I breastfed as well as supplemented. Her pediatrician concluded that she was allergic to my milk as well. We started supplementing with just soy but she was still gassy. It didn't seem to bother her either. She was just always grunting to get the gas out. So after her supplementing on soy for a month the doctor told me that it must be a lactose allergy and had me stop breastfeeding her. Two days after that she had stopped trying to push out the gas so hard
Yes my daughters rumbles all the time. She don't seem bothered by it and I read that it's a good thing because if you didn't hear it rumble they might not be digesting well. I also breastfeed and she's also gassy all the time.