The components of refluxed gastric juice are known to cause mucosal injury but their effect on esophageal function is less appreciated. Our aim was to determine the impact of acid and/or bile on mucosal injury and esophageal function.

Methods:
From 1994 to 2004, 402 patients with GERD symptoms and no previous foregut surgery had manometry, 24-hour pH and Bilitec^® monitoring, and endoscopy with biopsies.

Results:
Of the 402 patients, 127 (32%) had normal esophageal exposure to acid and bile. Of the remaining 275 patients, 36 (13%) had increased exposure to bile alone, 84 (31%) to acid alone and 155 (56%) to a mixture of both. Degree of mucosal injury and measurements of esophageal function are shown.

LES measurements in the bile and no reflux groups were similar. LES abdominal length was shorter and resting pressure lower in the acid compared to the no reflux and bile groups (p<0.05). The mixed group had the shortest total and abdominal lengths and lowest resting pressure (p<0.05). Contraction amplitudes were lower in the acid and mixed groups (p<0.05). In patients with mixed reflux, the odds ratio was 7.3 for esophagitis and 19 for Barrett’s mucosa.

Conclusions:
More than half of GERD patients have mixed acid and bile reflux. This is associated with the most severe mucosal injury and the greatest deterioration of esophageal function. This suggests that composition of gastric juice is the primary determinant of the loss of esophageal function by inflammatory mucosal injury, and encourages early surgical therapy for this type of reflux.