DefinitionPeritoneal fluid analysis is a laboratory test to examine fluid that has collected in in the area of the abdomen that contains the gastrointestinal organs. This area is called the peritoneal space.How the test is performedThe sample of fluid is removed from the periotoneal space using a needle and syringe.The health care provider will clean and numb a small area of your belly area (abdomen). Next, the doctor inserts a needle through the skin of your abdomen, and into the peritoneal space, and withdraws a sample of fluid. The fluid collects into a tube (syringe) attached to the end of the needle.See: Abdominal tapThe fluid is sent to a laboratory where it is examined. Tests will be done on the fluid to measure red and white blood cell counts, protein, and albumin, and to check for