my baby is sensitive to cow's milk. he won't diarrhea but he will break into rashes. it could be lactose intolerance. so my son has been drinking HA formulas from NAN.
when he had diarrhea at 7mths due to introduction of solids, i asked pediatrician if i needed to switch him to soy milk but my pediatrician says no need. you might want to check with your pediatrician to ask if switching to HA formula might work since HA formula is still cow's milk and not soy.
HA stands for hypo-allergenic, where the lactose in the cow's milk is suppressed.