A pathophysiologic framework for the overlap of disorders of gut-brain interaction and the role of the gut microbiome.

The International Rome Committee defines Disorders of Gut-Brain Interactions (DGBI) based upon distinct combinations of chronic and/or recurrent unexplained gastrointestinal symptoms. Yet patients often experience overlapping DGBI. Patients with DGBI frequently also suffer from extraintestinal symptoms, including fatigue, sleep disturbances, anxiety, and depression. Patients with overlapping DGBI typically experience more severe GI symptoms and increased psychosocial burden. Concerning the pathophysiology, DGBI are associated with disruptions in gut motility, function of the brain and enteric neurons, immune function, and genetic markers, with recent findings revealing gut microbiome alterations linked to these mechanisms of DGBI. Emerging evidence summarized in this review suggests that the microbiome influences various established disease mechanisms of different DGBI groups. Overall, changes in the gastrointestinal microbiome do not seem to be linked to a specific DGBI subgroup but may play a key role in the manifestation of different DGBI and, subsequently, overlap of DGBI. Understanding these shared mechanisms and the role of the gastrointestinal microbiome, particularly for overlapping DGBI, might aid in developing more precise diagnostic criteria and treatment strategies while developing personalized interventions that target specific mechanisms to improve patient outcomes.

A systematic review of the association between environmental risk factors and the development of irritable bowel syndrome.

BACKGROUND AND AIM: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with roots in genetic, immune, psychological, and dietary factors. Recently, the potential correlation between environmental exposures, such as air pollution, and IBS has gained attention. This review aimed to systematically examine existing studies on environmental factors associated with IBS, elucidating this interplay and guiding future research. METHODS: A literature search was conducted in Medline, EMBASE, Scopus, and Cochrane databases from database inception to October 10, 2023, using the keywords "Irritable Bowel" or IBS or "Irritable Colon" or "Mucous Colitis" or "Spastic Colitis" or "Spastic Colon" AND "environment* exposure*". Studies were included if they were original, published in English, described defined environmental exposure(s), and had documented diagnosis of IBS. For the purposes of this review, articles reporting physical (e.g. radiation and climate change), biological (e.g. bacteria and viruses), and chemical (e.g. harmful gases) exposures were included while psychological and dietary factors, which have been reviewed in detail elsewhere, are outside of the scope. RESULTS: A total of seven studies focusing on air quality, microbial exposure, and other environmental factors were reviewed. Studies highlighted a potential association between air pollutants and increased IBS incidence. Microbial exposure, post-natural disaster or due to poor sanitation, was linked to IBS development and gut dysbiosis. Other exposures, such as early pet ownership, were also associated with IBS risk. CONCLUSION: Existing research demonstrates an epidemiologic relationship between environmental exposures and the development of IBS. Further research is needed to understand these associations.

Infectious etiologies of persistent and chronic diarrhea in Asian developing countries: A systematic review and meta-analysis.

Infectious causes of diarrhea contribute significantly to morbidity in Asia. We conducted a systematic review and meta-analysis of the prevalence of infectious etiologies of persistent and chronic diarrhea in Asian adults. Searches were performed on PubMed and Scopus for studies from January 1, 1970, to May 30, 2023. Sixteen studies were identified and included. The meta-analysis was conducted with the random-effects method, estimating the pooled prevalence of groups of infectious pathogens as causes of persistent and chronic diarrhea among Asian adults. The findings were highly heterogeneous and indicative of publication bias. The majority of studies were conducted on persons living with human immunodeficiency virus infection (PLHIV). The studies were predominantly from low-income and middle-income Asian countries. The most common cause was parasitic, with a pooled prevalence of 0.52 (95% confidence interval 0.28-0.65, I2 = 99%, Cochran's Q = 1027.44, P < 0.01), followed by bacterial, fungal, and viral causes, which were substantially rarer. Negative microbiological testing was also common, with a pooled prevalence for a negative test being 0.37 (95% confidence interval 0.17-0.52, I2 = 99%, Cochran's Q = 1027.44, P < 0.01). Subgroup analyses of studies conducted among PLHIV, from year 2000 and among those conducted in Southeast Asia showed a similar prevalence of parasitic causes of diarrhea. In conclusion, in Asian adults with persistent and chronic diarrhea, parasitic causes were most prevalent. However, the estimate of true prevalence is limited by significant heterogeneity among the available studies. More study in this field is required, especially examining PLHIV in the post-antiretroviral therapy era and from high-income countries.

Insights and future prospects of traditional Chinese medicine in the treatment of functional dyspepsia.

BACKGROUND: Functional dyspepsia (FD) is a prevalent and challenging gastrointestinal disorder. Conventional medicine often faces limitations in providing effective treatment for FD, thus indicating the need to explore alternative approaches. Traditional Chinese medicine (TCM), which is rooted in ancient Chinese traditions and has evolved over thousands of years, offers a holistic approach to well-being. TCM incorporates herbal remedies, acupuncture, and other therapies while shaping the future of complementary and alternative medicine. PURPOSE: To review the existing literature on the current status and future prospects of using TCM to treat FD. METHODS: We extensively searched the PubMed, Google Scholar, Embase, an China National Knowledge Internet databases from inception to May 31, 2023 to identify relevant literature. We also searched the reference lists of the included articles. RESULTS: Clinical evidence-based research has explored the efficacy of TCM in treating FD. Recent research has illuminated the multifaceted mechanisms through which TCM interventions affect FD. TCM is a promising alternative, as it emphasizes a holistic approach and holds potential advantages in addressing the complex nature of FD. CONCLUSIONS: The integration of TCM and Western medicine offers a comprehensive approach to understanding and managing FD by bridging traditional wisdom with modern scientific understanding. This paper highlights the practical implications of this integration, the challenges to be addressed, and the potential for international collaboration to further elucidate the efficacy of TCM. However, continued research and dialog are needed to advance the modern development of TCM and to improve the quality of life of FD patients.

Chemical structures, extraction and analysis technologies, and bioactivities of edible fungal polysaccharides from Poria cocos: An updated review.

Poria cocos is a popular medicinal food. Polysaccharides are the key component of Poria cocos, forming 70-90 % of the dry sclerotia mass. Recent studies indicate that Poria cocos polysaccharides (PCP-Cs) have multiple beneficial functions and applications. A literature search was conducted using the Web of Science Core Collection and PubMed databases. For this review, we provided an updated research progress in chemical structures, various extraction and analysis technologies, bioactivities of PCP-Cs, and insights into the directions for future research. The main polysaccharides identified in Poria cocos are water-soluble polysaccharides and acidic polysaccharides. Hot water, alkali, supercritical fluid, ultrasonic, enzyme, and deep eutectic solvent-based methods are the most common methods for PCP-Cs extraction. Technologies such as near-infrared spectroscopy, high-performance liquid chromatography, and ultraviolet-visible spectrophotometry, are commonly used to evaluate the qualities of PCP-Cs. In addition, PCP-Cs have antioxidant, immunomodulatory, neuroregulatory, anticancer, hepatoprotective, and gut microbiota regulatory properties. Future research is needed to focus on scaling up extraction, enhancing quality control, elucidating mechanisms of bioactivities, and the utilisation of PCP-Cs in food industries. Overall, Poria cocos is a good source of edible fungi polysaccharides, which can be developed into functional foods with potential health benefits.

Proton Pump Inhibitors Increases Longitudinal Risk of Mortality, Decompensation, and Infection in Cirrhosis: A Meta-Analysis.

BACKGROUND/AIMS: Proton pump inhibitors (PPIs) are frequently prescribed to cirrhotic patients, but there is limited longitudinal evidence regarding their effects. This study aimed to assess the impact of PPIs on adverse events in cirrhotic patients. METHODS: A comprehensive search was conducted using the Medline and Embase databases to identify relevant articles. Pooled hazard ratios (HRs) using DerSimonian and Laird random-effects model were calculated to evaluate the risk of adverse events such as long-term mortality, hepatic decompensation, hepatic encephalopathy (HE), spontaneous bacterial peritonitis (SBP), and overall infection in cirrhotic patients with PPI use. RESULTS: The analysis included 28 studies with 260,854 cirrhotic patients. The prevalence of PPI use among cirrhotic patients was 55.93%. The use of PPIs was not significantly associated with short-term mortality in cirrhotic patients. However, long-term mortality (HR 1.321, 95% CI 1.103-1.581, P = 0.002), decompensation (HR 1.646, 95% CI 1.477-1.835, P < 0.001), HE (HR 1.968, 95% CI 1.372-2.822, P < 0.001), SBP (HR 1.751, 95% CI 1.649-1.859, P < 0.001), and infection (HR 1.370, 95% CI 1.148-1.634, P < 0.001) were significantly associated with PPI use. Sensitivity analysis with prospective studies yielded similar results. CONCLUSION: PPIs should be reserved for appropriate indications at lowest effective dose for cirrhotic patients due to the potential harm.

Involving patients in the process: Development of a constipation patient-reported outcome measure for symptoms and quality of life.

Objective: Patient-reported outcome measures (PROMs) are useful standardized tools to measure current patient health status and well-being. While there are existing constipation-related PROMs, the majority of PROMs were not developed with adequate patient involvement and few examined content validity. Accordingly, the current study aimed to develop a constipation PROM with multiple phases of patient and clinician involvement. Methods: To generate PROM items, 15 patients with chronic constipation (age range =28-79 years, 10 females) underwent a qualitative interview exploring their experiences with chronic constipation. Following that, eight clinical experts completed the content validity index (CVI) ratings of all the items generated to assess content validity. Based on results of the content validity assessment, relevant items were maintained and 12 participants with chronic constipation were re-interviewed to obtain feedback about comprehensibility, comprehensiveness and relevance. Results: Six themes and 25 sub-themes emerged from the qualitative interview, and an initial list of 33 symptom items and 18 quality of life (QoL) items were generated. Based on the CVIs calculated, 11 symptom items and nine QoL items were maintained with the scale-content validity index indicating excellent content validity. Overall, participants indicated the PROM to be relevant, comprehensive and easy to understand however, minor amendments were made to improve the three qualities of interest. Conclusion: The current study developed a constipation PROM that measures both symptom severity and constipation-related QoL, with supporting evidence for relevance, comprehensiveness and comprehensibility. Further prioritization should be given to validating and exploring new digital modalities of PROM administration.

Dental trauma in endoscopy: A systematic review and experience of a tertiary endoscopy centre.

BACKGROUND: Dental injury is the leading cause of litigation in anaesthesia but an underrecognized preventable complication of endoscopy. AIM: To determine frequency and effects of dental injury in endoscopy, we present findings from an audit of outpatient endoscopy procedures conducted at a tertiary university hospital and a systematic review of literature. METHODS: Retrospective review of 11265 outpatient upper endoscopy procedures over the period of 1 June 2019 to 31 May 2021 identified dental related complications in 0.284% of procedures. Review of literature identified a similar rate of 0.33%. RESULTS: Pre-existing dental pathology or the presence of prostheses makes damage more likely but sound teeth may be affected. Pre-endoscopic history and tooth examination are key for risk stratification and may be conducted succinctly with limited time outlay. Tooth retrieval should be prioritized in the event of dental injury to minimize aspiration and be followed by prompt dental consultation for specific management. CONCLUSION: Dental complications occur in approximately 1 in 300 of upper endoscopy cases. These are easily preventable by pre-endoscopy screening. Protocols to mitigate dental injury are also suggested.

Associations between irritable bowel syndrome and non-alcoholic fatty liver disease: A systematic review.

BACKGROUND: Irritable bowel syndrome (IBS) is associated with obesity and metabolic syndrome. IBS and non-alcoholic fatty liver disease (NAFLD) are highly prevalent entities worldwide and may share similar mechanisms including gut dysbiosis, impaired intestinal mucosal barrier and immune system activation. AIM: To systematically review their association according to the Preferred Reporting Items for Systemic Review and Meta-analyses guidelines. METHODS: PubMed, EMBASE and Cochrane Database of Systematic Reviews were searched for relevant papers. Manual searches were also performed. RESULTS: Six studies were included. Both IBS and NAFLD subjects had significantly more metabolic risk factors like hypertension, obesity, dyslipidaemia and diabetes. Our review showed that 23.2% to 29.4% of NAFLD patients had IBS. IBS was significantly higher in NAFLD patients compared with patients without NAFLD (23.2% vs 12.5%, P < 0.01). A higher proportion of IBS patients had NAFLD (65.8% to 74.0%). IBS patients were three times more likely to have NAFLD compared with non-IBS patients (P < 0.001). Two studies showed a significant correlation between the severity of IBS and NAFLD. The proportion of NAFLD subjects with IBS increased with NAFLD severity. CONCLUSION: Further prospective studies are warranted to evaluate the relationship and shared pathways between IBS and NAFLD, potentially leading to the development of future therapeutics.

Comparison of LED and LASER Colonoscopy About Linked Color Imaging and Blue Laser/Light Imaging of Colorectal Tumors in a Multinational Study.

INTRODUCTION: In light-emitting diode (LED) and LASER colonoscopy, linked color imaging (LCI) and blue light/laser imaging (BLI) are used for lesion detection and characterization worldwide. We analyzed the difference of LCI and BLI images of colorectal lesions between LED and LASER in a multinational study. METHODS: We prospectively observed lesions with white light imaging (WLI), LCI, and BLI using both LED and LASER colonoscopies from January 2020 to August 2021. Images were graded by 27 endoscopists from nine countries using the polyp visibility score: 4 (excellent), 3 (good), 2 (fair), and 1 (poor) and the comparison score (LED better/similar/LASER better) for WLI/LCI/BLI images of each lesion. RESULTS: Finally, 32 lesions (polyp size: 20.0 ± 15.2 mm) including 9 serrated lesions, 13 adenomas, and 10 T1 cancers were evaluated. The polyp visibility scores of LCI/WLI for international and Japan-expert endoscopists were 3.17 ± 0.73/3.17 ± 0.79 (p = 0.92) and 3.34 ± 0.78/2.84 ± 1.22 (p < 0.01) for LED and 3.30 ± 0.71/3.12 ± 0.77 (p < 0.01) and 3.31 ± 0.82/2.78 ± 1.23 (p < 0.01) for LASER. Regarding the comparison of lesion visibility about between LED and LASER colonoscopy in international endoscopists, a significant difference was achieved not for WLI, but for LCI. The rates of LED better/similar/LASER better for brightness under WLI were 54.5%/31.6%/13.9% (International) and 75.0%/21.9%/3.1% (Japan expert). Those under LCI were 39.2%/35.4%/25.3% (International) and 31.3%/53.1%/15.6% (Japan expert). There were no significant differences in the diagnostic accuracy and the comparison score of BLI images between LED and LASER. CONCLUSIONS: The differences of lesion visibility for WLI/LCI/BLI between LED and LASER in international endoscopists could be compared to those in Japanese endoscopists.

Comparison of pancreatic enzyme abnormalities and protease-activated receptor-2-positive eosinophils in the duodenum of patients with functional dyspepsia-irritable bowel syndrome overlap with functional dyspepsia alone in Asian populations.

BACKGROUND AND AIM: Some patients with functional gastrointestinal disorders exhibit pancreatic dysfunctions and pancreatic enzyme abnormalities. Thus, we aimed to clarify whether significant differences in clinical characteristics, prevalence of pancreatic enzyme abnormalities, duodenal inflammation, and protease-activated receptor 2 (PAR2) expression levels related to hypersensitivity exist between functional dyspepsia (FD) alone and FD-irritable bowel syndrome (IBS) overlap group. METHODS: Ninety-three patients based on the Rome IV criteria, FD alone (n = 44) and FD overlapped with IBS (n = 49) group were enrolled. The patients scored their own clinical symptoms after consuming high-fat meals. Serum trypsin, PLA2, lipase, p-amylase, and elastase-1 levels were measured. PAR2, eotaxin-3, and TRPV4 mRNA levels in duodenum were determined using real-time polymerase chain reaction methods. PRG2- and PAR2 in the duodenum were evaluated using immunostaining. RESULTS: FD score and global GSRS in patients with FD-IBS overlap were significantly higher than FD alone. Although the prevalence of pancreatic enzyme abnormalities in patients with FD alone was significantly (P < 0.01) higher than that in FD-IBS overlap, the ratio of aggravation of clinical symptoms following high-fat intake in patients with FD-IBS overlap was significantly higher (P = 0.007) than that in patients with FD alone. PAR2- and PRG2-double positive cells were localized in the degranulated eosinophils in the duodenum of patients with FD-IBS overlap. The number of PAR2- and PRG2-double positive cells in FD-IBS overlap was significantly (P < 0.01) higher than FD alone. CONCLUSIONS: Pancreatic enzyme abnormalities and PAR2 expression on degranulated eosinophils infiltrations in the duodenum may be associated with the pathophysiology of patients with FD-IBS overlap in Asian populations.

Volatile organic compounds as potential biomarkers of irritable bowel syndrome: A systematic review.

BACKGROUND: Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disease characterized by intermittent abdominal pain with altered bowel habits. Due to the condition's chronicity, patients suffer from poor quality of life, while the healthcare burden continues to grow. There is currently no reliable biomarker for the diagnosis of IBS, and the current approach depends on ruling-out organic diseases such as inflammatory bowel disease (IBD) and colorectal cancer by markers of inflammation like fecal calprotectin and C-reactive protein, or invasive procedures like a colonoscopy. Volatile organic compounds (VOCs) are growing in popularity as a biomarker due to its accuracy and ease of use. PURPOSE: This systematic review of Medline and Cochrane's databases aimed to identify VOCs in the diagnosis of IBS. 57% of the studies proved that VOCs could identify IBS patients from healthy controls with AUC ranging from 0.83 to 0.99. Studies that distinguished IBS from IBD patients had slightly higher AUC of 0.87-0.98. Combining VOC into panels allowed the creation of discriminative algorithms. Though current research is limited by areas of heterogeneity in VOC sampling and small sample sizes, our review shows that VOC analysis has the potential to be a noninvasive point-of-care test that differentiates IBS from other organic gastrointestinal diseases.

Asia-Pacific guidelines for managing functional dyspepsia overlapping with other gastrointestinal symptoms.

Contemporary systems for the diagnosis and management gastrointestinal symptoms not attributable to organic diseases (Functional GI Disorders, FGID, now renamed Disorders of Gut-Brain Interaction, DGBI) seek to categorize patients into narrowly defined symptom-based sub-classes to enable targeted treatment of patient cohorts with similar underlying putative pathophysiology. However, an overlap of symptom categories frequently occurs and has a negative impact on treatment outcomes. There is a lack of guidance on their management. An Asian Pacific Association of Gastroenterology (APAGE) working group was set up to develop clinical practice guidelines for management of patients with functional dyspepsia (FD) who have an overlap with another functional gastrointestinal disorder: FD with gastroesophageal reflux (FD-GERD), epigastric pain syndrome with irritable bowel syndrome (EPS-IBS), postprandial distress syndrome with IBS (PDS-IBS), and FD-Constipation. We identified putative pathophysiology to provide a basis for treatment recommendations. A management algorithm is presented to guide primary and secondary care clinicians.

Factors early in life associated with hepatic steatosis.

BACKGROUND: The rise in prevalence of non-alcoholic fatty liver disease (NAFLD) mirrors the obesity epidemic. NAFLD is insidious but may gradually progress from simple steatosis to steatohepatitis, fibrosis and cirrhosis and/or hepatocellular carcinoma. Intervention strategies to ameliorate developmental programming of NAFLD may be more efficacious during critical windows of developmental plasticity. AIM: To review the early developmental factors associated with NAFLD. METHODS: Databases MEDLINE via PubMed, and EMBASE and Reference Citation Analysis were searched and relevant publications up to April 30, 2021 were assessed. Original research studies that included risk factors associated with early development of NAFLD in human subjects were included. These factors include: Maternal factors, intrauterine and prenatal factors, post-natal factors, genetic and ethnic predisposition, childhood and adolescence environmental factors. Studies were excluded if they were review articles or animal studies, case reports or conference abstracts, or if NAFLD was not clearly defined and assessed radiologically. RESULTS: Of 1530 citations identified by electronic search, 420 duplicates were removed. Of the 1110 citations screened from title and abstract, 80 articles were included in the final analysis. Genetic polymorphisms such as patatin-like phospholipase domain-containing protein 3 (PNPLA3) and membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) were associated with increased risk of NAFLD. Familial factors such as maternal obesogenic environment and parental history of hepatic steatosis was associated with offspring NAFLD. Longer duration of exclusive breastfeeding in infancy was associated with a lower risk of developing NAFLD later in life while metabolic dysfunction and/or obesity in adolescence was associated with increased risk of NAFLD. Studies relating to socioeconomic factors and its association with NAFLD reported confounding results. CONCLUSION: Maternal metabolic dysfunction during pregnancy, being exclusively breastfed for a longer time postnatally, diet and physical activity in childhood and adolescence are potential areas of intervention to decrease risk of NAFLD.

Understanding the user: Patients' perception, needs, and concerns of health apps for chronic constipation.

Objective: Chronic constipation is a prevalent gastrointestinal disorder that requires long-term management and treatment adherence. With increasing smartphone usage, health app adoption represents an opportunity to incorporate personalized, patient-led care into chronic constipation management. Despite the number of apps available targeting patients with constipation, studies have not yet examined user needs and barriers towards successful app adoption and sustained usage. Accordingly, the current study explored user perception, needs, and concerns of health apps in patients with chronic constipation. Methods: Fifteen participants with chronic constipation (age range = 28-79 years, 10 females) in Singapore completed a 60 min semi-structured qualitative interview exploring participant's experiences with and attitudes towards chronic constipation and health apps. Participants also completed two questionnaires regarding their constipation symptoms and general technology usage. Interviews were audio-recorded, transcribed verbatim, and coded using NVivo. Results: Four themes and 10 sub-themes were identified using inductive thematic analysis. Themes and sub-themes cover importance of patient identity, disease-based expectations of health apps, barriers towards adoption and sustained usage of health apps, necessary conditions when adopting health apps (including perception of supportive benefits, clear understanding of app intention, personalized technology, and trusted sources), and push factor expectations which includes creative engagement and incentivization embedded within the app. Conclusion: The findings captured barriers and key elements necessary for successful health app adoption and continued usage by patients with chronic constipation. Identified elements that matter to patients can provide app developers with user-focused insights and recommendations to develop effective health apps that sustain user engagement.

Association between irritable bowel syndrome and micronutrients: A systematic review.

BACKGROUND AND AIM: Irritable bowel syndrome (IBS) is a highly prevalent disorder of gut brain interaction with a multifactorial etiology. Food trigger avoidance is common among individuals with IBS and exclusion diets are gaining popularity. However, recent guidelines on IBS management cautioned regarding the use of unsupervised dietary therapy with concerns of development of poor eating habits and even nutritional deficiencies. We aimed to review the available literature on the effect of habitual and exclusion diets on micronutrient status as well as the role of micronutrient supplementation in alleviating IBS symptoms. METHODS: Four electronic databases (PubMed, Embase, Cochrane, Web of Science) were searched for articles that reported micronutrient data in patients with IBS. Serum micronutrient levels and dietary intake of micronutrients in patients with IBS were collected. The extracted data were tabulated and organized by micronutrient type to observe for trends. RESULTS: Twenty-six articles were included in this systematic review (12 interventional and 14 observational studies). Studies showed that generally IBS subjects had lower levels of vitamin B2, vitamin D, calcium, and iron at baseline compared with non-IBS subjects. Studies also found that exclusion diets were associated with lower intake of micronutrients especially vitamin B1, B2, calcium, iron, and zinc. There was a lack of interventional studies on micronutrients. CONCLUSION: Irritable bowel syndrome patients are at risk of developing multiple micronutrient deficiencies that may have both localized gastrointestinal as well as systemic effects. Dietary management of IBS patients should include a proper dietitian review to ensure nutritional adequacy where possible.

Comparison of clinical characteristics, eating behaviors, and clinical symptoms following fat intake in functional dyspepsia with functional dyspepsia with pancreatic enzyme abnormalities between Singapore and Japan.

BACKGROUND AND AIM: To clarify whether there were any significant differences in clinical symptoms and eating patterns between functional dyspepsia (FD) patients and FD with pancreatic enzyme abnormalities (FD-P) patients as refractory FD, we compared these factors in multicenter studies in Singapore and Japan. METHODS: One hundred ninety-eight consecutive patients presenting with FD (n = 88), FD-P patients (n = 81) based on Rome III classification and controlled group (n = 39) recruited from six institutions in Singapore and Japan. Clinical characteristics, clinical symptoms for dietary fat intake, and eating behaviors were estimated using questionnaires. Anxiety and health-related quality of life were determined by STAI-state/-trait and SF-8, respectively. RESULTS: There were no significant differences in age, sex, BMI, smoking, alcohol intake, past medical history, and history of allergy in FD and FD-P patients between Singapore and Japan. There were no significant differences in FD subtypes, gastrointestinal symptom rating scale score, severity of FD symptoms, and eating pattern in Singapore and Japan. Moreover, there were significant differences in certain eating behaviors between FD and FD-P patients in Singapore and Japan. Interestingly, epigastric pain and early satiety following fat meals in FD-P patients were significantly (P = 0.003 and P = 0.008, respectively) higher compared with those in FD patients in Japan. Physical component score in FD-P patients was significantly (P = 0.019) disturbed compared with those in FD patients in Japan. CONCLUSIONS: Epigastric pain and early satiety following fat meals in FD-P patients may be useful tools to differentiate FD-P patients from FD patients in Japan.