Diarrhea, commonly known as “diarrhea”, is a common clinical symptom in the Department of Spleen and Gastrointestinal Diseases. In the eyes of many people, diarrhea is as common as a cold and fever, and is a minor problem. According to the World Health Organization, the number of people suffering from diarrhea amounts to 1.4 billion per year worldwide, so diarrhea is not a minor problem. Knowing the general knowledge of diarrhea is crucial for us to better prevent and treat it. When it comes to diarrhea, many people think that it may be caused by eating unclean food or by cold weather, and that it may be okay to drink some ginger water or take some antibiotics. Indeed, the above two conditions are the most common causes of diarrhea, but bacterial infections and viral infections can trigger diarrhea; in addition, if diarrhea symptoms exceed 2 months, it is called chronic diarrhea. Infections of the intestinal tract, non-infectious diseases, small intestine malabsorption, tumors, or functional diseases can trigger chronic diarrhea. Diarrhea is not just diarrhea, but has a complex etiology and a complicated pathogenesis, which still needs to be taken seriously. Simple cases can be diagnosed by routine stool and blood tests, while complex cases require stool culture, colonoscopy, capsule endoscopy, barium enema, etc. Only when the cause is clear can effective treatment measures be taken. Diarrhea is equivalent to what is called “diarrhea” in Chinese medicine. The treatment of diarrhea (cathartic diarrhea) cannot simply stop the diarrhea. If the diarrhea is caused by the deficiency of spleen and kidney yang and the sinking of middle qi, the abdomen is often cold, the stool is loose, and undigested food is present. If the diarrhea is caused by damp-heat congestion or dietary stagnation, the use of astringent antidiarrheal drugs will close the door and aggravate the condition. We have to treat the root of the problem, clear heat and dampness for damp-heat congestion, and eliminate food and stagnation for dietary stagnation, so that the diarrhea will stop if the evil is removed. Diarrhea caused by liver qi multiplying the spleen is often seen in female patients and is triggered by depression, anger or emotional stress. Chinese medicine is concerned with “treating the disease before it happens”. To prevent diarrhea, we must first develop good personal hygiene habits and not eat unclean and rotten food. Eat less cold, spicy, greasy and other irritating food, and be wary of disease from the mouth. Secondly, reduce contact with patients with diarrhea to prevent cross-infection. The most important thing is to maintain a relaxed mood, increase physical exercise, enhance physical fitness and improve immunity.