The causes of diarrhea are numerous and can be summarized into the following categories: 1. Infectious diarrhea: It is the most common clinical diarrhea, including diarrhea caused by viruses, bacteria, fungi and other microorganisms. The most common is bacterial diarrhea, which is often caused by eating something unhygienic. 2, stress diarrhea: this condition is mostly seen in relatively large surgery, more serious burns, etc., resulting in stress intestinal inflammation and diarrhea symptoms. 3, allergic: because the body is more sensitive to certain foods, drugs, etc., and lead to diarrhea.