15 patients will receive AEMCOLO (Rifamycin SV MMX) 194 mg two tablets to take twice daily for 14 days (56 Tablets)

15 patients will receive AEMCOLO (Rifamycin SV MMX) 194 mg tablets to take two tablets three times daily for 14 days (84 Tablets).

Participants will be issued a patient kit containing AEMCOLO (Rifamycin SV MMX) 194 mg tablets for the 1st or the 2nd treatment regimen in a random order.

A hydrogen and methane breath test will be used to measure presence or absence of Small Intestinal Bacterial Overgrowth (SIBO). Study subjects will be assessed for the presence of SIBO. A rise of ≥ 20 ppm from baseline in hydrogen by 90 minutes or a level of ≥ 10 ppm for methane is considered a positive test for SIBO on a breath test. When combining both hydrogen and methane in the breath test, a rise of ≥ 15 ppm from baseline at 90 minutes is considered a positive test for SIBO. We plan to measure these parameters at baseline and after completion of study medication.

There will be a measurement of symptoms as assessed by a validated visual analogue scale (VAS) questionnaire. Symptoms will be assessed on a 0-4 scale to generate a maximum score of 20 and a minimum score of 0. The change in this composite score will be compared between two treatment arms at baseline, after completion of study medication, and 3 months after treatment. A positive clinical response defined as a 50% reduction in CS will be assessed. This method of analysis closely follows the multinational consensus recommended guidelines for data analysis in IBS clinical studies.