Role of duodenogastroesophageal reflux in the pathogenesis of esophageal mucosal injury and gastroesophageal reflux symptoms.

BACKGROUND AND AIM: Patients with gastroesophageal reflux disease (GERD) usually suffer from acid reflux and duodenogastroesophageal reflux (DGER) simultaneously. The question of whether DGER has an important effect on the development of GERD remains controversial. The aim of the present study was to investigate the role of DGER in the pathogenesis of GERD and its value for the diagnosis of nonerosive reflux disease (NERD). METHODS: GERD was initially diagnosed using the reflux disease questionnaire. For further diagnosis, results of the upper gastrointestinal endoscopy (excluding a diagnosis of Barrett's esophagus) were considered in conjunction with simultaneous 24 h esophageal pH and bilirubin monitoring. RESULTS: According to endoscopic findings, 95 patients (43 men, 50+/-10 years of age) were divided into two groups: the reflux esophagitis (RE) group (n=51) and the NERD group (n=44). Three DGER parameters, the percentage of time with absorbance greater than 0.14, the total number of reflux episodes and the number of bile reflux episodes lasting longer than 5 min, were evaluated in the study. For the RE group, the values of the DGER parameters (19.05%+/-23.44%, 30.56+/-34.04 and 5.90+/-6.37, respectively) were significantly higher than those of the NERD group (7.26%+/-11.08%, 15.68+/-20.92 and 2.59+/-3.57, respectively, P<0.05 for all) but no significant difference was found in acid reflux. Of NERD patients, 18.5% were diagnosed with simple DGER. The positive diagnosis rate of NERD could be significantly elevated from 65.9% to 84.1% (P<0.05), if bilirubin monitoring was employed in diagnosis. CONCLUSIONS: DGER may occur independently but plays an important role in the development of RE and GERD symptoms. Simultaneous 24 h esophageal pH and bilirubin monitoring is superior to simple pH monitoring in helping identify patients at risk for NERD.