Chloe is on Aptimil and yep hers are yellow and runny and smell quite bad too, this has been since she was on Aptimil, she started out on SMA Gold but it made her constipated to the point that she was crying when trying to poo, now she has no problems!
Does yours poo after every feed?
I spoke to HV about it and she said its cause that particular formula is closest to breast milk so thats why