Comforter problems... any ideas?

I think my little boy is not sleeping through the night because he is waking up without his comforter, which is his sleeping bag!! He's had his bag since he was little and likes to pull the hood over his face while he nods off... he's done this one way or another since he was tiny!! Trouble is that now he is mobile, he is waking during the night. When I go in to his room he isn't in his sleeping bag and is sitting up the other end of the cot! I have tried putting him back into the bag but he always crawls out of it in his sleep.... he's in a grobag too but he seems to need this sleeping bag as a comforter more than anything....

This afternoon, I tried to put him down without his sleeping bag but he wouldn't lie down and started crying!! Tried to get him to sleep without it for about 20 minutes. Then I went back in and put the sleeping bag down but just open on his mattress, lay him on top of it and he was out like a light!!

Has anyone got any ideas as to how I can gradually persuade him to let go of the sleeping bag... or any other ways of dealing with this issue!?

Can you give him the bag to hold rather than putting him in it? He might be happy just to feel the fabric on his face. Yasin still likes to hold his old wraps beside his face when he goes to sleep. If it makes him happy it might be easiest to take the path of least resistance and let him have it as a comfort object until he's ready to get rid of it.
If it works you can later cut the bag in 2 so that you have a spare - it makes washing easier and if one gets lost its not such a tragedy.

I will see how I go tonight.... I think that is better than trying to take it away from him completely..!! Its his blankey... I don't mind it except I'm up every 2 - 3 hrs putting him back in it!! :doh: