Relapse at night??

So ds1 has been toilet trained for well over a year now. He day and night trained at the same time so he has been out of nappies completely for well over a year. Over that time he has had the very occasional accident at night. Except recently he has started wetting the bed quite a lot. Not every night and he will go days without wetting it just to then wet it 3 nights in a row. Last night he wet the bed twice, once at about 1:30am and then again before he got up in the morning. On the mornings that he is dry I generally have to remind him to go to the toilet so its not like he is completely busting. So I just don't understand why he has suddenly started wetting the bed. Did anyone's kids relapse long after the were toilet trained??? Is it just a phase??

Just a couple of things spring to mind. Just ideas so may be off track but this is the list I run through with my DS1 when he has an accident out of the blue.

1. DS1 if he's going to have an accident tends to do it on cold nights. this is my first thought as here in Melb (not sure where you are) the nights are getting pretty cool.

2. How much did he drink before bed & what? Generally milk here!

3. Did he go to the toilet just before getting into bed?

4. At 3 my DS1 has become more aware of monsters etc & has come bursting into our room re: a monster but also needing the toilet.

5. Has anything upset him, routine changed?

hope something out of the list helps

Hansie x

They had a thing on Dr Carl (triple j lol) about why we pee more when its cold,and I cant remember why but its true, we do. In the last 2 weeks, I have had to get up a couple of times during the night to pee. I have not done that since last winter.
Just a bit of trivia for you :D
GL

My 4 y.o daughter is doing this as well. She toilet trained when she was 2 and has been dry at night for ages.. then all of a sudden about 2 months ago, she started wetting at night. She started doing it once every few days and within about 2 weeks she was doing it every night. She still does it and I've had to start putting a nappy on her at night because i was sick of washing sheets everyday. Even when I dont give her a drink before bed or if i get her to do a wee before bed (or even if i wake her up in the middle of the night and get her to do a wee on the toilet) she still manages to do a huge wee in her bed.
No idea why (no changes in routines and it was still quite warm when she started doing it??) but I'm hoping she stops soon.

What else can I do though? I've tried a few things (as listed above, plus some other things) but she just keeps doing it.