Has diarrhea for many days is usually a symptom of diarrhea, mostly considered to be due to gastrointestinal diseases, such as acute gastroenteritis, indigestion,, intestinal flora imbalance. 1. Acute gastroenteritis: when the diet or drinking water is not clean, it may lead to pathogen infection of the gastrointestinal mucosa, so that the gastrointestinal mucosa appeared to be congested, edema and other injuries, affecting the digestion and absorption of food, resulting in diarrhea for several days. 2. Dyspepsia: patients are usually accompanied by damage to digestion, absorption and peristalsis, and gastrointestinal dysfunction, which can also cause patients to have diarrhea all the time. 3. Intestinal flora imbalance: the normal intestinal homeostasis of the patient is disrupted, which also affects the normal digestion and absorption of food, leading to diarrhea for several days. In addition, overeating, irregular diet, eating too much cold, spicy and other stimulating foods or abdominal cold and other bad eating habits, can also lead to diarrhea. When the patient has diarrhea for many days, it is recommended to seek timely medical treatment to identify the cause of the disease and carry out targeted treatment to avoid delaying the condition.