Not wanting milk?

L

My son used to guzzle down 5oz a week ago and suddenly he’s barely taking in 3oz. If I offer more he starts screaming. I know he’s still hungry.

Any ideas?

It’s not the nipple size, I already tried a size up and he screams even more. It’s not the bottle or the formula. Not sure if it’s teething. I don’t see or feel any teeth on the surface yet.