My GI doctor's take on SIBO

I had an appointment with a gastrointestinal specialist (Dr. L) today to discuss the results of my recent positive SIBO breath test.  Mostly I was curious if the diagnosis of SIBO is taken seriously in "mainstream medicine" or if it's considered a sort of "fringe" diagnosis.  I also wanted to know how he would propose treating it, to get a second opinion.  (Dr. M. has suggested treating with the antibiotic Rifaximin.)

Dr. L said that he usually only discusses SIBO after he has ruled out all other potential causes of symptoms.  "SIBO comes last," he said.  He said that a few years ago, he used to be more interested in SIBO and would jump to a SIBO diagnosis more often, but he also said he considers it a bit of a "wastebasket diagnosis."  He explained that he used to treat SIBO with Rifaximin but he said that patients almost always came back in a few months when the SIBO had returned.  "...And I can't just keep prescribing you Rifaximin," he said.  Apparently, it was for this reason--futility--that Dr. L was less likely to jump to a SIBO diagnosis in recent years. He also suggested that the test results can be questionable.  Again, I wish I had asked more questions to clarify this, but I always seem to think of these questions when I'm driving away.

Dr. L said that when he does treat SIBO, he prefers probiotics (to "overwhelm the bad bacteria with the good bacteria") to antibiotics, although he is not adverse to trying antibiotics once.  Despite his reluctance to diagnose SIBO before other conditions have been ruled about, he did admit, without prompting by me, that my symptoms do seem consistent with SIBO.

In the end, he sent me away with some samples of VSL#3 and told me to try to treat if with probiotics, and if I still didn't feel better in a few weeks, I could call back. However, he said that if I call back, he would first have to rule out other possibilities by either doing a CT scan of the abdomen, and/or scopes, and/or stool sample testing.  (My feeling is these would probably not lead to anything useful.)  Previously he had ordered an abdominal ultrasound and some scopes and these were completely negative.

I have an appointment back with Dr. M (the doctor who originally diagnosed me with SIBO) on Monday.  I'm going to see if she can get me approved for one round of Rifaximin to see if it helps at all.  If not, I will try the probiotics/diet/herbal antibiotics route.