I agree, your son is too little to be locked in his room, have you any idea as to why he is getting up in the night, is he scared of something or having night terrors? Or does he simply want to play and is not tired any more? Look at what he is eating or drinking before he goes to bed, anything with a stimulus in will not allow him a good nights sleep (do not give him fizzy drinks, high sugar foods or food with the dreaded 'e' numbers in after 4.00 in the afternoon, as these will stay in his system for a long time) Instead give him warm milky drinks, or a cereal (not sugar coated) before he goes to bed. I hope you find a remedy to restore peace in the house for all your sakes!
I would agree with last two comments - believe me, you spend half their life trying to get them to stay in bed and the other half trying to get them out of bed!!
Only other thing is, and not to scare you, you may find that you have to return him to be LOADS of times even up to 70 or 80 the first night BUT they will get less and less. I don't say this to frighten you only to point out that although it seems useless, it will work and you must persevere. You are not alone - think we have all been there. The ones who did not keep at it still have 6YO's in their marital beds!!
