I'm not sure if this is a possibility for you since it is mixed with whole milk, but I have tried drinking a high calorie instant shake mix called "Scandishake". Here is their website:
Mixed with 8 oz of whole milk = 600 calories 21grams of fat, 54 grams of carbohydrates
I don't know if the high fat content would be suitable either. Please do the research before giving to a "new ostomy baby".
Diagnosed with CD in 1979, many resections and meds
Perm Ileostomy July 1984 at Cleveland Clinic
Disease free since surgery