My four month old son breast and bottle fed sicks up huge quantities of undigested and partially digested milk whether the feed is breast or bottle. It doesn't seem to bother him and he's gaining wait but I'm worried. Getting through so many bibs and tops each day. MW suggested giving him a hungry baby formula so that he drank less, that didn't help. Also tried switching formulas from aptimil to cow and gate - initial improvement but now back to a river of vomit coming out of his dear little mouth. Anyone got any suggestions??