I had SIBO, did Rifaximin as well. Works as long as you’re on it but go off and symptoms return. Antibiotics kill bacteria and they do not distinguish between good and bad bacteria in the gut. Our upper and lower gut each have their own bacteria BUT, when antibiotics are introduced the bacteria in the lower gut migrate to the upper gut to feed and you get symptoms like acid reflux. My doctor put me on a prebiotic first followed by a probiotic.
And any doctor that tells you the low fodmap diet doesn’t help does not understand the difference between treating symptoms or treating the cause of symptoms.
I also did the low fodmap diet and my doctor’s nutritionist told me that foods I need to omit i eventually can go back to once my gut microbiome is healthy.