The causes of duodenal bleeding in patients include the following: 1. Helicobacter pylori infects the intestine, resulting in damage to the duodenal mucosa, which causes bleeding. H. pylori is a parasitic bacterium in the intestinal tract, which can enter the intestine through oral infection, thus destroying the gastrointestinal mucosa and causing lesions. 2, excessive secretion of gastric acid caused by a variety of reasons, so that the duodenum is attacked, thus destroying the intestinal mucosa and causing bleeding, usually uncontrolled diet and a lot of alcohol, etc., can cause the phenomenon of excessive secretion of gastric acid. 3, poor diet and indigestion For reasons such as poor diet and poor digestion, resulting in gastrointestinal dysfunction, and a large amount of food residues can not be completely decomposed, will cause damage to the duodenal mucosa, thus causing ulcerative bleeding phenomenon.