Upgrade the teat - how long it takes?

[whosthis]

DS is about to be 5 months but still using Avent 1m+ teat with two holes. Attempted to upgrade after he's 3months, gave up after a day as the feedings ended up as a battle with bad wind each time.

I thought he was feeding alright so didn't insist. But these two days it seemed he's bored with the slow feeding and would not bother to finish it.

How long shall I try before he could learn to cope? Last time, he couldn't even finish half of his bottle. I just don't want to see it each time.

Help~

Anyone can help?

My DS took a little while to get used to the bigger ones. The tip is to sit him a bit more upright as the faster flow will take him by surprise. Keep going with it, he will get used to it, it took me 2 or 3 attempts.

My DS is almost 7 months so I need to upgrade him to the 6+ teats as he gets fed up of the milk not coming fast enough!

It was always obvious that when my two were at the getting bored as its too slow stage, it was time to change.

Agree about sitting them up- also having breaks to wind them. They got used to it in a day or so.