Case Study of a Refractory Idiopathic Peptic Ulcer in Which 24-h Intragastric pH Monitoring Contributed to Its Pathophysiological Analysis.

Introduction: In recent years, the frequency of idiopathic peptic ulcers (IPUs) has increased. However, the clinicopathological characteristics of IPU have not been fully elucidated and treatment methods for recurrent and refractory cases have not yet been established.

Case presentation: A man in his forties complained of epigastric discomfort. Esophagogastroduodenoscopy revealed a gastric ulcer in the lesser curvature of the gastric angle. After Helicobacter pylori was eradicated, the gastric ulcer recurred despite the administration of a potassium competitive acid blocker (PCAB), and a diagnosis of IPU was made. Twenty-four-hour intragastric pH monitoring revealed insufficient gastric acid suppression. Misoprostol was added to the patient's treatment. Subsequently, the ulcer healed and recurrence was not observed.

Conclusion: For refractory IPU, the evaluation of pathophysiological function through 24-h gastric pH monitoring may lead to the selection of an appropriate treatment. If a proton pump inhibitor and PCAB do not improve the IPU, combination treatment with misoprostol may be considered as an option.