From my knowledge, the losec doesnt stop the milk coming up, more neutralizes the acids so it doesnt hurt as much when it does come up. The only thing you could do is maybe try giving something like gaviscon before you feed him to help thicken the milk in his tummy. How long has he been on the losec? DD2 has been on it for a few weeks for silent relux and even though it has made a drastic improvement, she still has the occasional acid attacks.