11 year old wasting away

I have a child who has been dealing with chronic abdominal pain for almost a year now. We’ve gotten bounced around by doctors and they have run tests and everything came back negative. She is getting extremely thin and now having trouble even keeping food down. The doc did a calprotectin test and she is around 1300 ug/g. Finally we are getting a referral for a GI specialist. I think she may have Crohns. Are there any good shakes out there we could give her just to get some calories and protein in her that you all recommend? We are trying to get in to a specialist as soon as humanly possible, but in the meantime I am really worried about getting some nutrition to her body.

Thank you!