I used to feed my baby with similac 1 since when he was one month old after completion of three month one day he was suffering with loose motion then doctor advised to use Similac Isomil instead of Similac 1 but when i tried to change his powder he spilt out all the milk in 4 to 5 times. I want to know why he spilt out all the milk when I used other formula milk powder/ dairy products. He is 6 month 20 days old.