Routine and biochemical examination of ascites can reflect the lesions inside the patient’s abdominal cavity, for example, after surgery, the patient’s abdominal cavity exudes more, or there are color-like changes, bile or celiac disease, clear color, etc., and routine and biochemical examination of ascites can be checked when there is suspicion of abdominal lesions. Routine tests include white blood cells, red blood cells, pus cells, etc., and biochemical tests may include amylase, celiac disease, etc. If the patient has an anastomotic fistula after surgery, the biochemical examination will reveal a significant increase in amylase, and if there is a lymphatic leak after surgery, the result of celiac disease examination will be significantly higher, which will guide the next step of treatment.