My Lo is 5 months old. Exclusively Bf and he has a cow milk intolerance. We have tried most of the prescribed formulas but he just spits it out fussing on the bottle. We have tried different bottles, diffrent teats, different times of the day and no luck. He has now also started spitting out my expressed milk from the bottle too. Trying to get him on the bottle as recurring mastitis. Any advice would be greatly appreciated