Duodenal bulb gastric mucosal ectasia exists a certain harm, may cause mucosal ulcer, gastrointestinal bleeding, intestinal obstruction and so on. 1. Mucosal ulcer: Duodenal bulb gastric mucosal ectasia is a disease in which the mucosal surface of the intestinal tract is completely covered by the mucosa of the gastric fundus, which will stimulate the secretion of gastric acid to increase and cause mucosal damage, resulting in mucosal ulcers, and the patient will experience different degrees of pain or acid reflux. 2. Gastrointestinal bleeding: due to the ectopic gastric mucosa of the duodenal bulb will cause an increase in gastric acid secretion, so in the long-term stimulation of gastric acid will cause mucosal damage, thus triggering local intestinal mucosal bleeding. If the bleeding is serious, endoscopic hemostasis or surgical treatment can be performed. 3. Intestinal obstruction: if the symptoms of gastric mucosal ectasia in the duodenal bulb are serious, it will repeatedly stimulate the secretion of gastric acid and cause tissue damage, which may lead to local polyp hyperplasia or dyspepsia, thus leading to intestinal obstruction. Since the chance of malignant transformation of gastric mucosal ectasia in the duodenal bulb is not high, but the digestive complications are more frequent, it is recommended to treat it as early as possible and have regular digestive system checkups.