prostate) or PVP (Photoselective Vaporization of Prostate)

Inclusion Criteria: * Screening * Patients who are willing and able to accurately complete the voiding diary, IPSS, and OABSS * Patients who have been diagnosed with BPH and are scheduled to receive TURP or PVP * Randomization (after TURP or PVP) * Patients who have been diagnosed with OAB by the investigators * Patients who underwent catheter removal 5±2 days beforehand and will have more than an average of three urgency episodes per 24 hrs and more than an average of eight micturitions per 24 hrs in a row before Visit 3, as recorded in the voiding diary * Patients who will score more than 5 in questions 2, 4, and 7, which are on the storage symptoms in IPSS * Patients who will score more than 4 in question 3 and more than 5 in the OABSS * Patients who have not been treated with any medication for overactive bladder (OAB) symptoms 14 days before the randomization Exclusion Criteria: * Screening * Patients who have been diagnosed with prostate cancer or bladder cancer and who have a present or resolved malignant disease in any pelvic organ * Patients who have neurological diseases that affect micturition and can cause neurogenic bladder disease such as multiple sclerosis, Parkinson's disease, severe cerebral arteriosclerosis, dementia, stroke, or myelitis * Patients who have had serious adverse events or are hypersensitive to anticholinergics * Patients who have a severe gastrointestinal obstruction disease such as toxin megacolon, ulcerative colitis, intestinal atonia, paralytic ileus, and gastric retention * Patients who have been diagnosed with severe myasthenia * Patients who have been diagnosed with narrow-angle glaucoma * Patients who have serious hepatic impairment (child class C) * Patients who are being treated with a CYP3A4 inhibitor (e.g., Ketoconazole) * Patients who have severe renal impairment or who are undergoing hemodialysis * Patients who have diabetic neuropathy * Patients who have a significant urinogenital disease such as UTI, interstitial cystitis, urothelial tumor, bladder stone, or urinary retention * Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption * Patients who have another medical or psychiatric condition that will make them inappropriate for participate in this study in the opinion of the investigators * Patients who have participated in other clinical trials within 30 days before the screening visit * Randomization * Patients who have been diagnosed with clinically significant bladder outlet obstruction by investigators * Patients whose PVR is greater than 100 mL * Patients who have been diagnosed with prostate cancer or bladder cancer and who have a present or resolved malignant disease in any pelvic organ * Patients who have neurological diseases that affect micturition and can cause neurogenic bladder disease such as multiple sclerosis, Parkinson's disease, severe cerebral arteriosclerosis, dementia, stroke, or myelitis * Patients who have had serious adverse events or are hypersensitive to anticholinergics * Patients who have a severe gastrointestinal obstruction disease such as toxin megacolon, ulcerative colitis, intestinal atonia, paralytic ileus, and gastric retention * Patients who have been diagnosed with severe myasthenia * Patients who have been diagnosed with narrow-angle glaucoma * Patients who have serious hepatic impairment (child class C) * Patients who are being treated with a CYP3A4 inhibitor (e.g., Ketoconazole) * Patients who have severe renal impairment or who are undergoing hemodialysis * Patients who experienced severe side effects after their operation * Patients who have diabetic neuropathy * Patients who have a significant urinogenital disease such as UTI, interstitial cystitis, urothelial tumor, bladder stone, or urinary retention * Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption * Patients who have another medical or psychiatric condition that will make them inappropriate for participate in this study in the opinion of the investigators * Patients who have participated in other clinical trials within 30 days before the screening visit