Rather the pressure of the LES is the primary determinant of whether reflux occurs or not. Furthermore, it is clear that LES pressure varies remarkably throughout the day and in all of us there are periods of relaxation in which LES pressure approaches or reaches zero. During these latter periods, reflux occurs - even in normal and asymptomatic persons. Alternatively, scintiscanning using isotopic material instilled into the stomach in association with abdominal pressure may be used to demonstrate reflux. Finally, if available in your area, ambulatory or stationary 24-hour pH monitoring can be done with an intraesophageal pH electrode and recorder.
High correlation suggests causality but the system is imperfect.
If one wishes to assess the degree of esophagitis, stricture formation, or the presence of metaplastic epithelium, fiberoptic endoscopy and mucosal biopsy can be performed by consultants trained in this technique. Alternatively, barium study with air contrast, although somewhat less sensitive, is usually reliable in diagnosing erosive esophagitis, ulceration or stricture. It has been suggested that GERD is a problem which is symptomatic by day but in which much damage is done by night. In many patients, GERD is a chronic, relapsing disease. Long term maintenance is the key to therapy.