I recently learned another friend of mine suffered from diverticulitis, and did some research on it to see if there was anything I could find that could help them that doctors weren't providing. I learned that diverticulitis is pockets that bulge out from the lining of the intestines, where digestive material can accumulate, which doesn't sound like 'leaky gut' you seem to have. There are several different problems, Crohn's disease is another, that have similar symptoms - terrible abdominal pain - but different specific causes.
About the only thing I could find that had been shown to help was probiotics. There were some stem cell trials that were potentially promising, but that's not something I can do from home yet. All I can offer is to hit the information about trials that are undertaken for intestinal issues, and read up on those, on probiotics, and see if there's maybe stuff you're eating too little or too much of that could be affecting your suffering. I wish I could do more, but these conditions are out of my reach, both literally and figuratively speaking.
Thanks!