There are several cases of farts that do not come out: First, under normal circumstances, it may be constipation caused by anal exhaustion is not smooth, you can use the open plug to defecate. Second, after surgery, the anal exhaust is not open, within twenty-four hours after surgery, the role of anesthesia continues to exist, the intestinal function has not fully recovered, so there will be the situation of exhaust is not open. You can get out of bed as early as possible or eat a small amount of liquid diet, which can promote the recovery of intestinal function and help the anal exhaust, so the anal exhaust is also a very important criterion for post-operative recovery.