Change of milk powder

Switching formulas can really upset their tummy for a while, so the hard stools and vomiting might just be their system adjusting, though it's worth watching how long it goes on. A few mums I know mentioned that doing a gradual transition helps, like mixing the old and new formula together over a week or two rather than switching cold turkey. My neighbour actually tried warm baths and gentle tummy massages when her toddler got constipated during a formula change, and she said it really helped move things along, along with offering more water throughout the day. Some mums have also found that if the cow's milk-based formula keeps causing issues across multiple switches, trying a gentler option like a partially hydrolysed or goat milk formula sometimes makes a difference, though of course every child reacts differently. Since your daughter is also coughing and vomiting on top of the hard stools, it would really be best to check with your paediatrician just to rule out any sensitivity or reflux that needs proper attention.