Poo and lies....

Paige has continued to tell me when she has a poo diaper. Sometimes she even tells me when she has to go. She'll say "poo" and there is nothing, but then 5 minutes later, there it is! I'm thinking this is a good thing for toilet training. However, sometimes she likes to lie. I say, "Do you have poo?", and she says "no?". I ask her again and she says "no?", when I know that she clearly does have poo. She just wants to get out of having her diaper changed which she can't stand.