I also suffered from IBS and about two years ago I quit all sugar (for reasons totally unrelated to my IBS) and low and behold, the first thing that changed was that my IBS symptoms disappeared. I still eat bread, I’m vegetarian so no meat, only a small amount of cheese sometimes.
Then about 6mths ago I started on a green smoothie kick and was adding fruit to the smoothies (bananas, apples, grapes, kiwi etc) and wham my IBS came back with a vengence. So I figured I am either fructose intolerant or the sugar intensified some other imbalance. But all I know is if I stay 99% sugar free (hard to be 100% as they put it in EVERYTHING) I am IBS free.
That’s my story anyway, hope it might help in some way.
Good luck with your back to health journey.