The cause of bleeding diarrhea depends on the way, amount and color of bleeding, the specific causes are as follows: First, if yellow stool with a small amount of fresh blood or dripping blood, consider hemorrhoids or anal fissures caused by. Second, if the diarrhea with mucus-purulent blood stool, the amount of small times more, accompanied by urgent after heavy, consider ulcerative colitis or acute bacterial dysentery. Third, if the first yellow stool, followed by complete blood stool, bright red or dark red, mostly considered acute gastroenteritis mucosal erosion bleeding caused by gastrointestinal bleeding. Fourth, if the whole bloody stool is red or dark red, it suggests a large amount of gastrointestinal bleeding, which is common in acute erosive hemorrhagic gastritis, gastric ulcer, duodenal ulcer, gastric cancer, or esophagus-fundus varices and their ruptured bleeding, when the condition is serious. When diarrhea with bloody stools occurs, it is necessary to go to the hospital for systematic examination in time to clarify the cause of bleeding, the amount of bleeding and the site of bleeding, and give comprehensive treatment such as stopping bleeding and protecting the gastric mucosa.