Gassier when breastfed than when bottle fed

jlb08

I've read that bottle fed babies are often gassier than breastfed babies, but with DS this doesn't seem to be the case. In fact, he seems to be the opposite.

I went back to work this week and DS spent two days at daycare. I nursed him in the morning, evening, and during my lunch break but the rest of the time he was bottle fed. (I had sent frozen BM). On those days, he seemed less gassy than usual. Yesterday I was home with him, so he nursed when he was hungry. Last night and today, he's been fussy due to gas.

Any ideas why? If he's sensitive to something in my diet, would frozen BM not make him react as much? (I know you lose some antibodies when you freeze milk, not sure how it works with foods you've eaten). Could the gassiness be due to using a nipple shield? Or it could just be coincidence.

Does anyone see a difference in LO's gassiness with breast vs. bottle?