If you are still willing to try the crib, get a crib tent and use that on the crib, your child wont be able to get out of the crib. I have a 3.5 year old that is not mature enough to stay in his bed and he uses the crib and crib tent. We have always LOVED the crib tent with all my kids!I personally dont think a child is old enough or mature enough to stay in a big boy bed until they are fully potty trained...
The way, we trained our oldest to stay in his bed was we had a big boy bed and a crib with a crib tent in his room and we told him if he did not stay in his big boy bed then he has to sleep in his crib. if he gets out of the big boy bed then calmly put him in his crib and zip the tent... he will throw a fit but tell him you will try again tomorrow and he can sleep in his bed if he stays in his bed. a few nights of this and he will get that you mean business and will learn real fast to stay in the bed.
But we had a Dr. tell us that you can also take everything out of the bedroom except the matress and lock the door and do this for a few nights and he will learn to stay in his bed... obviously this is just for temporary until he learns to stay in the bed...not a perminate thing.
Its real important to have a night time routine that you do every night. if his bedtime is at 7:30 then at 6:50 you need to give him a 10 minute count down until bath time "BOBBY, 10 minutes until bath time" then 5 minutes and so on...
Then at 7:00 give him a bath and play in bath then get him dressed and brush teeth then read a bedtime story or 2 (let him choose the ones he wants to read and say ok after 2 stories its bed time, then after the 1st one say ok one more story and then bed time...)
then tuck him in, kiss him good night and walk out of the room and shut the door..( you need to leave a good night light on and have everything in the bed that he sleeps with so there are no trips to get stuff he forgot) Also, if he gets out of bed NO BIG DEAL, the first time, pick him up with out getting mad and say its bed time honey. and place him back in bed,
the second time do the same thing but say "its bed time"
the 3rd time and after pick him up and put him in bed calmly with out saying a word and shut the door. This may take a few times even a few nights... but be persist and and consistant. if you give in you will have to start ALL OVER from square one.
Do this same routine each and every night and he will get it I PROMISE!!
You can even make a bed time chart with photos of him doing each thing like brushing teeth and bath time and put them in order of how you do them and then have him point out what is next... this will get him involved in the process and make it fun and pretend like you dont know what is next and have him help you put the photo in the spot it goes in order for what is next...
Good luck- A.