Background. Abdominal distention is produced by an abnormal somatic postural tone. The authors developed an original biofeedback technique based on electromyography-guided control of abdominothoracic muscular activity. In a randomized, placebo-controlled trial the authors demonstrated the superiority of biofeedback over placebo for the treatment of abdominal distention. However, the technique is technically complex and unpractical.

Aim. To prove the efficacy of a non-instrumental biofeedback technique for the treatment of abdominal distension.

Selection criteria. Visible abdominal distension after meal ingestion; patients are able to identify the offending meal.

Intervention. Patients will be randomized into biofeedback in placebo groups. Three sessions of either biofeedback or placebo intervention will be performed during the first 3 weeks of the intervention period.

Biofeedback: patients will be taught to control abdominal and thoracic muscular activity by providing instructions using an original video support. Patients will be instructed to perform the same exercises before and after breakfast, lunch and dinner during the 4-week intervention period.

Placebo: sham measurements of abdominal and thoracic motion will be performed, and a pill of placebo containing 0.21 g glucose will be administered; patients will be instructed to take a pill of placebo before breakfast, lunch and dinner during the 4-week intervention period.

Inclusion Criteria:

• episodes of visible abdominal distension triggered by meal ingestion
• patients are able to identify the offending foodstuff

Exclusion Criteria:

• organic cause detected by clinical work-up
• constipation
• abdominal distension not confirmed by the 7-day clinical questionnaires or after the probe meal in the pre-intervention evaluation