How to manage SIBO symptoms?

My wife, after years of suffering from debilitating nausea and fatigue, has finally been diagnosed with SIBO as confirmed by a hydrogen breath test. It is estimated the bacteria has had at least two years to grow and may be well established. She has started on Xifaxan, at $35 per pill, but it is estimated that elimination of the SIBO may take up to six months. Her day now starts with her waking up with nausea and when she has a cup of tea and toast in the morning she gets sick within fifteen minutes thereafter. Her sickness is accompanied by violent belching, and at times she regurgitates liquid vile. The only drug she has for nausea is Zofran which does nothing for her. Are there any other SIBO sufferers that are experiencing the same symptoms, and what are you taking to reduce the nausea?