 Sacral nerve stimulation SNS has become a well-established treatment for patients with fecal incontinence since 1995. The mechanism of action of SNS is still not fully understood but recent studies have shown changes in both colonic motility and rectal sensibility. We have previously shown IBS patients to benefit from sacral nerves stimulation. With the present study, we aim to evaluate if subsensory sacral nerve stimulation is as effective as suprasensory sacral nerve stimulation. 