Functional gastrointestinal disorders (FGIDs) are common and from the most recent global
epidemiology study, an estimated 40% of the world population suffer from the condition. FGIDs
cause significant morbidity to patients, despite not influencing mortality. IBS is among the
most important functional gastrointestinal disorder with an estimated 3.8 to 9.2 % of the
general population worldwide were affected by this disorder.
Rifaximin (gut specific antibiotic) and low FODMAP diet (dietary based therapy) were proven
to be effective in treating irritable bowel syndrome (IBS), however there was no head-to-head
study comparing both treatments. This study will help doctors to understand the efficacy of
different IBS/SIBO treatments. With the evaluation of factors that can predict treatment
response, doctor could potentially treat IBS and SIBO more effectively in future.
The purpose of the study is to compare the clinical symptoms and psychological improvement in
patients with irritable bowel syndrome (IBS) after treatment with Rifaximin versus treatment
with low FODMAP diet. The factors that is associated with treatment response will also be
evaluated. In IBS patients with small intestinal bacterial overgrowth (SIBO), eradication
rate of SIBO will be evaluated.