Hydrogen breath tst for sibo accurate?only have tummy bloating no other problems and ibs. gi says test is pos need xifaxan (rifaximin). but no symptoms of sibo. ?

No test has perfect: accuracy. Study: https://www.google.com/#q=hydrogen+breath+test+for+SIBO for overview. Medical industry commonly promotes simple ideas for complex issues, yet does not mean true. Who is primarily in charge of your medical decisions? Yourself or others? Do you carefully pay attention to results of suggestions others make/promote and how you possibly accept/implement them? I would suggest doing so.