Akinari Sawada

Trends and safety of small bowel endoscopy in Crohn’s disease in Japan: a large-scale claims database analysis

Background: Supragastric belching (SGB) can trigger reflux episodes, but the contribution of SGB to pathological reflux burden is incompletely understood. Objective: To characterise and identify clinical predictors for excessive SGB-related gastro-oesophageal reflux disease (GERD) phenotype. Design: This was a multicentre cross-sectional study of patients with acid exposure time (AET) >6% on pH-impedance monitoring off therapy across 11 international tertiary centres. SGB episodes were manually identified. Excessive SGB was defined by ≥13 episodes/24 hours. SGB-related AET was determined by duration of pH 56 proximal reflux episodes achieved >90% specificity for excessive SGB. Conclusions: Excessive SGB is found in up to 20% of patients with conclusive GERD, with 25% of AET attributable to SGB. Higher TRE (>115 TRE, >56 proximal episodes) and more SGB-associated symptoms are predictors of excessive SGB-related GERD phenotype.

Background and Aims: Supragastric belches (SGB) are not detected by commercial software and are cumbersome to identify manually. We determined whether machine learning can accurately identify SGBs. Methods: pH‐impedance studies from a convenience cohort (20 patients each of pathologic GERD, excessive SGB, and healthy volunteers) were randomly assigned to training (2), validation (4), and testing (4) from each group. First, studies were manually reviewed to mark SGBs, then converted to .csv files and input into a convolutional neural network (CNN) developed de novo using open‐source software. The training set was utilized for hyperparameter and epoch optimization. Subsequently, clinical utility was assessed using a validation set followed by test set to confirm accuracy. False positives were reviewed, allowing recognition of novel CNN‐detected events. Results: 339 SGB events (median 8.0) were manually identified in the GERD cohort, > 2000 in the SGB cohort and 163 (median 3.0) in healthy volunteers. When analyzed by group, sensitivity was highest in healthy volunteers and lowest in the GERD cohort, while false positive rates were similar. Unique new SGB events were most common in the SGB cohort ( p < 0.001 compared to the other cohorts). On ROC analysis, machine learning segregated SGB patients from GERD and healthy volunteers with high accuracy (AUC 0.859, p = 0.001) at an optimal threshold of 11 events, with sensitivity of 100% and specificity of 62.5%. Conclusions: In this proof‐of‐concept investigation, a machine learning algorithm accurately identifies SGB events, including events missed by manual review, and reliably segregates SGB patients from healthy volunteers and GERD patients.

INTRODUCTION: Reflux esophagitis (RE) frequently occurs after peroral endoscopic myotomy (POEM). However, its underlying mechanism has not been completely understood. POEM may cause pathological gastroesophageal reflux by impairing the crural diaphragm (CD), a key component of the antireflux barrier. The aim of this study was to investigate the impact of POEM on CD function and its association with post-POEM RE. METHODS: We retrospectively analyzed patients who underwent POEM and completed routine 3-month follow-up between January 2018 and February 2025. In the follow-up, esophagogastroduodenoscopy and high-resolution manometry assessed post-POEM RE and CD function (i.e. inspiratory augmentation of esophagogastric junction [EGJ] pressure), respectively, after a 1-month cessation of acid-suppressive therapy. A subset of patients also underwent the same follow-up protocol 1 year post-POEM. We examined changes in CD function after POEM and identified factors associated with post-POEM RE using logistic regression. RESULTS: Ultimately, 200 patients were analyzed. Inspiratory augmentation of EGJ pressure significantly decreased 3 months post-POEM compared with preoperatively ( P = 0.011) and partially recovered from 3 months to 1 year post-POEM. RE (grade B or higher) was observed in 102 patients (51%) 3 months post-POEM. This RE group showed significantly weaker inspiratory augmentation of EGJ pressure compared with the non-RE group (none or grade A) ( P < 0.001). Multivariable analysis demonstrated that weak CD contraction was associated with post-POEM RE, along with older age and several modifiable factors such as alcohol consumption, smoking, and gastric myotomy length. DISCUSSION: POEM can impair CD contraction, and weak CD contraction was associated with post-POEM RE.

Introduction: Functional abdominal bloating (FAB) is a bowel disorder of gut-brain interaction (DGBI) characterized by predominant bloating symptom. Given gas dynamics in the digestive tract, gas-related symptoms (belching and flatulence) and behaviors may contribute to the development of FAB. This study aimed to examine their relationships. Methods: We conducted an Internet survey for individuals aged from 18 to 79 years using a questionnaire including items on demographic and clinical characteristics, lifestyle, and gas-related symptoms and behaviors. DGBIs including FAB were diagnosed based on the Rome IV criteria. The severity of bloating was assessed using visual analog scale. Health-related quality of life (HRQOL) was evaluated using the SF-8. Logistic and multiple regression analyses identified factors associated with FAB and their bloating severity. Results: A total of 9,995 individuals were included in the analysis, in which 123 (1.2%) were classified as having FAB. HRQOL was significantly impaired in the FAB group compared to the non-FAB group. Multivariable analysis demonstrated that gas-related symptoms and behaviors such as frequent flatulence (OR: 2.55, 95% CI: 1.74–3.72, p < 0.001), frequent suppression of flatulence (OR: 2.09, 95% CI: 1.32–3.32, p = 0.002), and resisting the urge to defecate (OR: 2.77, 95% CI: 1.57–4.90, p < 0.001) were significantly and independently associated with an increased odds of FAB, in addition to lower BMI and gastroesophageal reflux disease. Younger age and resisting the urge to defecate were related to increased severity of bloating in patients with FAB. Conclusion: Gas-related symptoms and behaviors may contribute to the pathophysiology of FAB.

INTRODUCTION: No bowel preparation (BP) for colonoscopy achieves optimal efficacy and tolerability. Combining polyethylene glycol plus ascorbic acid (PEG-Asc) with adjuvants has been explored to enhance cleansing efficacy and reduce the required volume. The aim of this study was to evaluate whether adding 0.5 mg linaclotide to 1 L PEG-Asc (1 L-PEG/AL) improves superior cleansing compared with adding 24 mg senna (1 L-PEG/AS), which we previously reported to be noninferior to the standard regimen of 2 L PEG-Asc. METHODS: A multicenter, endoscopist-blinded, randomized controlled trial was conducted at 5 centers in Japan with outpatients scheduled for colonoscopy. The primary outcome was adequate BP, evaluated using the Boston Bowel Preparation Scale. Analyses were stratified based on low-risk and high-risk groups for inadequate BP. RESULTS: Between April 2022 and April 2023, 1,464 patients were randomized to the 1L-PEG/AL (n = 731) or 1L-PEG/AS (n = 733). The 1L-PEG/AL demonstrated higher adequate BP rates (92% vs 86%, P = 0.001) compared with 1L-PEG/AS. Both groups experienced similar adverse events and expressed high willingness for repeat BP (83% vs 81%, P = 0.49). In high-risk patients (n = 892), 1L-PEG/AL had significantly higher adequate BP rates (94% vs 86%, P < 0.001), whereas rates were comparably high in low-risk patients (n = 539) (94% vs 94%, P = 0.66). DISCUSSION: The linaclotide regimen was superior to the senna regimen reagrding BP efficacy without reducing tolerability. It can be a promising new option for BP, especially in patients at a high risk of inadequate BP.

Background: The Esophageal Hypervigilance and Anxiety Scale (EHAS) is an English questionnaire created in the USA to assess these factors in all patients with esophageal diseases. The aim of this study was to develop and validate the Japanese version of EHAS and investigate the relationship between EHAS scores and symptoms in untreated disorders of esophagogastric junction (EGJ) outflow. Methods: This prospective study recruited patients who underwent high-resolution manometry (HRM) at six tertiary centers in Japan. The EHAS was translated to Japanese using standard forward and backward translation methods. Patients completed the following questionnaires: the Japanese EHAS, Eckardt score, Gastroesophageal Reflux Disease Questionnaire, and Hospital Anxiety and Depression Scale for assessment of construct validity. Logistic regression analysis identified factors associated with esophageal symptom severity in untreated disorders of EGJ outflow. Results: Overall, we analyzed 432 patients. Their main symptoms were dysphagia and reflux. The most common HRM diagnosis was normal (35.9%), followed by achalasia (29.4%). The Japanese EHAS demonstrated excellent reliability, and construct validity, with two subscales similar to the original EHAS. Total EHAS score moderately correlated to Eckardt score (r = 0.545, p < 0.001). In 113 patients with untreated disorders of EGJ outflow, multivariable analysis demonstrated that younger age, type II achalasia, and higher EHAS score were independently associated with higher Eckardt score. Conclusions: The Japanese EHAS is a reliable and valid questionnaire. Its subscale scores can be used as in the original version with some caution. Future studies are warranted to assess the appropriateness of factor loading.