<s>[INST] Hi. My niece had an appendix surgery last Mon (April 1). The appendix was bad and near rupture when the surgery happened. Two days later she started getting a low grade fever which would sometimes rise to 101 or 102 degrees centigrade. She has been hospitalised again. There was water in the lining of her lungs which has been drained out. Fever persists twice a day. Doctors has some preliminary diagnosis of pneumonia or TB but both have now been ruled out. No conclusive diagnosis yet, any suggestions [/INST] Hi welcome to Chat Doctor forum.  Thanks for choosing Chat Doctor. Forum.  Your niece, got operated for appendicitis, on April 1st, still she is getting low grade fever. There was water in the lining of the lungs. It is called pleural effusion, and suggests tuberculosis infection.  I advise you to consult a chest physician for diagnosis and treatment. You may have to get the fluid in the lining of the lungs tested after pleurocentisis, besides other routine tests for confirmation.  The pain of the right lower abdomen also could be due to tuberculosis of the iliocaecal junction, that is to be operated and biopsy done, for confirmation.  Wishing for a quick recovery.  Best regards. </s>