Urinary urgency is a key symptom of overactive bladder syndrome (OAB) and may be more bothersome to a patient than the symptom of urinary frequency. Unfortunately, controversy continues to surround the term 'urgency' and there is no good tool to evaluate the severity of urgency. This fact has constrained the performance of clinical research in this field. The cause of urinary urgency is not fully understood and may vary from patient to patient.

Although clinicians regularly obtain measures of bladder sensation during cystometry, little attention has been paid to the patient experience of urinary urgency. In this study, the researchers will use a non-significant risk device (i.e., an Urgeometer) to measure urinary urgency in women with overactive bladder.

At baseline, a small catheter is placed inside the participant's bladder. The bladder is filled with sterile water through the catheter. As the bladder is filled, the participant is asked to rate their urinary urgency using the Urgeometer. The Urgeometer lever marks a continuous scale from 0 'no urge at all' to 100 'maximum urge which you can tolerate'. The testing is stopped once the bladder is filled. To minimize the chance of infection, participants receive one dose of oral antibiotics prior to the bladder testing.

Following completion of the bladder test, participants will take 10mg solifenacin succinate (VesicareR) daily for 30 days. Afterward, participants repeat the bladder test. The change in participants' maximal tolerated cystometric capacity (MCC) will be measured in milliliters and used to evaluate the effectiveness of the drug.

Inclusion Criteria:

• Have symptoms of urge or mixed incontinence (urge predominant) and desire treatment with anticholinergic medication.
• Demonstrated detrusor overactivity with or without incontinence during urodynamic testing.
• Are able to consent and fill out study documents, complete repeated urodynamic testing, and follow-up in 4 weeks.

Exclusion Criteria:

• Have been treated with any anticholinergic medication in the previous month.
• Have an elevated post -void residual volume as determined during their routine clinical care.
• Have had a urinary tract infection in the last month, as determined by history.
• Have untreated narrow angle glaucoma, by patient history.
• Have a known allergy or intolerance to solifenacin, as determined by patient history.

Due to restrictions on the availability of individual participant data (IPD), IPD are not publicly available

The baseline analysis population comprises all women who signed informed consent and have a valid diagnosis of OAB

Adverse event data were collected during the 30 day trial

The trial experienced significant attrition. Otherwise, there are no limitations or caveats to report.