Hey sweetheart,
When he is struggling to settle down to sleep for naps and bedtime is he crying a lot or just mucking around? I only ask because Dyllan is talking a lot more now too (and has just cut a molar on top of being so ill) and he seems to be taking longer because he has to "talk down" before he can settle down iykwim....he will even wake in the middle of the night, yell out tractor and heater a few times then go back to sleep....funny really!
Also I remember when we first started having my step daughter sleep over she tossed and turned and cried out all night long, it was exhausting...but SHE actually slept ok, she wasn't fully awake (even though we were) for the most of it. It took a while for that to settle down and even occasionally now when she gets OT or stressed out by something she will sleep walk or stress because she "can't sleep" (although usually she has been, she just doesn't realise it!!).
Can I just point out one positive about Oliver sleep too (don't hit me!!) he CAN put himself back to sleep...he has the skills to settle back down and fall asleep again, that is GREAT. My hubby is a shocking sleeper and it's because if he is disturbed he can't switch back off....it is encouraging that Oliver can do this. Obviously something is upsetting his sleep cycle, but he manages to sort himself out and go back to sleep...it does bode well for the future honey
Oh and one thing I was wondering is you are back on dairy now aren't you? Did he have a very big dairy day yesterday (you mentioned he said his tummy hurt?)...just a thought xx