Development and evaluation of a modified Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease to distinguish functional dyspepsia from non-erosive reflux disease

Background and Aim: The Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG) is the standard questionnaire used in Japan for the diagnosis of gastroesophageal reflux disease (GERD) and assessment of the response to treatment. We modified the FSSG in order to assess dyspepsia symptoms, and evaluated the modified questionnaire. Methods: We modified the FSSG by adding two questions on interdigestive and postprandial epigastric pain. We then assessed the modified FSSG with 100 new untreated symptomatic patients presenting to hospital and in 200 subjects undergoing health checks. Endoscopic assessment of the esophagogastric junction was performed according to the modified Los Angeles classification with addition of Grade N (normal appearance) and Grade M (minimal change). Endoscopic images were assessed by five experienced endoscopists blinded to the questionnaire results. Results: The 100 new patients included 16 with erosive GERD (>Grade A), 12 with peptic ulcer, and two with gastric cancer. Among the 70 patients with no evidence of organic disease, the modified FSSG diagnosed functional dyspepsia (FD) in 41 and non‐erosive gastric disease (NERD) in 29. A significant difference was seen in the dyspepsia score between patients with FD and NERD. Subjects with endoscopic GERD undergoing health checks had significantly higher scores for all symptoms, reflux symptoms, and dyspeptic symptoms on the modified FSSG. Conclusion: The modified FSSG can clearly distinguish FD from NERD, and is useful for the assessment of dyspeptic symptoms.