You can try using Benedryl or Alkaseltzer Gold - be sure though that you get the "gold" type. I know that the Benedryl will suppress the central nervous system. I know that normally this isn't a good idea, but if the herx is really irritating the central nervous system, then it becomes the 'fix'!
I've had some pretty serious gastro stuff, but mine is all constipation issues, so my heart goes out to you. I do know that Lyme can bring on Celiac's, among a whole host of other auto-immune things.
Here is an article by Virginia T. Sherr, " PRACTICAL GASTROENTEROLOGY" (
thehumansideoflyme.net/viewarticle.php?aid=62)
about
half way down the page, you will see this:
"Lyme-associated Motility Variation and Other BB Related Gut Problems". In the very next paragraph is where SIBO is talked about
.
All of the other things that I'm finding all link back to this one paper.
I do hope that this is helpful for you!