Evacuation denial

Aimee currently has a rather embarassing problem. Let me see, how can I put this delicately without putting people off their dinner...well, Aimee seems to be 'scared' to poo. We thought at first, her rather sparse nappy output was down to constipation. And maybe it was in the beginning. A changre of diet to copious fruit, veggie and 'good' carbs and her gut must be in overdrive. And yet, when the mood to go takes over her, she will stand there and fight it with every ounce of energy. It is a strange sight. Aimee curves her entire body to one side, clenches her backside and forcibly resists any natural instinct to empty her bowels. When we check her nappy, there is only a tiny hint of what should actually come out. It is concerning us, we'll monitor it and consult a doctor if it continues.
On a plus note, we bought Aimee a potty and she loves it. But not to poo in. She carries it around like the seasons must-have accessory handbag!