The causes of diarrhea due to mood swings are considered to be caused by conditions such as vegetative nerve disorders, irritable bowel syndrome, and gastrointestinal dysfunction. 1. Vegetative nerve disorders: mood swings may cause vegetative nerve disorders, resulting in abdominal distension, abdominal pain, diarrhea and other gastrointestinal neurological symptoms. 2. Irritable bowel syndrome (IBS): mood swings or frequent anxiety, depression and other psychological emotions may trigger IBS, resulting in diarrhea, accompanied by abdominal pain or constipation and other symptoms. 3. Gastrointestinal dysfunction: mood swings or anxiety, depression and other negative psychological state may cause gastrointestinal dysfunction, resulting in increased intestinal peristalsis and then cause diarrhea symptoms. It is recommended to go to the hospital to consult a doctor to determine the cause of diarrhea after mood swings.