Urinary Bladder Neurogenesis

The goal of this clinical trial is to assess if a mix of nitrous oxide and oxygen can improve pain control during bladder Botox injections. The primary question it aims to answer is: Does using nitrous oxide lower the overall level of pain during the procedure? Researchers will compare a 50:50 nitrous oxide/oxygen mixture (administered with the Pro-Nox system) plus standard care (with lidocaine in the bladder) to sham mask plus standard care to see if nitrous oxide works better for lowering pain. Participants will: * Receive their bladder Botox injection in the office setting * Either use nitrous oxide/oxygen plus standard care during the procedure, or sham mask plus standard care * Answer brief questions about pain, anxiety, satisfaction, and willingness to repeat the procedure