Background: Cyclic administration of rifaximin in association with dietary fibre achieves symptomatic relief in uncomplicated diverticular disease (DD) by means of a still undefined mechanism.
Aim: To investigate the effects of a combination of rifaximin and fibre on both hydrogen production by intestinal microflora and oro-anal transit time.
Methods: In a controlled, double-blind crossover trial, 64 patients with uncomplicated DD were given bran (20 g/day) and randomly treated with rifaximin (1200 mg/day) or a placebo for 14 days. Evaluation was based on clinical status, breath test, oro-anal transit time and faecal weight.
Results: The global symptomatic score was significantly reduced after rifaximin (7.1 +/- 4.1 to 4.1 +/- 3.3; P < 0.005) but not after placebo (6.8 +/- 3.8 to 6.1 +/- 3.5). Hydrogen production significantly increased after placebo from 198 +/- 134 to 267 +/- 161 ppm/min, while Rifaximin reduced it from 222 +/- 187 to 166 +/- 131 ppm/min (P = 0.05). The total oro-anal transit time decreased from 56.1 +/- 28.2 to 51.3 +/- 28.0 h in placebo and from 54.4 +/- 31.9 to 45.1 +/- 32.4 h (P < 0.05) in rifaximin-treated patients.
Conclusions: The administration of rifamixin improves the benefits of dietary fibre in uncomplicated DD by preventing its bacterial degradation.