I’m pretty much symptom free now due to dietary measures and some probiotic supplements.
About 70% of people with IBS have SIBO (Small Intestinal Bacterial Overgrowth) or IMO (Intestinal Methanogenic Overgrowth) or a combination of the two. The work of Dr Mark Pimentel of Cedars-Sinai is informative on this.
There are antibiotic therapies for SIBO and IMO which are often successful to the point of total cure, depending on the underlying causes. Acid reflux is also a common symptom of SIBO.
Many cases of SIBO are caused by a bout or bouts of food poisoning. This will often be called post-infectious IBS. Repeated bouts for food poisoning can mean that the illness progresses to being an autoimmune condition.
There is a blood test, called IBS-Smart that can I form you whether food poisoning is the underlying cause and if it has progressed to an autoimmune stage (the latter is more likely to recur- treatment is possible but may need to be repeated).
Another common underlying cause of SIBO is EDS so that would be worth looking into.
I have SIBO but it’s not the post-infectious kind, so the antibiotic therapies are less likely to be effective for me so I have taken a dietary management route.
This is basically components from Low Fodmap and Fast Tract Diets, and I keep an eye on the sulfur content of foods too (this is because the the bacteria implicated in the form of SIBO I have is also implicated in IBD and there is a Japanese diet based on lowering sulphur that has been shown to be effective in managing IBD symptoms).
I also take:
L Plantarum 299v
L Rhamnosus
L Reutri
These are all probiotic supplements and also molybdenum (helps with sulphur processing).
I have also found that both live lactose free Greek yoghurt and Roquefort cheese (or any low lactose aged hard blue cheese) are helpful as regular parts of my diet.