BACKGROUND: TREATMEN The contribution of eosinophilic esophagitis (EoE) to refractory gastroesophageal reflux disease (GERD) remains unknown. When EoE and GERD overlap, the clinical, endoscopic and histological findings are nonspecific and cannot be used to distinguish between the two disorders. Limited data are available on this topic, and the interaction between EoE and GERD is a matter of debate.AIM:We have conducted a prospective study of adult patients with refractory GERD to evaluate the overlap of reflux and EoE.METHODS:Between July 2006 and June 2008, we consecutively and prospectively enrolled 130 male and female patients aged 18 to 70 years old who experienced persistent heartburn and/or regurgitation more than twice a week over the last 30 days while undergoing at least six consecutive weeks of omeprazole treatment (at least 40 mg once a day). The patients underwent an upper digestive endoscopy with esophageal biopsy, and intraepithelial eosinophils were counted after hematoxylin/eosin staining. The diagnosis of EoE was based on the presence of 20 or more eosinophils per high-power field (eo/HPF) in esophageal biopsies.RESULTS:Among the 103 studied patients, 79 (76.7%) were females. The patients had a mean age of 45.5 years and a median age of 47 years. Endoscopy was normal in 83.5% of patients, and erosive esophagitis was found in 12.6%. Only one patient presented lesions suggestive of EoE. Histological examination revealed >20 eo/HPF in this patient.CONCLUSION:Our results demonstrated a low prevalence of EoE among patients with refractory GERD undergoing omeprazole treatment.