Objective Eosinophilic esophagitis (EoE) is diagnosed by the presence of dysphagia and intraepithelial eosinophilic infiltration of ≥15 per high-power field (HPF). EoE should be distinguished from proton pump inhibitor-responsive esophageal eosinophilic infiltration (PPI-R EEI) in patients that are responsive to PPI treatment. The aim of this study was to determine the prevalence of EoE and PPI-R EEI in Japanese patients in a multicenter study. Methods Ten hospitals participated in this study. Esophageal biopsy was performed when the patients had typical EoE symptoms or when endoscopic findings revealed a typical EoE appearance. EEI was defined as the intraepithelial eosinophilic infiltration of ≥15 per HPF. Patients with EEI received rabeprazole for 8 weeks to distinguish EoE from PPI-R EEI. Results A total of 13,634 subjects that underwent upper gastrointestinal endoscopy because of further examination or as a routine checkup were enrolled. Seventy-one (0.5%) patients suspected with EoE were examined by biopsy. A histological examination of 7 (9.9%) cases revealed EEI. Two of these 7 patients showed no symptoms and the other 5 were treated with PPI. Two (0.01%) patients were diagnosed with EoE and 3 (0.02%) with PPI-R EEI. Conclusion EoE and PPI-R EEI were rare in Japanese patients that underwent upper gastrointestinal endoscopy.

Background Gastroesophageal reflux disease (GERD), functional dyspepsia (FD), and irritable bowel syndrome (IBS) are common gastrointestinal diseases. Several studies have shown a significant occurrence of overlap among these 3 diseases. The purpose of this study was to examine the factors associated with such disease overlap in Japanese adults. Methods We performed a cross-sectional study on Japanese workers who visited a clinic for a routine health check-up and asked them to fill out a self-report questionnaire. GERD was defined as episodes of heartburn and/or acid regurgitation at least once a week, and the diagnosis of FD and IBS was based on Rome III criteria. A logistic regression model was used to identify risk factors, and odds ratio (OR) was calculated with 95% confidence intervals (CIs). Results Disease overlaps were found in 160 (6.0%) of the 2680 eligible subjects. Female gender was associated with GERD + IBS (OR=1.99; 95% CI, 1.06-3.75), and FD + IBS (OR=1.72; 95% CI, 1.03-2.85), and lower body mass index was negatively associated with FD + IBS (OR=0.54; 96% CI, 0.34-0.87). Cigarette smoking was a common factor associated with the overlaps: GERD + FD (OR=2.14; 95% CI, 1.22-3.76), GERD + IBS (OR=3.16; 95% CI, 1.75-3.71), FD + IBS (OR=2.26; 95% CI, 1.40-3.66), and GERD + FD + IBS (OR=4.08; 95% CI, 1.66-10.07). The associations between smoking habits and overlaps were stronger in smokers who smoked ≥1 pack per day as compared to those who smoked <1 pack per day. Conclusion Cigarette smoking was significantly associated with overlaps among GERD, FD, and IBS in Japanese adults.

Summary: Background: Vonoprazan (V), a potassium‐competitive acid blocker, has a more durable acid‐inhibitory effect as compared with standard‐dose proton pump inhibitors (PPIs) but has not been compared with 2‐4 times higher daily PPI doses administered in two divided doses.Aims: To evaluate the acid‐inhibitory effect of V 10/20 mg once‐daily (OD; V10/V20) vs rabeprazole (R) 10/20 mg twice‐daily (BID; R20/R40) in healthy Japanese volunteers.Methods: This multicentre, randomised, open‐label, two‐period, crossover study compared V10 or V20 vs R20, or V20 vs R40 using three cohorts of 10 healthy Japanese adults. Within each cohort, subjects were randomised to receive V or R for 7 days and, following a washout period ≥7 days, the other treatment for 7 days. On day 6 of each period, 24‐hours multichannel gastric impedance‐pH monitoring was performed. Percent times pH ≥ 3, ≥4 and ≥5 (pH 3, 4 and 5 holding time ratios [HTRs]) in 24 hours were evaluated as primary pharmacodynamic endpoints.Results: Acid‐inhibitory effect (24‐hours pH 3 HTR) of V20 was greater than those of R20 (91.0% vs 65.3%; P = .0049) and R40 (98.5% vs 85.9%; P = .0073). Similar results were obtained for 24‐hours pH 4 and 5 HTRs. V20 also achieved greater nocturnal pH 4 (91.5% vs 73.2%; P = .0319) and 5 HTRs (78.8% vs 62.2%; P = .0325) as compared with R40. One subject (20%) developed diarrhoea while receiving R40 which was considered treatment‐related.Conclusions: Compared with 2‐4 times the standard daily dose of R, V20 exerts a more potent and durable acid‐inhibitory effect. Trial identifier: UMIN000022198 (www.umin.ac.jp/ctr/index.htm).