have you tried green papaya enzymes (papain)? its a very powerful enzyme and is the only enzyme that will digest in both an acidic or alkaline environment. i got a pound of green papaya enzyme powder that is pretty good. bromelain is good to, it helps break down protein. most likely you have tried both tho.
i would suggest you look into bone broths. bone borth is the source of the MOST assimable minerals, amino acids, and nuerotrasmitters i know of. and SUPER easy to digest and assimilate. i have been posting a lot about it recently so maybe you have seen my posts. every single person who has tried has had only great things to say. here are some educational posts, plus one experiential one. i would highly recommend for someon with digestive issues. drinking a big glassful almost feels like eating a meal. so nourishing and energizing.