Hi - Thanks for your question! While we wait for others to respond, I thought I'd share a couple of articles where our writers have mentioned their experience with rifaximin: https://irritablebowelsyndrome.net/living/could-food-poisoning-be-the-cause-of-your-ibs/, https://irritablebowelsyndrome.net/living/sibo-treatment-cured-my-ibs/, & https://irritablebowelsyndrome.net/living/prescribed-ibs-treatments-tried-did-they-work/. In terms of dosage, we'd encourage you to determine that with your healthcare provider. Take care. - Chris, IrritableBowelSyndrome.net Team