Any ideas?

For the past month or so,  DS goes down at 8pm with bedtime routine relatively easily around 8pm (about half the time he falls asleep on his own in his crib, without crying..no CIO here).  He sleeps well for the first part of the night, normally until 1 or 2. Then I feed him (EBF) and he falls asleep after nursing for about 8-10 minutes. I take him off the boob, give him his paci, and he is fast asleep in my arms, but when I put him down he starts squirming (usally after 2-3 minutes of looking like he is going to stay asleep in the crib) and eventually crying. I pick him back up, and he is immediately fast asleep. I put him back down, squirm, cry. Nothing I can do will soothe him without picking him up. No matter how long I hold him and rock him (30 minutes of rocking), and no matter how asleep he is, he wakes back up when I put him down. This can go on for up to 1.5 to 2 hours each waking after 2-3am

We do not have this problem at bedtime or during naps. Only in the last half of the night. Tylenol doesn't help (he has two teeth and more on the way), origel doesn't help, mylicon doesn't help. I have changed the temperature in his room, changed his diaper. We tried putting him to bed earlier a few nights and later a few nights. I kept him awake during nighttime feedings so he would eat more. We tried rice cereal before bed for a week. No luck with anything.

I cannot for the life of me figure out what is causing this. It seems like he is in some sort of discomfort, only not really because its only between 3-6am. Pedi says to let him CIO, I'm not comfortable with that and am changing pedi's. Anyone else go through this and were you able to figure out what was wrong with LO?