The subjects who have symptoms of overactive bladder (many trips to the bathroom, and urgency with or without the inability to hold your urine until you get to the toilet) are invited to participate in this research study. Overactive bladder is a common sequelae of long-term bladder outlet obstruction in men. Unfortunately, it does not often resolve after treatment of the obstruction (transurethral resection of the prostate). These patients are usually started empirically on alpha-blockers or occasionally anticholinergic agents, former used to treat enlarged prostate medically, and latter, to treat overactive bladder. The investigators hypothesize that these patients would be significantly improved with a long-acting anticholinergic agent such as Detrol LA (tolterodine).

Earlier studies have shown that anticholinergic drugs seem to have a beneficial effect on symptoms of patients with bladder outlet obstruction and overactive bladder. In addition, anticholinergic drug tolterodine is not associated with increased incidence of complication like acute urinary retention, a state where patient is unable to empty the bladder as an adverse effect of the drug.

A large proportion of our patients that are undergoing treatment for bladder outlet obstruction also have overactive bladder. The investigators propose a double blind, randomized, placebo-controlled trial to evaluate the efficacy of Detrol LA 4mg, an anticholinergic in patients that have continued symptoms of overactive bladder one month following transurethral resection of the prostate. Patients with overactive bladder on urodynamic test preoperatively will be considered. If these patients continue to have symptoms at the one-month post-operative visit, they will be enrolled into the study. The investigators expect a total of 50 patients to be enrolled within 4 months. One arm will receive placebo, the other will receive Detrol LA 4 mg. The patients will be followed at 3 months post-op, 4 months post-op, and 7 months post-op. At each post-op visit, the patients will fill out an American Urological Association (AUA) symptom score questionnaire, have noninvasive uroflowmetry performed, and have a post-void residual measured by bladder scan. Using standard statistical analysis, the investigators will see if there is a difference in symptoms, post-void residual, or maximum flow rate between the two arms at 6 months. The investigators will continue in an open-label manner after six months. If the Detrol LA arm has better outcomes, the investigators will offer the placebo group Detrol LA 4mg at the six month period and continue the study to evaluate long-term efficacy, dropout rate, and complications. No dosing adjustments will be allowed for the duration of the study.