Generally the fluids inputted by postoperative patients include anti-infective drugs, hemostatic drugs, volume expanding drugs, and drugs to reduce gastrointestinal reactions. 1. Anti-infective drugs: mainly used to prevent postoperative infection, as well as because of postoperative infection caused by inflammation and swelling of the incision and other problems. In addition to this, many surgeries are themselves contaminated surgeries, which also require the use of anti-infective drugs. Commonly used include cephalosporins, penicillins and antibiotic drugs of the salacin type. 2. Hemostatic drugs: after surgery, there may still be bleeding in the operative area, a variety of postoperative surgery can be added in the infusion of hemostatic drugs, such as aminocaproic acid, aminomethylenic acid, tranexamic acid and so on. 3. Volume-expanding drugs: mainly for patients who are not allowed to eat or drink before surgery, and need to replenish the body fluids lost during the surgery, mainly crystalloid and colloid fluids, and intravenous nutritional therapy is also needed for patients who are not allowed to eat. 4. Reduce gastrointestinal reaction drugs: mainly to reduce the gastrointestinal discomfort caused by surgical stress, can use famotidine (dissolved in saline) and so on. Specific medication should follow the doctor’s instructions.