Diarrhea mainly refers to an increase in the number of bowel movements, increased fecal content and thin feces. The mechanisms of diarrhea include four main categories, but clinically diarrhea is not caused by a single mechanism, but occurs by a combination of mechanisms. Osmotic diarrhea, which is mainly due to the presence of large amounts of hyperosmotic food or drugs in the intestinal cavity, with a large amount of body fluid water entering the luminal surface of the intestine in a hyperosmotic state, characterized by the cessation or significant reduction of diarrhea after 48 hours of feeding. Secretory diarrhea, mainly due to irritation of the intestinal mucosa, resulting in excessive secretion of water and electrolytes or inhibition of absorption, is characterized by daily stools, relatively large in volume, with a watery pus and blood pattern. Exudative diarrhea, also known as inflammatory diarrhea, is mainly due to the destruction of the integrity of the intestinal mucosa by inflammation, ulcers and other lesions, resulting in massive exudation, which is characterized by stools containing exuded live blood, often mixing stools with blood. Abnormal power diarrhea, mainly due to excessive intestinal peristalsis, so that the rapid passage of intestinal lumen contents through the intestinal lumen and the contact time with intestinal mucosa is too short, which affects digestion and absorption, and the absorption of water and electrolytes is weakened and diarrhea occurs.