Cindy, we experienced this with our ds 1 and sadly like you, I could not find any real reason for it to occur. He actually started doing this after we moved him to a bed prior to no 2 coming, but like you he was fine if we were in the room, but screamed as soon as we left and some nights it would be for 4 hours at a time.

I wish I had some suggestions for you, but we just found that we continually put him back, and sadl,y had to let him cry and scream, but eventually he got the idea and started to sleep longer, or if he woke, did not take as long to settle.

Now he can still get up a few times a night, but it is generally no more than putting him back to bed and he goes back to sleep.

Hugs to you hun, cause I know how awful it is feeling like the nights will never end.