Diarrhea generally refers to diarrhea, drinking black coffee diarrhea may be black coffee stimulation of the stomach and intestines, allergy to black coffee, acute gastroenteritis and other factors. 1. Black coffee stimulates the stomach and intestines: black coffee contains a lot of caffeine, which can accelerate the stimulation of gastrointestinal peristalsis, and even cause gastrointestinal dysfunction, thus leading to diarrhea. 2. Allergy to black coffee: some people are allergic to black coffee, which may stimulate the gastrointestinal tract after drinking black coffee, triggering a perverse reaction, thus leading to diarrhea. 3. Acute gastroenteritis: If the black coffee is placed for too long or the production process is not clean, it may breed bacteria and molds, and these substances enter the body and attack the mucous membrane of the gastrointestinal tract, leading to acute gastroenteritis, abdominal pain, diarrhea and other symptoms. Drinking black coffee diarrhea causes more, such as stop using black coffee diarrhea improves, it is not recommended to drink again, such as stop using black coffee diarrhea does not improve, it is recommended to consult a doctor in a timely manner, under the guidance of a physician for the cause of standardized treatment, so as not to delay the condition.