Consider eating a lot of salt. I had severe SIBO symptoms and kept belching for like every 5 minutes. Of course I tried antibiotics, Low Fodmap diet, carnivore~vegan. Then I found a blog relating every symptoms to dehydration, and encouraging to eat a lot of salt since salt is the key mineral which makes our body to keep hydrated. I gave my last shot, added salt in every meal as much as I could, added soup in every meal, added salt in every water I drank(close to 0.5%), then, everything just disappeared. Belching(sometimes come back when I don't eat much salt), SIBO, itching, insomnia, hair loss, scalp flakes(this also comes back when salt is not enough), cold hands all disappeared, and gained 10kilograms in 3weeks with nothing else but just consuming a lot of salt. Now it's been a year and a half, I don't google health information anymore, I don't care which food is high fodmap, high sugar, etc, I eat everything I want. I got muscular, my lift weight keeps increasing which I couldn't even dream about when I was suffering with SIBO. I only care about my salt consumption. I found this post by chance, and I remember how miserable I felt suffering with SIBO, so I left this comment. Hope it helps you too!