Assessment of Esophagogastric Junction Integrity by High‐Resolution Manometry Identifies Upright and Recumbent Predominant Reflux Phenotypes

Background and Aims Esophagogastric junction (EGJ) integrity influences gastroesophageal reflux disease (GERD) pathophysiology, but its association with positional reflux patterns remains unclear. This study evaluated whether upright and recumbent acid exposure differs based on EGJ status on high‐resolution manometry (HRM). Methods Retrospective study of patients undergoing HRM and 24‐h pH‐impedance monitoring off‐therapy. EGJ was defined disrupted if any of the following HRM features were present: type II/III morphology, basal pressure < 10.4 mmHg, or EGJ‐CI < 9.6 mmHg·cm; intact otherwise. Acid exposure time (AET) and additional reflux metrics were calculated in both positions. Conclusive GERD was defined per Lyon 2.0 (AET > 6%). Results Among 283 patients, 102 (36%) had a disrupted EGJ. These patients showed higher total AET (4.7% vs. 1.9% in the intact EGJ, p < 0.001), primarily driven by recumbent exposure (1.9% vs. 0.2%, p < 0.001). In patients with conclusive GERD ( n = 91), total and upright AET were similar across EGJ subgroups, while recumbent AET was significantly higher in the disrupted EGJ group (11.5% vs. 3.1%, p < 0.001). Pathologic recumbent AET (> 6%) and severe esophagitis (LA C–D) were observed only in patients with disrupted EGJ (72% vs. 0%, p < 0.001; 14% vs. 0%, p = 0.015, respectively). Conclusion EGJ integrity stratifies GERD phenotypes by positional pattern: upright‐predominant in patients with intact EGJ and recumbent‐predominant in those with disrupted EGJ, the latter also associated with severe esophagitis. This suggests distinct pathophysiologic GERD mechanisms depending on EGJ integrity and may guide personalized management.