Baby taking Zantac for reflux

My baby girl is 3 months old and 12.8lbs and was started on Zantac yesterday for reflux. She takes 1ml 3 times a day. Normally she only poops once a day but today she’s pooped 3 times and it’s getting more and more watery. I’ve been keeping track of her temp. and it’s went from 99.5 to 98.1 since yesterday. She has also eaten more today (formula) than normal but i think that maybe the medicine is making her comfortable enough to finally eat more. 19.5oz total today.

Has anyone else experienced this or any other side effects???