DS2 toilet trained just before he was 3, no problems, and went dry at night about 3 months later. He had the occasional incident but nothing we weren't expecting. He was pretty reliable in the daytime too although he always let himself get too desperate before breaking off and going to the loo.
He's now 5.3. I've got to the stage where I'm changing his bed at least 3 times a week, maybe more, because he's wet himself. Sometimes when we check on him before going to bed, around 11, he'll be wet. Sometimes he seems to wet himself on waking. He went back in pull-ups for a while in the spring and then was dry for at least 2 weeks so came out of them again. Bedwetting has come and gone in fits and starts since then, currently he's doing it a lot. I'm careful not to let him drink too much near bedtime, but also conscious that he probably doesn't drink much at school - his water bottle is rarely empty.
Re the daytime, this has been going on at least 6 months and I just put it down to laziness on his part. He doesn't want to break off what he's doing so just lets it get too far and wets himself. We tell him off but don't make a big deal about it. He has also never, not once, had an accident at school since starting Reception last September which made me think it was down to laziness at home - but now I wonder if it's the strict toilet regime at school that keeps his bladder in check?
I'm now (just looking at my laundry pile this week) wondering if he has a problem and if we should go and see someone. Anyone had anything similar?