Single-site prospective observational pilot feasibility study of women with overactive bladder/urge urinary incontinence undergoing onabotulinum toxin type A intradetrusor injections in order to achieve the following objectives: * Establish a record of successful collaboration with Dr. Ravel, an expert researcher in the female microbiome based at the University of Maryland * Demonstrate the investigators' ability to recruit subjects from the diverse population of postmenopausal women undergoing BTX for OAB within MedStar Health Urogynecology clinics * Collect, process and analyze urine specimens collected prior to and 4-weeks after BTX injection, and to compare the GU microbiome of self-collected versus clinic-collected samples * Assess response to BTX treatment and explore rates of and risk factors for urinary tract infection and incomplete voiding requiring catheterization within the first 4-weeks after BTX