Repetitive Transcranial Magnetic Stimulation in Irritable Bowel Syndrome

IBS patients frequently demonstrate a rectal hypersensitivity which could participate to the abdominal pain. rTMS is an effective treatment of neurogenic chronic pain. The aim of the study is to evaluate the efficacy of rTMS on rectal hypersensitivity in patients with IBS in a prospective, randomized, double-blind study.

Patients and method: 20 patients with rectal hypersensitivity secondary to IBS will have one active session of rTMS located on the cortical area of the abdominal muscles during 5 consecutive days and one session of simulated rTMS during 5 over consecutive days corresponding to the placebo session. The order of the two session will be randomized. The efficacy of rTMS will be assessed by a rectal barostat to determine the pain or discomfort threshold and by a RIII reflex. The barostat and RIII reflex will be performed at the beginning and at the end of each session.

The investigators hope to demonstrate an improvement of the rectal hypersensitivity during the active stimulations compared to the placebo one.

Inclusion criteria

• more than 18 years old
• IBS defined by Rome III criteria
• Rectal hypersensitivity evaluated by barotat with a pain or inconfort volume less than 28 mmHg
• IBS for more than 3 months
• With an organic exploration for less than 6 months
• Without any knowledge concerning the rTMS

Exclusion criteria

• Pregnant women or women without any contraception
• Patients with pace-maker or other metallic implant
• Patients complaining of epilepsia or with past of epilepsia
• Patients with psychiatric disorders
• Patients treated by any drugs which could interfere with rTMS
• Patients having participate to another protocol within the month preceeding the inclusion
• Patients who could not stop the antalgic drugs within the week preceeding the onset of the study
• patients with a significant lesion on RMI.