My son did six weeks of enteral nutrition to induce remission, however, he also had flagyl through IV for the week he was in the hospital (so not sure how much that affected things). But, he started exclusive EN on the Sunday, came home Tuesday, stayed home from school the remainder of that week but, by the following Monday (one week + plus one day of EN), was back at school and participing in two phys.ed. classes and starting back on his hockey teams. He definitely took the activity at a slower pace (for him), however, was probably at an 'class average' level. The EN (plus flagyl) took away his symptoms almost immediately.
Having said that, he did EN overnight through an NG tube and was allowed only clear fluids during the day (ie gatorade, broth, jello, freezies, etc.). He did have diarrhea the entire six weeks but no real urgency - our dietitien said this was often the case (ie liquid in, liquid out) although, from what I've read here, it doesn't seem all the common???
He may not have felt some of the bloating, etc. you mention as he ingested the formula while sleeping???
His formula was Tolerex (by Nestle).
Joshuaaa - what formula are you using? Some are more broken down (the elemental or semi-elemental) so are easier to digest, provide more bowel rest, etc. Some of these, in drinkable version, would be Peptamin or e028. I have read of some people have difficulty using Boost or Ensure.