gastroduodenoscopy

例句：

1. 1. He underwent a gastroduodenoscopy to investigate the cause of his persistent stomach pain.
   他接受了一次胃镜检查，以查明持续的胃痛原因。
2. 2. The procedure is often used to diagnose and treat gastric and duodenal ulcers.
   该程序常用于诊断和治疗胃和十二指肠溃疡。
3. 3. During the examination, the doctor inserted a flexible tube into the patient's esophagus and then guided it throughthe mouth to the stomach.
   在检查过程中，医生将一根柔软的管子插入患者的食管，然后引导它通过口腔到达胃部。