I was diagnosed with SIBO years ago- part of IBS with constipation. Treated on and off with Xifaxan- usually worked for a while. SIBO seems to come back. One answer for me is controlling constipation. Years ago I also spoke to a Mayo GI doctor about this. No test needed- it smells like methane. He started me on temporary regular tap water enemas - this was very helpful. Since then I use laxatives as needed and start PeptoBismol as soon as I suspected it was back. Nowadays I have more success with Amitiza and/ or Motegrity.