High prevalence of irritable bowel syndrome in medical outpatients in Japan

Characteristics of disorders of gut-brain interaction in the Japanese population in the Rome Foundation Global Epidemiological Study

BACKGROUND

The aims were to use Japanese data from the Rome Foundation Global Epidemiological Study (RFGES) to test the hypotheses that severity of gastrointestinal (GI) symptoms and psychosocial disturbance are ordered as Rome IV irritable bowel syndrome (IBS) > Rome III IBS > DGBI, not IBS > others.

METHODS

Subjects were 2504 Japanese in the RFGES. We assessed DGBI/IBS diagnoses with Rome IV/III, IBS Symptom Severity Scale (IBS-SSS), Patient Health Questionnaire (PHQ) for anxiety/depression and non-GI somatic symptoms, PROMIS-10 for quality of life (QOL), Work Productivity and Activity Impairment (WPAI) Questionnaire, parts of Self-reported IBS Questionnaire (SIBSQ) for meal effect and stress effect, Food Frequency Questionnaire, and medication questions.

KEY RESULTS

The prevalence of Rome IV DGBI was as follows; IBS-C 0.5%, IBS-D 0.8%, IBS-M 0.8%, IBS-U 0.1%, unspecified functional bowel disorder 10.7%, postprandial distress syndrome 2.2%, and epigastric pain syndrome 0.3%. Rome III IBS prevalence; IBS-C 3.0%, IBS-D 3.1%, IBS-M 2.7%, and IBS-U 0.6%. Comparison among Rome IV IBS (n = 54), Rome III IBS (n = 197), other DGBI (n = 746), others (n = 1389) revealed significant order as Rome IV IBS > Rome III IBS > other DGBI > others in IBS-SSS, anxiety/depression, activity impairment, non-GI symptoms, physical QOL, mental QOL, exacerbated symptoms by meals and perceived stress (all p < 0.001).

CONCLUSIONS & INFERENCES

These findings support the study hypotheses. Data from Japan as a culturally homogenous country suggest Rome IV IBS is more severe and hence has more gut-brain psychobehavioral involvement than Rome III IBS.

Maternal separation and TNBS-induced gut inflammation synergistically alter the sexually differentiated stress response in rats

BACKGROUND

Neonatal maternal separation (MS) has been used to model long-lasting changes in behavior caused by neuroplastic changes associated with exposure to early-life stress. Earlier studies showed that transient gut inflammation can influence the development of irritable bowel syndrome (IBS). A prevailing paradigm of the etiology of IBS is that transient noxious events lead to long-lasting sensitization of the neural pain circuit, despite complete resolution of the initiating event. This study characterizes the changes in behaviors and neuroendocrine parameters after MS and early-phase trinitrobenzene sulfonic acid (TNBS)-induced colitis. We tested the hypothesis that MS and gut inflammation synergistically induce (1) hyperactivity in male rats and anxiety-like behaviors in female rats and (2) activation of the HPA axis in female rats and deactivation of the HPA axis in male rats after colorectal distention (CRD).

METHODS

Male and female rat pups were separated from their dams for 180 min daily from postnatal day (PND) 2 to PND 14 (MS). Early-phase colitis was induced by colorectal administration with TNBS on PND 8. The elevated plus-maze test was performed at 7 weeks. Tonic CRD was performed at 60 mmHg for 15 min at 8 weeks. Plasma ACTH and serum corticosterone were measured at baseline or after the CRD. Analysis of variance was performed for comparison among controls, TNBS, MS, and MS + TNBS.

RESULTS

In male rats, the time spent in open arms significantly differed among the groups (p < 0.005). The time spent in open arms in male MS + TNBS rats was significantly higher than that of controls (p < 0.009) or TNBS rats (p < 0.031, post hoc test). Female rats showed no difference in the time spent in open arms among the groups. MS and gut inflammation induced an increase in plasma ACTH in female rats but not in male rats at baseline.

CONCLUSIONS

These findings suggest that MS and gut inflammation synergistically induce hyperactive behavior or exaggerated hypothalamic-pituitary-adrenal axis function depending on sex.

The relationship between meal regularity with Irritable Bowel Syndrome (IBS) in adults

BACKGROUND

The irregular meal pattern and meal-skipping might be related to irritable bowel syndrome (IBS), however, findings of previous investigations are contradictory. We aimed to examine the relation of meal regularity with IBS in Iranian adult population.

METHODS

Data on 4599 adults who worked in 50 different health centers were used in this cross-sectional study. Dietary habits were measured using a pretested questionnaire. IBS identification was performed through the use of a modified version of Rome III questionnaire.

RESULTS

IBS was prevalent among 18.6% of men and 24.1% of women. After adjustment for potential confounders, those with regular meal pattern, in comparison to those with irregular meals, had 40% lower odds for IBS (OR:0.60, 95%CI: 0.41-0.87). Individuals with regular meals had also 82 lower risk for IBS-Mixed, in comparison to those who had irregular meals (OR:0.18, 0.95%CI: 0.08-0.43). Stratified analysis by gender revealed that women with regular meals, compared with those who did not, had 44% lower risk for IBS (OR: 0.56, 0.95%CI: 0.34-0.91). Normal-weight individuals who had regular meal pattern, compared to those who did not, had 63% lower risks for IBS (OR:0.37, 95%CI: 0.22-0.64). Furthermore, subjects who had regular meal pattern had 53% lower risk for severe symptoms of IBS (OR:0.47, 95%CI: 0.30-0.71).

CONCLUSION

We found that participants with regular meal pattern had reduced odds of IBS, IBS-Mixed and the syndrome severity. Meal regularity was also linked to reduced IBS prevalence in women, and in normal-weight individuals. More prospective studies are needed to affirm these associations.

Review article: epidemiology of IBS and other bowel disorders of gut-brain interaction (DGBI)

The disorders of gut-brain interactions (DGBI) are a spectrum of gastrointestinal (GI) disorders that involve the entire GI tract and are usually categorised into four major anatomic GI regions, oesophageal, gastroduodenal, bowel and anorectal. Irritable bowel syndrome (IBS), a bowel DGBI, is one of the most researched DGBI and has been the subject of copious epidemiological studies. Prevalence rates are based on diagnostic criteria. In the case of IBS, there are three central obstacles to attaining a clear picture of prevalence: the absence of biomarkers, the multitude of diagnostic criteria used over the years, and the heterogeneous nature of the methodology used in epidemiologic surveys. When the results of multiple studies, conducted over a long period of time, using different diagnostic criteria and different research methodology, and involving different study populations are pooled to determine a single summary prevalence rate it is difficult to interpret the results and to determine their reliability and significance. This pitfall is insufficiently recognised and unfortunate because prevalence rates are important for understanding the burden of disease, for allocating healthcare and research resources, and for incentivising and prioritising new treatments. The aims of the present paper are to highlight our knowledge and understanding of IBS epidemiology within the context of other DGBI, and to present strategies to improve epidemiological research, especially in advance of the new Rome V criteria, to be published in 2026.

Development of colonic transit time and ultrasound imaging tools as objective indicators for assessing abnormal defecation associated with food intake: a narrative review based on previous scientific knowledge

Background

Functional gastrointestinal disorders (FGIDs) involve chronic or persistent gastrointestinal symptoms. Laboratory tests show no organic lesions, and the symptoms are due to dysfunction. The most typical FGID is irritable bowel syndrome (IBS). In IBS patients, defecation disorders are common and have adverse effects on daily life. The proper evaluation and analysis of colonic transit are important for the management of defecation disorders in IBS patients. In addition, dietary intake and lifestyle affect colonic transit. An accurate assessment of such factors can guide management, leading to improvements in colonic transit and the resolution of defecation disorders.

Main topic

The Rome IV diagnostic criteria for IBS are based on subjective symptoms, which must be communicated and explained by the patient, limiting their application. Colonic transit time and ultrasonography are objective tools that can be used to diagnose IBS. In particular, previous studies used colonic transit to accurately distinguish between constipation and normal stool passage and to assess delayed gastrointestinal motility. Diet and lifestyle modifications can improve colonic transit and ameliorate bowel dysfunction.

Conclusion

Colonic transit can be improved by modifying lifestyle factors. Defecation disorders in IBS patients may be resolved by focusing on such factors. In the future, methods of visualizing defecation disorders due to impaired gastrointestinal motility and objective indicators of the associated abdominal symptoms need to be investigated.

Epidemiology and Burden of Irritable Bowel Syndrome: An International Perspective

Irritable bowel syndrome (IBS) prevalence rates are based on diagnostic criteria, the basis for case definitions. Diagnostic criteria have a substantial impact on prevalence rates, which are significant for understanding burden of disease, comparing global subpopulations, generating pathophysiologic research, allocating of health care and research resources, and incentivizing and prioritizing new treatments. There are substantial methodological pitfalls in epidemiologic research, so determining regional and global IBS prevalence rates is problematic. The Rome Foundation Global Epidemiology Study was designed to resolve these problems and achieve more valid results. The results of this study are presented in detail; future directions are discussed.

Characteristic dysbiosis of gut microbiota of Chinese patients with diarrhea-predominant irritable bowel syndrome by an insight into the pan-microbiome

Background:

Irritable bowel syndrome (IBS) is reported associated with the alteration of gut microbial composition termed as dysbiosis. However, the pathogenic mechanism of IBS remains unclear, while the studies of Chinese individuals are scarce. This study aimed to understand the concept of dysbiosis among patients with Chinese diarrhea-predominant IBS (IBS-D), as a degree of variance between the gut microbiomes of IBS-D population and that of a healthy population.

Methods:

The patients with IBS-D were recruited (assessed according to the Rome III criteria, by IBS symptom severity score) from the Outpatient Department of Gastroenterology of Peking University Third Hospital, and volunteers as healthy controls (HCs) were enrolled, during 2013. The 16S rRNA sequences were extracted from fecal samples. Ribosomal database project resources, basic local alignment search tool, and SparCC software were used to obtain the phylotype composition of samples and the internal interactions of the microbial community. Herein, the non-parametric test, Wilcoxon rank-sum test was carried out to find the statistical significance between HC and IBS-D groups. All the P values were adjusted to q values to decrease the error rate.

Results:

The study characterized the gut microbiomes of Chinese patients with IBS-D, and demonstrated that the dysbiosis could be characterized as directed alteration of the microbiome composition leading to greater disparity between relative abundance of two phyla, Bacteroidetes (Z = 4.77, q = 1.59 × 10^–5) and Firmicutes (Z = –3.87, q = 5.83 × 10^–4). Moreover, it indicated that the IBS symptom features were associated with the dysbiosis of whole gut microbiome, instead of one or several certain genera even they were dominating. Two genera, Bacteroides and Lachnospiracea incertae sedis, were identified as the core genera, meanwhile, the non-core genera contribute to a larger pan-microbiome of the gut microbiome. Furthermore, the dysbiosis in patients with IBS-D was associated with a reduction of network complexity of the interacted microbial community (HC vs. IBS-D: 639 vs. 154). The disordered metabolic functions of patients with IBS-D were identified as the potential influence of gut microbiome on the host (significant difference with q < 0.01 between HC and IBS-D).

Conclusions:

This study supported the view of the potential influence of gut microbiome on the symptom of Chinese patients with IBS-D, and further characterized dysbiosis in Chinese patients with IBS-D, thus provided more pathological evidences for IBS-D with the further understanding of dysbiosis.

Second Asian Consensus on Irritable Bowel Syndrome

BACKGROUND/AIMS

There has been major progress in our understanding of the irritable bowel syndrome (IBS), and novel treatment classes have emerged. The Rome IV guidelines were published in 2016 and together with the growing body of Asian data on IBS, we felt it is timely to update the Asian IBS Consensus.

METHODS

Key opinion leaders from Asian countries were organized into 4 teams to review 4 themes: symptoms and epidemiology, pathophysiology, diagnosis and investigations, and lifestyle modifications and treatments. The consensus development process was carried out by using a modified Delphi method.

RESULTS

Thirty-seven statements were developed. Asian data substantiate the current global viewpoint that IBS is a disorder of gut-brain interaction. Socio-cultural and environmental factors in Asia appear to influence the greater overlap between IBS and upper gastrointestinal symptoms. New classes of treatments comprising low fermentable oligo-, di-, monosacharides, and polyols diet, probiotics, non-absorbable antibiotics, and secretagogues have good evidence base for their efficacy.

CONCLUSIONS

Our consensus is that all patients with functional gastrointestinal disorders should be evaluated comprehensively with a view to holistic management. Physicians should be encouraged to take a positive attitude to the treatment outcomes for IBS patients.

Prevalence of sleep disorder in irritable bowel syndrome: A systematic review with meta-analysis

Background/Aims

We conducted this meta-analysis to evaluate the prevalence of sleep disorder in irritable bowel syndrome (IBS) patients and study the association between IBS and sleep disorder.

Materials and Methods

A systematic search was conducted by searching PubMed, Embase, and Cochrane library databases using the following search terms: "functional gastrointestinal disorders," "Sleep disturbance," "Sleep disorder," "insomnia," "Dysomnias," "irritable bowel syndrome," and "IBS." Studies evaluating the association between IBS and sleep disorder were identified. Data analysis was conducted using meta-analysis software Comprehensive Meta-Analysis (CMA) 2.0. Heterogeneity across studies was evaluated by χ2and I2statistics. Publication bias was evaluated by funnel plot, Begg's test, and Egger's test. Sensitivity analysis was also performed by removing each single study separately.

Results

The bibliographical search yielded a total of 2866 studies. Finally, 36 studies including 63620 participants were identified. The prevalence of sleep disorder in IBS was 37.6% (95% CI: 31.4% to 44.3%) based on this meta-analysis. The pooled odds ratio was 2.618 (95% CI: 2.052% to 3.341). Publication bias was not determined. Regarding the sensitivity analysis, the outcome was stable regardless of which study was removed.

Conclusions

The prevalence of sleep disorder was higher in IBS compared to healthy controls and may be associated with the pathogenesis of IBS. The prevalence of sleep disorder in IBS may differ according to different areas, age, gender, occupation, and IBS diagnostic criteria. Further studies are needed to investigate any possible causal relationship between sleep disorder and IBS.

Empirically derived dietary habits are associated with irritable bowel syndrome

BACKGROUND/OBJECTIVES

The associations between empirically derived dietary habits and irritable bowel syndrome (IBS) have not been investigated. This study aimed to assess the relationship between empirically derived dietary habits and IBS in a large population of Iranian adults.

SUBJECTS/METHODS

In a cross-sectional study, dietary habits of 4763 adults were assessed in three domains, "meal pattern", "eating rate" and "intra-meal fluid intake". We used latent class analysis to identify classes of dietary habits. IBS was defined based on ROME III criteria.

RESULTS

IBS was prevalent in 20.3% (n = 966) of the study population. Two distinct classes of meal patterns: "regular" and "irregular", three classes of eating rates: "moderate", "moderate-to-slow" and "moderate-to-fast" and two classes of fluid ingestion with meals: "moderate" and "heavy intra-meal drinking" were identified. After adjustment for confounders, "heavy intra-meal fluid intake" was protectively associated with IBS (OR = 0.79; 95% CI:0.64-0.96). When potential confounders were considered, "meal pattern" and "eating rate" were not significantly associated with IBS in the whole population. After adjustment for confounders, women with "irregular meal pattern" had a 30% greater risk of having IBS, compared with those with "regular meal pattern" (OR = 1.30; 95% CI:1.02-1.67). Overweight participants with "fast eating rate" were 70% more likely to have IBS, compared to those with "moderate eating rate" (OR = 1.70; 95% CI:1.13-2.55). "Irregular meal pattern" was related to frequency and severity of abdominal pain.

CONCLUSIONS

We found a significant association between heavy intra-meal fluid intake" and IBS. More large-scale prospective studies are needed to affirm this association.

Change of appetite in patients with functional digestive disorder. Association with psychological disorders: A cross-sectional study

BACKGROUND AND AIMS

Changes in appetite are a frequent complaint in patients with functional gastrointestinal disorders (FGIDs). The aims of this study are to evaluate whether the changes in appetite are associated with specific FGIDs and to explore associations of these changes with symptoms of anxiety or depression.

METHODS

This study included 1009 consecutive FGID patients (71% female), aged 48.9 years who all filled out a Rome III questionnaire for the evaluation of FGIDs, submitted to a psychological evaluation of symptoms of anxiety, and completed the Beck Depression Inventory questionnaire. The patients were classified according to their appetite change using a 7-point grading scale and split into three groups: those with appetite loss, those with no change in appetite, and those with increased appetite.

RESULTS

Among the 1009, 496 patients (49%) reported a change in appetite, of which 332 (33%) patients reported a decrease in appetite and 164 (16%) patients reported an increase in appetite. Appetite was not affected in 51% of patients. Changes in appetite depended on gender, body mass index and psychometric evaluation scores. Increased appetite did not have specific FGIDs associations, while decreased appetite was associated with esophageal, gastroduodenal, bowel, and anorectal symptoms. The presence of depressive symptoms was also a predictor for the majority of FGIDs in decreased appetite, while anxiety trait was significant for globus and dysphagia.

CONCLUSIONS

Decreased appetite was associated with FGIDs, especially in the presence of depressive symptoms. A reduced appetite would help to predict psychological disorders associated with FGIDs.

FINANCIAL DISCLOSURE

None declared.

LEGAL REGISTRATION

This study was a registered study in the French National Drug Agency (ANSM, Agence Nationale de Securité du Medicamentet des produits de santé, Study Number 2016-A01120-51).

COMPETING INTERESTS

Michel Bouchoucha, Marinos Fysekidis, Florence Mary, Gheorghe Airinei, Cyriaque Bon, and Robert Benamouzig have no competitive interests.

Smoking in Irritable Bowel Syndrome: A Systematic Review

OBJECTIVE

The aim of this review was to examine (1) the prevalence of smoking in subjects with irritable bowel syndrome (IBS), (2) whether smoking prevalence significantly differs between subjects with and without IBS, and (3) whether smoking significantly predicts the presence or the development of IBS.

METHODS

Articles were retrieved by systematically searching the Scopus, Web of Science, and PubMed electronic databases from inception to July 2016, using the keywords "smoking" and "tobacco" combined with "irritable bowel syndrome." Reference lists of included articles were also searched. Articles were included if they (1) reported data on smoking prevalence in subjects with IBS and/or on the association (assessed by means of multivariate analyses) between smoking and IBS, (2) identified IBS according to Manning criteria or Rome I-III criteria, (3) were English-language articles, and (4) involved only adult subjects.

RESULTS

The electronic searches yielded a total of 1,637 records, and 42 articles met inclusion criteria. Another 13 articles were retrieved through manual search, leading to a total of 55 included articles. Smoking prevalence in subjects with IBS was assessed by 48 articles and ranged from 0% in university students to 47.1% in patients with microscopic colitis. Thirty-three articles compared smoking prevalence between subjects with and without IBS. In 25 articles no significant difference was found. In seven articles smoking was significantly more frequent in subjects with IBS compared to those without IBS, while one study found a significantly higher smoking prevalence in controls. Eighteen multivariate analyses assessing the association between smoking and IBS were presented in 16 articles. Only one study employed a prospective design. In 11 analyses, smoking was not significantly associated with IBS after adjusting for covariates. In seven studies smoking independently predicted the presence of IBS.

CONCLUSIONS

According to the selected articles, a significant association between smoking and IBS cannot be confirmed. However, different shortcomings may hinder generalizability and comparability of many studies. A dimensional assessment of smoking, a prospective design, the differentiation between IBS subgroups, and the recruitment of patients in clinical settings, especially in primary care, are necessary to clarify the role of smoking in IBS.

Psychological Factors Influence the Irritable Bowel Syndrome and Their Effect on Quality of Life among Firefighters in South Korea

OBJECTIVE

The purpose of this study was to investigate the characteristics of psychological factors that are related to irritable bowel syndrome (IBS) and their effects on the quality of life (QOL) of firefighters in South Korea.

METHODS

This study examined data collected from 1217 firefighters in South Korea. After identifying firefighters with IBS according to the Rome III diagnostic criteria for functional gastrointestinal disorders (FGIDs), we collected demographic data and psychological variables through self-administered questionnaires. In order to observe the distribution of the high-risk group in the Korean occupational stress scale (KOSS) subcategories, we conducted logistic multiple linear regression. The correlations between psychological factors and QOL were analyzed and we performed a stepwise regression analysis.

RESULTS

The groups (firefighters with and without IBS) showed differences by sex, working period, task, working pattern, Patient Health Questionnaire-9, Generalized Anxiety Disorder Questionnaire-7, Korean Occupational Stress Scale, Rosenberg's Self-Esteem Scale, and the World Health Organization Quality of Life-BREF. IBS risk was higher in the following KOSS subcategories: job demand (OR 1.79, 95% CI: 1.11-2.89), interpersonal conflict (OR 2.21, 95% CI: 1.25-4.33), organizational system (OR 1.87, 95% CI: 0.58-3.30), and lack of reward (OR 2.39, 95% CI: 1.08-5.26). The final regression model explained 42.6% of the variance in overall quality of life.

CONCLUSION

The findings of this study indicate that a number of psychological factors increase the likelihood of irritable bowel syndrome (IBS) and affect QOL. Therefore, when diagnosing IBS in the future, mental health aspects should be considered in addition to physical health.

Epidemiology and risk factors of uninvestigated dyspepsia, irritable bowel syndrome, and gastroesophageal reflux disease among students of Damascus University, Syria

Uninvestigated dyspepsia (UD), irritable bowel syndrome (IBS), and gastroesophageal reflux disease (GERD) are common disorders universally. Many studies have assessed their epidemiological characteristics around the world. However, such information is not known for Syria. We aim to estimate the epidemiologic characteristics and possible risk factors for UD, IBS, and GERD among students at Damascus University, Damascus, Syria. A cross-sectional study was conducted in July-September 2015 at a campus of Damascus University. A total of 320 students were randomly asked to complete the survey. We used ROME III criteria to define UD and IBS, and Montreal definition for GERD. In total, 302 valid participants were included in the analysis. Prevalence for UD, IBS, and GERD was 25%, 17%, and 16%, respectively. Symptom overlap was present in 46 students (15%), with UD+IBS in 28 (9.3%), UD+GERD in 26 (8.6%), and IBS+GERD in 14 (4.6%) students. Eleven (3.6%) students had symptoms of UD+IBS+GERD. Each of these overlaps occurred more frequently than expected by chance. Significant risk factors included cigarettes smoking, waterpipe consumption, and body mass index <18.5kg/m² for UD; female gender and three cups of coffee/d for IBS; and two cups of tea and one to five cigarettes/d for GERD. Risk factors for these disorders remain poorly characterized and need further investigations.

Functional dyspepsia and irritable bowel syndrome in teenagers: Internet survey

BACKGROUND

Only a handful of studies have investigated children with functional dyspepsia (FD) and irritable bowel syndrome (IBS) classified according to the Rome III criteria, and limited information is available on the lifestyle of affected patients.

METHODS

We conducted an Internet questionnaire survey of 2060 parents among the general public in Japan who lived with their children aged 10-15, who were screened for FD and IBS.

RESULTS

The prevalence of FD and IBS was 2.8% and 6.1%, respectively, and 1.4% of the subjects met the criteria for both FD and IBS. The lifestyles of 155 subjects who met the criteria for FD, IBS, or both were compared with those of 1745 control subjects. In comparison with the controls, a significantly higher percentage of subjects with FD, IBS, or both thought that their sleep was insufficient, ate meals irregularly, were susceptible to stress and to dizziness on standing, had difficulty in getting out of bed or felt sluggish in the morning, had a tendency to faint when standing, and had migraine/chronic headache.

CONCLUSIONS

Children with FD and IBS are susceptible to stress, have impaired sleep and eating habits, and have more frequent symptoms of comorbid orthostatic dysregulation and headache.

Epidemiology of Functional Gastrointestinal Disorders in Japan and in the World

Functional gastrointestinal disorders (FGIDs), represented by functional dyspepsia (FD) and irritable bowel syndrome (IBS), are a group of disorders that include variable combinations of chronic or recurrent gastrointestinal symptoms not explained by structural or biochemical abnormalities. FGIDs account for a significant percentage of patients seen in primary care settings with abdominal symptoms. Although the definition of FGIDs can easily affect the prevalence, the prevalences of dyspepsia/FD and IBS diagnosed by the Rome III criteria in the general population are 5.3–20.4% and 1.1–29.2%, respectively. Recent reports of FD and IBS defined by the Rome III criteria indicated a female predominance. Regarding the subtype prevalence of FD, postprandial distress syndrome was more prevalent than epigastric pain syndrome (5.6–13.9% vs 0.9–9.5%). The subtype prevalence of IBS is characterized by male predominance for IBS with diarrhea and female predominance for IBS with constipation. Factors affecting the development of FGIDs such as epidemiological factors including genetic and environmental factors, are important. Gene polymorphisms are involved in the development of FGIDs. The prevalence differs among races and geographic areas. Foods may affect the development of FGIDs, but the causal relationships between food and FGIDs are not conclusive. The symptoms often regress and appear in the course of these entities. Building a favorable patient-doctor relationship is effective for controlling symptoms of FGIDs. Physicians should explain that FGIDs are highly prevalent conditions, impair the patients’ quality of life even without evident underlying organic causes and are not life-threatening conditions to ensure patients’ understanding.

Staple foods consumption and irritable bowel syndrome in Japanese adults: a cross-sectional study

Background

Carbohydrates can cause gastrointestinal symptoms due to incomplete absorption in the small bowel. Thus, high-carbohydrate diets may induce symptoms of irritable bowel syndrome (IBS).

Objective

This observational and cross-sectional study assessed the association between consumption of several carbohydrate-enriched staple foods, such as rice, Japanese wheat noodles, Chinese noodles, bread, pasta, and buckwheat noodles, and the prevalence of IBS in Japanese adults.

Subjects and Methods

One thousand and eighty-two (837 men) Japanese adult employees aged 19-85 were included in this cross-sectional study conducted in 2011. IBS diagnosis was based on the Rome III criteria. Consumption of staple foods was assessed using a brief self-administered diet history questionnaire, and divided into three categories (low, middle, high) depending on their distribution.

Results

In the multivariate analysis, daily consumption of rice (odds ratios [ORs] and [95% confidence interval (CI)]: middle, 1.36 [0.93–1.99]; high, 1.67 [1.12–2.49]; P for trend = 0.01), bread (middle, 1.88 [1.28–2.75]; high, 1.63 [1.10–2.41]; P for trend = 0.01), pasta (middle, 1.47 [1.01–2.15]; high, 1.68 [1.12–2.52]; P for trend = 0.01), and buckwheat noodles (middle, 1.76 [1.18–2.61]; high, 1.98 [1.31–3.00]; P for trend = 0.001) were associated with higher prevalence of IBS after adjustment for socio-demographic, anthropometric, and lifestyle-related factors. Buckwheat noodles, but not other staple foods, retained an association with the prevalence of IBS even after adjustment for daily intake of carbohydrates or plant proteins.

Conclusions

This cross-sectional study demonstrated that the consumption of staple foods, such as rice, bread, pasta, and buckwheat noodles is associated with the prevalence of IBS. Of these, the consumption of buckwheat noodles, but not other staple foods, is associated with IBS independent of carbohydrate or plant protein contents.

Survey of clinical practice for irritable bowel syndrome in East asian countries

AIM

Sociocultural factors are important because their different effects on the features of irritable bowel syndrome (IBS) between countries will provide clues towards solving this problem. The aims of this study were to depict the clinical realities of IBS in East Asian countries and test the hypothesis that the diagnosis and treatment of IBS differ between countries.

SUBJECTS AND METHODS

Study participants were 251 physicians involved in the clinical practice of IBS at major institutions in Japan, South Korea, China, the Philippines, Indonesia and Singapore. The questionnaire contained 45 questions focused on the clinical practice of IBS.

RESULTS

Subjects in Japan, South Korea, China, Indonesia, the Philippines and Singapore accounted for 55.4, 17.9, 8.8, 8.0, 6.4 and 3.6% of the study cohort, respectively. Amongst East Asian physicians, the most important symptom was considered to be abdominal pain by 33.4%, whilst 24.3% regarded alternating diarrhea and constipation to be the most important symptoms. Total colonoscopy and histopathology use showed no difference among countries. Prescriptions given for mild (p < 0.0001), moderate (p < 0.0001), severe (p < 0.0001), intractable (p = 0.002), diarrheal (p < 0.0001) and constipating (p < 0.0001) patients with IBS significantly differed between the countries. Except for several minor points, IBS specialists showed no significant difference in their diagnosis and treatment of IBS when compared to nonspecialists.

CONCLUSION

This survey provided data on the clinical treatment of IBS among East Asian countries. The results supported the hypothesis that the diagnosis and treatment of IBS differs between countries.

Impact of eating attitude and impairment of physical quality of life between tertiary clinic and primary clinic functional dyspepsia outpatients in Japan

BACKGROUND/AIMS

There is no available data on factors associated with healthcare-seeking behavior for functional dyspepsia (FD) symptoms at ei-ther tertiary or primary clinics in Japan. Therefore, we aimed to compare clinical symptoms and life styles such as sleep dis-orders and eating attitude in FD patients visiting general practitioners at primary clinics with those consulting gastro-enterologists at tertiary clinics to clarify healthcare-seeking patterns in Japanese patients.

METHODS

Fifty-one FD outpatients in a tertiary clinic (college hospital), 50 FD outpatients visiting primary clinics and 50 healthy volunteers were enrolled. Clinical symptoms, quality of life, sleep disorders, eating attitude and anxiety were estimated using the Gastroin-testinal Symptom Rating Scale (GSRS), Social Functioning-8 (SF-8) test, Pittsburg Sleep Quality Index (PSQI) test and State-Trait Anxiety Inventory (STAI) for FD outpatients and healthy volunteers.

RESULTS

FD outpatients exhibited higher mean scores of GSRS than healthy volunteers. The SF-8 physical component summary scores in the tertiary clinic group were significantly lower than those in the primary clinic group. GSRS scores were significantly (P < 0.001, P = 0.002) associated with global PSQI scores in FD outpatients as well as with STAI-trait scores (P = 0.006, P = 0.001) compared to healthy volunteers. The frequency of eating between meals in the primary clinic group was significantly (P < 0.05) higher than that in the tertiary clinic group.

CONCLUSIONS

It may be important for clarification of healthcare-seeking behavior to determine the difference in both impairment of physical quality of life and eating attitudes between tertiary clinic and primary clinic FD outpatients in Japan.(J Neurogastroenterol Motil 2014;20:506-515).

Diarrhea caused by proton pump inhibitor administration: comparisons among lansoprazole, rabeprazole, and omeprazole

BACKGROUND

The number of patients who require treatment with proton pump inhibitors (PPIs) is increasing in Japan. One of their adverse effects is diarrhea.

OBJECTIVES

We investigated the incidence of diarrhea caused by 3 different PPIs: lansoprazole, rabeprazole, and omeprazole.

METHODS

Patients using PPIs for >1 month were enrolled. Enrolled patients recorded daily stool frequency, stool consistency using the Bristol Stool Scale Form, and impaired quality of life caused by diarrhea for 1 month. Their attending physicians described the types and dosages, and duration of PPI administration, as well as other necessary information.

RESULTS

A total of 255 patients participated. Mean age of the patients was 70.7 years old. During the 1-month observation period, 3.5% of the patients complained of diarrhea. There was no significant difference for the incidence of diarrhea among the 3 types of PPIs. Furthermore, no correlations between diarrhea and length and dosage of PPI administration were found.

CONCLUSIONS

The incidence of diarrhea in patients receiving long-term therapy did not differ among 3 different PPIs. ClinicalTrials.gov identifier: UMIN ID 000005300.

Tyrosine phosphorylation of the NR2B subunit of the NMDA receptor in the spinal cord contributes to chronic visceral pain in rats

The roles of spinal N-methyl-d-aspartic acid receptor 2B (NR2B) subunit in central sensitization of chronic visceral pain were investigated. A rat model with irritable bowel syndrome (IBS) was established by colorectal distention (CRD) on post-natal days 8-14. Responses of the external oblique muscle of the abdomen to CRD were measured to evaluate the sensitivity of visceral pain in rats. The sensitivity of visceral pain significantly increased in IBS-like rats. Expressions of spinal NR2B subunit and phosphorylated NR2B subunit significantly increased by 50-55% in IBS-like rats when compared with those in control rats. Ro 25-6981, a selective antagonist of NR2B subunit, has a dose-dependent anti-allodynic and anti-hyperalgesic effect without causing motor dysfunction in IBS-like rats. Furthermore, the activation mechanism of the spinal NR2B subunit in chronic visceral pain was also investigated. Spinal administration of genistein, a specific inhibitor of tyrosine kinases, also decreased the visceral pain hypersensitivity of IBS-like rats in a dose-dependent manner. In addition, the expression of phosphorylated NR2B subunit was decreased after spinal administration of Ro 25-6981 or genistein in IBS-like rats. In conclusion, tyrosine kinase activation-induced phosphorylation of NR2B subunit may play a crucial role in central sensitization of chronic visceral pain.

The economic impact of loss of performance due to absenteeism and presenteeism caused by depressive symptoms and comorbid health conditions among Japanese workers

We aimed to determine the economic impact of absenteeism and presenteeism from five conditions potentially comorbid with depressive symptoms-back or neck disorders, depression, anxiety, or emotional disorders, chronic headaches, stomach or bowel disorders, and insomnia-among Japanese workers aged 18-59 yr. Participants from 19 workplaces anonymously completed Stanford Presenteeism Scale questionnaires. Participants identified one primary health condition and determined the resultant performance loss (0-100%) over the previous 4-wk period. We estimated the wage loss by gender, using 10-yr age bands. A total of 6,777 participants undertook the study. Of these, we extracted the data for those in the 18-59 yr age band who chose targeted primary health conditions (males, 2,535; females 2,465). The primary health condition identified was back or neck disorders. We found that wage loss due to presenteeism and absenteeism per 100 workers across all 10-yr age bands was high for back or neck disorders. Wage loss per person was relatively high among those identifying depression, anxiety, or emotional disorders. These findings offer insight into developing strategies for workplace interventions on increasing work performance.

Life style in persons with functional gastrointestinal disorders--large-scale internet survey of lifestyle in Japan

BACKGROUND

Care of patients with functional gastrointestinal disorders (FGIDs) commonly includes offering guidance on diet, exercise, and other lifestyle factors, but there is little information available on the actual lifestyles of FGID sufferers.

METHODS

An internet questionnaire survey of 15,000 adult members of the general public in Japan who were screened for functional dyspepsia (FD) and irritable bowel syndrome (IBS) using the Rome III adult FGID questionnaire was conducted.

KEY RESULTS

The prevalence of FD and IBS was 6.5% and 14.0%, respectively, and 3.0% of the subjects met the criteria for both FD and IBS. The prevalence of both FD and IBS was higher in women than in men. The lifestyles of 2,547 subjects who met the Rome III criteria for FD, IBS, or both were compared with the lifestyles of 1,000 control subjects who did not meet the criteria for FD or the criteria for IBS. Compared to the control subjects, a significantly lower percentage of subjects with FD, IBS, or both exercised frequently, and a significantly higher percentage thought that their sleep was insufficient, ate meals irregularly, did not have an appetite, did not like meat, thought that their vegetable consumption was insufficient, felt stress in their daily lives, and regarded themselves as being highly susceptible to stress.

CONCLUSIONS & INFERENCES

Persons with FGIDs are affected by impairment of sleep, eating habits, diet, exercise and other lifestyle factors, and feel excessive stress. This suggests that offering lifestyle guidance to FGID patients may be useful.

A global perspective on irritable bowel syndrome: a consensus statement of the World Gastroenterology Organisation Summit Task Force on irritable bowel syndrome

Irritable bowel syndrome (IBS) is common in western Europe and North America, and many aspects of its epidemiology, risk factors, and natural history have been described in these regions. Recent data suggest, however, that IBS is also common in the rest of the world and there has been some evidence to suggest some differences in demographics and presenting features between IBS in the west and as it is experienced elsewhere. The World Gastroenterology Organization, therefore, established a Task Force comprising experts on the topic from all parts of the world to examine IBS from a global perspective. IBS does, indeed, seem to be common worldwide though with some significant variations in prevalence rates between regions and countries and there may well be some potentially interesting variations in presenting symptoms and sex distribution. The global map of IBS is far from complete; community-based prevalence data is not available from many areas. Furthermore, while some general trends are evident in terms of IBS impact and demographics, international comparisons are hampered by differences in diagnostic criteria, study location and methodology; several important unanswered questions have been identified that should form the basis for future collaborative research and have the potential to shed light on this challenging disorder.

Effects of β-(1,3-1,6)-D-glucan on irritable bowel syndrome-related colonic hypersensitivity

Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by chronic abdominal pain associated with altered bowel habits. Since the prevalence of IBS is very high and thus, involves elevated health-care costs, treatment of this condition by methods other than prescribed medicines could be beneficial. β-(1,3)-D-glucan with β-(1,6) branches (β-glucan) has been used as a nutritional supplement for many years. In this study, we examined the effect of β-glucan on fecal pellet output and visceral pain response in animal models of IBS. Oral administration of β-glucan suppressed the restraint stress- or drug-induced fecal pellet output. β-Glucan also suppressed the visceral pain response to colorectal distension. These results suggest that β-glucan could be beneficial for the treatment and prevention of IBS.

Efficacy and safety of oral lubiprostone in constipated patients with or without irritable bowel syndrome: a randomized, placebo-controlled and dose-finding study

BACKGROUND

Lubiprostone is a prostone analog with a novel mechanism of action involving type-2 chloride channel activation. The aim of this work was to perform a dose-finding study for lubiprostone for the treatment of constipation with or without irritable bowel syndrome (IBS) in Japan.

METHODS

A total of 170 patients (128 without IBS and 42 with IBS) with chronic idiopathic constipation (CIC) randomly received a placebo (n=42) or 16μg (n=41), 32μg (n=43), or 48μg (n=44) of lubiprostone daily for 2weeks.

KEY RESULTS

There was a statistically significant and dose-dependent increase in change from baseline in the weekly average number of spontaneous bowel movements at week 1 (placebo: 1.5±0.4; 16μg: 2.3±0.4, 32μg: 3.5±0.5; and 48μg: 6.8±1.1, per week, mean±SE; P<0.0001). These primary endpoint results were significant on stratified analysis when patients were limited to those without IBS (P<0.0001). The primary endpoint in patients with IBS treated with 48μg of lubiprostone was significantly better than those given placebo (P=0.0086). Dose dependency was also seen for the secondary efficacy endpoints. Lubiprostone produced no serious side effects.

CONCLUSIONS & INFERENCES

Our results suggest that lubiprostone produced a steady and effective improvement in the symptoms of CIC with or without IBS in a dose-dependent manner with a good safety profile and tolerability in a Japanese population.

Gene, environment, and brain-gut interactions in irritable bowel syndrome

The genetic predisposition and influence of environment may underlie in the pathogenesis and/or pathophysiology of irritable bowel syndrome (IBS). This phenomenon, gene x environment interaction together with brain-gut interactions is emerging area to be clarified in IBS research. Earlier studies focused on candidate genes of neurotransmitters, cytokines, and growth factors. Among them, some studies but not all studies revealed association between phenotypes of IBS and 5-hydroxytryptamine (5-HT)-related genes, noradrenaline-related genes, and cytokine genes. Recent prospective cohort study showed that genes encoding immune and adhesion molecules were associated with post-infectious etiology of IBS. Psychosocial stressors and intraluminal factors especially microbiota are keys to develop IBS. IBS patients may have abnormal gut microbiota as well as increased organic acids. IBS is disorder that relates to brain-gut interactions, emotional dysregulation, and illness behaviors. Brain imaging with or without combination of visceral stimulation enables us to depict the detailed information of brain-gut interactions. In IBS patients, thalamus, insula, anterior cingulate cortex, amygdala, and brainstem were more activated in response to visceral stimulation than controls. Corticotropin-releasing hormone and 5-HT are the candidate substances which regulate exaggerated brain-gut response. In conclusion, gene x environment interaction together with brain-gut interactions may play crucial roles in IBS development. Further fundamental research on this issue is warranted.

The features of adolescent irritable bowel syndrome in Japan

OBJECTIVE AND BACKGROUND

The onset of IBS is in adolescence in many cases. However, the features of adolescent IBS were generally lacking. The objective of this research was to know the features of adolescent IBS in Japan.

METHODOLOGY

In 2004 and 2009, we randomly selected Junior high school students in Miyagi prefecture, Japan, according to population of each area. Eight hundred thirty-three boys and 888 girls (age: 15 years old) in 2004 and 256 boys and 335 girls (age: 14 years old) in 2009 participated in this study. They fulfilled self-reported questionnaires those include Rome-II Modular Questionnaire, Self-reported IBS Questionnaire, Generalized Self-Efficacy Scale, Short Form-36 ver.2, other questions on their lives and Toronto Alexithymia Scale-20.

RESULTS

The prevalence of adolescent IBS was 14.6% in 2004 and 19% in 2009. Compare with students without abdominal symptoms, IBS showed lower health-related QOL and self-efficacy and complained more sleep disturbance, traumatic episodes and perceived stress in both researches. IBS girls were worse in both physical and psychological aspects. They also have alexithymic tendency and it influenced on severity of IBS symptoms.

CONCLUSIONS

Adolescent IBS had almost the same prevalence as adult IBS, however the rate of IBS subtypes was different. They also had psychological problems in addition to physical conditions even though most of them were non-consulters. Improvement of self-efficacy and alxithymia may help to prevent and treat IBS.

Differences between risk factors among irritable bowel syndrome subtypes in Japanese adults

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. Detailed clinical characteristics of patients with different IBS subtypes have not been well established. Our aim was to examine the prevalence and risk factors of IBS and its subtypes in Japanese adults.

METHODS

We performed a cross-sectional study of Japanese workers who visited a clinic for a routine health check-up and asked them to fill out a self-report questionnaire. Irritable bowel syndrome and its subtypes were defined by ROME III criteria. A logistic regression model was used to identify risk factors.

KEY RESULTS

Irritable bowel syndrome was present in 367 (13.5%) of 2717 eligible subjects; 79 had IBS with constipation (IBS-C); 102 had IBS with diarrhea (IBS-D); 89 had mixed IBS (IBS-M); and 97 had unsubtyped IBS (IBS-U). Irritable bowel syndrome was significantly associated with young age [odds ratio (OR) = 0.87, 95% confidence interval (CI) 0.80-0.95], female gender (OR = 1.78, 95% CI 1.38-2.29), low body mass index (BMI) (OR = 0.95, 95% CI 0.92-0.99), and the presence of allergic disease (OR = 2.19, 95% CI 1.40-3.54). Analysis of IBS subtypes revealed that IBS-C was associated with young age and female gender; IBS-D with young age, low BMI, and drinking habit; IBS-M with female gender, smoking habits, and allergic diseases; and IBS-U with age, female gender, and allergic diseases.

CONCLUSIONS & INFERENCES

Irritable bowel syndrome was common and associated with young age, female gender, low BMI, and presence of allergic diseases in Japanese adults. Several differences were noted between the risk factors among different IBS subtypes.

The current prevalence of irritable bowel syndrome in Asia

Irritable bowel syndrome (IBS) has been one of the commonly presented gastrointestinal disorders. It is of interest how commonly it presents in the society. Western studies indicated that most population-based IBS prevalences range 10%-15%. It is believed that IBS is prevalent in both East and West countries without a significant prevalence difference. Most recently, the Asia IBS prevalence has a higher trend in the affluent cities compared to South Asia. Since many Asia IBS prevalence studies have been published in the recent decade, we could compare the IBS prevalence data divided by various criteria in looking whether they were also comparable to this of West community. Summarized together, most Asia community IBS prevalences based on various criteria are usually within the range 1%-10% and are apparently lower than these of selected populations. Within the same population, the prevalence orders are first higher based on Manning criteria, then followed by Rome I criteria and finally reported in Rome II criteria. Overall, the median value of Asia IBS prevalences defined by various criteria ranges 6.5%-10.1%. With regard to gender difference, female predominance is usually found but not uniquely existed. For the IBS subtypes, the proportions of diarrhea predominant-IBS distribute widely from 0.8% to 74.0%, while constipation predominant-IBS proportion ranges 12%-77%. In conclusions, current Asia IBS prevalence is at least equal to the Western countries. Female predominant prevalence in Asia is common but not uniquely existed, while the proportions of IBS subtypes are too variable to find a rule.

Asian consensus on irritable bowel syndrome

BACKGROUND AND AIMS

Many of the ideas on irritable bowel syndrome (IBS) are derived from studies conducted in Western societies. Their relevance to Asian societies has not been critically examined. Our objectives were to bring to attention important data from Asian studies, articulate the experience and views of our Asian experts, and provide a relevant guide on this poorly understood condition for doctors and scientists working in Asia.

METHODS

A multinational group of physicians from Asia with special interest in IBS raised statements on IBS pertaining to symptoms, diagnosis, epidemiology, infection, pathophysiology, motility, management, and diet. A modified Delphi approach was employed to present and grade the quality of evidence, and determine the level of agreement.

RESULTS

We observed that bloating and symptoms associated with meals were prominent complaints among our IBS patients. In the majority of our countries, we did not observe a female predominance. In some Asian populations, the intestinal transit times in healthy and IBS patients appear to be faster than those reported in the West. High consultation rates were observed, particularly in the more affluent countries. There was only weak evidence to support the perception that psychological distress determines health-care seeking. Dietary factors, in particular, chili consumption and the high prevalence of lactose malabsorption, were perceived to be aggravating factors, but the evidence was weak.

CONCLUSIONS

This detailed compilation of studies from different parts of Asia, draws attention to Asian patients' experiences of IBS.

Effects of a probiotic fermented milk beverage containing Lactobacillus casei strain Shirota on defecation frequency, intestinal microbiota, and the intestinal environment of healthy individuals with soft stools

The effects of drinking a fermented milk beverage that contains Lactobacillus casei strain Shirota (LcS) at 40 billion bacterial cells/bottle for 4 weeks (probiotics, 1 bottle/day) on defecation frequency, intestinal microbiota and the intestinal environment of healthy individuals with soft stools were evaluated. Thirty-four healthy adults who had soft stools were randomised into 2 groups, and the effects of a regular 4-week intake of probiotics were evaluated by a placebo-controlled, double-blind, parallel-group comparative design. Defecation frequency significantly decreased after the 4-week intake period compared with before the probiotic treatment. The stool quality significantly improved (hardened) compared to the placebo. Also, the water content of the stools was lower in the probiotic group than in the placebo group. Live LcS was recovered at 6.9 ± 1.3 and 7.2 ± 0.8 log(10) CFU per 1g of stool after 2 and 4 weeks, respectively, of probiotic treatment. The number of bifidobacteria in the stools also increased significantly compared with the level before starting the probiotics. The organic acid levels (total, acetic acid, propionic acid, and butyric acid) significantly increased compared with the level before intake in both the probiotic and placebo groups, but they returned to the original levels after the end of the intake period. These results suggest that probiotic fermented milk beverage has an intestine-conditioning effect by improving the frequency of defecation and stool quality and increasing the intrinsic bifidobacteria in healthy individuals with soft stool.

Altered profiles of intestinal microbiota and organic acids may be the origin of symptoms in irritable bowel syndrome

BACKGROUND

The profile of intestinal organic acids in irritable bowel syndrome (IBS) and its correlation with gastrointestinal (GI) symptoms are not clear. We hypothesized in this study that altered GI microbiota contribute to IBS symptoms through increased levels of organic acids.

METHODS

Subjects were 26 IBS patients and 26 age- and sex-matched controls. Fecal samples were collected for microbiota analysis using quantitative real-time polymerase chain reaction and culture methods, and the determination of organic acid levels using high-performance liquid chromatography. Abdominal gas was quantified by image analyses of abdominal X-ray films. Subjects completed a questionnaire for GI symptoms, quality of life (QOL) and negative emotion.

KEY RESULTS

Irritable bowel syndrome patients showed significantly higher counts of Veillonella (P = 0.046) and Lactobacillus (P = 0.031) than controls. They also expressed significantly higher levels of acetic acid (P = 0.049), propionic acid (P = 0.025) and total organic acids (P = 0.014) than controls. The quantity of bowel gas was not significantly different between controls and IBS patients. Finally, IBS patients with high acetic acid or propionic acid levels presented with significantly worse GI symptoms, QOL and negative emotions than those with low acetic acid or propionic acid levels or controls.

CONCLUSIONS & INFERENCES

These results support the hypothesis that both fecal microbiota and organic acids are altered in IBS patients. A combination of Veillonella and Lactobacillus is known to produce acetic and propionic acid. High levels of acetic and propionic acid may associate with abdominal symptoms, impaired QOL and negative emotions in IBS.

Asian motility studies in irritable bowel syndrome

Altered motility remains one of the important pathophysiologic factors in patients with irritable bowel syndrome (IBS) who commonly complain of abdominal pain and stool changes such as diarrhea and constipation. The prevalence of IBS has increased among Asian populations these days. Gastrointestinal (GI) physiology may vary between Asian and Western populations because of differences in diets, socio-cultural backgrounds, and genetic factors. The characteristics and differences of GI dysmotility in Asian IBS patients were reviewed. MEDLINE search work was performed including following terms, 'IBS,' 'motility,' 'transit time,' 'esophageal motility,' 'gastric motility,' 'small intestinal motility,' 'colonic motility,' 'anorectal function,' and 'gallbladder motility' and over 100 articles were categorized under 'esophagus,' 'stomach,' 'small intestine,' 'colon,' 'anorectum,' 'gallbladder,' 'transit,' 'motor pattern,' and 'effect of stressors.' Delayed gastric emptying, slow tansit in constipation predominant IBS patients, rapid transit in diarrhea predominant IBS patients, accelerated motility responses to various stressors such as meals, mental stress, or corticotrophin releasing hormones, and altered rectal compliance and altered rectal accomodation were reported in many Asian studies regarding IBS. Many conflicting results were found among these studies and there are still controversies to conclude these as unique features of Asian IBS patients. Multinational and multicenter studies are needed to be performed vigorously in order to elaborate characteristics as well as differences of altered motililty in Asian patients with IBS.

Prevalence of functional dyspepsia in an outpatient clinic with primary care physicians in Japan

BACKGROUND

Since little is known about the prevalence of patients with functional gastrointestinal disorders (FGID), this study was performed to clarify the prevalence of FGID, especially functional dyspepsia (FD), in new patients of an outpatient clinic with primary care physicians in Japan.

METHODS

We analyzed consecutive outpatients (n = 5183) who first visited the Department of General Medicine, Asahikawa Medical College Hospital, between April 2004 and March 2009.

RESULTS

Out of 5813 patients, 818 (14.1%) visited because of abdominal symptoms. Final diagnoses of the 818 patients were FGID (n = 320, 39.1%), organic gastrointestinal diseases (n = 237, 28.9%), organic non-GI disease (n = 135, 16.5%), and others (n = 126, 15.4%). The 320 patients with FGID had FD (n = 170), irritable bowel syndrome (IBS) (n = 68), and other FGIDs (n = 88). The rate of FGID or FD in all patients was 5.5% or 2.9%, respectively. Among outpatients (n = 381) who complained of upper abdominal symptoms, approximately 45% had FD. There was no gender difference in the frequency of FGID, FD, or IBS in all ages of patients. A lower incidence of FD was shown in female patients over 70 years old and a higher incidence of IBS in male patients under 29 years old.

DISCUSSION

These results suggest that the prevalence of FGID, especially FD, is very high in an outpatient clinic with primary care physicians in Japan.

Advances in understanding the pathogenesis of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal motility disorder characterized by abdominal discomfort/pain associated with altered bowel habits. At present, the pathophysiology of IBS is still unknown. Genetic factors, psychosocial factors, and changes in gastrointestinal motility and visceral hypersensitivity are traditionally thought to play a crucial role in symptom generation in IBS. Recent studies have identified new additional factors (such as dysregulation of the brain-gut axis, gastrointestinal infection, and activation of mast cells in the intestinal mucosa with consequent release of bioactive substances) that are correlated with the pathogenesis of IBS. In this article, we will review the recent advances in the research on the pathogenesis of IBS.

Epidemiology of irritable bowel syndrome in Asia: something old, something new, something borrowed

In this review we have unearthed epidemiological data that; support the 'old' concept of irritable bowel syndrome (IBS) as a disorder of civilization, build a 'new' symptom profile of IBS for Asia, and persuade us against the use of 'borrowed' Western diagnostic criteria and illness models by Asian societies. In the 1960s, IBS was described as a disorder of civilization. Early studies from Asia suggested a prevalence of IBS below 5%. Recent studies from Asia suggest a trend for the more affluent city states like Singapore and Tokyo, to have higher prevalence of 8.6% and 9.8%, respectively, while India had the lowest prevalence of 4.2%. Furthermore, there was a trend among the better educated and more affluent strata of society in several urban Chinese populations for a higher prevalence of IBS, as well as a trend for a higher consultation rate. Across Chinese and Indian predominant populations, a majority of patients with IBS criteria report upper abdominal symptoms such as epigastric pain relieved by defecation, bloating and dyspepsia. Bloating and incomplete evacuation appear to be more important determinants of consultation behavior, than psychological factors. The failure of the Rome criteria to recognize the relationship to meals, may have led to a substantial misclassification of IBS as dyspepsia. The relevance of the Western model of psychological disturbance as a determinant of consultation behavior is questionable because of the accessibility and acceptability of medical consultation for gastrointestinal complaints in many Asian communities.

Analysis of the gastrointestinal symptoms of uninvestigated dyspepsia and irritable bowel syndrome

Background/Aims

Epidemiological studies suggest that there is a considerable overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS). The aim of this study was to examine concurrent gastrointestinal symptoms in FD and IBS.

Methods

A total of 186 college students filled out a questionnaire regarding whether they had uninvestigated dyspepsia (UD, FD without endoscopic examination) and IBS based on Rome-II criteria. Gastrointestinal symptoms were measured using the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire.

Results

A total of 181 students (98 males, mean age 24.6 years) completed both questionnaires. The prevalence of UD, IBS, and UD+IBS overlap was 12 (6.7%), 40 (22.1%), and 8 (4.4%), respectively. A significant UD+IBS overlap was observed (66.7% IBS in UD, 20.0% UD in IBS). Reflux scores of GSRS in either UD or IBS were significantly greater than in those without. Gastroesophageal reflux disease (GERD), defined as weekly occurring moderate symptoms of heartburn and/or acid regurgitation and evaluated using the GSRS, was found in 16 (8.8%) of the subjects. The prevalence of IBS was significantly higher in GERD patients than in non-GERD patients (50.0% vs 19.4%).

Conclusions

The considerable overlap not only between UD and IBS, but also between GERD and IBS, suggests the involvement of common pathophysiological disturbances in the two conditions.

Treatment of diarrhea-predominant Post-infectious irritable bowel syndrome with Deanxit: an analysis of 30 cases

AIM: To observe the effect and safety of Deanxit in combination with Birid Triple Viable (BIFICO) in treatment of diarrhea-predominant postinfectious irritable bowel syndrome (PI-IBS) without obvious psychiatric symptoms.

METHODS: Sixty cases of diarrhea-predominant PI-IBS without obvious psychiatric symptoms were divided into 2 groups, and each group had 30 cases. Combination treatment group received both Deanxit and BIFICO treatment, while the control group received BIFICO treatment only. After 2-wk treatment, the therapeutic effect and drug safety were compared between the 2 groups.

RESULTS: The total effective rate was 90.0% in combination treatment group, and 60.0% in BIFICO group. The total effective rate in combination treatment group was significantly higher than that of BIFICO group (P < 0.05). There were no obvious side-effects found in both groups.

CONCLUSION: Deanxit combined with BIFICO is safe and effective in treatment of PI-IBS without obvious psychiatric symptoms.

A prospective study of the psychobehavioral factors responsible for a change from non-patient irritable bowel syndrome to IBS patient status

Background

To investigate non-patient irritable bowel syndrome (IBS) change to IBS and to determine factors predictive of the onset of IBS, individual biological factors, psychological factors, behavioral factors, and environmental factors were examined.

Methods

The subjects were 105 non-patient IBS (male = 59, female = 46, average age:21.49 ± 2.37), including 68 of the diarrhea-predominant type and 37 of the constipation-predominant type selected from 1,409 university and technical college students by use of a questionnaire based on the Rome II diagnostic criteria. The subjects were followed for three years, and various characteristics and IBS symptoms were serially observed (12 times). The IBS incidence rate was calculated.

Results

During the three years, 37 non-patient IBS (35.24%) changed to IBS: 28 diarrhea-predominant type and 9 constipation-predominant type. All IBS symptoms disappeared in 26 non-patient IBS subjects (24.76%). According to quantification method II (discriminant analysis), seven factors (stressor, two kinds of stress coping styles, cognitive appraisal, eating habits, sleeping time, and psychologically abuse) were adopted as a predictive model for IBS incidence and were confirmed as predictive of IBS.

Conclusion

The results of this research show that non-patient IBS is a changeable state that can change into IBS or persons without symptoms. Most of the non-patient IBS subjects who became asymptomatic had had symptoms for six months or less. Furthermore, the longer a non-patient IBS subject had symptoms, the higher the risk of a change to IBS became. The findings suggest the usefulness of identifying and approaching non-patient IBS as early as possible to prevent the onset of IBS. It must be noted that the persons surveyed in the present study had only the diarrhea-predominant and constipation-predominant types. Therefore, the findings of the present study are limited only these two types. Further study including the mixed type is needed.

Relationship between cognitive appraisals of symptoms and negative mood for subtypes of irritable bowel syndrome

Background

The onset and course of irritable bowel syndrome (IBS) are strongly influenced by psychological factors, and treatment often includes cognitive-behavioral therapy. We conducted a study of the relationships between cognitive appraisal of IBS symptoms and negative mood for the subtypes of IBS.

Method

The participants were 1087 college students who completed a set of questionnaires that included the Rome II Modular Questionnaire, Self-reported IBS Questionnaire, Cognitive Appraisal Rating Scale, and the Hospital Anxiety and Depression Scale.

Results

The participants included 206 individuals with IBS; 61 had diarrhea-predominant IBS (IBSD) and 45 had constipation-predominant IBS (IBSC). The overall IBS group scored higher on anxiety and depression than the control group. The IBSD and IBSC groups each had significantly higher scores for anxiety but did not significantly differ from the control group in scores for depression. There were no significant differences between the IBSD and IBSC groups in their cognitive appraisal of IBS symptoms. For the IBSD group, anxiety was significantly, positively correlated with commitment, effect, and threat, and depression was significantly, negatively correlated with controllability. In contrast, there were no significant correlations between mood and cognitive appraisal for the IBSC group. Multiple regression analyses with abdominal symptoms as dependent variables and cognitive appraisals as independent variables showed that for the IBSD group, abdominal pain was significantly, positively correlated with commitment, and abdominal discomfort was significantly, positively correlated with appraisal of effect and threat. For the IBSC group, abdominal pain and hard stool were significantly, positively correlated with commitment, and abdominal discomfort was significantly, positively correlated with appraisal of effect and threat.

Conclusion

IBS patients as a general group report high levels of anxiety and depression. However, IBSD and IBSC were both associated only with high anxiety, but not depression, when compared to the non-IBS control group. For the IBSD group, anxiety was associated with cognitive appraisals, but this association was not found for the IBSC group. These groups did not differ in their associated cognitive appraisals, and are similar in terms of the positive relationship between abdominal pain and discomfort and the cognitive appraisals of coping.