My sons had SIBO later diagnosed as Crohns disease. Things that helped them the most were Aloe Vera, Probiotics, Slippery Elm powder, Colloidal Silver and DMSO combined, accupuncture chinese medicinal herbs and marijuana.
Actually the marijuana made the biggest impact and put one of my sons in remission. The other has been helped by it too but also went down the Chinese medicine path with acupuncture and various herbal mixtures which helped quite a bit.
Even if you're against smoking marijuana you can look into cannabis oils etc - but it's really helped them.