What's the matter with black in yellow stool?

Black in yellow stool may be related to dietary factors, drug factors, upper gastrointestinal bleeding and other reasons. 1. Dietary factors patients due to eating a large number of animal blood, iron-rich green leafy vegetables and other foods, may appear yellow stool doped black phenomenon. 2. Drug factors patients due to iron deficiency anemia correction when taking iron, protection of gastric mucosa when taking bismuth, may appear yellow stool doped black phenomenon. 3. Upper gastrointestinal bleeding patients due to esophageal injury, esophagitis, peptic ulcer, gallstones and other diseases, caused by upper gastrointestinal bleeding may appear yellow stool doped black phenomenon.