CIRCADIAN VARIATIONS IN GASTRIC-ACID AND PEPSIN-SECRETION AND INTRAGASTRIC BILE-ACID IN PATIENTS WITH REFLUX ESOPHAGITIS AND IN HEALTHY CONTROLS

Objectives: Duodenogastric reflux is a physiological phenomenon in bot h fasting and postprandial state. Because this suggests that bile acid s may reflux into the esophagus together with the acid in patients wit h 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 se cretion and bile acid concentrations were measured by continuous gastr ic aspiration and intragastric titration. Results: Bile acids were fou nd in 85 and 59% of gastric samples (p < 0.05). Intragastric bile acid concentrations were 6-8-fold higher in esophagitis patients than cont rols during the day. Approximately 10% of gastric samples from reflux esophagitis patients had a pH greater than 7, and all contained more t han 500 mu mol/L bile acids. Bile acids and pepsin were simultaneously revealed in 98% of the gastric samples from patients with reflux esop hagitis,vith pH less than 4. Mean daily acid output (meal excluded) av eraged 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 dail y pepsin output. Conclusions: Our data indicate that almost all ''acid '' gastroesophageal refluxes should be considered as ''mixed'' refluxe s. Because bile acids are found in the stomach irrespective of whether the environment was acid or alkaline, pa-metry provides no useful inf ormation on the pattern of duodenogastric reflux into the esophagus. V ariability in the composition of the gastroesophageal refluxate may ex plain why the severity of esophageal lesions differs in patients with similar pattern of acid refluxes.