Prematurely stopped, as no beneficial effect was evident for bilateral stimulation after interim analysis of the first 20 patients.

Faecal incontinence is a devastating condition causing psychological stress, affecting daily living and influences quality of life. Faecal incontinence affects 2,2 to 5 % of the adult population. The magnitude of the problem is probably underestimated, because most patients don't discuss this affliction with their general practitioner. A new treatment, sacral nerve stimulation (SNS), has over the last decade given hope to these patients. The treatment is divided in two; first a test operation (PNE-test) has to reveal if the patient will benefit from treatment with permanent sacral nerve stimulation. Second if the patient benefit from the PNE-test, they proceed to final implant. 75-80% of the patients with idiopathic fecal incontinence benefit from the PNE-test, 70% of those get satisfactory functional results and the remaining 30% get suboptimal improvement in continence after permanent unilateral sacral nerve stimulation. The aim of this project is to investigate if bilateral sacral nerve stimulation can produce better fecal continence results than standard unilateral stimulation, through a double blind, randomized crossover study.

Sacral nerve stimulation is a very good and effective treatment for faecal incontinence The method was introduced to patients with voiding disorders in 1981. In 1995 sacral nerve stimulation was used for three patients with faecal incontinence, two were afterwards fully continent. The method has over the last decade been used increasingly in Europe. The method is now used routinely in the treatment of faecal incontinence in Europe.

Recent studies have shown that the effect of sacral nerve stimulation is due to a neuromodulation in the central nervous system, whereas direct stimulation of efferent nerves to anal sphincter and the pelvic floor has less significance.

The sacral nerve stimulation is performed in two steps, first a test stimulation, if positive the patients proceed to permanent implant.

Test stimulation (PNE-test) is performed over a 3 week period. If this test stimulation produces a decrease in incontinence episodes of more than 50 per cent, a permanent electrode and neurostimulator are implanted. The test period has a success rate of approximately 75-80% in patients with idiopathic fecal incontinence or incontinence after anal surgery. These 75-80% will normal be candidates to unilateral implantation of permanent electrode and neurostimulator.

All permanently implanted has less incontinence symptoms after the treatment. Satisfactory continence results after permanent implantation are seen in 70% of the patients, the remaining 30% only obtain a suboptimal efficacy. It is unclear whether these patients could have a more optimal function if they were stimulate on more than one sacral nerve simultaneously.

Hypothesis: Is it possible to improve the functional result in faecal incontinent patients treated with routine unilateral sacral nerve stimulation by stimulating the sacral nerves bilaterally.

Inclusion Criteria:

• Informed Consent
• Diagnosed with idiopathic faecal incontinence and planned sacral nerve stimulation
• Age> 40 years normal sigmoid/colonoscopic prior to operation

Exclusion Criteria:

• Pregnant or breastfeeding
• Patients who are not deemed able to follow the planned testing program, including mental illness or mentally unstable patients
• Medication with known effects on gastrointestinal motility, thyroid disease, diabetes, coeliaki, neurological disorders.
• Irritable Bowel Syndrome