Just wnat to let you know we just went through this about 2 weeks ago. My lo 6 months on saturday about 2 weeks ago started refusing bottles after 3oz and we couldn't figure it out. Finally I went up to size 3 nipple. The first 2 days were horrendous. He would sputter, gasp, let it flow out the corner of his mouth but when he did drink would down a 6oz bottle in 10 minutes, end up with hiccups and sometimes vomitting. So the next 2 days if I saw him start having really hard time with the level 3 I'd switch to the level 2 till he calmed then switch it back and that worked for him. (he's spirited). It took about 4-5 days to get him to take the 3oz nipple on it's own and now no more hiccups and he'll take the full bottle again. It just takes some adjustment and time. Just feed him propped up so that he's taking in less air, and the flow is a bit slower.
