Baby throwing up food he had hours ago

[edin16]

DS is 11 months old. He has reflux that doesn't seem to be allergy related.
He's started throwing up food that he had hours ago. Today it was his lunch that he had 5 hours before. Surely this should have digested by now?
Is this ok? I've been told to wait till he's one to see if he grows out of the reflux.

Dts had reflux related to prematurity as the sphincter muscle wasn't formed properly they were sick until around 18 months and medicated until around 3ish. It's within the realms of normal for reflux. Have you seen a pead, is he medicated?

@idontlikealdi
He's on omeprazole daily and gets gaviscon before bed. I can't give him anymore as it makes him constipated which makes him more sick. He also has comfort milk when I'm not around (like today).

My DD is 11 months and has reflux too. As I was putting her to bed a little while she bought up some of her dinner from 2.5 hours earlier - she does it quite often and it’s usually because she’s got a bit of trapped wind that I never got out properly. Could be the same reason?