IAS,
I understand your being fed up with taking "all the stuff" and its associated cost as well.
It certainly wouldn't hurt to try an "all inclusive amino acid product", however IMO, I don't think it will accomplish what the additional L-Threonine amino acid powder can bring to the table.
I say this based on several things:
1) The actual content of bio-available L-Threonine within certain foods is hard to determine and calculate.
2) I found a huge difference in results when I tried freshly steamed lobster (from live tank) vs. frozen lobster - and that's due to live tank ones having a huge amount of bio-available threonine vs. frozen ones having depleted levels.
3) Since so much of our foods are processed, etc... and don't come directly from the farm to the table, etc... if we extrapolate the live tank vs. frozen lobsters to other foods, how do we know it wouldn't yield similar results?
4) Based on the results and the scarce studies showing threonine promoting and involved in mucosal lining repair, could it be that IBDers are missing this important Threonine or perhaps are deficient, and thereby need more of it?
5) Lastly, I am consuming several whey protein shakes daily, which do contain the whole range all amino acids, and yet I had no such results. BUT once I added threonine, BINGO!
Ultimately, it's your decision, and I well understand your being sick and tired of taking supplements.