Botox is the trade name for purified botulinum toxin which is produced by certain bacteria. Botox has been used for several years for the treatment of a variety of conditions which result in muscle spasms. It has used for the past ten years to treat over-activity of the bladder wall muscle, which causes urinary frequency (having to pass urine often, during the day and/or at night) and an urgent desire to pass urine – sometimes associated with urinary leakage (incontinence). Botox is not as yet licensed for this purpose, but we are allowed to use it for patients who have tried, but have not responded to other treatments (tablets such as oxybutynin, tolterodine, solifenacin, fesoterodine).