Been using these with my baby since just after birth. We've had a terrible time with them leaking but they did seem to make a difference to my baby. I've complained to tommee tippee and they replaced them. Anyway they've started leaking again and so I've thought about just using the original bottles. Has anyone changed from the anti colic ones to the normal ones and the baby has been fine? I'll need to buy New Teats if I change bottles. So I'd rather have some opinions before paying out. We used them because my baby had reflux. Not for colic.