Multimodal Stimulation Before and After Sacral Nerve Stimulation for Irritable Bowel Syndrome

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. The investigators have previously shown IBS patients to benefit from sacral nerves stimulation. With the present study, the investigators aim to evaluate if sacral nerve stimulation alters the gastro-colic response in IBS patients.

Twenty four patients with IBS-D or IBS-M according to the ROME III criteria, will be enrolled in the study. Having meet inclusion criteria, the patients will be examined with Multimodal Stimulation at baseline and at six weeks in the sacral nerve stimulation test period. During the Multimodal Stimulation the patients will have impedance planimetry conducted before and after a standardised meal to evaluate on their gastro-colic response without and during sacral nerve stimulation. The patients enrolled in the study will in the same time period participate in another study evaluating subsensory sacral nerve stimulation. A study registered at clinical trials. Here patients are randomised to receive either OFF-subsensory or subsensory-OFF stimulation in a 2+2-week period followed by 2 weeks of suprasensory stimulation. Hereby rendering a stimulation test period of a total of 6 weeks (a permanent electrode is used).

A single armed study to evaluate the on the gastro-colic response in IBS patients treated with sacral nerve stimulation

Patients will be examined with Multimodal Stimulation using impedance planimetry measuring the cross sectional area before and after a standardised meal at baseline and at 6 weeks of stimulation

Patients will be examined with Multimodal Stimulation using impedance planimetry calculating the wall stiffness before and after a standardised meal at baseline and at 6 weeks of stimulation

Patients will be examined with Multimodal Stimulation using impedance planimetry measuring the compliance before and after a standardised meal at baseline and at 6 weeks of stimulation

Patients will be examined with Multimodal Stimulation using impedance planimetry measuring the cold tolerance before and after a standardised meal at baseline and at 6 weeks of stimulation

Patients will be examined with Multimodal Stimulation using impedance planimetry measuring the heat tolerance before and after a standardised meal at baseline and at 6 weeks of stimulation

Inclusion Criteria: Patients aged over 18 Patients who are psychologically stable and suitable for intervention and able to provide informed consent. Patients who are diagnosed with IBS-D or IBS-M according to the Rome III criteria Minimum average of 40 points in the symptom questionnaire evaluated at baseline Exclusion Criteria: Overt bowel diseases including inflammatory bowel disease Pregnant or breast feeding Patients who are considered unable to follow the planned programme of the study, including mentally illness or physiological instability Patients who are on medication with known influence on gastrointestinal motility including those for thyroid disease, diabetes mellitus, celiac disease and neurological disease