Just saw this. For me, I found a medication that helped me a lot and I worked on my diet as well. Not just fodmaps but slowly becoming vegan. That helped me regrow my gut biome a lot. I also experimented with fecal transplants, believe it or not. And I went to a pian clinic and they injected a numbing agent into my nerves. This may or may not have been effective. I tried a lot of things. But I think the diet and medication were the most helpful. Then when I was a bit stronger I slowly tried a lit bit more garlic and onion powder and then eventually fresh garlic and onions. I would have a bit of a response but not much. And after a while that response went away.