ROLE OF ACID AND DUODENOGASTROESOPHAGEAL REFLUX IN GASTROESOPHAGEAL REFLUX DISEASE

Background & Aims: Acid and pepsin are known to cause esophagitis. How ever, the role of duodenogastroesophageal reflux (DGER) in producing e sophageal mucosal injury across the spectrum of gastroesophageal reflu x disease (GERD) is controversial. Methods: Twenty controls (13 men; m ean 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 measure ments were obtained with Bilitec 2000 using a glass pH electrode and f iberoptic sensor. Results: Percentage times pH was <4, bilirubin level was greater than or equal to 0.14, and fasting gastric bile acid conc entrations showed a graded increase across the GERD spectrum. Esophage al exposure to both acid and DGER was the most prevalent reflux patter n (100% in patients with complicated and 89% in patients with uncompli cated Barrett's esophagus, 79% in patients with esophagitis, and 50% i n patients without esophagitis). The majority (70%-91%) of DGER episod es occurred in an acidic environment (pH < 4). Linear regression analy sis found a significant correlation (r = 0.73; P < 0.01) between perce ntage time pH was <4 and percentage time bilirubin absorbance level wa s 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.