Fighting to Go to Sleep and Waking up at Night Wanting to Co-sleep at 20 Months

i know he seems young for it, but when they're ready they're ready! i like the suggestion to get him a floor-bed to help with the transition and keep it safe for him.
it's so frustrating when they keep hollering and keeping everyone awake, but if there was ever a time for calm consistency this is it. just rub his back or sit quietly (no interaction at all! no talking or even eye contact) until he's quiet and then go out again. if he melts down again, remind him 'nighttime is for sleeping' and go back to the quiet soothing presence. it may take enough repetitions to make you nut up, but in the long run it will pay off.
good luck!
khairete
S.

Try putting his crib mattress on the floor like a "cot" and see how it goes. My 21 month old still co-sleeps, but spends most of the night in the crib pushed against our bed.

My cousin's first kid was ready for a Big Girl Bed at age 18 months. My first daughter was able to climb into her crib but was not able to get out and so we waited until she was 2 years and 3 months. She went into a toddler bed. Our second daughter we moved her to a twin bed the week she turned 2. With her I started her out with just naps for two days and then she asked for the big bed on the third night and she did not go back to the crib.
So, short story long, there is no set time to transition them. For both of our daughters I wanted them to know what a Big Girl Bed was like because we were going on a cruise and I didn't want to take a Port-a-crib.
My opinion is that once they feel the freedom of beds (or cot in your case) that they don't really want to go back to the crib.
With our second daughter, the crib was still up in her room for a week and when she would get out of bed or cry because she didn't want to go to bed yet, we stood there and asked her which bed she wanted. She would stop crying and asked for the big bed and went right to sleep.
Good Luck. It is hard to think that your baby is growing up and won't need the crib anymore.

I know that it may be a little frustrating because he can't speak yet. However, you may have answered your own question. He may be ready for the "big boy" bed and yours is the closest that he has.

My son is 22 months and we made the switch to a twin bed about a month ago. He was in a toddler bed for 2 months before this and fought horribly to go to sleep and was waking up overnight. We determined he felt too confined. So we took to the crib down, put a twin bed in his room and he's back to being a great sleeper!