Last update:
09-Mar-2009

Irritable bowel syndrome (IBS) belongs to a unified group of functional diseases of gastrointestinal tract. Typical symptoms are abdominal pain, bloating and alterations of bowel habits. Recent data reveal that bacterial overgrowth of the microflora of upper gastrointestinal tract is the main pathogenetic mechanism leading to IBS. This mechanism could explain the symptom of bloating. Rifaximin is a semi-synthetic derivative, produced by modification of the molecule of rifamycin. It is a poorly absorbable antimicrobial with localized action at the intestinal level. Six clinical trials have been conducted in patients with IBS where rifaximin was administered in an effort to inhibit bacterial overgrowth. Clinical benefit was observed, consisting of significant and persistent relief of symptoms, mainly bloating and abdominal distention which was sustained on cessation of treatment. Alterations of bacterial gut flora observed during therapy fully returned to normal on cessation of treatment. The administration of 800 mg of rifaximin daily relieves bloating; monthly periodic treatment leads to sustained clinical benefit.

Key words: Bacterial overgrowth, Irritable bowel syndrome, Local antimicrobials, Rifaximin.