Stage A1 bulbar ulcer is an active peptic ulcer in the bulb of the duodenum that requires prompt management such as dietary modifications and medications such as omeprazole. Based on the results of gastroscopy, duodenal ulcers can generally be categorized into stage A (active stage), stage H (healing stage) and stage S (scarring stage). Stage A1 is the period when the ulcer activity is more obvious. Gastroscopy shows that there is a deep and large sunken ulcer in the duodenal bulb, with yellow moss at the bottom of the ulcer, which may be accompanied by congestion and swelling of the surrounding mucosa. If the diagnosis of stage A1 duodenal bulb ulcer is confirmed, timely medical treatment should be sought. Dietary adjustments such as light diet; application of omeprazole, famotidine and other medications, etc. for treatment. It is recommended to consult a doctor in time and choose an appropriate treatment plan under the guidance of the doctor according to your condition. The use of specific drugs should be under the guidance of a doctor.