Role of esophageal function tests in diagnosis of gastroesophageal reflux disease

Clinicians typically make the diagnosis of gastroesophageal reflux disease (GERD) from the clinical findings and then prescribe acid-suppressing drugs. Endoscopy is usually done for persistent or severe symptoms. Esophageal function tests (EFTs: esophageal manometry and 24-hr pH monitoring) are generally reserved for patients who have the most severe disease, including those being considered for surgery. We hypothesized that EFTs are more accurate than symptoms and endoscopy in the diagnosis of GERD. This was a retrospective study undertaken in a university tertiary care center. Between October 1989 and November 1998, 822 patients with a clinical diagnosis of GERD (based on symptoms and endoscopic findings) were referred for EFTs. The patients were divided into two groups depending on whether the 24-hr pH monitoring score showed GERD (group A, GERD^-; group B, GERD⁺). The groups were compared with respect to the incidence and severity of symptoms, presence of a hiatal hernia on barium x-rays, presence and severity of esophagitis on endoscopy, and esophageal motility. In all, 247 patients (30%) had normal reflux scores (group A, GERD^-), and 575 patients (70%) had abnormal scores (Group B, GERD⁺). Eighty percent of group A and 88% of group B had been treated with acid-suppressing medications. The incidence of heartburn and regurgitation was similar in the two groups. Grade I-II esophagitis was diagnosed by endoscopy in 25% of group A and 35% of group B, and grade III esophagitis in 4% of group A and 11% of group B. Esophageal manometry showed that group B more often had esophageal dysmotility, consisting of a hypotensive lower esophageal sphincter and abnormal esophageal peristalsis. These data show that: (1) symptoms were unreliable for diagnosing GERD; (2) endoscopic evidence of grade I-II esophagitis was diagnostically nonspecific, and grade III was much less certain than claimed in other reports; and (3) pH monitoring identified patients with GERD and stratified them according to the severity of the disease. We conclude that esophageal manometry and pH monitoring are important in diagnosing GERD accurately. More liberal use of these tests early in patient management would avoid much improper and costly medical therapy and would help single out for special attention the patients with GERD who have the most severe disease.