DS aged 2.10 has been potty trained well over 6months. In the last two weeks he has decided he will only poo in his potty at home even if he is desperate.
He spends a day a week with each set of grandparents- never had a problem before.
He started nursery this week but the problem started a couple of weeks ago.
He will happily wee in a toilet or any potty.
He was in obvious discomfort when I picked him up from his nanny's today.
What can I do to help him?