Three year old poo in pants, not aware/doesn't care

[SEsofty]

DS,three, has been potty training for about six months. He is completely consistent with wee, and was with poo.

However, about six months ago he started poo in pants. And now it's multiple times a day.

He doesn't say that he has pooed or even seem aware of it. It's only when I take to toilet as reminder or smell it.

Have tried lots of positive reinforcement, big appalasue when he gets it right. Incentive of chocolate/TV for a clean day. But nothing is working.

Nursery, who are all experienced professionals, have no idea what to do either.

Any help gratefully received.

Any one

This might be tmi, but what is the consistency of the poo? If he's constipated then there could be loose leakage that he can't control. If there is food in it then it could be toddler's diarrhoea. TD can cause a lack of control because of how the body fails to properly digest certain foods, sugar, certain fruits, squash.