Hi Rickman
I had this problem with ds (still do very occasionally) but it started with us at about 4-5 months old. As he got older the time he stayed awake just got longer. I'm not sure we ever solved it really (as opposed to it resolving itself). However I did find that after 1-2 hrs or whatever it was of him poking, climbing etc (this was on top of the 2-3 feeds a night he had) I just started putting him in his cot and to my amazement he often was quiet for a while and went to sleep. He also slept longer there.
He was like this from a very early age though so despite my trying co-sleeping from 4 months to about 6/7 months old, I realised that he slept worse if anything with me.
I also believe he was overtired so once he woke up he had trouble getting back to sleep then got more tired - a vicious circle so to speak.
I worked on his daytime naps and put him to bed early to help him catch up on sleep. It took a while but he definitely improved.
He was always put to bed in his cot but I used to bring him into bed when he woke up (if it was after about 11pm)so he was used to the cot.
You say you are are co-sleeping, what time does your ds go to bed? Has he ever used a cot for naps etc?.
He is now much better though I wouldn't say he is a great sleeper still. In an average week he sleeps 7-5am without a wake-up about 3-5 times though 5am/5.30m is pretty much when he wakes. The other nights he wakes maybe onnce but only for about 30mins or so and feed gets him asleep again.
Muc better than it was
This morning we had a 4.30 wake-up though and he stayed awake until about 6am then fell into a doze for about 30mins than was up at 6.30am. He was however looking really tired at 8am.
I have a feeling that this because we have been cutting back on his day naps a bit to try and get him to sleep longer in the morning and it has backfired a bit and he is now overtired. He seems really sensitive to sleep and needs 'just the right amount' otherwise he gets completely wired - difficult to work out sometimes.