Dairy? I have seen a number of babies do poorly on dairy-based formulas or when their breastfeeding mothers drank milk. Rarely, soy can also be an issue. Discuss this with the ent. It may be an issue of a more restricted diet for a breastfeeding mom or a different formula. Note that lactose free doesn't mean dairy free.
Sometimes. Sometimes infants with laryngomalacia aspirate and so develop an oral aversion. This goes away when the aspiration resolves.