Neuromodulation for functional bowel disorders.

In patients with functional bowel disorders not responding to maximal medical treatment, bowel lavage or biofeedback therapy, can nowadays be treated by sacral nerve neuromodulation (SNM). SNM therapy has evolved as a treatment for faecal incontinence and constipation. The exact working mechanism remains unknown. It is known that SNM therapy causes direct stimulation of the anal sphincter and causes changes in rectal sensation and several central nervous system areas. The advantage of SNM therapy is the ability to do a minimally invasive temporary screening phase to assess permanent stimulation outcome. Ideal candidates for SNM therapy are not known. Several studies have described positive and negative predictive factors, but the temporary screening remains the instrument of choice. Clinical results are good and as the technique is developing, fewer complications occur. New indications for SNM include constipation and anorectal or pelvic pain.