Duodenal bulbous erosions generally do not require pathologic tissue biopsy. Duodenal bulbous erosions refer to mucosal injury only up to the level of the lamina propria of the mucosa, whereas ulcers refer to mucosal injury that has reached the submucosal layer, which is more severe than erosions, and in some cases can reach the muscularis propria. There is no data to suggest that duodenal bulbous erosions or ulcers can become cancerous, and the purpose of biopsy is to determine whether there are pathological changes in the mucosa of the lesion, such as heterogeneous hyperplasia, precancerous lesions, or cancerous lesions. Thus duodenal bulbous erosions generally do not require pathologic tissue biopsy. In addition, the intestinal wall of the duodenal bulb is very thin and biopsy carries the risk of causing perforation. In conclusion, biopsy is not recommended for patients with duodenal bulbous erosion, and reasonable diagnosis and treatment under the guidance of clinicians is recommended to avoid progression of the disease.