If the formula is milk-based, that could be a reason. Even when parents switch children from formula to milk, children have bouts of constipation. I'd probably discuss this with your pediatrician. I've noticed, though that whenever you change a baby's diet, (i.e., milk to solid, breast to formula, formula to milk), there's bound to be some constipation and gassiness. It's new to the body. Now, if you or your husband are lactose-intolerant, the baby might be having trouble with a milk-based formula. You could try something like Prosobee LIPIL, which is what the hospital gave my daughter when she was born. More expensive but she didn't have any stomach problems. We tried something cheaper when we came home from hospital, and she started having gassiness and harder stools. Switched back, she was fine. (She's now 4 yo.) Meanwhile, if your daughter's not having diarrhea and is taking the formula ok, but is just gassy, try pumping her legs and gently rubbing her belly for her. Hold her upright and rub her back. She might not have the stomach muscles yet to relieve herself. I'd still follow-up with her pediatrician to make sure there's nothing else going on.