I'm celiac with IBS
I eat to sustain gluten free 100% and nothing else. Wheat rye barley malt spelt and Oats irritate my whole digestive system so gluten is very bad..I've been living and dealing with IBS for more than 30 years and diagnosed celiac in 2013. Since diet correction the only time my IBS flairs is when I get stressed.. so I stay away from stressful people and situations.

You asked about IBS but you should really ask about IBS-D or IBS-C as the food answers may be different. Some will say nothing helps nor hurts. Some may find there are triggers for IBS-D but you’ll have to do a food diary to figure that out. For IBS-C use Metamucil & Citrucel in combination, plenty of water, and go as soon as you feel even the slightest urge are your best bets. IBS-M & IBS-D are probably also stress related.

There's NO diet that helps with IBS. The only thing that helps is not to eat food.

After multiple tests, scans etc and no diagnosis I myself went gluten free and use almond milk. It really helped but I would still have 3 day flares of diarrhea off and on. Decided to go sugar and caffeine free and amazing change. Now just occasional issues. Seems I still need to watch my intake of raw vegetables and beans😂

I have been told the Fodmap diet or the Mediterranean diet could help but I just can't seem to give up the foods I love.