Do gastroenteroscopy a week later or black stool may be physiological reasons, may also be digestive bleeding, etc., if it is often eat duck blood within a week and other physiological causes, without special treatment. If gastritis, gastric ulcer and other causes of gastrointestinal bleeding, you can use aluminum thioglycollate, omeprazole, etc. to protect the mucous membrane, to reduce the gastric acid on the gastrointestinal mucous membrane stimulation. Doing gastroenteroscopy damages the mucous membrane of the gastrointestinal tract and causes bleeding, which may result in black stools, and this will usually be relieved in about three days, while there will be no other symptoms. If you have had a gastroenteroscopy and have eaten foods such as duck blood and pig blood regularly in the last week, this can also lead to dark stools. After avoiding these foods, the symptoms will usually subside. This is a normal physiological phenomenon and does not require special treatment. A week after gastroenteroscopy or black stools may also be caused by gastritis, gastric ulcer and other gastrointestinal bleeding, which may be accompanied by abdominal distension, abdominal pain and other symptoms. You can take aluminum sulfate, magnesium aluminum carbonate, etc., to protect the gastrointestinal mucosa, promote mucosal repair and reduce bleeding. You can also take omeprazole, pantoprazole, etc. to inhibit gastric acid secretion and reduce the stimulation of gastric mucosa by gastric acid. The appearance of the phenomenon, excluding eating and other physiological reasons, may also be caused by other diseases, should be timely consultation, under the guidance of the doctor to identify the causes, and reasonable treatment. After gastroenteroscopy to avoid alcohol, hot pot and other stimulating food, pay attention to diet light.