Thanks the extra information is helpful.
I came back in and rolled him onto his side and shush patted him. I know it isn't age appropriate but it works for us. And he fell asleep.
There's nothing at all wrong with using shush/pat. Some older LOs don't like it but LOs who are used to shush/pat often do find it soothing. I always used our adapted shush/pat even with a toddler and pre-schooler
Any time of illness, teething or separation anxiety etc it was my go-to for the times my DS needed some help.
Do you think silent reflux could be the reason for his night wakings?
Based on the info you've given, yes, I do think there is a good chance that the reflux is bothering him.
I was scratching my head wondering what on earth was going on with your LO as the routine is not significantly poor to be causing such long and numerous NWs and reflux was really the only thing I could think of. The back arching and bad breath are signs, plus his history of silent reflux of course.
Personally I'd get an appointment with the doc, explain the numerous NWs and other symptoms and say that you'd like to try some meds. Was he on meds before (other than the gavi?)? Infant gavi doesn't control the acid like adult gavi does, it only forms a barrier to help keep the milk down, I found it only helped for a very short time with my DS.
I know so much information says they out grow reflux at 6 months but mine wasn't even diagnosed until about 5 months and stayed on meds until about 2yo. He still has flare ups now at almost 6yo. Mine no longer needs daily meds but he goes back onto ranitidine for a few weeks or couple of months when needed.
Obviously it is a decision only you and your DH can make, I know not everyone likes LOs to be on meds, I'm just saying what I'd do, I saw so much relief and calm in my DS on his reflux meds.