The investigators will assess the incidence of Overactive Bladder/Detrusor Overactivity (OAB/DO) post-operatively in patients post robotic assisted radical prostatectomy (RARP) and to investigate whether fesoterodine will alter the incidence of OAB/DO in these patients. Additionally, the correlation between OAB symptoms and urodynamic DO will be analyzed.

Inclusion Criteria:

• Men aged 30 to 90 years old with prostate adenocarcinoma who have already made their treatment selection of RARP, and only men with an AUA symptom score greater than 7 will be included. All subjects must be able to read and comprehend fully the informed consent.

Exclusion Criteria:

• Men with prostate neoplasms other than adenocarcinoma
• Subjects receiving other treatments for prostate cancer will be excluded.
• Any subject with a preexisting bladder disease will be excluded.
• Subjects with acute urinary retention and/or deceased gastrointestinal motility.
• Subjects with glaucoma.
• Subjects with hepatic or renal impairment.
• Subjects taking CYP3A4 Inhibitors (e.g.ketoconazole, itraconazole, clarithromycin).
• Subjects with myasthenia gravis
• Subjects who are unwilling or unable to complete the subject questionnaires
• Subjects, who in the opinion of the investigator, would be non-compliant with the majority of the visits scheduled or study procedures.