Drinking coffee diarrhea may be drinking too much, fasting coffee, coffee spoilage or itself suffering from gastrointestinal diseases, as follows: 1, too much coffee, coffee is stimulating, can stimulate gastric acid secretion, moderate drinking coffee can help gastrointestinal peristalsis, promote digestion and absorption, but excessive drinking will lead to diarrhea. 2, fasting coffee, coffee on the gastric mucosa is irritating, can damage the gastric mucosa, especially in the morning on an empty stomach. Especially in the morning to drink on an empty stomach, especially prone to stomach injury. The long term fasting coffee, may lead to gastritis, gastric ulcer, duodenal ulcer and other digestive diseases. 3, drinking spoiled coffee, expired or spoiled coffee has a large number of bacteria and mold, drinking will stimulate the gastrointestinal mucosa, causing inflammatory reactions. 4, suffering from gastrointestinal digestive diseases, patients with gastrointestinal digestive diseases, the spleen and stomach digestive function is reduced, drinking coffee is more likely to stimulate the gastric mucosa leading to disease seizures.