Role of acid and duodenogastroesophageal reflux in gastroesophageal reflux disease

Background & Aims: Acid and pepsin are known to cause esophagitis. However, the role of duodenogastroesophageal reflux (DGER) in producing esophageal mucosal injury across the spectrum of gastroesophageal reflux disease (GERD) is controversial. Methods: Twenty controls (13 men; mean age, 41 years), 30 patients with GERD (15 men; mean age, 41 years), and 20 patients with Barrett's esophagus (17 men; mean age, 58 years) were studied. Twenty-four-hour ambulatory acid and bilirubin measurements were obtained with Bilitec 2000 using a glass pH electrode and fiberoptic sensor. Results: Percentage times pH was <4, bilirubin level was greater than or equal to 0.14, and fasting gastric bile acid concentrations showed a graded increase across the GERD spectrum. Esophageal exposure to both acid and DGER was the most prevalent reflux pattern (100% in patients with complicated and 89% in patients with uncomplicated Barrett's esophagus, 79% in patients with esophagitis, and 50% in patients without esophagitis). The majority (70%-91%) of DGER episodes occurred in an acidic environment (pH < 4). Linear regression analysis found a significant correlation (r = 0.73; P < 0.01) between percentage time pH was <4 and percentage time bilirubin absorbance level was greater than or equal to 0.14. Conclusions: Both acid and DGER show a graded increase in severity across the GERD spectrum. Acid and DGER occur simultaneously in the majority of the reflux episodes.