I'm guessing that you are wondering if you should be billed because you believe that the dr should have removed the ovary in the first surgery? Just not sure I know what your thinking is. If it is because you feel he should have removed it in the first surgery then there is no way anyone could answer that without the op notes. However, based solely on what you are describing below it sounds as if he believed that the ovary was ok or he wouldn't have left it in during the first surgery. Not all physicians are the best of citizens but most are truly looking out for the well being of their patient. There are not many drs that would purposely leave the ovary knowing that they would have to go back in to remove it sometime later, hoping to collect on two surgeries. They had to do another CT scan because it could have been a completely different reason for the problem the next day.
Sorry for what you had to go thru, but that's JMO.