A diagnosis of gastroesophageal reflux disease (GERD) may be established by using various modalities, including upper gastrointestinal endoscopy, esophageal pH monitoring, radiologic studies and acid infusion tests. However, no one method is 100 percent accurate in confirming the diagnosis, and each has limitations that decrease the probability of an accurate overall diagnosis. Endoscopy alone lacks sensitivity, and pH monitoring is not always available. The classic symptoms of GERD are heartburn and acid regurgitation, both of which are relieved with a two- to four-week course of therapy with omeprazole. Schenk and colleagues studied whether treatment with omeprazole also could be used as an easy, noninvasive, safe and reliable test for diagnosing GERD.

Patients eligible for the study had a history of signs and symptoms of GERD, including heartburn, acid regurgitation and dysphagia. A total of 98 patients were evaluated on the basis of results of an upper gastrointestinal endoscopy. If results of endoscopy appeared normal or showed only mild abnormalities, the patient was enrolled in the study. Patients then underwent 24-hour esophageal pH monitoring in which a pH level below 4 was considered abnormal. In addition, patients completed a survey that asked them to rate their GERD symptoms during the previous week. Patients were then randomized into one of two groups—a treatment group that received 40 mg of omeprazole or a placebo group. Each group completed another survey after weeks one and two of the study.

The effectiveness of treatment was based on patient report of heartburn relief, since more than 92 percent of the patients reported this symptom. More than one half of the patients (54 percent) in the treatment group reported improved symptoms. Treatment response was as accurate in confirming the diagnosis as was pH monitoring.

The authors conclude that relief of symptoms following a two-week course of omeprazole therapy can be diagnostic for GERD. However, patients who did not respond to treatment would require further diagnostic testing. Use of a treatment-based approach provides physicians with a simple, inexpensive diagnostic test for GERD that is as effective as esophageal pH monitoring.