Update... Ensure failing

Pumpkin had a check in on Tuesday.  She had been experiencing a lot of diarrhea, but that seemed to resolve on Wednesday.  Tuesday she had gained another pound.  Starting 3 days ago, she started having issues with the Ensure again.  It makes her tummy hurt when she drinks it and she isn't able to get the full 7 cans down.  Twice in the past 2 days she has mentioned wanting the NG tube so that she can get another kind of formula that will be easier on her tummy.  All the better formulas taste terrible.  She tried one and said it tasted like vomit...well that makes sense, since it is predigested...  I guess I'll be talking to the pediatrician tomorrow about our options.  :(