Gims,
I have never digested meats very well. I never intended to be a vegan and I am not in any way. I can eat eggs at times, and fish, but chicken, sometimes, beef always, and pork are hard for me to digest and always have been.
Remember, I worked hard enough to burn it off but that did not work.
I don't know if it has to do with age but it may be that you are developing an intolerance of those meats that are hard to digest, (and they are.) Beef, Pork, even chicken, are hard for the body to break down in the system. If you study on line what the body does to break down these things to digest them you could take suppliments to aid you in doing so.
Still, It's good to know you are healthy. If you have an ounce of pain it is worth a doctors visit, I've learned that.
Please tell us how it goes?

Best to you!
Dancer