BACKGROUNDGastroesophageal reflux disease is a prevalent condition with significant clinical variability, complicating its evaluation and treatment. The gastroesophageal flap valve is a fundamental evaluation method, but have shown limitations in specificity and reliance on subjective endoscopists' experience. Recent insights suggest that gastroesophageal junction laxity may offer an objective and quantifiable measurement for the presence of gastroesophageal reflux disease.METHODSThis retrospective study analyzed data from 401 patients who underwent comprehensive evaluations, including a symptom questionnaire, endoscopy, pH-impedance monitoring, high-resolution manometry, and treatment directions, between January 1, 2022 and October 31, 2023. Gastroesophageal junction laxity was assessed using a modified approach based on endoscopic image analysis, with the diameter of endoscope as reference to estimate the long diameter of the laxity ring. The independent association of gastroesophageal junction laxity with pathologic acid exposure, esophagitis, and hiatal hernia were assessed by adjusting with age and sex.RESULTSThe mean age was 44.5 ± 5.5 years old, and 49.9% (200/401) were male. The most common symptoms (≥ 1 point) were acid regurgitation (333/401, 83.0%), heartburn (315/401, 78.6%), belching (278/401, 69.3%), bloating (241/401, 60.1%), and globus sensation (241/401, 60.1%). The gastroesophageal junction laxity was significantly associated with pathologic acid exposure, esophagitis, hiatal hernia, and lower esophageal sphincter resting pressure. Notably, with the increase in gastroesophageal junction laxity, the rates of pathologic acid exposure, esophagitis, and hiatal hernia increased gradually, the lower esophageal sphincter resting pressure decreased gradually. The gastroesophageal junction laxity was independent associated with pathologic acid exposure (OR = 2.33, 95%CI 1.77-3.07, p < 0.001), esophagitis (OR = 2.10, 95%CI 1.62-2.73, p < 0.001), and hiatal hernia (high-resolution manometry: OR = 3.39, 95%CI: 2.46-4.67, p < 0.001) (endoscopy: OR = 21.65, 95%CI 11.70-40.06, p < 0.001).CONCLUSIONThe gastroesophageal junction laxity was significantly associated with the indicators of pathophysiology in gastroesophageal reflux disease.