If you've switched formulas..

How did your baby transition? Did it take a few days to settle well? This week we've slowing been switching to gerber soothe from elecare. Yesterday and today LO has been very gassy. We had tried the elecare due to gas/tummy issues since the pediatrician said a GI doc will usually have you test out the hypoallergenic forumula first. He was never actually diagnosed with an mspi so I wanted to try a milk based formula again. Now I'm not sure if it's the milk affecting him, or he's just adjusting to a new formula.