How can I get 4yr old to sleep before 10pm

[Notgrownupinmyhead]

Sticker charts, 6am wake ups, exercise, fresh air, no sugar or cartoons, bedtime routines we have tried and he'll just not go to sleep til gone 11pm some nights when we've been in bed since 8.30 pretending to be asleep. He's bloody exhausted and fights sleep all the way. His appetite is piss poor too and most days will only gave half a bowl if cereal for b.fast, half a sandwich for lunch and the past few nights has refused to eat his tea. Nothing has changed in his life recently and we only told him today that he will be starting big school in September. I'm really worried he is going to burn out the way he is going and don't know what else I can try to encourage him to sleep. He is under the Paed about his eating and lack of weight gain and have to go back in October so she can she if the Movicol he is on has helped (even though he poops properly).

Any advice would be appreciated.

He generally falls asleep about 10.30each night.

Stupid question, but do you have blackout blinds/curtains in his room? DSS2 was impossible during the summer months when I first moved in when he was 4, waking up as early as 5am because the sun was up. A couple of months later, DP & I got a blackout blind for DSS2's room which improved the situation no end. Can't see how a darker room at bedtime wouldn't have the same effect.