I am highly intolerant to all dairy products and can no longer consume anything dairy. It's been a slow progression over the years to reach this stage .... starting with milk.
It's good you are already aware of some of the things you are unable to tolerate. But maybe you could think about getting some food allergy/intolerance tests done? I finally did this as I could no longer see for looking what was causing me so much stress and upset. As well as the things I suspected, it threw quite a few suprises at me and now having cut out all the allergy causing foods, my IBS has improved quite dramatically. Still not perfect but MUCH better and manageable!