Diarrhea is a change in the nature, color and frequency of stools due to intestinal dysfunction. The treatment principle of diarrhea is firstly to actively correct dehydration and maintain electrolyte and acid-base balance; secondly to treat the cause symptomatically; finally to use drugs to regulate intestinal flora or reduce intestinal fluid secretion, and to use antidiarrheal drugs and painkillers with caution. Oral rehydration salts are more suitable for patients with acute diarrhea because they can replenish sodium, potassium and body fluids and regulate the water-electrolyte balance, but they need to be taken orally. Because the main pathogens of infectious diarrhea are bacteria and viruses, bacteria are mainly enterobacteria, which can be treated with three generations of cephalosporins and quinolones, such as ceftazidime, ceftriaxone, cefoperazone sulbactam and levofloxacin; if the diarrhea is caused by viruses, it is mostly self-limiting and does not need to be treated against the pathogens. Drugs to regulate intestinal flora can be used such as bifidobacterium capsules and Lactobacillus LB; berberine has certain anti-infective effects and can also reduce intestinal fluid secretion. In the case of a clear diagnosis of the cause of diarrhea, antidiarrheal drugs, such as montelukast, can be used as appropriate. In summary, the treatment of diarrhea is mainly active rehydration and supportive treatment, followed by symptomatic medication according to the etiology.