Background: Simethicone, activated charcoal and antimicrobial drugs have been used to treat gas-related symptoms with conflicting results.
Aim: To study the relationship between gaseous symptoms and colonic gas production and to test the efficacy of rifaximin, a new non-absorbable antimicrobial agent, on these symptoms.
Methods: Intestinal gas production was measured by hydrogen (H2) and methane (CH4) breath testing after lactulose in 21 healthy volunteers and 34 functional patients. Only the 34 functional patients took part in a double-blind, double-dummy controlled trial, receiving, at random, rifaximin (400 mg b.d per 7 days), or activated charcoal (400 mg b.d per 7 days). The following parameters were evaluated at the start of the study and 1 and 10 days after therapy: bloating, abdominal pain, number of flatus episodes, abdominal girth, and cumulative breath H2 excretion.
Results: Hydrogen excretion was greater in functional patients than in healthy volunteers. Rifaximin, but not activated charcoal, led to a significant reduction in H2 excretion and overall severity of symptoms. In particular, in patients treated with rifaximin, a significant reduction in the mean number of flatus episodes and of mean abdominal girth was evident.
Conclusions: In patients with gas-related symptoms the colonic production of H2 is increased. Rifaximin significantly reduces this production and the excessive number of flatus episodes.