Formula difficulties!!! Helpppp!

so here’s a backstory my daughter was on nutramigen but had really bloody stools so they switched her to elecare and she’s been on it for 2 months but still continued having bloody stools and her stomach at times would get really big so she had a GI appointment to do a sigmoidoscopy and it turns out she has a milk allergy to elecare so the GI doctor put her on neocate but what I’m reading is it’s the same thing just different brand and she’s been on it since Tuesday & she’s just miserable with this new formula and just looks like her belly hurts her by the way she moves. Doctors aren’t any help so hopefully someone that’s a mommy on here & that’s gone thru something similar or the same can help. 😔😭😭😭