Background/Aims: Reflux symptoms frequently present in patients diagnosed with functional dyspepsia (FD). This investigation sought to elucidate the contribution of gastroesophageal reflux in the overlap relationship. Methods: Consecutive patients presenting with reflux symptoms and/or FD symptoms were prospectively included. Comprehensive assessments, including symptoms evaluation, endoscopy, esophageal functional examinations (high-resolution manometry and reflux monitoring), and proton pump inhibitor (PPI) treatment efficacy evaluation, were conducted in these patients. Results: The study enrolled 315 patients, 43.2% of which had concurrent FD symptoms and overlapping reflux symptoms. Notably, a mere 28.7% of patients in the overlap symptoms group had objective gastroesophageal reflux disease evidences (the grade of esophagitis≥ B or the acid exposure time ≥ 4.2%). Functional heartburn was demonstrated to be the main cause of overlapping reflux symptoms(55.1%). Reflux parameters analysis revealed that the reflux burden in the overlap symptoms group paralleled that of the FD symptoms group, with both registering lower levels than the reflux symptoms group (P < 0.05). Furthermore, PPI response rates were notably diminished in the overlap symptoms group (P < 0.001), even for those with objective gastroesophageal reflux disease evidences. Conclusions The study illuminated that overlapping reflux symptoms in FD was common. Strikingly, these symptoms primarily diverged from reflux etiology and exhibited suboptimal responses to PPI intervention. These findings challenge prevailing paradigms and accentuate the imperative for nuanced therapeutic approaches tailored to the distinctive characteristics of overlapping reflux symptoms in the context of FD.

Background/Aims: Reflux symptoms frequently present in patients diagnosed with functional dyspepsia (FD). This investigation sought to elucidate the contribution of gastroesophageal reflux in the overlap relationship. Methods: Consecutive patients presenting with reflux symptoms and/or FD symptoms were prospectively included. Comprehensive assessments, including symptoms evaluation, endoscopy, esophageal functional examinations (high-resolution manometry and reflux monitoring), and proton pump inhibitor (PPI) treatment efficacy evaluation, were conducted in these patients. Results: The study enrolled 315 patients, 43.2% of which had concurrent FD symptoms and overlapping reflux symptoms. Notably, a mere 28.7% of patients in the overlap symptoms group had objective gastroesophageal reflux disease evidences (the grade of esophagitis≥ B or the acid exposure time ≥ 4.2%). Functional heartburn was demonstrated to be the main cause of overlapping reflux symptoms(55.1%). Reflux parameters analysis revealed that the reflux burden in the overlap symptoms group paralleled that of the FD symptoms group, with both registering lower levels than the reflux symptoms group (P < 0.05). Furthermore, PPI response rates were notably diminished in the overlap symptoms group (P < 0.001), even for those with objective gastroesophageal reflux disease evidences. Conclusions The study illuminated that overlapping reflux symptoms in FD was common. Strikingly, these symptoms primarily diverged from reflux etiology and exhibited suboptimal responses to PPI intervention. These findings challenge prevailing paradigms and accentuate the imperative for nuanced therapeutic approaches tailored to the distinctive characteristics of overlapping reflux symptoms in the context of FD.

Background/Aims: Reflux symptoms frequently present in patients diagnosed with functional dyspepsia (FD). This investigation sought to elucidate the contribution of gastroesophageal reflux in the overlap relationship. Methods: Consecutive patients presenting with reflux symptoms and/or FD symptoms were prospectively included. Comprehensive assessments, including symptoms evaluation, endoscopy, esophageal functional examinations (high-resolution manometry and reflux monitoring), and proton pump inhibitor (PPI) treatment efficacy evaluation, were conducted in these patients. Results: The study enrolled 315 patients, 43.2% of which had concurrent FD symptoms and overlapping reflux symptoms. Notably, a mere 28.7% of patients in the overlap symptoms group had objective gastroesophageal reflux disease evidences (the grade of esophagitis≥ B or the acid exposure time ≥ 4.2%). Functional heartburn was demonstrated to be the main cause of overlapping reflux symptoms(55.1%). Reflux parameters analysis revealed that the reflux burden in the overlap symptoms group paralleled that of the FD symptoms group, with both registering lower levels than the reflux symptoms group (P < 0.05). Furthermore, PPI response rates were notably diminished in the overlap symptoms group (P < 0.001), even for those with objective gastroesophageal reflux disease evidences. Conclusions The study illuminated that overlapping reflux symptoms in FD was common. Strikingly, these symptoms primarily diverged from reflux etiology and exhibited suboptimal responses to PPI intervention. These findings challenge prevailing paradigms and accentuate the imperative for nuanced therapeutic approaches tailored to the distinctive characteristics of overlapping reflux symptoms in the context of FD.

Background::Erosive esophagitis (EE) is a gastroesophageal reflux disease characterized by mucosal breaks in the esophagus. Proton pump inhibitors are widely used as maintenance therapy for EE, but many patients still relapse. In this trial, we evaluated the noninferiority of vonoprazan vs. lansoprazole as maintenance therapy in patients with healed EE. Methods::We performed a double-blind, double-dummy, multicenter, phase 3 clinical trial among non-Japanese Asian adults with endoscopically confirmed healed EE from April 2015 to February 2019. Patients from China, South Korea, and Malaysia were randomized to vonoprazan 10 mg or 20 mg once daily or lansoprazole 15 mg once daily for 24 weeks. The primary endpoint was endoscopically confirmed EE recurrence rate over 24 weeks with a noninferiority margin of 10% using a two-sided 95% confidence interval (CI). Treatment-emergent adverse events (TEAEs) were recorded.Results::Among 703 patients, EE recurrence was observed in 24/181 (13.3%) and 21/171 (12.3%) patients receiving vonoprazan 10 mg or 20 mg, respectively, and 47/184 (25.5%) patients receiving lansoprazole (differences: -12.3% [95% CI, -20.3% to-4.3%] and -13.3% [95% CI, -21.3% to -5.3%], respectively), meeting the primary endpoint of noninferiority to lansoprazole in preventing EE recurrence at 24 weeks. Evidence of superiority (upper bound of 95% CI <0%) was also observed. At 12 weeks, endoscopically confirmed EE recurrence was observed in 5/18, 2/20, and 7/20 of patients receiving vonoprazan 10 mg, vonoprazan 20 mg, and lansoprazole, respectively. TEAEs were experienced by 66.8% (157/235), 69.0% (156/226), and 65.3% (158/242) of patients receiving vonoprazan 10 mg, vonoprazan 20 mg, and lansoprazole, respectively. The most common TEAE was upper respiratory tract infection in 12.8% (30/235) and 12.8% (29/226) patients in vonoprazan 10 mg and 20 mg groups, respectively and 8.7% (21/242) patients in lansoprazole group.Conclusion::Vonoprazan maintenance therapy was well-tolerated and noninferior to lansoprazole for preventing EE recurrence in Asian patients with healed EE.Trial Registration::https://clinicaltrials.gov; NCT02388737.

Background/Aims: Abdominal bloating or distension (AB/D) is a common complaint in the outpatient of gastroenterology department. Since the potential contributors are numerous and complex, a longitudinal study on the disease spectrum and natural history of patients was performed to better understand the key factors of AB/D. Methods: Consecutive patients with the chief complaint of AB/D referred to the outpatient clinic were screened. Functional gastrointestinal disorders (FGIDs) were diagnosed according to Rome IV criteria. A 3-year follow-up was performed to seek for the changes in symptoms as well as disease spectrum. Results: A total of 261 participants were enrolled and 139 completed the follow-up. Most patients suffered from moderate to severe symptoms more than 1 day per week. Common causes of AB/D were FGIDs (51.7%) and organic diseases (17.2%). The latter group was older with lower body mass index (BMI). Functional dyspepsia was the most common type of FGIDs in AB/D. The symptoms of 18.0% of participants failed to improve at the end of the 3-year follow-up, and those diagnosed with FGIDs were most likely to continue to suffer. Abdominal pain was a positive predictive factor for good prognosis in the FGIDs group. Besides, only 22.7% of participants had a consistent diagnosis of FGIDs during follow-up. Conclusions FGIDs are the most common diagnosis in patients with AB/D. Symptoms were especially hard to be improved. Classification diagnoses of FGIDs in AB/D patients fluctuated significantly over time.

Achalasia is a primary esophageal motility disorder manifested by dysphagia and chest pain that impair patients’ quality of life, and it also leads to chronic esophageal inflammation by food retention and increases the risk of esophageal cancer. Although achalasia has long been reported, the epidemiology, diagnosis and treatment of achalasia are not fully understood. The current clinical dilemma of achalasia is mainly due to its unclear pathogenesis. In this paper, epidemiology, diagnosis treatment, as well as possible pathogenesis of achalasia will be reviewed and summarized. The proposed hypothesis on the pathogenesis of achalasia is that genetically susceptible populations potentially have a higher risk of infection with viruses, triggering autoimmune and inflammation responses to inhibitory neurons in lower esophageal sphincter.

Objective:To establish the normal values of water-perfused high resolution esophageal manometry (HREM)(GAP-36A) at resting period, water swallowing, semisolid swallowing and solid swallowing in Chinese population.Methods:From September 1, 2019 to June 30, 2020, 91 healthy volunteers receiving water-perfused HREM (GAP-36A) at resting period, water swallowing, semisolid swallowing and solid swallowing were selected from 9 hospitals (Union Hospital, Tongji Medical College, Huazhong University of Science and Technology; the First Affiliated Hospital of Dalian Medical University; the Second Hospital of Hebei Medical University; the Second Affiliated Hospital, Naval Medical University; the First Affiliated Hospital, Sun Yat-sen University; the First Affiliated Hospital, University of Science and Technology of China; Aviation General Hospital of China Medical University; the Affiliated Hospital of Medical School of Nanjing University and the First People′s Hospital of Yichang). Parameters included the position of the upper and lower edges of the upper esophageal sphincter (UES) and lower esophageal sphincter (LES), the length of the LES and UES, the position of the pressure inversion point (PIP), the resting pressure of UES and LES and swallow-related parameters such as the distal contraction integral (DCI), 4 s integrated relaxation pressure (IRP), distal latency (DL) and UES residual pressure. One-way analysis of variance, post-hoc test and sum rank test were used for statistical analysis.Results:A total of 87 healthy volunteers were enrolled, including 40 males and 47 females, aged (38.5±14.2) years old (ranged from 19 to 65 years old). The position of the upper and lower edges of the LES was (42.7±2.8) and (45.6±2.8) cm, respectively, the length of the LES was (2.9±0.4) cm, and the position of PIP was (43.3±2.8) cm. The position of the upper and lower edges of the UES was (18.1±3.0) and (22.6±2.0) cm, respectively, and the length of the UES was (4.8±1.0) cm. The resting pressure of LES and UES was (17.4±10.7) and (84.1±61.1) mmHg (1 mmHg=0.133 kPa), respectively. The DCI value at solid swallowing was higher than those at water swallowing and semisolid swallowing ((2 512.4±1 448.0) mmHg·s·cm vs. (2 183.2±1 441.2) and (2 150.8±1 244.8) mmHg·s·cm), and the differences were statistically significant ( t=-4.30 and -3.74, both P<0.001). The values of 4 s IRP at semisolid swallowing and solid swallowing were lower than that at water swallowing ((4.6±4.1) and (4.9±3.9) mmHg vs. (5.4±3.9) mmHg), and the differences were statistically significant ( t=3.38 and 2.09, P=0.001 and 0.037). The DL at water swallowing was shorter than those at semisolid swallowing and solid swallowing ((8.5±1.8) s vs. (9.8±2.2) and (10.6±2.8) s), and the DL at semisolid swallowing was shorter than that at solid swallowing, and the differences were statistically significant ( t=-10.21, -13.91 and -4.68, all P<0.001). The UES residual pressure at water swallowing was higher than those at semisolid swallowing and solid swallowing (9.5 mmHg, 6.5 to 12.3 mmHg vs. 8.0 mmHg, 4.5 to 11.7 mmHg and 5.5 mmHg, 2.0 to 9.3 mmHg), and the UES residual pressure at semisolid swallowing was higher than that at solid swallowing, and the differences were statistically significant ( t=3.48, 10.30 and 6.35, all P<0.001). Conclusions:The normal values of water-perfused HREM (GAP-36A) in Chinese population at resting period, water swallowing, semisolid swallowing and solid swallowing can provide a reference basis for clinical diagnosis and treatment for patients receiving water-perfused HREM examination.

Background/Aims: Gastroparesis is identified as a subject that is understudied in Asia. The scientific committee of the Asian Neurogastroenterology and Motility Association performed a Knowledge, Attitude, and Practices survey on gastroparesis among doctors in Asia. Methods: The questionnaire was created and developed through a literature review of current gastroparesis works of literature by the scientific committee of Asian Neurogastroenterology and Motility Association. Results: A total of 490 doctors from across Asia (including Bangladesh, China, Hong Kong, Indonesia, Japan, Malaysia, Myanmar, the Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam) participated in the survey. Gastroparesis is a significant gastrointestinal condition. However, a substantial proportion of respondents was unable to give the correct definition and accurate diagnostic test. The main reason for lack of interest in diagnosing gastroparesis was “the lack of reliable diagnostic tests” (46.8%) or “a lack of effective treatment” (41.5%). Only 41.7% of respondents had access to gastric emptying scintigraphy. Most doctors had never diagnosed gastroparesis at all (25.2%) or diagnosed fewer than 5 patients a year (52.1%). Conclusions Gastroparesis can be challenging to diagnose due to the lack of instrument, standardized method, and paucity of research data on normative value, risk factors, and treatment studies in Asian patients. Future strategies should concentrate on how to disseminate the latest knowledge of gastroparesis in Asia. In particular, there is an urgent need to estimate the magnitude of the problems in high risk and idiopathic patients as well as a standardized diagnostic procedure in Asia.

Background/Aims: There is less acid burden in Chinese gastroesophageal reflux disease (GERD) patients. However, the Lyon consensus proposed a higher threshold of acid exposure time (AET > 6%) for GERD. The aims are to apply the updated criteria in Chinese GERD patients and clarify its influence on clinical outcome. Methods: Patients who were referred for both esophageal high-resolution manometry and 24-hour esophageal pH monitoring due to reflux symptoms were retrospectively screened. Those patients with AET > 4% was included and grouped into either AET 4-6% or AET > 6%. Their manometric profile, reflux profile, and response to proton pump inhibitors (PPIs) were evaluated. Adjunctive evidence proposed in the Lyon consensus was added in patients with AET 4-6% for therapeutic gain. Another group of patients (n = 144) with AET < 4% were included as non-GERD patients. Results: In total, 151 patients (102 males) were included with 113 patients AET > 6% (74.9%). GERD patients with AET > 4% were with more male, older patients, and higher body mass index compared with non-GERD patients. Meanwhile, GERD patients were less competent in esophagogastric junction pressure. However, the manometric and reflux profile were similar between patients with AET > 6% and 4-6%. The response rate of PPI therapy was 64.6% and 63.2%, respectively, in groups of AET > 6% and 4-6% (P > 0.05). When adjunctive evidence was added in patients with AET 4-6%, no therapeutic gain was obtained. Conclusions The efficacy of PPI therapy was similar in patients with AET > 6% and 4-6%. The increase of the AET threshold did not influence the clinical outcome of Chinese GERD patients.

Background/Aims: Esophagogastric junction outflow obstruction (EGJOO) is characterized by elevated integrated relaxation pressure (IRP) and preserved esophageal peristalsis. The clinical significance of EGJOO is uncertain. This study aim to describe the clinical characteristics of these patients and to find out potential parameters to predict patients’ symptom outcome. Methods: Consecutive patients who received high-resolution manometry examination in our hospital in 2013-2019 and met the diagnostic criteria of EGJOO were retrospectively included. Motility and reflux parameters as well as endoscopy and barium esophagogram results were studied and compared. Patients were also followed up to record their treatment methods and symptom outcomes. Results: A total of 138 EGJOO (accounting for 5.2% of total patients taking high-resolution manometry examination in our hospital) patients were included. Only 2.9% of these patients had persistent dysphagia. A total of 81.8% of EGJOO patients had symptom resolution during follow-up. Patients with persistent dysphagia had significantly higher upright IRP (16.6 [10.3, 19.8] vs 7.8 [3.2, 11.5]; P = 0.026) than those without. Upright IRP can effectively distinguished patients with persistent dysphagia (area under curve: 0.826; P = 0.026) using optimal cut-off value of 9.05 mmHg. Conclusion EGJOO patients with persistent dysphagia and higher upright IRP (median > 9.05 mmHg) needs further evaluation and aggressive management.