Sacral neuromodulation (SNM) is a therapy that can work for urinary incontinence, retention, and faecal incontinence. WILL SACRAL NEUROMODULATION (OR SNM) WORK FOR YOU? START WITH THE TEST. THE TEST GIVES AN INDICATION OF THE LONG-TERM OUTCOME OF THE SNM THERAPY. We are looking for an improvement in your symptoms – depending on your condition this could be a reduction in accidents, a return to normal toilet habits, improved hold time, less incontinence products used, less medications and/or improvements to your quality of life.