Pain and systemic inflammation after eating meat - fish - protein

Since a year or so i feel pain in my joints and muscles approx. an hour after consuming meat, but also fish - even salmon. I also notice a sharp increase in systemic inflammation.

I'm allergic (IgE) and intolerant to most foods, my IBD (crohn's, now in "remission") doesn't help either.
Only meat and fish has tested IgE-negative.

So, what might be causing the pain and systemic inflammation?
I made a list of what the cause might be, if anyone has some insights then please let me know...

Pain and systemic inflammation after eating meat - fish - protein