Despite of the widespread use of hydrogen and methane breath test, the variability in testing protocols, gas measurement techniques, and interpretation criteria continues to challenge the reproducibility and comparability across centers, especially in the Asia-Pacific region. The Asian Neurogastroenterology and Motility Association hence presents the first Asian monograph guiding application and interpretation of breath test. The monograph was formulated according to the framework of indications, preparatory process, performance, and interpretation of results, as well as future direction for research.

Background/Aims: Ineffective esophageal motility (IEM) is the most frequently encountered esophageal manometric abnormality. Nonobstructive dysphagia is frequently associated with severe esophageal peristaltic dysfunction. This study aims to evaluate the presenting symptoms and association between dysphagia and specific manometric findings in patients with IEM. Methods: We retrospectively reviewed 228 IEM patients diagnosed on high-resolution manometry at an academic institution (2010-2013). We collected data regarding the main presenting symptoms and manometric findings: bolus transit, distal esophageal pressure amplitude, and lower esophageal sphincter (LES) resting and relaxation pressure. Results: Dysphagia was the main presenting symptom (25%) in IEM patients. Bolus transit was incomplete in either liquid or viscous swallows (30%) and incomplete in both liquid and viscous swallows (59%) in IEM patients. The LES resting pressure and LES relaxation pressure were elevated (9% and 36%, respectively) in IEM patients. There was no significant difference between dysphagia and either poorly relaxing LES (P = 0.725) or defective bolus transit (DBT) to liquid and viscous swallows (P = 0.372) compared to the rest of the IEM patients. However, there was a significant association between dysphagia and the combination of poorly relaxing LES and DBT in liquid and viscous swallows (P = 0.006). Subgroup analysis comparing dysphagia with heartburn/regurgitation demonstrated a similar significant association between dysphagia and the combination of poorly relaxing LES and DBT during viscous and liquid swallows (P = 0.016). Conclusions Dysphagia is a variable symptom associated with complex esophageal motility abnormalities. IEM patients with a combination of poorly relaxing LES and DBT are more likely to have dysphagia.

Background/Aims: The International Anorectal Physiology Working Group (IAPWG) has proposed a standardized protocol and the London classification to enhance the consistency and diagnostic accuracy of anorectal manometry (ARM). However, real-world adoption in Asian countries has not been systematically assessed. This study aims to evaluate current ARM practices and adherence to the IAPWG protocol across Asian centers. Methods: A cross-sectional, 50-item web-based survey was distributed to gastroenterologists and motility specialists practicing in Asian countries. Results: Thirty-one centers from 8 countries responded (20 in Korea, 3 in Japan, 2 in Taiwan, 1 in China, and 7 in other countries). High-resolution ARM was used in 80.6% of centers, primarily with solid-state catheters. While all centers performed rest and short squeeze maneuvers, only 58.1% conducted all maneuvers recommended by the IAPWG protocol.Considerable variation was observed in test methodology and interpretation, including definitions of resting pressure, squeeze duration, push maneuver repetition, and rectal balloon volume for rectoanal inhibitory reflex. For balloon expulsion and rectal sensory testing, centers differed in patient positioning, balloon type, inflation methods, and threshold definitions. Only 38.7% of centers reported having institutional normative values for test interpretation, and 64.5% applied the London classification. Conclusions Across Asian centers, ARM practice shows marked regional variation and incomplete implementation of the IAPWG standardized protocol and London classification, highlighting persistent gaps in standardization. Strengthening procedural guidance, regionally appropriate normative data, and interpretation criteria through coordinated education and international collaboration is needed to support more consistent and clinically meaningful use of ARM in routine practice.

Background/Aims: Endoscopic anti-reflux therapy is a therapeutic option for gastroesophageal reflux disease (GERD), providing durable effects. However, clinical data from Korea remain limited. This study evaluates the clinical outcomes of endoscopic radiofrequency Stretta therapy in Korean patients. Methods: A retrospective analysis was conducted on 71 patients with GERD who underwent Stretta therapy at 2 tertiary hospitals in Korea between November 2015 and July 2021. Clinical outcomes, including patient satisfaction, medication cessation or reduction, and complications, were evaluated. Pre- and post-procedural esophageal manometry and 24-hour pH monitoring test results were also analyzed. Results: Patient satisfaction rates at 1, 6, and 12 months post-procedure were 54.7% (35/64), 70.0% (28/40), and 75.0% (21/28), respectively. Medication cessation or reduction was achieved in 31.2% (20/64) at 1 month, 70.0% (28/40) at 6 months, and 67.9% (19/28) at 12 months. Esophageal manometry (n = 21) showed no significant changes in mean lower esophageal sphincter pressure (18.7 mmHg [2.5-52.9] vs 17.4 mmHg [0.0-43.0], P = 0.702) or mean integrated relaxation pressure (8.2 mmHg [0.0-28.0] vs 10.1 mmHg [0.0-31.0], P = 0.840). The 24-hour pH monitoring (n = 18) demonstrated a nonsignificant decrease in acid exposure time (pH < 4) from 2.3% (0.0-8.4) to 1.6% (0.0-7.3) (P = 0.182). Similarly, the DeMeester score decreased non-significantly from 8.4 (0.8-27.7) to 6.6 (0.8-21.8) (P = 0.352). No procedure-related complications occurred. Conclusion Endoscopic radiofrequency Stretta therapy appears to be a safe treatment option for GERD and may provide favorable patient satisfaction and medication reduction.

Background/Aims: Non-pharmacological treatments are crucial for managing irritable bowel syndrome (IBS), yet patient engagement remains a challenge. Understanding patients' knowledge, attitudes, and practices regarding these treatments is essential for improving care. Methods: A cross-sectional study was conducted across 5 hospitals, from October 2023 to February 2024. A self-designed knowledge, attitudes, and practices questionnaire along with the IBS quality of life and IBS severity scoring system was administered, and 496 valid responses were analyzed. Statistical analyses included correlation tests, multivariate linear regression, and mediation effect analysis. Results: The median scores for knowledge, attitude, and practice were 28, 25.5, and 21, respectively. Significant positive correlations were found between knowledge-attitude (r = 0.195), knowledge-practice (r = 0.364), and attitude-practice (r = 0.151). The multivariate linear regression analysis further indicated that knowledge (β = 0.399, P < 0.001) and attitude (β = 0.219, P = 0.022) positively correlated with the practical performance. SEM revealed that knowledge had a significant direct effect on both attitude (β = 0.186, P = 0.013) and practice (β = 0.356, P = 0.006). However, the direct effect of attitude on practice was not significant, and attitude did not mediate the relationship between knowledge and practice. Conclusions IBS patients exhibit a significant gap between their positive attitudes and their actual practices concerning non-pharmacological treatments. Knowledge is a direct driver of practice, but positive attitudes alone are insufficient to translate into behavior. Healthcare providers must move beyond simply fostering positive attitudes and focus on targeted educational interventions that provide actionable knowledge and skills to improve patient outcomes.

Background/Aims: Belching can occur either independently or concurrently with reflux symptoms. This study aims to explore the relationship between belching and reflux and explore the underlying mechanisms involved. Methods: Firstly, patients with isolated belching symptoms or concurrent belching and reflux symptoms were retrospectively enrolled. High-resolution esophageal impedance manometry (HRIM) and 24-hour pH impedance monitoring were used to assess belching types and temporal relationship between belching and reflux. Secondly, subjects with belching disorder were prospectively recruited. Postprandial HRIM monitoring was used to clarify the relationship and underlying mechanisms between belching and reflux. Results: In the initial phase, 139 subjects were enrolled. Regardless of patients' symptom spectrum (with or without gastroesophageal reflux symptoms), the proportion of preceding-reflux belching was significantly higher in those with objective evidence of gastroesophageal reflux disease, compared to those without (both P < 0.05), which indicated that belching could trigger reflux events and led to more severe reflux burden. To clarify the potential mechanisms involved, 44 belching subjects were prospectively enrolled in the second phase of this study. HRIM analysis demonstrated that maximum intragastric pressure, gastric–lower esophageal sphincter pressure gradient and gastric–esophageal pressure gradient were significantly higher in preceding-reflux belching than those in independent belching. Conclusions This study demonstrated that belching might trigger reflux by increasing intragastric pressure, elevating the gastric-sphincter pressure gradient, which enables gastric contents to pass through the esophagogastric junction.These findings have crucial clinical significance, suggesting that reducing the occurrence of belching might be a potential treatment for refractory reflux.

Background/Aims: To evaluate the quality of life (QOL) of patients with chronic intestinal pseudo-obstruction (CIPO) before and after treatment. Methods: This study enrolled 50 adult patients diagnosed with CIPO at 4 institutions, of whom 42 underwent therapy.Patient background, body mass index, treatment, palliative care intervention, numerical rating scale for abdominal pain or bloating, the medical outcomes study 36-item short-form health survey (SF-36) and summary scores (physical component summary, mental component summary, and role/social component summary), Japanese version of the Patient Assessment of Constipation Quality of Life (JPAC-QOL) and subscales (physical discomfort, psychosocial discomfort, worries and concerns, and satisfaction), and Patient Assessment of Constipation Symptoms (PAC-SYM) and subscales (stool, rectal, and abdominal symptoms) were prospectively sampled and collected. Results: The patients (n = 50; 35 females and 15 males) had an average age of onset of 44.7 years and, body mass index of 17.3 kg/m², and 38 (76%) required palliative care intervention. Effective therapeutic interventions included intestinal sterilization (19/42), decompression therapy with percutaneous endoscopic gastrojejunostomy (PEG-J) (6/42), and dietary restriction (6/42). The numerical rating scale for abdominal distension and pain decreased significantly after treatment. All SF-36 summary scores showed improvements. The JPAC-QOL and PAC-SYM both showed improvement overall and in all subscales. Conclusions Patients with CIPO have a lower physical, psychological and social QOL, which is equivalent to or lower than that of adult patients with inflammatory bowel disease or psychiatric disorders. Sterilization of the intestinal tract and PEG-J decompression effectively improve the QOL of patients.

Background/Aims: Semaglutide is associated with gastroduodenal symptoms, such as nausea and vomiting. This pilot study used body surface gastric mapping (BSGM) to measure the effect of semaglutide on gastric function and associated symptoms. Methods: Patients without gastrointestinal symptoms (n = 8) underwent BSGM at baseline and on 1 mg semaglutide, as per standard subcutaneous dosing. Spectral metrics included Principal Gastric Frequency, Gastric Alimetry Rhythm Index (GA-RI), body mass index-adjusted amplitude, fed:fasted amplitude ratio, and meal response ratio. Symptoms were assessed using validated questionnaires. Data were compared using paired t tests. Results: Body mass index-adjusted amplitude showed a significant decrease on the drug (P = 0.04). Five patients (63%) developed spectral abnormalities on the drug, with 2 displaying a low or undetectable GA-RI (< 0.25). The patient assessment of upper gastrointestinal disorders-symptom severity index fullness/early satiation subscale significantly increased on the drug (P = 0.005). Conclusions Semaglutide appears to alter gastric electrical activity on BSGM and increase early satiation, offering potential biomarkers for detecting drug effects. Further studies are needed.

Background/Aims: Patients with postural tachycardia syndrome (POTS) commonly experience gastrointestinal (GI) symptoms. We aim to assess the feasibility and preliminary efficacy data for DA-9701, a prokinetic agent targeting 5-hy-droxytryptamine 1A, 5-hydroxytryptamine 4, and dopamine D 2 receptors, in patients with POTS. Methods: In a randomized, double-blind, placebo-controlled, single-center crossover trial, patients with POTS were given either 30 mg of DA-9701 or a placebo 3 times daily for eight weeks in a 1:1 ratio. After a 4-week washout, patients received the alternate treatment for another 8 weeks. The primary endpoint focused on assessing the change in GI symptoms (total Nepean Dyspepsia Index-Korean version [NDI-K] symptom score) from baseline over the 8 week-treatment period. Endpoints were assessed in all enrolled and randomized patients (intention-to-treat), and in those who completed the trial (per-protocol analysis). Results: Between January 2022 and August 2023, 24 patients were randomized (n = 12 per group), with 3 discontinuing after randomization. DA-9701 did not significantly improve primary endpoints for total NDI-K symptom scores in either the intention-to-treat (least-squares means, –13.9 vs. –9.5, P = 0.326) or per-protocol analyses (–17.2 vs –12.0, P = 0.242).Notably, a trend toward improvement in specific GI symptoms, such as upper abdominal pain, was observed in both intention-to-treat (–0.6 vs 0.7; P = 0.066) and per-protocol analyses (–0.9 vs 0.6; P = 0.045). No serious adverse events were observed. Conclusion DA-9701 did not improve GI symptoms in this crossover trial; however, its potential effect on specific GI symptoms merits further investigation.

Probiotics have gained increasing clinical attention as adjunctive treatment for lower gastrointestinal disorders. However, evidence supporting their therapeutic efficacy remains limited, particularly with regard to sex-related differences. This expert review provides evidence-based insights and practical recommendations for the use of probiotics in patients with irritable bowel syndrome (IBS), functional constipation (FC), and Clostridioides difficile infection (CDI), considering possible sex-related differences. Evidence from randomized controlled trials and meta-analyses indicates that probiotics can modestly improve global symptoms, abdominal pain, and bloating in IBS and enhance bowel movement frequency and stool consistency in FC. However, these effects are strain-specific and heterogeneous. Although clinical studies on probiotics in IBS have not confirmed significant sex-related differences, experimental animal studies using stress-induced IBS models have demonstrated sex-dependent responses to specific probiotic strains, supporting the biological plausibility of such differences. For CDI, the efficacy of probiotics in preventing primary or recurrent infections remains inconsistent across large trials, and current guidelines usually do not recommend their routine use. However, sex and age difference of immunology supports the clinical differences of CDI. Probiotics are generally considered safe for healthy individuals, although caution is advised in patients who are immunocompromised or critically ill. Clinicians should select probiotic products based on strain-specific clinical evidence, adequate viable doses, patient's characteristics, or patient’s sex. In conclusion, probiotics might play a role as adjunctive therapy for IBS and FC, with variability in responses influenced by microbial, host, and potential sex-related factors. Further research is needed to establish optimized personalized probiotic strategies.