Could it be his reflux? I've wondered, because I give M his PPI first thing in the morning. So technically by the time it's early morning, not sure how effective it is since he's due for his next dose. I've given some thought to moving it over to the evening and seeing if it helps. He's not in pain when he wakes, but he hasn't slept enough, yk so I think it's because something's bothering him. Although now he's teething so that may be it more than the reflux, but I figured I've got nothing to lose by moving the PPI in the evening and seeing if it helps....
I don't recall what meds he's on, and whether he's getting them once or twice a day, and when you give them?
Have you also tried pain meds to see if it helped him go back to sleep? Last night we had one of those longer NW's (it rarely happens to M) and I think if DH had given him Advil it might've helped him go back to sleep faster.