<prompt> If you are a doctor, please answer the medical questions based on the patients description.I had an ultra sound done today because of pressure pain in my lower right abdomen that I have had for about 4 weeks. I do not have a fever or blood anywhere. My ultra sound was inconclusive, but found extra fluid in my abdomen. My doctor was thinking I will need a CAT scan. Any idea what could be causing the pain?  <response>: Hi. Thanks for your query. You have a pressure in the lower right abdomen for 4 weeks for which ultrasonography was done. Found extra fluid in the abdomen and Doctor feels for a need of a Ct scan. The probable causes of pain in right lower abdomen and fluid inside are:-Appendicitis -Enteric Fever meaning Typhoid.-Some inflammatory process that the ultrasonography can not pick up such as Tuberculosis or so. I would advise you the following in such a case:-Investigations of the blood, urine and stool.-Tests for TB, Typhoid and such specific diseases.-CT scan of the abdomen as advised by your Doctor.-Paracentesis, meaning get the fluid from the abdominal cavity for analysis.-Diagnostic Laparoscopy. All these investigations will give you a diagnosis and a plan for the treatment. 