Sudden diarrhea should be treated according to the cause. It may be caused by improper diet, which should be adjusted; it may be caused by acute gastroenteritis, which should be treated with anti-infective therapy such as levofloxacin; and it may be caused by functional bowel disease, which should be treated with montelukast, tricyclic antidepressant and so on. 1. Improper diet: Eating too much cold, greasy, spicy and stimulating food, stimulating the gastrointestinal tract, can cause sudden diarrhea, you should adjust your diet, eat warm, well-digested food. 2. Acute gastroenteritis: unhygienic diet leads to bacteria and other pathogens into the digestive tract leading to intestinal infections, causing gastrointestinal mucosal congestion, edema, oozing, resulting in sudden diarrhea, should be applied to levofloxacin and other quinolones, ceftriaxone and other cephalosporins antibiotics to fight infection, montelukast to stop the diarrhea, rehydration, to correct the electrolyte-acid-base balance disorders. 3. Functional enteropathy: mental psychological factors such as functional enteropathy, intestinal tract without pathological damage, but there can be diarrhea and other symptoms, should be montelukast to stop diarrhea, probiotics to regulate the intestinal flora, but also the application of tricyclic antidepressant treatment. Sudden diarrhea should be timely to the hospital, under the guidance of the doctor according to the cause of treatment.