A recent randomised, controlled, crossover study has shown that sacral nerve stimulation (SNS) significantly reduces symptoms and improves quality of life of highly selected patients with irritable bowel syndrome (IBS). Relief of IBS symptoms during SNS is associated with consistent changes in rectal sensitivity and biomechanical wall properties.

The aim of the present study is to evaluate long-term efficacy of sacral nerve stimulation on symptoms and quality of life in patients with IBS in a randomised, placebo-controlled, crossover study.

Twenty two patients with IBS-D or IBS-M according to the ROME III criteria, will be enrolled by invitation in the study.

Having meet inclusion criteria, the patients are first set subsensory for 4 weeks and then randomised to receive either OFF-subsensory or subsensory-OFF stimulation in a 4+4-week period.

During the PNE test the effect of the stimulation is evaluated by specific IBS symptom and quality of life questionnaires (GSRS-IBS and IBS-IS) and bowel habit diaries.

Inclusion Criteria:

• Patients who are psychologically stable and suitable for intervention and able to provide informed consent
• Patients who are diagnosed with IBS according to the Rome III criteria and characterised with IBS-D or IBS-M.
• Patients who have been treated with sacral nerve stimulation for a minimum of 3 years.

Exclusion Criteria:

• Other 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 diseases.