I came across this article and thought it might possibly be useful for those who have a longer term problem with diarrhoea and digestion problems. Bear in mind that it has not been written for people who have had major Upper GI surgery, it is US-linked, and it does tend to link SIBO and heartburn, so you will have to pick and choose the parts of it that seem most relevant:
howtotreatheartburn.com/sib...
There is also an article on GORD - Reflux