The onset of de novo irritative voiding symptoms after anti-incontinence surgery for stress urinary incontinence is troubling to both patient and physician alike. At present, mechanisms responsible for the development of these symptoms are incompletely elucidated. Although bladder outlet obstruction may certainly be a cause, correct diagnosis and treatment of this condition in its more insidious manifestation may be difficult. In addition, alternative etiologic factors related to surgical technique during outlet enhancing surgery may play a role, prompting a rethinking of these procedures. In this discussion, we review changes in voiding physiology and mechanisms for voiding dysfunction after anti-incontinence surgery, emphasizing de novo urge syndrome and detrusor instability. In addition, we present our approach to the evaluation, diagnosis, and treatment of these challenging patients.