Don't know if it will help you. But, I'm right there with you. I have 2 yr old twins & my girl won't poo-poo in the potty. She will tell me & ask for a pull-up, but is scared to go poo-poo, because she is mostly constipated & it hurts. Well, last night we had a breakthrough!!! So, maybe it will help you: We went to Wal-Mart Saturday & let the kids ride tricycles in the store & act like we were going to buy them, them we changed our minds & told them we will later. After we got in the car we started talking about going poo-poo in the potty. Well, all day we said we were going to buy the trike for our boy, but not the girl, until she goes poo-poo in the potty. Well, it took about an hour of sitting with her & reading & talking & her not happy about it, but she did poop in the potty last night & it was the big potty & she finally heard it go "plop, plop, plop". She then got up and asked to go buy the trike!!! I told her tomorrow.
So, maybe some kind of big prize would entice your sweetheart.
I hope mine will continue this.