My husband couldn't digest jevity but does ok with osmolite. The dietician told us there are quite a few formulas to try and it can be an individual thing in terms of what agrees with you. Ensure plus has the same calories, protein, etc. as osmolite 1.5, but not all the trace minerals. Jevity has more fiber.
For us, it helped a lot to use a pump overnight at a very slow rate. The head of the bed is up on blocks to keep him at about a 30 degree angle.
Hang in there! It gets better.