My daughter has had problems with constipation for the entire time she's been on formula. She was originally breastfed, and we really didn't have any issues other than I lost my milk. She spits up a lot too. Should I switch to soy? Her father needed soy when he was a baby, too. Literally she goes days without pooping and then blows out a diaper, then it's another couple days. She projectile spits up. I just don't know what else to do because she's already on a gentle formula that we found works better than others, but still isn't perfect.