A review of sacral nerve stimulation parameters used in the treatment of faecal incontinence.

Sacral nerve stimulation (SNS) was originally developed in the field of urinary incontinence. Without adaptation, it was subsequently applied to treat faecal incontinence. SNS has now become a first line therapy for this socially disabling condition, however the mechanism of action is unknown. This review examines the evidence for stimulation parameters currently used for SNS in humans and considers the potential electrophysiological effects of changing these parameters. However, without a proper understanding of the physiology of SNS, changing stimulation parameters remains empirical.