I'd love to know more about this, too. I can't seem to eat much, and the docs here won't put me on an elemental diet because I'm in a US military medical system and they don't support it (the GI used the words "tip of the spear" twice to refer to the medical care available...apparently the elemental diets are far away from the tip).
I tried two of the ones I heard about on this site. The first caused some malabsorbtion symptoms and the second...had trace amounts of casein. Which I'm pretty sure I'm intolerant to.
Do you want the casein one? I'm happy to ship it to you, free of charge -- I hate the thing going to waste. It's sealed, unopened, and supposedly works great. (I can send along the other one but it's already opened.)
PM me if you're interested. I can give you all the details of both and you can see what you think.
Little off topic: if you have leaky gut - are you aware that the vegetable oils, eggs and ultramarathons are probably contributing to that?