S.K.
N.,
Did your son recently hit a growth spurt? Sometimes my boys go through a growth spurt and start wetting the bed for a while. I think maybe their body doesn't grow proportionally, but a system at a time, and the bladder grows a little behind the curve. I didn't put my kids in pull ups after they refused them. We just made sure to have changes of sheets until they outgrew it.
I also sometimes need to take my oldest son to the bathroom before I go to bed - around 10pm. This works well for him even though he is a zombie for the whole bathroom trip. This doesn't work on every kid, however. My younger son cries hysterically when we wake him in the middle of the night and can't calm down enough to pee. I think you just have to try it to see what works for each kid.
Good luck,
S.