In case of acute onset, it is usually caused by acute inflammation of the gastrointestinal tract, such as eating raw, cold, unclean food and some spoiled or expired food, which may contain some toxins that stimulate the gastrointestinal tract and cause inflammatory manifestations of the gastrointestinal tract. If chronic onset occurs frequently, it may be caused by chronic enteritis or gastrointestinal tract dysfunction, or it may be caused by intestinal polyps or intestinal tumors. If there is chronic diarrhea, it is recommended to do a fiberoptic colonoscopy to see clearly the lesions inside the intestine and do the corresponding treatment.