A newly released study sheds some light on the effectiveness of Interstim implants. Hope this helps.
March issue of the Annals of Surgery:
"At 12 months of follow-up, 83 percent of patients experienced therapeutic success, defined as a greater than 50 percent reduction in the number of fecal incontinent episodes per week." An hsa or other strong coverage may fund these operations. "Furthermore, perfect continence (100 percent improvement) was achieved in approximately 40 percent of the patients. Improvement remained stable over time, with 87 percent therapeutic success rate in patients who had passed three years of therapy (n=30 patients who had completed the diary requirements in the study)."
Here is the story
maybe give the implant some time, or try to find more information in the Annals of Surgery