Objectives: Duodenogastric reflux is a physiological phenomenon in both fasting and postprandial state. Because this suggests that bile acids may reflux into the esophagus together with the acid in patients with reflux esophagitis, we investigated the circadian variations of acid and pepsin secretion and intragastric bile acid concentrations in 25 patients with reflux esophagitis and in 15 healthy controls.
Methods: Between-meal, nocturnal gastric and meal-stimulated acid and pepsin secretion and bile acid concentrations were measured by continuous gastric aspiration and intragastric titration.
Results: Bile acids were found in 85 and 59% of gastric samples (p < 0.05). Intragastric bile acid concentrations were 6-8-fold higher in esophagitis patients than controls during the day. Approximately 10% of gastric samples from reflux esophagitis patients had a pH greater than 7, and all contained more than 500 mumol/L bile acids. Bile acids and pepsin were simultaneously revealed in 98% of the gastric samples from patients with reflux esophagitis with pH less than 4. Mean daily acid output (meal excluded) averaged 3.5 +/- 0.1 in healthy subjects and 2.7 +/- 0.2 mmol/30 minutes in esophagitis patients (p < 0.05); meal-induced acid secretions were similar. Total (24-h) acid secretion averaged 192.3 +/- 12.4 and 162.4 +/- 10.5 mmol/24 h (p < 0.05). There were no differences in the daily pepsin output.
Conclusions: Our data indicate that almost all "acid" gastroesophageal refluxes should be considered as "mixed" refluxes. Because bile acids are found in the stomach irrespective of whether the environment was acid or alkaline, pH-metry provides no useful information on the pattern of duodenogastric reflux into the esophagus. Variability in the composition of the gastro-esophageal refluxate may explain why the severity of esophageal lesions differs in patients with similar pattern of acid refluxes.