Heartburn diarrhea is usually caused by improper diet, mental factors or acute gastroenteritis, as follows: First, improper diet, overeating, irregular diet or eating too much food with irritation, too cold, too hot, can stimulate the esophageal mucosa and gastric mucosa, producing symptoms of heartburn, abdominal pain and diarrhea. Second, mental factors, long-term mental tension, anxiety or emotional instability, easy to stimulate the cerebral cortex, affecting the secretion of gastric acid, resulting in gastrointestinal dysfunction. Clinically common are irritable bowel syndrome, with abdominal pain and abnormal bowel movements as the main symptoms. Third, acute gastroenteritis is an acute inflammation of the gastrointestinal mucosa, with sudden abdominal pain and diarrhea as the main symptoms, and if accompanied by bacterial or viral infection, it can also cause an inflammatory reaction and fever, mostly due to unclean diet.