I am sorry about the pain your sister is having. Her medical problem could be multiple different things. I would recommend she go to her family md and ask what Dr. he or she would recommend for the continued issues she is having. She could need a gastrointestinal dr, renal dr, there are so many things it could be, her best bet is to do more tests to find out exactly what is the problem causing her such pain. Also another issue could be appendix, if she still has them. I wish you all the luck in the world in finding help for her. Also, if her md. doesn't want to continue testing or recommend specialists, then she should get a second opinion. Take care!