Urology · University Urology, PC · Knoxville, TN
Voiding Dysfunction, Overactive & Underactive Bladder
Bladder control problems are among the most common urologic conditions — and among the most undertreated. University Urology offers a full spectrum of evaluation and treatment options, from behavioral therapy to advanced neuromodulation.
About Voiding Dysfunction
What Is Voiding Dysfunction?
Voiding dysfunction is an umbrella term for any condition in which the bladder does not store or empty urine normally. It includes overactive bladder (OAB) — characterized by urgency, frequency, and urge incontinence — as well as underactive bladder, in which the bladder fails to contract effectively and empties incompletely. Both conditions significantly impact quality of life and are frequently underreported by patients who assume symptoms are a normal part of aging.
Accurate diagnosis requires a thorough evaluation — including a voiding history, bladder diary, post-void residual measurement, and in many cases formal urodynamic testing. Treatment is always individualized based on the underlying dysfunction, symptom severity, and patient goals.
Treatment Options
How We Treat Voiding Dysfunction
We take a stepwise approach — starting with the least invasive options and advancing as needed. Most patients see meaningful improvement. The right path depends on whether the primary problem is overactivity, underactivity, or a combination of both.
Behavioral & Lifestyle Therapy
Bladder training, timed voiding, fluid management, and dietary modifications form the foundation of OAB treatment. These interventions are effective for many patients and carry no side effects. Our team provides structured guidance as part of every voiding dysfunction evaluation.
Medication Therapy
Anticholinergic agents (oxybutynin, tolterodine, solifenacin, trospium) and beta-3 agonists (mirabegron, vibegron) are well-established pharmacologic options for OAB. We select agents based on your symptom profile, other medications, and comorbidities — and adjust over time based on response and tolerability.
Pelvic Floor Physical Therapy (PFPT)
Pelvic floor dysfunction is a contributing factor in many cases of OAB and urge incontinence. We refer to experienced pelvic floor physical therapists for targeted rehabilitation — including bladder retraining, pelvic muscle coordination, and biofeedback. PFPT is often recommended alongside or before procedural treatments.
Bladder Botox (OnabotulinumtoxinA)
For patients who have not responded adequately to medications, Botox injected directly into the bladder muscle is an effective next step. It reduces involuntary bladder contractions and provides relief that typically lasts 6–12 months. The procedure is performed in the office under local anesthesia via cystoscopy. A full bladder on arrival is required.
- Typically 100 units for OAB / urge incontinence
- Results begin within 2–4 weeks
- Repeat treatments available as needed
- Small risk of temporary urinary retention — patients should be willing to self-catheterize if needed
Percutaneous Tibial Nerve Stimulation (PTNS)
PTNS is a minimally invasive neuromodulation therapy performed in the office. A small needle electrode is placed near the tibial nerve at the ankle and mild electrical stimulation is delivered for 30 minutes. A course of 12 weekly sessions is standard, followed by maintenance treatments. PTNS is well tolerated and effective for urgency, frequency, and urge incontinence without the need for implantation.
- No implant required
- 12-week initial treatment course
- No anesthesia — performed in office
- Good option for patients who prefer to avoid surgery or implants
Sacral Neuromodulation (SNM) — Axonics
Sacral neuromodulation delivers mild electrical stimulation to the sacral nerves that control bladder and bowel function, modulating the communication between the brain and bladder. University Urology offers the Axonics system — an MRI-compatible, rechargeable implant with long-term battery life. SNM is indicated for OAB, urge incontinence, urinary retention, and fecal incontinence refractory to conservative therapy.
- Two-stage process: PNE trial followed by permanent implant if successful
- Axonics system is MRI-compatible (full-body 1.5T and 3T)
- Outpatient procedure at UTMC
- Highly effective for carefully selected patients
Diagnostic Testing
Urodynamic Study (UDS)
Urodynamic testing provides an objective assessment of bladder and urethral function. It is the most accurate way to characterize voiding dysfunction — distinguishing overactive bladder from underactive bladder, identifying outlet obstruction, measuring bladder capacity and compliance, and evaluating sphincter function. Not every patient with voiding symptoms requires UDS, but it is essential for complex or refractory cases, prior to surgical intervention, and whenever the diagnosis is uncertain.
What UDS Measures
- Bladder capacity and compliance
- Detrusor overactivity (involuntary contractions)
- Urethral sphincter function
- Post-void residual urine volume
- Voiding pressure and flow rate
- Bladder outlet obstruction
- Stress incontinence provocation
How to Prepare
- Complete a 48-hour bladder diary before your appointment
- Arrive with a comfortably full bladder
- No fasting required
- No medication holds unless specifically instructed
- No driver required for UDS alone
- The study takes approximately 45–60 minutes
- A $50 no-show / late cancellation fee applies
What to Expect
- Small catheters are placed in the bladder and rectum to measure pressures
- The bladder is filled with saline while pressures are recorded
- You will be asked to report sensations during filling
- A voiding phase measures flow and pressure during urination
- Mild discomfort is possible — the study is not typically painful
- Results require physician interpretation — not given at the time of testing
After Your UDS
- Some urinary burning or mild discomfort for 24–48 hours is normal
- Increase fluid intake to flush the bladder
- Contact the office if you develop fever, chills, or inability to urinate
- Results are reviewed by your provider and discussed at a follow-up visit
- Results will not be given by phone without urologist approval
For full preparation instructions including the bladder diary template and what to bring, see our complete UDS preparation page →
UDS testing at University Urology is performed by Kathryn L. Mantey, FNP-BC and Meghan Shotwell, PA-C.
Your Care Team
Voiding Dysfunction & UDS at University Urology
Voiding dysfunction is evaluated and managed across our practice. Urodynamic testing is performed by our specialized APPs who work closely with our urologists to develop individualized treatment plans.
Bladder Control Problems Are Treatable
You don’t have to live with urgency, leakage, or incomplete emptying. Reach out to get started.