Neuromodulation for Accidental Bowel Leakage

Inclusion Criteria: * Women ≥ 18 years of age * FI symptoms ≥ 3 months * Baseline St. Mark's score of ≥ 12 * Attended ≥ 2 supervised PMT for ABL * Intolerance, unwillingness, or inadequate response to constipating medications * Current negative colon cancer screening based on the USPSTF's recommendation for colorectal cancer screening (2016) Exclusion Criteria: * Previous PTNS treatment * History of uncontrolled diarrhea in the past 3 months (usual or most common stool type over the preceding 3 months of 7 on the Bristol Stool Form Scale) * History of severe constipation in the past 3 months (usual or most common stool type over the preceding 3 months of 1 on the Bristol Stool Form Scale) * History of inflammatory bowel disease (includes Crohn's disease and ulcerative colitis, but does not include irritable bowel disease) * Unrepaired rectovaginal fistula/chronic 4th degree laceration * Full thickness rectal prolapse * History of congenital anorectal malformation * History of bowel resection surgery for any indication * Minor anal procedures within 6 months for treatment of ABL (injection of bulking agent or radiofrequency energy) or ligation of hemorrhoids * Prior pelvic or abdominal radiation * Diagnosis of cancer of the descending colon or anus * Diagnosis of cancer in the region where the PTNS or sham needles or surface electrodes would be placed * Pacemaker, implantable defibrillator * Current use of Interstim sacral nerve stimulator or TENS in the pelvic region, back…