Prevalence of Irritable Bowel Syndrome in Singapore and Its Association with Dietary, Lifestyle, and Environmental Factors

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.

Epidemiology of Irritable Bowel Syndrome in a Large Academic Safety-Net Hospital

(1) Background: Irritable bowel syndrome (IBS) is a highly prevalent disorder of gut-brain interaction (DGBI) that is known to reduce the quality of life and raise healthcare costs. The aim of this study was to describe the epidemiology of IBS in a large multiracial academic safety-net hospital. (2) Methods: An electronic query was performed using ICD-9 codes to identify 740 IBS outpatients seen at the Boston Medical Center (BMC) between 1 January 2005 and 30 September 2007. Demographic data were collected from electronic medical records. Bivariate analyses using chi-square tests and ANOVA were used to calculate the significance of categorical and continuous dependent variables, respectively. (3) Results: Compared with the general BMC outpatient population, the IBS cohort consisted of significantly higher proportions of White and Asian patients and lower proportions of Black and Hispanic patients (p < 0.0001). White and Asian patients predominantly had private insurance, while Black and Hispanic patients mostly had government/state-funded or no insurance (p < 0.0001). The IBS subgroup frequencies were similar across racial groups; however, Hispanic patients had IBS with constipation (32%, p < 0.02) more often compared to non-Hispanic patients. (4) Conclusions: Significant differences were found across the racial groups studied in this large outpatient IBS cohort. These findings are likely attributed to racial and socioeconomic disparities in healthcare access and utilization.

Evolutionary medicine approaches to chronic disease: The case of irritable bowel syndrome

Irritable bowel syndrome (IBS), a gastrointestinal disease, is a global phenomenon correlated with industrialization. We propose that an evolutionary medicine approach is useful to understand this disease from an ultimate perspective and conducted a scoping literature review to synthesize the IBS literature within this framework. Our review suggests five potential evolutionary hypotheses for the cause of IBS, including (a) a dietary mismatch accompanying a nutritional transition, (b) an early hygienic life environment leading to the immune system and microbiotic changes, (c) an outcome of decreased physical activity, (d) a response to changes in environmental light-dark cycles, and (e) an artifact of an evolved fight or flight response. We find key limitations in the available data needed to understand early life, nutritional, and socioeconomic experiences that would allow us to understand evolutionarily relevant risk factors and identify a need for further empirical research to distinguish potential causes and test evolutionary hypotheses.

Survey-Based Analysis of the Clinical Treatment Status of Irritable Bowel Syndrome in Korea

BACKGROUND

The quality-of-life of patients with irritable bowel syndrome is low; incorrect diagnosis/treatment causes economic burden and inappropriate consumption of medical resources. This survey-based study aimed to analyze the current status of irritable bowel syndrome treatment to examine differences in doctors' perceptions of the disease, and treatment patterns.

METHODS

From October 2019 to February 2020, the irritable bowel syndrome and Intestinal Function Research Study Group of the Korean Society of Neurogastroenterology and Motility conducted a survey on doctors working in primary, secondary, and tertiary healthcare institutions. The questionnaire included 37 items and was completed anonymously using the NAVER platform (a web-based platform), e-mails, and written forms.

RESULTS

A total of 272 doctors responded; respondents reported using the Rome IV diagnostic criteria (amended in 2016) for diagnosing and treating irritable bowel syndrome. Several differences were noted between the primary, secondary, and tertiary physicians' groups. The rate of colonoscopy was high in tertiary healthcare institutions. During a colonoscopy, the necessity of random biopsy was higher among physicians who worked at tertiary institutions. 'The patient did not adhere to the diet' as a reason for ineffectiveness using low-fermentable oligo-, di-, and mono-saccharides, and polyols diet treatment was higher among physicians in primary/secondary institutions, and 'There are individual differences in terms of effectiveness' was higher among physicians in tertiary institutions. In irritable bowel syndrome constipation predominant subtype, the use of serotonin type 3 receptor antagonist (ramosetron) and probiotics was higher in primary/secondary institutions, while serotonin type 4 receptor agonist was used more in tertiary institutions. In irritable bowel syndrome diarrhea predominant subtype, the use of antispasmodics was higher in primary/secondary institutions, while the use of serotonin type 3 receptor antagonist (ramosetron) was higher in tertiary institutions.

CONCLUSION

Notable differences were observed between physicians in primary/secondary and tertiary institiutions regarding the rate of colonoscopy, necessity of random biopsy, the reason for the ineffectiveness of low-fermentable oligo-, di-, and mono-saccharides, and polyols diet, and use of drug therapy in irritable bowel syndrome. In South Korea, irritable bowel syndrome is diagnosed and treated according to the Rome IV diagnostic criteria, revised in 2016.

The association between dietary acid load and odds and severity of irritable bowel syndrome in adults

No study has been conducted to investigate the association between dietary acid load and irritable bowel syndrome (IBS). So, this cross-sectional study was performed to investigate the association between dietary acid load and odds of IBS, its severity, and IBS subtypes. A sample of 3362 Iranian subjects was selected from health centers in Isfahan province. A validated semi-quantitative food frequency questionnaire (DS-FFQ) was applied to estimate dietary intakes. The dietary acid load was measured using net endogenous acid production (NEAP), dietary acid load (DAL), and potential renal acid load (PRAL) scores. In crude models, the highest compared with the lowest category of the PRAL score was significantly associated with increased odds of IBS severity in participants with BMI ≥ 25 (kg/m²) (OR = 1.54; 95% CI = (1.03-2.32). Also, the results indicated a significant positive association between the PARL and odds of mixed subtype of IBS (OR = 1.74; 95% CI = (1.11-2.74); P trend = 0.02). In propensity score-adjusted model with potential confounders, only a positive association was found between PRAL and odds of mixed subtype of IBS (OR = 1.78; 95% CI = (1.05-3.00); P trend = 0.03). The DAL and NEAP scores tended to show non-significant similar findings. This study indicates that dietary acid load might be associated with odds of mixed type of IBS. However, further research is warranted to infer these findings.

The association between dietary acid load and odds and severity of irritable bowel syndrome in adults

No study has been conducted to investigate the association between dietary acid load and irritable bowel syndrome (IBS). So, this cross-sectional study was performed to investigate the association between dietary acid load and odds of IBS, its severity, and IBS subtypes. A sample of 3362 Iranian subjects was selected from health centers in Isfahan province. A validated semi-quantitative food frequency questionnaire (DS-FFQ) was applied to estimate dietary intakes. The dietary acid load was measured using net endogenous acid production (NEAP), dietary acid load (DAL), and potential renal acid load (PRAL) scores. In crude models, the highest compared with the lowest category of the PRAL score was significantly associated with increased odds of IBS severity in participants with BMI ≥ 25 (kg/m2) (OR = 1.54; 95% CI = (1.03-2.32). Also, the results indicated a significant positive association between the PARL and odds of mixed subtype of IBS (OR = 1.74; 95% CI = (1.11-2.74); P trend = 0.02). In propensity score-adjusted model with potential confounders, only a positive association was found between PRAL and odds of mixed subtype of IBS (OR = 1.78; 95% CI = (1.05-3.00); P trend = 0.03). The DAL and NEAP scores tended to show non-significant similar findings. This study indicates that dietary acid load might be associated with odds of mixed type of IBS. However, further research is warranted to infer these findings.

Helicobacter pylori Infection—A Risk Factor for Irritable Bowel Syndrome? An Updated Systematic Review and Meta-Analysis

Nowadays, the relationship between Helicobacter pylori infection (HPI) and irritable bowel syndrome (IBS) remains controversial. Objective: The aim of this study is to investigate the relationship between HPI and IBS through a systematic review and meta-analysis based on the current evidence. Methods: We performed a systematic literature search in electronic databases (PubMed, EMBASE, and the Cochrane library) by computer to identify all reports published before 8 August 2021. The odds ratio (OR) and confidence interval (CI) were calculated to evaluate the association between HPI and IBS. Subgroup analyses were conducted for further assessment and exploration of heterogeneity sources. In addition, we assessed publication bias through funnel plots, Egger’s test, and Begg’s test. Finally, we conducted a sensitivity analysis to evaluate the robustness of the results. Results: Thirteen studies with 13,173 participants were included in the meta-analysis. The pooled OR of the association between HPI and IBS was 1.03 (95% CI [0.80,1.31]; p = 0.84). The adjusted OR of the association between HPI and IBS after excluding the studies with confounding factors defined by our team was 1.29 (95% CI [1.03,1.62]; p = 0.03). We found a positive association between HPI and IBS-D (diarrhea subtype) (OR: 1.54; 95% CI [1.22,1.95]; p = 0.0003). The OR of the relationship between cytotoxin-associated gene A (Cag A) positive HPI and IBS was 4.3 (95% CI [0.51,36.17]; p = 0.18). Conclusions: The likelihood of HPI in IBS patients is relatively higher than that of non-IBS participants but not statistically significant, implying that HPI is not significantly associated with IBS, albeit we may underestimate this association. Moreover, we found a positive association between HPI and IBS-D. We also observed an increased likelihood of Cag-A positive HPI in IBS patients than that of non-IBS participants but not statistically significant.

Investigating the Role of Low-FODMAP Diet in Improving Gastrointestinal Symptoms in Irritable Bowel Syndrome

Background

A low–fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet (LFD) appeared to improve gastrointestinal symptoms in patients with Irritable Bowel Syndrome (IBS). However, evidence of its efficacy in Asia remains scarce.

Objectives

This study aims to investigate the clinical effectiveness of LFD intervention among Asian IBS patients and barriers to its adherence.

Methods

Patients with IBS who were instructed to follow LFD by dietitians at a tertiary hospital in Singapore between July 2013 and December 2014 were retrospectively reviewed. Severity scores of 19 gastrointestinal symptoms were recorded using an 11-point rating scale (0 = “no symptoms,” 10 = “extremely severe”) pre- and post-LFD intervention. Adherence to LFD was assessed based on patients’ diet history and a high-FODMAP food checklist.

Results

Eighty-two patients with a median follow-up of 5.8 weeks were investigated. The LFD adherence rate was 61.0% ( n = 50). Overall, statistically significant improvement was observed in 14 of 19 gastrointestinal symptoms (median difference = −2.0 to −0.5, p < .05). The proportion of patients who had improvement in 10 individual symptoms (defined as ≥1 point reduction in symptom severity rating) was significantly higher in LFD-adherent patients (67.5%–82.4%) than that of the non-adherent group (27.8%–55.0%). Reasons reported for non-adherence included “limited availability of low-FODMAP alternatives” ( n = 9), “limited understanding of LFD” ( n = 7), and “perceived lack of benefit” ( n = 4).

Conclusions

LFD intervention improved gastrointestinal symptoms in a cohort of Asian IBS patients. Limited access to low-FODMAP alternatives was the main barrier to adherence.

(Poly)phenols in Inflammatory Bowel Disease and Irritable Bowel Syndrome: A Review

(Poly)phenols (PPs) may have a therapeutic benefit in gastrointestinal (GI) disorders, such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). The aim of this review is to summarise the evidence-base in this regard. Observational evidence does not give a clear indication that PP intake has a preventative role for IBD or IBS, while interventional studies suggest these compounds may confer symptomatic and health-related quality of life improvements in known patients. There are inconsistent results for effects on markers of inflammation, but there are promising reports of endoscopic improvement. Work on the effects of PPs on intestinal permeability and oxidative stress is limited and therefore conclusions cannot be formed. Future work on the use of PPs in IBD and IBS will strengthen the understanding of clinical and mechanistic effects.

Parental, Perinatal, and Childhood Risk Factors for Development of Irritable Bowel Syndrome: A Systematic Review

Background/Aims

Adverse early life experiences are associated with the development of stroke, cancer, diabetes, and chronic respiratory and ischemic heart diseases. These negative experiences may also play a role in the development of irritable bowel syndrome (IBS)--a functional gastrointestinal disease. This review discusses the research to date on the parental, perinatal, and childhood risk and protective factors associated with the development of IBS.

Methods

A literature search was completed for studies published between 1966 and 2018 that investigated premorbid factors occurring during the perinatal and childhood periods as well as parental factors that were associated with the development of IBS.

Results

Twenty-seven studies fulfilled the review criteria. Risk factors that appeared in more than one study included: (1) parental IBS, substance abuse, parental punishment, and rejection as parental risk factors; (2) low birth weight as a perinatal risk factor; and (3) crowded living conditions in low-income families, childhood anxiety, depression, or child abuse as childhood risk factors. Protective factors for IBS were emotional warmth from the parents and being born to an older mother.

Conclusions

More effort is needed to identify what fetal and maternal factors are associated with low birth weight and IBS. A well-executed prospective birth cohort with a collection of bio-samples and functional data will provide a better understanding of how adversity and the interplay between genetics, epigenetics, and numerous risk factors affect the development of IBS.

Global burden of irritable bowel syndrome: trends, predictions and risk factors

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction worldwide, defined according to patterns of gastrointestinal symptoms as described by the Rome diagnostic criteria. However, these criteria, developed with reference to research conducted largely in Western populations, might be limited in their applicability to other countries and cultures. Epidemiological data show a wide variation in the prevalence of IBS globally and more rigorous studies are needed to accurately determine any differences that might exist between countries as well as the potential explanations. The effects of IBS on the individual, in terms of their quality of life, and on health-care delivery and society, in terms of economic costs, are considerable. Although the magnitude of these effects seems to be comparable between nations, their precise nature can vary based on the existence of societal and cultural differences. The pathophysiology of IBS is complex and incompletely understood; genetics, diet and the gut microbiome are all recognized risk factors, but the part they play might be influenced by geography and culture, and hence their relative importance might vary between countries. This Review aims to provide an overview of the burden of IBS in a global context, to discuss future implications for the care of people with IBS worldwide, and to identify key areas for further research.

Global prevalence of irritable bowel syndrome according to Rome III or IV criteria: a systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common functional bowel disorders, but community prevalence appears to vary widely between different countries. This variation might be due to the fact that previous cross-sectional surveys have neither applied uniform diagnostic criteria nor used identical methodology, rather than being due to true global variability. We aimed to determine the global prevalence of IBS.

METHODS

We did a systematic review and meta-analysis of data from all population-based studies using relatively uniform methodology and using only the most recent iterations of the Rome criteria (Rome III and IV). We searched MEDLINE, Embase, and Embase Classic (from Jan 1, 2006, to April 30, 2020) to identify cross-sectional surveys reporting the prevalence of IBS in adults (≥90% of participants aged ≥18 years) according to the Rome III or Rome IV criteria. We also hand-searched a selection of conference proceedings for relevant abstracts published between 2006 and 2019. We extracted prevalence data for all studies, according to the criteria used to define the presence of IBS. We did a meta-analysis to estimate pooled prevalence rates, according to study location and certain other characteristics (eg, sex and IBS subtype).

FINDINGS

We identified 4143 citations, of which 184 studies appeared relevant. 57 of these studies were eligible, and represented 92 separate adult populations, comprising 423 362 participants. The pooled prevalence of IBS in 53 studies that used the Rome III criteria, from 38 countries and comprising 395 385 participants, was 9·2% (95% CI 7·6-10·8; I²=99·7%). By contrast, pooled IBS prevalence among six studies that used the Rome IV criteria, from 34 countries and comprising 82 476 individuals, was 3·8% (95% CI 3·1-4·5; I²=96·6%). IBS with mixed bowel habit (IBS-M) was the most common subtype with the Rome III criteria, reported by 33·8% (95% CI 27·8-40·0; I²=98·1%) of people fulfilling criteria for IBS (ie, 3·7% [2·6-4·9] of all included participants had IBS-M), but IBS with diarrhoea (IBS-D) was the most common subtype with the Rome IV criteria (reported by 31·5% [95% CI 23·2-40·5; I²=98·1% 61·6%] of people with IBS, corresponding to 1·4% [0·9-1·9] of all included participants having IBS-D). The prevalence of IBS was higher in women than in men (12·0% [95% CI 9·3-15·0] vs 8·6% [6·3-11·2]; odds ratio 1·46 [95% CI 1·33-1·59]). Prevalence varied substantially between individual countries, and this variability persisted even when the same diagnostic criteria were applied and identical methodology was used in studies.

INTERPRETATION

Even when uniform symptom-based criteria are applied, based on identical methodology, to define the presence of IBS, prevalence varies substantially between countries. Prevalence was substantially lower with the Rome IV criteria, suggesting that these more restrictive criteria might be less suitable than Rome III for population-based epidemiological surveys.

FUNDING

None.

Healthy lifestyle score and irritable bowel syndrome: A cross-sectional study in adults

BACKGROUND

Lifestyle modifications play an important role in the management of irritable bowel syndrome (IBS), but there is limited information on any associations of combined lifestyle-related factors with IBS in Middle Eastern populations. We, therefore, assessed the associations of a "lifestyle score," in analogy to lifestyle scores applied in studies of other disorders, with IBS in adults.

METHODS

In a cross-sectional study on 3363 Iranian adults, a healthy lifestyle score (HLS) was constructed using information about dietary habits, dietary intake, physical activity, smoking status, and psychological distress, which was collected using validated questionnaires. A modified version of the Rome III questionnaire (in Persian) was used to diagnose IBS and its subtypes.

KEY RESULTS

Individuals with the highest HLS had a 65% lower odds of having IBS compared with those in the lowest category (OR: 0.35; 95% CI: 0.26-0.48). Participants with healthy dietary habits, including regular meal pattern, slow/moderate eating rate, moderate intra-meal fluid consumption, moderate/long meal-to-sleep interval, and low/moderate consumption of fatty foods, had significantly lower odds of having IBS compared with those with unhealthy dietary habits (OR: 0.81; 95% CI: 0.69-0.96). Moreover, individuals with lower levels of psychological distress, compared with those with higher levels of distress, had significantly lower odds of IBS (OR: 0.49; 95% CI: 0.40-0.60).

CONCLUSIONS AND INFERENCES

Our data suggest that having an overall "healthy lifestyle" is related to substantially reduced odds of IBS, suggesting that adhering to a healthy lifestyle pattern, including dietary habits, diet quality, physical activity, smoking, and psychological distress, can be considered as a key management strategy for IBS.

Atopic Patients Who Fulfilled Rome III Criteria for Irritable Bowel Syndrome Had Higher Animal Danders Sensitization

Background/Aims

The relationship between animal exposure and irritable bowel syndrome (IBS) is debated. Epidemiological studies have shown that atopy is more prevalent in IBS patients and vice versa. We set out to examine the association between animal danders sensitization and IBS-like symptoms in atopic patients.

Methods

We recruited 69 consecutive atopic patients from the allergy clinic of a tertiary hospital. Subjects completed validated bowel questionnaires, underwent skin prick test, blood was collected for serum total immunoglobulin E, and ImmunoCAP immune solid-phase allergen chip (ISAC) IgE multiplex assay.

Results

Twenty-eight (41.0%) atopic patients fulfilled the Rome III IBS criteria (atopy-IBS). There were no differences in gender, age, pet ownership, total serum IgE, or food allergen sensitization between atopy-IBS group and atopy-non-IBS group. We found that atopy-IBS group had significantly higher number of positive skin prick test for cat dander (64.3% vs 24.4%, P < 0.001), dog dander (64.3% vs 41.5%, P = 0.015) and weed pollens (32.1% vs 14.6%, P = 0.050) compared to atopy-non-IBS group. Out of 112 components from 51 allergen sources (both aeroallergen and food allergens), only Fel d1 (a major cat dander antigen) IgE is significantly higher in atopy-IBS group than atopy-non-IBS group (21.4% vs 2.4%, P = 0.029). Majority of atopy-IBS patients had mixed-type IBS.

Conclusions

We demonstrated an association between animal danders sensitization, in particular cat dander sensitization, and IBS-like symptoms in atopic patients. Future studies are needed to explore the relationship between aeroallergen and functional gastrointestinal disorders. Sensitization may be related to the pathophysiology of IBS or it could be that we are missing aeroallergen-induced gut allergy.

Association between Irritable Bowel Syndrome and Allergic Diseases: To Make a Case for Aeroallergen

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease and the most common cause of prolonged abdominal pain and bowel disturbances in the developed world. While initially thought to be functional or psychosomatic in nature, IBS is now recognized as a heterogeneous group of conditions. A subset of IBS patients and patients with allergic diseases share some characteristic inflammatory features. In fact, atopic children show an increased likelihood of developing IBS as adults. Given these findings, a subset of IBS may be suffering from allergy-related gut diseases. In this review, we present the allergy-related comorbidities of IBS, including genetic, environmental, and immunologic factors. We discuss studies demonstrating an increased sensitization of IBS patients to aeroallergens compared to food allergens. We then postulate potential pathophysiological mechanisms underlying both IBS and aeroallergens in the gut, followed by potential implications in the screening and treatment of allergies in IBS patients.

Psychosocial Factors Associated With Irritable Bowel Syndrome Development in Chinese College Freshmen

Background/Aims

The role of psychosocial factors on irritable bowel syndrome (IBS) in adolescents is incompletely understood. The aim of this study is to investigate the association between the psychosocial factors and the risk of developing IBS in college freshmen.

Methods

A cross-sectional survey was conducted in a randomly selected freshmen population in Wuhan China (n = 2449). Questionnaire evaluated demographics and psychosocial risks. The population was divided into 3 groups: non-discomfort, chronic abdominal discomfort and IBS. The association between the development of IBS and psychosocial factors was analyzed by ordinal and multiple logistic regression analysis.

Results

A total of 2053 (83.8%) completed this survey (mean age, 18.2 ± 0.9 years; female, 35.6%). Among them, 82 (4.0%) fulfilled the Rome III criteria for IBS. Female (odds ratio [OR], 3.31; 95% confidence interval [CI], 2.47-4.45), experience of abuse (OR, 2.44; 95% CI, 1.10-5.56), and suicidal intention (OR, 2.17; 95% CI, 1.15-4.17) were more likely to have IBS. Compared with chronic abdominal discomfort, however, depression (OR, 5.55; 95% CI, 1.36-22.71) was the only dependent risk factor for IBS.

Conclusion

The prevalence of IBS in college freshmen is 4.0%, and to the freshmen, psychosocial factors such as experience of abuse, depression, and suicidal intention were associated with high risk of developing IBS.

The Relation between Dietary Patterns and Functional Gastrointestinal Disorders among Iranian Military Men

Background

Assessing the relation between dietary habits and functional gastrointestinal disorders (FGIDs) is less investigated among military personnel. In this study, we aimed to evaluate the association of certain eating patterns and FGIDs in Iranian army men.

Materials and Methods

This cross-sectional study was performed on 600 army personnel working in Kerman ground forces military station number 05, Iran. Participants were asked to define their weekly breakfast consumption, lunch intake time, and chewing efficiency. FGIDs were categorized as four groups including functional dyspepsia (FD), irritable bowel syndrome (IBS), functional constipation (FC) and functional diarrhea (FDi) diagnosed by Rome Ш criteria. Relation between variables was assessed through crude and multiple stepwise adjusted models.

Results

The prevalence of FD, IBS, FC, and FDi in our study was 20%, 32.3%, 3%, and 53.2%, respectively. After adjustment of all potential confounding variables, more weekly breakfast consumption was associated with decreased FDi prevalence (odds ratio [OR]: 0.57, 95% confidence interval [CI] = 0.38-0.84, P = 0.005). Slowly lunch consumption declined prevalence of IBS (OR: 0.33, 95% CI = 0.13-0.84, P = 0.02). Individuals chewing their meals well had a lower percentage of IBS, FC, and FDi (OR: 0.53, 95% CI = 0.33-0.83, P = 0.006; OR: 0.24, 95% CI = 0.06-0.89, P = 0.03; and OR: 0.52, 95% CI = 0.34-0.79, P = 0.003, respectively).

Conclusions

This study suggested that increasing breakfast intake, slowly lunch consumption, and better food chewing could be effective decreasing FGIDs' prevalence and increasing army crews' quality of lives and work efficiency. Further studies required to confirm this relationship and define accurate pathophysiological mechanisms.

Is body mass index associated with symptom severity and health-related quality of life in irritable bowel syndrome? A cross-sectional study

OBJECTIVE

The aim of this study was to describe the body mass index (BMI) distribution in patients with irritable bowel syndrome (IBS) based on the Rome III criteria and to evaluate the association of BMI with symptom severity and quality of life (QOL).

METHODS

A cross-sectional study was carried out in patients visiting our outpatient functional gastrointestinal disorders specialty clinic. IBS diagnosis was made based on Rome III criteria. IBS symptom severity was investigated using the IBS severity score system. QOL was assessed using the Short Form 36 Health Survey, which consists of physical health and mental health.

RESULTS

366 patients (252 women) who fulfilled Rome III criteria and provided complete BMI data (23.90±5.22 kg/m²) were included. Overall, 59.0% of patients with IBS were in the normal weight range, 30.3% were overweight or obese, and 10.7% were underweight. Both physical and mental health decreased significantly with the severity of symptoms (all p<0.01), while controlling for several covariates (age, gender, family status, education status and IBS subtypes). Obesity and symptom severity (β=-0.177,△R²=0.037, p<0.01; β=-0.387,△R²=0.147, p<0.01) were significant negative factors that influencing physical health. Symptom severity (β=-0.301,△R²=0.084, p<0.01) was significant negative factor that influencing mental health. However, BMI didn't account for additional variance in mental health (p>0.05).

CONCLUSION

Being overweight is a common phenomenon in patients with IBS regardless of IBS subtype. The association between QOL and symptom severity followed a negative dose-response pattern. Patients with higher BMI, especially obese patients, were more frequently in poor physical health. However, this kind of relationship was not found in BMI and mental health.

Clinical Practice Guidelines for Irritable Bowel Syndrome in Korea, 2017 Revised Edition

In 2011, the Korean Society of Neurogastroenterology and Motility (KSNM) published clinical practice guidelines on the management of irritable bowel syndrome (IBS) based on a systematic review of the literature. The KSNM planned to update the clinical practice guidelines to support primary physicians, reduce the socioeconomic burden of IBS, and reflect advances in the pathophysiology and management of IBS. The present revised version of the guidelines is in continuity with the previous version and targets adults diagnosed with, or suspected to have, IBS. A librarian created a literature search query, and a systematic review was conducted to identify candidate guidelines. Feasible documents were verified based on predetermined inclusion and exclusion criteria. The candidate seed guidelines were fully evaluated by the Guidelines Development Committee using the Appraisal of Guidelines for Research and Evaluation II quality assessment tool. After selecting 7 seed guidelines, the committee prepared evidence summaries to generate data exaction tables. These summaries comprised the 4 main themes of this version of the guidelines: colonoscopy; a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols; probiotics; and rifaximin. To adopt the core recommendations of the guidelines, the Delphi technique (ie, a panel of experts on IBS) was used. To enhance dissemination of the clinical practice guidelines, a Korean version will be made available, and a food calendar for patients with IBS is produced.

Irritable bowel syndrome is concentrated in people with higher educations in Iran: an inequality analysis

OBJECTIVES

Like any other health-related disorder, irritable bowel syndrome (IBS) has a differential distribution with respect to socioeconomic factors. This study aimed to estimate and decompose educational inequalities in the prevalence of IBS.

METHODS

Sampling was performed using a multi-stage random cluster sampling approach. The data of 1,850 residents of Kish Island aged 15 years or older were included, and the determinants of IBS were identified using a generalized estimating equation regression model. The concentration index of educational inequality in cases of IBS was estimated and decomposed as the specific inequality index.

RESULTS

The prevalence of IBS in this study was 21.57% (95% confidence interval [CI], 19.69 to 23.44%). The concentration index of IBS was 0.20 (95% CI, 0.14 to 0.26). A multivariable regression model revealed that age, sex, level of education, marital status, anxiety, and poor general health were significant determinants of IBS. In the decomposition analysis, level of education (89.91%), age (−11.99%), and marital status (9.11%) were the three main contributors to IBS inequality. Anxiety and poor general health were the next two contributors to IBS inequality, and were responsible for more than 12% of the total observed inequality.

CONCLUSIONS

The main contributors of IBS inequality were education level, age, and marital status. Given the high percentage of anxious individuals among highly educated, young, single, and divorced people, we can conclude that all contributors to IBS inequality may be partially influenced by psychological factors. Therefore, programs that promote the development of mental health to alleviate the abovementioned inequality in this population are highly warranted.

The Role of Visceral Hypersensitivity in Irritable Bowel Syndrome: Pharmacological Targets and Novel Treatments

Irritable bowel syndrome (IBS) is the most common disorder referred to gastroenterologists and is characterized by altered bowel habits, abdominal pain, and bloating. Visceral hypersensitivity (VH) is a multifactorial process that may occur within the peripheral or central nervous systems and plays a principal role in the etiology of IBS symptoms. The pharmacological studies on selective drugs based on targeting specific ligands can provide novel therapies for modulation of persistent visceral hyperalgesia. The current paper reviews the cellular and molecular mechanisms underlying therapeutic targeting for providing future drugs to protect or treat visceroperception and pain sensitization in IBS patients. There are a wide range of mediators and receptors participating in visceral pain perception amongst which substances targeting afferent receptors are attractive sources of novel drugs. Novel therapeutic targets for the management of VH include compounds which alter gut-brain pathways and local neuroimmune pathways. Molecular mediators and receptors participating in pain perception and visceroperception include histamine-1 receptors, serotonin (5-hydrodytryptamine) receptors, transient receptor potential vanilloid type I, tachykinins ligands, opioid receptors, voltage-gated channels, tyrosine receptor kinase receptors, protease-activated receptors, adrenergic system ligands, cannabinoid receptors, sex hormones, and glutamate receptors which are discussed in the current review. Moreover, several plant-derived natural compounds with potential to alleviate VH in IBS have been highlighted. VH has an important role in the pathology and severity of complications in IBS. Therefore, managing VH can remarkably modulate the symptoms of IBS. More preclinical and clinical investigations are needed to provide efficacious and targeted medicines for the management of VH.