Diarrhea the day after drinking alcohol is associated with chronic enteritis, irritable bowel syndrome, chronic pancreatitis and other factors. When chronic enteritis disease exists in the digestive system, alcohol should be avoided as much as possible, otherwise it can trigger an inflammatory bowel attack due to the irritating nature of alcohol. During an attack of chronic enteritis because of the presence of inflammation on the mucosa, it can lead to peristaltic resistance of the intestines and faster excretion of the contents of the intestines, so diarrhea symptoms can occur. Irritable bowel syndrome can be triggered by improper diet and bad mood, while alcohol consumption not only stimulates the intestines, but also leads to plant nerve dysfunction, thus triggering an attack of the disease. Some patients with irritable bowel syndrome are characterized by damaged bowel function and hyperactive bowel movements, so they may suffer from diarrhea. Some people have chronic pancreatitis, and these people may experience edema of the duodenal papilla after drinking alcohol, which can affect the discharge of pancreatic fluid. The digestion of fatty foods will be affected due to the lack of pancreatic fluid in the food, and diarrhea will then occur.