DS2 has started to always wait until we have changed his nappy to do a really big poo, necessitating another change! It is literally 2 minutes after he has a clean nappy on. Likes to wander off into a corner to do it & is very grumpy afterwards until he's changed again 
Is there any chance at all this is a sign that now could be a good time to try potty training? He is 2.8 & we have DC3 due in 8 weeks, plus I'm finding it increasing difficult to get on the floor to change him, so it would be perfect timing We have tried him on the potty/toilet before, but although he would sit there quite happily, he never produced anything. Then we moved house, so it's kind of been put on a back burner. Also he has severe speech delay, so am thinking this could impact potty training.
Any experience anybody? TIA 