Hi there,

Your son will indicate when he is ready for the potty/ big toilet.

The worst thing to do is to make a big deal out of it as it just makes your child more reluctant to go to the toilet. If he poos just say "It's alright sweetheart, maybe we can try a bit harder next time" and then just leave it and clean him up.

It is also common for children to find it harder to poo on the toilet/potty.

Good Luck