I need help.. I just opened my BP's tank, and I saw she went to the bathroom, so I picked her up, and looked on her underside to see if she was dirty.. she wasn't, but I saw that a section of her belly scales were swelled up with some sort of clear liquid.

As I said, she went to the bathroom.. she ate on saturday, so I hadn't looked at her up close between then and now. She shed a few days before she ate..

I've had her in that setup for a few months now, so I don't think it was the under tank heater burning her.. so I have no idea what it is. What should I do?