Fussy Due to Formula Change?

Changing formulas will cause some fussiness for a few days, and expect a stool change, as well. It's possible there is a milk allergy. How are her stools? Usually, the stools are the most noticeable signs. Green, runny, mucus-y stools are a big indicator. And there is usually a lot of gas and colicky behavior right after a feeding.
Give it a few days and see if you notice an improvement. My son was breastfed at first and had multiple food allergies. We had a real time with him while I was breastfeeding, even though I cut out just about everything except water and lettuce...lol With his allergies, we noticed the eczema starting around 3 mos, and ear infections starting not long after that. That was another pretty big clue as to some allergies were at play.
Also, I found it helps to keep the baby upright for a 10-15 minutes after a feeding. I know this isn't possible at night, but during the day it helped a little bit with the spitting up.
A final thought is to get the ready-to-use formula. Not sure if you are doing that now, or if they make it in this particular brand. But I found my son kept it down better than the powder variety.
Anyway, I hope this helps!

Changes in formula can cause upset tummy. Poor baby! I wish you the best luck! Do not start solids before 6 months, not even rice cereal to allow her poor tummy the best chance of healing.

I'd ask for a different kind of reflux med. It appears that Zantac doesn't work that well for her, but there are other options. I'm a little surprised the doctor didn't suggest it. When one of my babies wasn't responding to the med he was on, it was his pedi that suggested a different med- I wasn't aware there were any. The new med worked much better for him.
Best wishes!! :)

Why don't you do what I did, I went to Walmart and got the GoodStart formula, my son went from pain, spitting up or shall I say projectile vomiting to a happy and content baby who thrived. My pediatrician did not support me at first because the pharmaceutical companies don't bring it into the office but I told her it was my choice and I was desperate for a solution. GoodStart is made by Nestles so the doctors don't know a lot about it. With my older son I did what you are doing and never got anywhere, he did not eat solid foods until he was over 2 years of age and it was really hard when his 2 older siblings were eating and he couldn't. I was determined not to go through this with my next child so I did things on my own and am happy I did. If you decide to try it let me know how you make out.

My daughter had a true milk protein and soy allergy. Bloody stool, green foamy stool, and a body rash. They tested her stool. We discovered it when she was a few weeks old. I breastfed her, and had to drastically change my diet. My son had a milk intolerance, but could tolerate soy. I did not breastfeed him, he was on a soy formula. There was a huge difference between the two, he spit up a lot and was very very gassy and uncomfortable where she would break out in a rash and have bad stools.

Maybe change the type of formula, not the brand. My son could only tolerate the concentrated liquid in cans that you add water too, the powdered he would projectile vomit. My daughter after I stopped breastfeeding could only tolerate the powdered (she was on Enfamil Nutramigen, it's the same as Similac Alimentum.) I would give the new formula at least 2 weeks, that is what I was always told when we were trying to find the right formula for my son.