Drinking black tea diarrhea may be related to gastrointestinal dysfunction, black tea temperature is too low, intestinal intolerance and other reasons. 1. Gastrointestinal dysfunction: the gastrointestinal tract is highly sensitive, after drinking black tea, can stimulate the gastrointestinal tract leading to diarrhea. 2. Black tea temperature is too low: if you drink black tea temperature is too low, can lead to gastrointestinal smooth muscle spasm, diarrhea phenomenon. 3. Intestinal intolerance: If the human body is intolerant to substances such as ellagic acid and theophylline inside the tea, it can cause abdominal pain, diarrhea and other manifestations. It is recommended to drink black tea diarrhea to the hospital, clear causes, if you need treatment, should be standardized treatment under the guidance of a doctor, so as not to delay the condition.