I have a 7 month old and she sleeps through the night, most of the time. We actually stopped her night feedings all together very early on. We can usually get her to go back to sleep without a bottle. Sometimes, if I know she didn't get enough formula during the day I might give her a bottle, but otherwise I don't. We fed my son (now 4) everytime he woke up and he didn't sleep through the night until he was 2 1/2!!! He was so used to waking up for something. I guess I'm trying to stop that from happening this time. I figure, if she can sleep through the night, she really doesn't need the food. I don't know if that would stop the vomiting or not...we rub her head to get her to go back to sleep. Maybe a pacifier would help stop the screaming. Otherwise, maybe just give him some water...then maybe he won't want to wake up for it.
My daughter does spit up A LOT!!!! But she's a happy baby, so we don't think it's reflux.
My son had chronic ear infections and actually had to get tubes in his ears at 15 months. He NEVER acted like he was in pain and never grabbed his ears. I knew he had an ear infection when he got a fever.
Good luck!