This is an ethically approved randomised controlled study looking at whether Cystodistension(filling the bladder with fluid under pressure) provides any benefit over cystoscopy alone (looking in the bladder) in women with refractory overactive bladder. Urine samples will also be assessed for underlying infected cause of OAB using urinalysis, microscopy and culture and cytokine assays (In collaboration with the University of Kent). We hypothesize that Cystodistension has a therapeutic benefit to women with refractory OAB and the there is an increase prevalence in chronic urinary infections with raised cytokines in women with refractory OAB.

We aim to measure outcomes initially, 6 weels and 6months follow-up.

1. Resolution measured by Urgency Perception Scale (UPS). Resolution of urgency will be assessed with the UPS. The numbers of women with a Level 3 UPS score (hold and finish task) will be compared using Chi square test in patients treated with cystodistension vs non cystodistension arms.
2. Change in quality of life status determined by quality of life questionnaires will ismilarly be comapred between the 2 arms of the study.
3. Change in urinary symptoms defined by Patient's Perception of Intensity Scale. Change in uregncy scores will be compared between the 2 arms of the study.

Secondary Outcome Measure:1. Prevalence of chronic urinary infection and organisms in patients with refractory OAB 2. To identify whether urinary cytokines are present in a higher proportion of patients with OAB.

Inclusion Criteria

1. Women with only OAB symptoms
2. Women who have failed bladder drill and anticholinergic agents
3. Women who stopped medication due to side-effects or lack of efficacy
4. Currently receiving no treatment

Exclusion Criteria

1. Patient with co-existing urodynamic stress incontinence
2. Patients with neurological diseases
3. Patients with pre-existing voiding dysfunction

Inclusion Criteria

1. Women with only OAB symptoms
2. Women who have failed bladder drill and anticholinergic agents
3. Women who stopped medication due to side-effects or lack of efficacy
4. Currently receiving no treatment

Exclusion Criteria

1. Patients with co-existing urodynamic stress incontinence

2. Patients with neurological diseases

3. Patients with pre-existing voiding dysfunction

   • Free flow rate <5th centile or equivalent reduced pressure flow rate OR
   • Post-void residual volume greater than 100ml