Putting bars back up on cot bed for 3 year old?

[pjd]

DS is 3.3. His sleep has got much worse of late, he wakes regularly in the night and wants to come into bed with me. I have a 2 week old DS2, so am of course up half the night feeding him, and desperately need DS1 to stay in his own sodding bed! He is not frightened of being in his own bed, he would just prefer to come and snuggle up in the big bed, as he puts it! Last night he came wandering in at midnight, I put him back to bed. Then again at 2am - I put him back to bed. Same at 2.10am, 2.20am, 2.30am. DH then took over and put him back to bed at 3am. In he trots again at 5am, when I gave up and let him in the bed with me - he then slept till 7. This is obviously not a long term solution, when there is a newborn waking every couple of hours. So I have been thinking about putting the bars back up on his cot bed, hopefully just for a short while, until he gets the message that he has to stay in bed all night. I think he will loathe being back in a cot, but I am hoping it could have the desired effect. Has anyone else done this? Is 3.3 too old to be putting back in a cot? He has been in a bed since 2.9, but never actually learned to climb out of the cot. If anyone has any thoughts or experience on this, I'd be pleased to hear them.

I've put a stairgate up, Ds can climb out his cot and it gave me the willies knowing he could slip and land funny(etc etc pfb) He's been in a big bed for last 5 or so months and got into a habit of coming into my bed in the middle of the night. It wasnt pretty for the first 2 nights but i'm on the 4th night now and last night he stayed in his own bed the whole night (still woke but just chattered to himself and the occasional grizzle) i'm hoping eventually we can get him to sleep the whole night!!

He'll climb out and you won't solve the problem, he'll just become more determined or upset.

My 3yr old previous brilliant sleeper has recently started sneaking in with us earlier and earlier. The thing that works with him is lots of talking so we've told him he can't, there's not enough space, his teddy/toys on his bed will be lonely, if he doesn't sleep in his bed then we will because somebody has to sleep there...then said he had to wait till dh comes to get him (because he leaves v.early for work and ds doesn't want to miss saying goodbye) so if he waited he'd get a sticker and we'd all have had a lovely sleep and would all be very happy and proud of him. That worked!

positive works better than negative and putting up cot bars seems like a negative punishment rather than dealing with the actual issue.
I can totally sympathise with the newborn baby issue, i've had sleep regression twice with a baby+a toddler.