Thank you all for taking the time to post and suggestion some things. I think the only thing left is seperation anxiety. He has his bowels open daily or second daily and it's soft/liquid. He has been given panadol/nurofen/bonjela. I've been showering with him at all weird times of the night.
Sadly I've got no back up and that makes it that little bit harder knowing that I can't catch up on a nap during the day. I wish I could so I wasn't so grumpy with my older kids - I just hate that I'm grumpy/cranky with them, it's not their fault.
He is just the biggest mystery. If only he could talk and tell me.