This is a pilot study to evaluate the efficacy of the systematic effects of posterior tibial nerve stimulation (PTNS) treatment compared to an inactive sham intervention in female subjects with interstitial cystitis/bladder pain syndrome (IC/BPS) in an intent-to-treat analysis. The primary outcome measure will be the Patient Global Impression of Improvement (PGI-I) a single item questionnaire assessing overall impression of improvement over time at the initial 12 weeks endpoint.