Objective: To determine whether two dissimilar groups characterized by 24-h esophageal pH monitoring would have individual reflux events that occur under the same or different circumstances when challenged by a meal and monitored in different postures. These groups consisted of upright refluxers without esophagitis (n = 10) versus biopositional refluxers with esophagitis (n = 8).
Methods: Our evaluation consisted of a questionnaire completed prior to simultaneous manometry and pH monitoring. This monitoring was conducted over a 120-min period that incorporated the upright and recumbent postures both before and after a meal. Three of our four criteria for reflux were independent of a classic pH event.
Results: From the questionnaire, it was apparent that dyspeptic symptoms almost always occurred in the upright refluxers. In addition, provocation for their heartburn had atypical characteristics regarding posture, and their degree of regurgitation was intensified by the postprandial state. During dual monitoring, the upright posture and the meal provoked an increase in frequency of reflux in the upright refluxers, as opposed to only recumbency in the bipositional refluxers. Moreover, reflux events in the upright refluxers usually were associated with Valsalva maneuvers and were recognized as symptoms, two features that were less true in the bipositional refluxers. A similar percentage of reflux events occurred over a low basal lower esophageal sphincter pressure and after a lower esophageal sphincter relaxation, in both groups.
Conclusion: The two groups manifested distinctively different reflux characteristics, presumably due to dissimilar mechanisms.