Review article: the incidence and risk factors for irritable bowel syndrome in population-based studies

Associations of modifiable factors with risk of irritable bowel syndrome

Background

Modifiable factors were found to be associated with the risk of irritable bowel syndrome (IBS) in observational studies, but whether these associations are causal is uncertain. We conducted a Mendelian randomization (MR) study to systematically explore the causal associations of modifiable factors with IBS.

Methods

Summary-level statistical data for IBS was obtained from a genome-wide association study (GWAS) meta-analysis of UK Biobank (40,548 cases and 293,220 controls) and the international collaborative Bellygenes initiative (12,852 cases and 139,981 controls). Genetic instruments associated with the exposures at the genome-wide significance (p < 5 × 10-8) level were selected from previous GWASs. Mendelian randomization was performed using inverse-variance weighted (IVW) method, supplemented with several sensitivity analyses to evaluate potentially causal relationships between identified contributing factors and IBS. Furthermore, we applied another database from FinnGen (8,116 IBS cases and 276,683 controls) to testify the reliability of the significant associations.

Results

Seven convincing modifiable factors were significantly associated with IBS after correction for multiple testing. Genetically predicted smoking initiation (OR = 1.12, 95% CI = 1.06-1.18, p = 1.03 × 10-4), alcohol consumption (OR = 0.47, 95% CI = 0.34-0.64, p = 3.49 × 10-6), sedentary behavior (OR = 1.17, 95% CI = 1.07-1.28, p = 4.02 × 10-4), chronotype (OR = 0.92, 95% CI = 0.88-0.96, p = 4.42 × 10-4), insomnia (OR = 1.19, 95% CI = 1.15-1.24, p = 7.59 × 10-19), education (OR = 0.80, 95% CI = 0.74-0.88, p = 5.34 × 10-7), and visceral adiposity (OR = 1.15, 95% CI = 1.06-1.24, p = 7.96 × 10-4). We additionally identified several suggestive factors, including serum magnesium, serum phosphorus, physical activity, lifetime smoking, intelligence, lean body mass, and body mass index (BMI). After pooling the effect estimates from FinnGen, the associations remained significant except for chronotype.

Conclusion

This MR analysis verified several modifiable risk factors for IBS, thus prevention strategies for IBS should be considered from multiple perspectives on these risk factors.

Ultra-Processed Food Consumption and Long-Term Risk of Irritable Bowel Syndrome: A Large-Scale Prospective Cohort Study

BACKGROUND & AIMS

The considerable disease burden of irritable bowel syndrome (IBS) has coincided with the increase of ultraprocessed food (UPF) consumption over the past few decades. However, epidemiologic evidence for an association is lacking. We aimed to examine the long-term risk of IBS associated with UPF consumption in a large-scale prospective cohort.

METHODS

Participants who completed 24-hour dietary recalls during 2009 to 2012 from the UK Biobank, and free of IBS, celiac disease, inflammatory bowel disease, and any cancer at baseline, were included (N = 178,711; 53.1% female). UPF consumption was defined according to the NOVA food classification system, expressed as a percentage of UPF content in the total diet intake (as grams per day). The primary outcome was incident IBS. A Cox proportional hazard model was performed to estimate associated risk.

RESULTS

The mean UPF consumption was 21.0% (SD, 11.0%) of the total diet. During a median of 11.3 years of follow-up, 2690 incident IBS cases were identified. An 8% higher risk of IBS (hazard ratio, 1.08; 95% CI, 1.04-1.12) was associated with every 10% increment of UPF consumption. Compared with the lowest quartile of UPF consumption, the highest quartile was associated with a significantly increased risk of incident IBS (hazard ratio, 1.19; 95% CI, 1.07-1.33; Ptrend < .001). Subgroup analyses by age, sex, body mass index, smoking, and alcohol drinking status also showed similar results, except for the never/previous drinking subgroup. Further sensitivity analyses confirmed the positive association with a higher UPF consumption.

CONCLUSIONS

Our findings provide evidence that a higher UPF consumption is associated with an increased risk of incident IBS, with a significant dose-response relationship.

Irritable Bowel Syndrome in Veterans with Gulf War Illness Evaluated at VA's War-Related Illness and Injury Study Center

INTRODUCTION

Excess rates of Gulf War illness (GWI) and irritable bowel syndrome (IBS), two chronic multisymptom illnesses, have long been documented among nearly 700,000 veterans who served in the 1990-1991 Persian Gulf War. We sought to report the prevalence, characteristics, and association of GWI and IBS decades after the war in a clinical cohort of deployed Gulf War veterans (GWVs) who were evaluated at the Department of Veterans Affairs' War Related Illness and Injury Study Center (WRIISC) for unexplained chronic symptoms.

MATERIALS AND METHODS

We analyzed data gathered from clinical intake questionnaires of deployed GWVs who were evaluated at WRIISC clinics between 2008 and 2020. We applied Centers for Disease Control (CDC) criteria to determine the prevalence of severe GWI. IBS was identified using Rome IV diagnostic criteria (current IBS) and veterans' self-reported "history of physician-diagnosed IBS." We examined associations between IBS and GWI using bivariate analyses and multivariable logistic regression.

RESULTS

Among the N = 578 GWVs evaluated by the WRIISC, severe GWI (71.8%), history of physician-diagnosed IBS (50.3%) and current IBS (42.2%) were all highly prevalent. Nearly half of GWVs with severe GWI met Rome criteria for IBS (45.8%), and over half reported a history of physician-diagnosed IBS (56.1%). In multivariable models, severe GWI was significantly associated both with current IBS (adjusted odds ratio (aOR): 1.68, 95% CI: 1.11, 2.54) and with veteran-reported history of physician-diagnosed IBS (aOR: 2.15, 95% CI: 1.43, 2.23). IBS with diarrhea (IBS-D) was the most common subtype among GWVs with current IBS (61.1%). However, IBS-mixed affected a significantly greater proportion of veterans with severe GWI, compared to veterans who did not have severe GWI (P = .03).

CONCLUSIONS

More than 20 years after the Persian Gulf War, our findings indicate a high degree of comorbidity between severe GWI and IBS among deployed GWVs seeking care for unexplained illnesses. Our results suggest GWVs with GWI should be screened for IBS for which evidence-based treatments are available and could potentially reduce symptom burden. Conversely, symptoms of IBS should trigger additional evaluation for non-gastrointestinal symptoms in deployed Gulf War veterans to identify possible GWI and ensure a comprehensive approach to care.

Exploring the clinical significance of miR-148 expression variations in distinct subtypes of irritable bowel syndrome

Irritable bowel syndrome (IBS) belongs to chronic functional gastrointestinal diseases featured by abdominal pain and changes in bowel habits. This study aimed to investigate the clinical significance of serum miR-148 expression in different subtypes of IBS. We enrolled 86 IBS patients and 55 healthy controls. miR-148 expression levels were assessed in IBS patients classified into IBS-constipation (IBS-C), IBS-diarrhea (IBS-D), and IBS-mixed stool pattern (IBS-M) subtypes. Receiver-operating characteristic (ROC) curves were employed to evaluate the diagnostic potential of miR-148 in distinguishing among IBS subtypes. Additionally, we analyzed the correlation between miR-148 expression and clinical characteristics, including IBS symptom severity. miR-148 expression was highest in IBS-D (diarrhea) group, followed by IBS-M and IBS-C. With the exception of the IBS-C group, miR-148 expression was elevated in IBS patients compared to controls. ROC curve analysis demonstrated that serum miR-148 exhibited higher diagnostic accuracy for discriminating IBS-C and IBS-D than IBS-M. Correlation analysis revealed a positive relationship between serum miR-148 relative expression and IBS symptom severity system scores. Univariate logistic analysis indicated a positive association between miR-148 expression and IBS-D and a negative correlation with IBS-C. miR-148 expression exhibits differential patterns among IBS subtypes and holds a potential to distinguish IBS-C and IBS-D. Furthermore, miR-148 expression correlates with the severity of IBS symptoms.

Physical activity, sedentary behavior, and the risk of functional gastrointestinal disorders: A two-sample Mendelian randomization study

OBJECTIVES

Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are prevalent functional gastrointestinal disorders (FGIDs). In this study we aimed to explore the causal association between physical activity or sedentary behavior and the risk of FD and IBS.

METHODS

Mendelian randomization (MR) analysis was employed. Candidate genetic instruments for physical activity and sedentary behavior were retrieved from the latest published Genome-Wide Association Study (GWAS), which included up to 703 901 participants. Summary-level GWAS data for FD (8 875 cases and 320 387 controls) and IBS (9 323 cases and 301 931 controls) were obtained from the FinnGen study. The causal effects were mainly estimated by inverse variance weighted (IVW) method. Sensitivity analyses were implemented with Cochran's Q test, MR-Egger intercept test, leave-one-out analysis, and the funnel plot.

RESULTS

No significant association of moderate-to-vigorous intensity physical activity (MVPA), leisure screen time (LST), sedentary behavior at work (SDW), and sedentary commuting (SDC) with the risk of FD was found. However, there was a suggestive correlation between MVPA and the decreased risk of FD (odds ratio [OR] 0.63, 95% confidence interval [CI] 0.39-0.99, P = 0.047). Genetically predicted MVPA decreased the risk of IBS (OR 0.58, 95% CI 0.40-0.84, P = 0.004), while increased LST was positively associated with IBS risk (OR 1.33, 95% CI 1.15-1.53, P < 0.001). No causal effects of SDW or SDC on IBS risk were observed.

CONCLUSION

MVPA and LST are causally linked to the development of IBS, which will facilitate primary prevention of IBS.

Gender differences in gastrointestinal, biopsychosocial and healthcare-seeking behaviors in Chinese patients with irritable bowel syndrome predominant with diarrhea

BACKGROUND

Evidences of comparison of sex difference in Chinese irritable bowel syndrome (IBS) patients were few. We aim to compare gender difference in the biopsychosocial characteristics of Chinese patients of IBS predominant with diarrhea (IBS-D).

METHODS

IBS-D patients meeting Rome III criteria were enrolled. We administered IBS symptom questionnaires, evaluation of psychological status (HAMD and HAMA scales) and IBS quality of life (IBS-QOL), dietary habits, healthcare seeking behaviors, and compared biopsychosocial characteristics between male and female patients.

RESULTS

Four hundred and ninety patients were enrolled including 299 males and 191 females. More female patients reported abdominal pain associated with defecation (84.3% vs. 74.9%, P = 0.014) while males reported more abdominal discomfort (39.8% vs. 26.7%, P = 0.003). Females had higher IBS symptom score (9.7 ± 1.7 vs. 9.4 ± 1.4, P = 0.025) and more of females had severe abdominal pain/discomfort (17.8% vs. 12.4%, P = 0.013) while there were no significant differences of other bowel symptoms. Females reported higher incidence of comorbid anxiety state (64.9% vs. 52.8%, P = 0.008) and depression state (35.6% vs. 19.7%, P < 0.001) than males. Female patients also had lower IBS-QOL score (70.2 ± 20.4 vs. 75.1 ± 16.8, P = 0.028) and more frequent consultations, as well as less response for dietary modification than males.

CONCLUSIONS

Chinese female patients with IBS-D had more prominent psychosocial disorders compared to male patients and their abdominal symptoms had minor differences.

Chronic Sacral Nerve Stimulation Inhibits Visceral Hypersensitivity in Diarrhea-Predominant Irritable Bowel Syndrome Rats Model

OBJECTIVE

Sacral nerve stimulation (SNS) is emerging as a novel treatment for irritable bowel syndrome (IBS). However, its effects are limited, and the underlying mechanisms remain largely unknown.

MATERIALS AND METHODS

In this study, rats were divided into three groups (n = 12 rats per group): 1) the SNS group; 2) the sham SNS group (the sham group for short); and 3) the control group. The SNS and sham groups were exposed to chronic and acute stress to establish an IBS model. Electrode implantation surgery was performed in rats with the IBS model. The SNS group received electrical stimulation for 30 minutes every day for seven days. Abdominal withdrawal reflex (AWR) was used to evaluate the effect of SNS on visceral sensitivity in diarrhea-predominant IBS (IBS-D) rats. The frequency domain of heart rate variability (HRV) was analyzed to assess the effect of SNS on regulating the autonomic function. The expression of transient receptor potential vanilloid 1 (TRPV1) in the colon, spinal cord, and hippocampus was detected by immunohistochemistry to explore the mechanism of SNS in IBS-D rats.

RESULTS

Compared with the sham group, AWR scores were significantly decreased under different gas volumes of stimulation of 0.4, 0.6, and 0.8 ml for rectal distention in the SNS group (all p < 0.05). However, there was no significant difference <1.0 ml between the two groups (p > 0.05). Compared with the sham group, the frequency domain indexes of HRV were significantly altered. Normalized low-frequency power and low frequency-to-high frequency ratio were significantly decreased, and normalized high-frequency power was significantly increased in the SNS group (all p < 0.05). Moreover, the expression of TRPV1 in the spinal cord and colon in the SNS group was significantly decreased compared with the sham group (both p < 0.05). These results suggested that chronic SNS not only improved the visceral sensitivity and autonomic dysfunction but also decreased the expression of TRPV1 in the spinal cord-gut tissue in IBS-D rats.

CONCLUSION

Chronic SNS was found to have an inhibitory effect on visceral hypersensitivity in IBS-D rats, providing experimental evidence for its potential clinical application in IBS.

The aging gut: Symptoms compatible with disorders of gut-brain interaction (DGBI) in older adults in the general population

BACKGROUND

Little is known about changes in gastrointestinal symptoms compatible with disorders of gut-brain interaction (DGBI) with increasing age at the population level. The objective of this study was to describe the patterns of DGBI in individuals 65 years of age and above and contrasting them with those of younger adults.

METHODS

A community sample of 6300 individuals ages 18 and older in the US, UK, and Canada completed an online survey. Quota-based sampling was used to ensure equal proportion of sex and age groups (40% aged 18-39, 40% aged 40-64, 20% aged 65+) across countries, and to control education distributions. The survey included the Rome IV Diagnostic Questionnaire for DGBI, demographic questions, questionnaires measuring overall somatic symptom severity and quality of life, and questions on healthcare utilization, medications, and surgical history.

RESULTS

We included 5926 individuals in our analyses; 4700 were 18-64 years of age and 1226 were ages 65+. Symptoms compatible with at least one DGBI were less prevalent in participants ages 65+ vs. ages 18-64 years (34.1% vs. 41.3%, p < 0.0001). For symptoms compatible with upper GI DGBI, lower prevalence for most disorders was noted in the 65+ group. For lower GI DGBI, a different pattern was seen. Prevalence was lower in ages 65+ for irritable bowel syndrome and anorectal pain, but no differences from younger participants for the disorders defined by abnormal bowel habits (constipation and/or diarrhea) were seen. Fecal incontinence was the only DGBI that was more common in ages 65+. Having a DGBI was associated with reduced quality of life, more severe non-GI somatic symptoms, and increased healthcare seeking, both in younger and older participants.

CONCLUSION

Symptoms compatible with DGBI are common, but most of these decrease in older adults at the population level, with the exception of fecal incontinence which increases. This pattern needs to be taken into account when planning GI health care for the growing population of older adults.

Acupuncture and moxibustion for irritable bowel syndrome: An umbrella systematic review

BACKGROUND

Irritable bowel syndrome (IBS) is a functional bowel disease characterized by abdominal pain or discomfort associated with altered bowel habits. Several clinical studies have demonstrated the effectiveness of acupuncture and moxibustion for IBS. Many systematic reviews of acupuncture and moxibustion for IBS have been published in recent years, but their results are not entirely consistent.

OBJECTIVE

To evaluate the methodological, reporting, and evidence quality of systematic reviews of acupuncture and moxibustion for IBS.

SEARCH STRATEGY

Systematic reviews of acupuncture and moxibustion for IBS published before February 20, 2023 were searched in eight databases: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang Data, VIP Database for Chinese Technical Periodicals, and China Biology Medicine. The keywords used for literature search were acupuncture, moxibustion, systematic review, meta-analysis, and irritable bowel syndrome.

INCLUSION CRITERIA

Systematic reviews and meta-analyses of randomized controlled trials of acupuncture and moxibustion for IBS were included.

DATA EXTRACTION AND ANALYSIS

Relevant information was independently extracted by two investigators. The A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2), Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020), and Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used to evaluate the methodological quality, reporting quality and evidence quality, respectively.

RESULTS

A total of 342 studies were retrieved and 15 systematic reviews were included. The results of AMSTAR 2 showed low methodological quality in 2 studies and very low methodological quality in the remaining 13 studies, with main issues being failure to register a protocol, incomplete search strategy, not providing a list of excluded studies, incomplete consideration of the risk of bias in the included studies, and a failure to assess the publication bias. The results of PRISMA 2020 showed seriously deficient reporting quality of 2 studies, somewhat deficient reporting quality of 12 studies, and relatively complete reporting quality of 1 study, with the main problems being lack of a complete search strategy, non-availability of a list of excluded studies with justification for their exclusion, not conducting heterogeneity and sensitivity analyses, not evaluating the credibility of the evidence, and not registering the protocol. The results of GRADE showed that the quality of the evidence is low or very low.

CONCLUSION

Most included systematic reviews interpreted findings to suggest that acupuncture and moxibustion have benefits for IBS. However, there is a need to improve the methodological, reporting and evidence quality of the systematic reviews. Larger, multicenter, rigorously designed randomized controlled trials and high-quality systematic reviews are required to obtain more robust evidence.

PLEASE CITE THIS ARTICLE AS

Ma YY, Hao Z, Chen ZY, Shen YX, Liu HR, Wu HG, Bao CH. Acupuncture and moxibustion for irritable bowel syndrome: An umbrella systematic review. J Integr Med. 2024; 22(1): 22-31.

Prevalence and Burden of Illness of Rome IV Irritable Bowel Syndrome in the United States: Results From a Nationwide Cross-Sectional Study

BACKGROUND & AIMS

The estimated prevalence of irritable bowel syndrome (IBS) using Rome IV criteria in the United States (US) ranges from 4.7% to 5.3%, although these estimates arise from studies with relatively small sample sizes. This study assessed the prevalence of IBS and its associated burden of illness using a nationally representative data set with nearly 89,000 people in the US.

METHODS

From May 3 to June 24, 2020, we performed an online survey described to participating adults aged ≥18 years old as a "national health survey." We recruited a representative sample of people in the US to complete the survey, which included the Rome IV IBS questionnaire, National Institutes of Health Patient-Reported Outcome Measurement Information System (PROMIS) gastrointestinal scales, and questions on health care-seeking behavior.

RESULTS

Overall, 88,607 people completed the survey, of whom 5414 (6.1%) met Rome IV IBS criteria: mixed IBS (n = 1838 [33.9%]), constipation-predominant IBS (n = 1819 [33.6%]), diarrhea-predominant IBS (n = 1521 [28.1%]), and unsubtyped IBS (n = 236 [4.4%]). Women had higher odds for IBS compared with men, whereas racial/ethnic minorities had lower odds for IBS vs non-Hispanic Whites. Across the 3 main subtypes, 68.2% to 73.2% of people reported ever seeking care for their IBS symptoms, whereas 53.8% to 58.9% did so in the past 12 months.

CONCLUSIONS

In this nationwide US survey, we found that Rome IV IBS is slightly more prevalent (6.1%) vs prior estimates (4.7%-5.3%). Additional research is needed to determine whether this higher prevalence is in part due to the coronavirus disease 2019 pandemic during which this study was conducted.

Burden of anxiety and depression among hospitalized patients with irritable bowel syndrome: a nationwide analysis

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder that affects patients both physically and mentally. Our study aimed to investigate the burden of psychiatric disorders in IBS patients.

METHODS

We conducted a retrospective analysis of the National inpatient sample (NIS) from 2016 to 2019. We recruited patients admitted with a diagnosis of IBS and determined the prevalence of anxiety, depression, and suicide attempt/ideation.

RESULTS

We found a total of 1,256,325 hospitalizations with a diagnosis of IBS. Among them, 478,515 (38.1%) had anxiety and 344,165 (27.4%) had depression. The prevalence of psychiatric disorders including anxiety (38.1% vs. 15.1%), depression (38.1% vs. 15.1%), bipolar disorder (5.22% vs. 2.38%), suicidal attempt/Ideation (3.22% vs. 2.38%), and eating disorder (0.32% vs. 0.08%) was significantly higher in IBS patient population when compared to general adult population (p < 0.001). Patients with IBS had greater odds of anxiety (AOR 2.88, 95% CI 2.85-2.91, P < 0.001), depression (AOR 2.16, 95% CI 2.14-2.19, P < 0.001) and suicidal attempt/ideation (AOR 1.94, 95% CI 1.88-2.00, P < 0.001) in comparison to general population. IBS subtypes including diarrhea-predominant, constipation-predominant and mixed type were independently associated with increased odds of anxiety, depression, and suicide attempt/ideation. Patients with IBS and a co-diagnosis of anxiety or depression had increased mean length of hospital stay by 0.48 (95% CI 0.43-0.52, P < 0.001) and 0.52 (95% CI 0.06-0.97, P < 0.03) days, respectively.

CONCLUSION

The presence of IBS is associated with an increased associated prevalence of psychiatric disorders such as anxiety, depression, and suicide attempt/ideation.

Prevalence of Fibromyalgia and Chronic Fatigue Syndrome among Individuals with Irritable Bowel Syndrome: An Analysis of United States National Inpatient Sample Database

Background and Aim: Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder associated with other somatic disorders. We studied the prevalence and predictors of fibromyalgia and chronic fatigue syndrome (CFS) in IBS patients. Methods: We used the National Inpatient Sample and included hospitalization of individuals with IBS, using ICD-10 codes, from 2016-2019. The prevalence and predictors of fibromyalgia and CFS in IBS patients were studied. Univariate and multivariate patient- and hospital-level regression models were used to calculate the adjusted odds of fibromyalgia and CFS in the IBS patient population. Results: Of 1,256,325 patients with an ICD-10 code of IBS included in the study, 10.73% (134,890) also had ICD-10 codes for fibromyalgia and 0.42% (5220) for CFS. The prevalence of fibromyalgia and CFS was significantly higher in IBS patients (adjusted odds ratio (AOR) 5.33, 95% confidence interval (CI) 5.24-5.41, p < 0.001, and AOR 5.40, 95% CI 5.04-5.78, p < 0.001, respectively) compared to the general adult population without IBS. IBS-diarrhea, IBS-constipation, and IBS-mixed types were independently associated with increased odds of fibromyalgia and CFS. Increasing age (AOR 1.02, 95% CI 1.01-1.04, p 0.003; AOR 1.02, 95% CI 1.01-1.03, p 0.001), female gender (AOR 11.2, 95% CI 11.1-11.4, p < 0.001; AOR 1.86, 95% CI 1.78-1.93, p < 0.001) and white race (AOR 2.04, 95% CI 1.95-2.12, p < 0.001; AOR 1.69, 95% CI 1.34-2.13, p < 0.001) were independent predictors of increased odds of fibromyalgia and CFS, respectively. Conclusions: It appears that IBS is associated with an increased prevalence of somatic disorders such as fibromyalgia and CFS.

Prevalence of Irritable Bowel Syndrome in Saudi Arabia: A Systematic Review and Meta-Analysis

Irritable bowel syndrome (IBS) is a commonly found global functional pathology with no detectable structural changes. It affects the quality of life and often coexists with psychiatric and somatic issues. We reviewed all articles published between 1990 and April 2023. The databases used for the data search were Google Scholar, Web of Science, Cochrane Library, and PubMed/MEDLINE. Ovid search engine was also used to broaden the search strategy. Predefined keywords, including "Irritable bowel syndrome" (MeSH) OR "IBS" (all fields), along with "Saudi Arabia" and "Middle East," were used to avoid data loss and ambiguity. Any cross-sectional study that reported the prevalence of IBS in any gender, age, and group of the Saudi population was included. Data extraction was independently performed in duplicate to mitigate bias and data loss. Statistical analysis of proportion was conducted by using Miller (Freeman-Tukey double arcsine - exact inverse). Out of 350 records identified, only 38 studies were included in the quantitative synthesis. The total number of study participants was 26,567, on the basis of the predefined inclusion criteria of the study. StatsDirect software was used for the statistical analysis of the study parameters. Based on all 38 identified studies, the calculated pooled prevalence was 20.7% (95% confidence interval (CI) = 17.8% to 23.7% by applying random effects (DerSimonian-Laird method). IBS was identified in 21% (95% CI = 16.7% to 25.7%) of the general population, 22% (95% CI = 17.6% to 26.7%) of students, and 18.3% (95% CI = 13.3% to 23.9%) of healthcare workers. The pooled prevalence of IBS among the Saudi population was 20.7%. The pathophysiology of IBS is complexed and significantly affected by genetics, diet, cultural characteristics, age, anxiety, depression, stress, and sleep disorders. This study fills a gap in understanding IBS prevalence in Saudi Arabia, contributing valuable data to this region.

HLA-DQ and alcohol in the pathogenesis of irritable bowel syndrome in college students: a case-control study

Some researchers have shown that genetics contribute to the incidence of IBS. However, no research has focused on the interaction between HLA-DQ and living habits in the pathogenesis of IBS. The present study explored the risk factors for IBS in college students of Guangxi Han nationality and explored the interaction between HLA-DQ and living habits on the pathogenesis of IBS. Univariate and multivariate analyses were used to determine the risk factors for IBS. Logistic interaction analysis and the Excel table made by Andersson were used to explore the interaction between genes and living habits in the context of IBS. We found that low expression of HLA-DQ2 and DQ8 were associated with the pathogenesis of IBS, while mild to moderate alcohol consumption was associated with the occurrence of IBS symptoms. Only the HLA-DQ8 gene and alcohol consumption had additive interactions in the context of the occurrence of IBS. In other words, for college students of Guangxi Han nationality, HLA-DQ2 and HLA-DQ8 might be protective against IBS, while alcohol consumption might be an independent risk factor. There was an additive interaction between HLA-DQ8 and alcohol consumption in the occurrence of IBS.

Associations and gastrointestinal symptoms in women with endometriosis in comparison to women with irritable bowel syndrome: a study based on a population cohort

BACKGROUND

Endometriosis and irritable bowel syndrome (IBS) have similar symptoms, pathogenesis, and risk factors. These diagnoses often coexist and are frequently misdiagnosed leading to diagnostic delays. This study of a population-based cohort aimed to investigate associations relating to endometriosis and IBS and to compare gastrointestinal symptoms between endometriosis and IBS.

METHOD

The study cohort included women from the Malmö Offspring Study with information about endometriosis and IBS diagnoses from the National Board of Health and Welfare. The participants answered a questionnaire about lifestyle habits, medical and drug history, and self-reported IBS. The visual analog scale for IBS was used to estimate gastrointestinal symptoms the past 2 weeks. Endometriosis diagnosis and self-reported IBS were used as dependent variables to study associations with age, body mass index (BMI), education, occupation, marital status, smoking, alcohol habits, and physical activity using logistic regression. Mann-Whitney U Test or Kruskal-Wallis tests were used to calculate the differences in symptoms between groups.

RESULTS

Of the 2,200 women with information from medical records, 72 participants had endometriosis; 21 (29.2%) of these had self-reported IBS. Of the 1,915 participants who had answered the questionnaire, 436 (22.8%) had self-reported IBS. Endometriosis was associated with IBS (OR:1.86; 95%CI:1.06-3.26; p = 0.029), as well as with age 50-59 years (OR:6.92; 95%CI:1.97-24.32; p = 0.003), age ≥ 60 years (OR:6.27; 95%CI:1.56-25.17; p = 0.010), sick leave (OR:2.43; 95%CI:1.08-5.48; p = 0.033), and former smoking (OR:3.02; 95%CI:1.19-7.68; p = 0.020). There was an inverse association with BMI (OR:0.36; 95%CI:0.14-4.91; p = 0.031). IBS was associated with endometriosis (OR:1.77; 95%CI:1.02-3.07; p = 0.041) and sick leave (OR:1.77; 95%CI:1.14-2.73; p = 0.010), with a tendency to association with smoking (OR:1.30; 95%CI:0.98-1.72; p = 0.071). When excluding participants using drugs associated with IBS, the condition was associated with current smoking (OR:1.39; 95%CI:1.03-1.89; p = 0.033) and inversely with age 50-59 years (OR:0.58; 95%CI:0.38-0.90; p = 0.015). There were differences in the gastrointestinal symptoms between IBS and healthy participants, but not between endometriosis and IBS or healthy participants.

CONCLUSION

There were associations between endometriosis and IBS, without differences in gastrointestinal symptoms. Both IBS and endometriosis were associated with smoking and sick leave. Whether the associations reflect causality or depend on common risk factors and pathogenesis remains to be determined.

Managing pain in irritable bowel syndrome: current perspectives and best practice

INTRODUCTION

Irritable bowel syndrome (IBS) is characterized by chronic symptoms (>6 months) of abdominal pain in combination with a disturbed bowel habit. There is an association between the intensity of abdominal pain and the need for health care utilization. A bidirectionally disordered gut-brain interaction is central in the pathophysiology of IBS where a number of factors, gastrointestinal and non-gastrointestinal, can contribute to the illness experience. In order to treat abdominal pain in IBS, mapping these factors in a multidimensional clinical profile is helpful.

AREAS COVERED

This review covers basic epidemiology and pathophysiology of abdominal pain in IBS, the diagnostic approach, and a multidimensional treatment model where the management of abdominal pain is in focus.

EXPERT OPINION

A personalized treatment of abdominal pain in IBS is possible in patients who understand the diagnosis, the potential of therapies used, and where a good continuity in the patient-doctor relationship is established.

Sexual dysfunction worsens both the general and specific quality of life of women with irritable bowel syndrome. A cross-sectional study

Background

Irritable bowel syndrome (IBS) and sexual dysfunction (SxD) lowers quality of life (QOL) separately, but the effect of their overlap in unselected populations has not been studied.

Objective

To evaluate the QOL of IBS women with and without SxD and compare it with controls.

Methods

In this cross-sectional assessment, we studied 51 IBS women (Rome IV criteria) and 54 controls. SxD was determined using the female sexual function index questionnaire. QOL was evaluated by the Short Form 36 (SF-36) and IBS-QOL questionnaires.

Results

SxD prevalence was similar between IBS women (39.22%) and controls (38.89%). Compared with other groups, IBS patients with SxD showed lower scores in all domains as well as in the physical, mental summaries of the SF-36 and almost all domains (except for body image, food avoidance, and social reaction compared with IBS patients without SxD) and the total score of IBS-QOL.

Conclusions

These findings show that SxD worsens both general and specific QOL of women with IBS. The consideration of SxD in patients with IBS will allow us to make a more effective diagnostic and therapeutic approach. Clinical trial registry in Mexico City General Hospital: DI/19/107/03/080. Clinical trials registration: NCT04716738.

Healthy sleep, mental health, genetic susceptibility, and risk of irritable bowel syndrome

BACKGROUND

We aimed to investigate the prospective association of individual and combined sleep behaviors and mental health (psychological distress and neuroticism) with incident irritable bowel syndrome (IBS).

METHODS

A total of 302,839 participants without prior IBS in the UK Biobank were enrolled. A healthy sleep score was created according to five sleep factors and defined the low-risk groups as follows: sleep 7-8 h/day, early chronotype, never/rarely insomnia, no snoring, and no frequent excessive daytime sleepiness. Psychological distress and neuroticism were ascertained using the Patient Health Questionnaire and the Eysenck Personality Questionnaire-Revised Short Form, respectively. The primary outcome was incident IBS, based on self-report or linkage to death register and/or primary care and/or hospital admission data.

RESULTS

During a median follow-up of 12.0 years, 5574 participants developed IBS. Overall, low-risk sleep behaviors and a healthy sleep score (per one point increment, HR, 0.81, 95%CI, 0.79-0.83) were associated with a lower risk of incident IBS, 29.4 %-32.4 % of which was mediated by mental health. Psychological distress (per one point increment, HR, 1.16, 95%CI, 1.14-1.17) and neuroticism (HR, 1.11, 95%CI, 1.10-1.12) were positively associated with incident IBS, and healthy sleep scores mediated 8.3 %-9.7 % of the association. Moreover, participants with lowest healthy sleep score/highest mental health score and higher genetic risk of IBS showed the highest risk of incident IBS.

LIMITATIONS

Sleep behaviors and mental health were assessed by self-reported questionnaires.

CONCLUSIONS

Healthy sleep scores and low psychological distress/neuroticism were associated with a lower risk of IBS, regardless of genetic predisposition.

Predictors of Persistent Somatic Symptoms in the General Population: A Systematic Review of Cohort Studies

OBJECTIVE

Up to 10% of the general population experiences persistent somatic symptoms (PSS). Numerous studies in a variety of health domains are dedicated to identifying factors that are associated with PSS onset. The present study aimed to provide an overview of predictors for PSS onset in the general population and the related health domains.

METHODS

A systematic search was performed identifying longitudinal cohort studies that examined factors associated with PSS onset in the general population. Included studies measured potential predictors before PSS onset and were categorized according to the dynamic biopsychosocial model. Four levels of evidence were discerned for predictors, based on the number of studies and percentage of consistent findings.

RESULTS

In the 154 articles eligible for analysis, 27 PSS subtypes were studied, with primary focus on fibromyalgia (25.0%) and irritable bowel syndrome (23.3%). Of the >250 predictors of PSS onset, 46 were investigated more than once and showed consistent results. Strong evidence identifies biological (e.g., infections, body weight-related metrics), psychological (e.g., sleep problems, psychopathology), interpersonal (life events, childhood/interpersonal stress), contextual (employment), and health behavioral (health care utilization) predictors.

CONCLUSIONS

The results provide strong evidence for factors from all dynamic biopsychosocial domains, although interpersonal and health behavioral factors are relatively under investigated. Thus, evidence suggests that reduction of predictors of PSS onset to a specific factor/domain may be too restrictive. There is no evidence that this differs per PSS subtype. Exploring all domains and measuring common factors across subtypes are essential to improve the clinical course of PSS.

Functional Implications and Clinical Potential of MicroRNAs in Irritable Bowel Syndrome: A Concise Review

MicroRNAs (miRNAs) are tiny (20-24 nucleotides long), non-coding, highly conserved RNA molecules that play a crucial role within the post-transcriptional regulation of gene expression via sequence-specific mechanisms. Since the miRNA transcriptome is involved in multiple molecular processes needed for cellular homeostasis, its altered expression can trigger the development and progression of several human pathologies. In this context, over the last few years, several relevant studies have demonstrated that dysregulated miRNAs affect a wide range of molecular mechanisms associated with irritable bowel syndrome (IBS), a common gastrointestinal disorder. For instance, abnormal miRNA expression in IBS patients is related to the alteration of intestinal permeability, visceral hyperalgesia, inflammatory pathways, and pain sensitivity. Besides, specific miRNAs are differentially expressed in the different subtypes of IBS, and therefore, they might be used as biomarkers for precise diagnosis of these pathological conditions. Accordingly, miRNAs have noteworthy potential as theragnostic targets for IBS. Hence, in this current review, we present an overview of the recent discoveries regarding the clinical relevance of miRNAs in IBS, which might be useful in the future for the development of miRNA-based drugs against this disorder.

Hypnotherapy and IBS: Implicit, long-term stress memory in the ENS?

The association between irritable bowel syndrome (IBS) and psychiatric and mood disorders may be more fundamental than was previously believed. Prenatal, perinatal, postnatal, and early-age conditions can have a key role in the development of IBS. Subthreshold mental disorders (SMDs) could also be a significant source of countless diverse diseases and may be a cause of IBS development. We hypothesize that stress-induced implicit memories may persist throughout life by epigenetic processes in the enteric nervous system (ENS). These stress-induced implicit memories may play an essential role in the emergence and maintenance of IBS. In recent decades, numerous studies have proven that hypnosis can improve the primary symptoms of IBS and also reduce noncolonic symptoms such as anxiety and depression and improve quality of life and cognitive function. These significant beneficial effects of hypnosis on IBS may be because hypnosis allows access to unconscious brain processes.

Acupuncture and related therapies for the anxiety and depression in irritable bowel syndrome with diarrhea (IBS-D): A network meta-analysis of randomized controlled trials

Objective

A growing number of clinical studies have suggested the value of acupuncture-related therapies for patients with irritable bowel syndrome with diarrhea (IBS-D), and the patient's mental state plays an important role, but there are many types of acupuncture-related therapies involved. This study aimed to evaluate the mental status, efficacy and safety of the different acupuncture-related therapies for IBS-D patients.

Methods

We searched seven databases to collect randomized controlled trials of acupuncture-related therapies for IBS-D. After independent literature screening and data extraction, the quality of the final included literature was evaluated. Hamilton anxiety rating scale (HAMA), hamilton depression rating scale (HAMD), self-rating anxiety scale (SAS), and self-rating depression scale (SDS) was used as the primary outcome indicator. And the network meta-analysis (NMA) was performed by using Revman 5.4, Stata 15.0 and WinBUGS 1.4.3 software, and the surface under the cumulative ranking curve was conducted to rank the included interventions.

Results

We analyzed 24 eligible studies with 1,885 patients, involving eight types of acupuncture and related therapies along with comprehensive therapies. The NMA result shows that: for SAS scores, combined therapies were more efficacious than anti-diarrheal or antispasmodic (western medicine, WM) (SMD: -8.92; 95% CI: -15.30, -2.47); for SDS scores, combined therapies were more efficacious than WM (SMD: -8.45; 95% CI: -15.50, -1.41). For HAMA scores, moxibustion (MOX) was more efficacious than placebo (SMD: -8.66; 95% CI: -16.64, -0.38). For HAMD scores, MOX was more efficacious than all other included interventions. For response rate, MOX was more efficacious than the following interventions: acupuncture (ACU) (SMD:0.29; 95% CI:0.08,0.93), Chinese herb medicine (CH) (SMD:0.09; 95% CI:0.02,0.36), combined therapies (SMD:0.23; 95% CI:0.06, 0.85), electroacupuncture (EA) (SMD:0.06; 95% CI:0.01,0.33), warm acupuncture (WA) (SMD:22.16; 95% CI:3.53,148.10), WM (SMD:15.59; 95% CI:4.68,61.21), and placebo (SMD:9.80; 95% CI:2.90,45.51). Combined therapies were more efficacious than the following interventions: CH (SMD:0.39; 95% CI:0.19,0.80), WA (SMD:4.96; 95% CI:1.30,21.62), and WM (SMD:3.62; 95% CI:2.35,5.66). The comprehensive ranking results show that MOX, ACU, combined therapies, and EA had high SUCRA rankings involving different outcome indicators.

Conclusion

MOX, ACU, combined therapies, and EA better alleviate anxiety and depression among IBS-D patients, and with a higher safety level, may be the optimal therapies. In addition, combining acupuncture-related treatments and other therapies also delivers a higher global benefit level.

Systematic review registration

[https://www.crd.york.ac.uk/], identifier [CRD42022364560].

The Role of Calcium, 25-Hydroxyvitamin D, and Parathyroid Hormone in Irritable Bowel Syndrome: A Bidirectional Two-Sample Mendelian Randomization Study

Several observational studies have indicated the potential associations among calcium, vitamin D (Vit-D), and irritable bowel syndrome (IBS). However, the causal relationship deduced from these studies is subject to residual confounding factors and reverse causation. Therefore, we aimed to explore the bidirectional causal effects among serum calcium, Vit-D, PTH, and IBS at the genetic level by a two-sample Mendelian randomization (MR) analysis of the datasets from IEU OpenGWAS database. Sensitivity analyses were performed to evaluate the robustness. The estimates were presented as odds ratios (ORs) with their 95% confidence intervals (CIs). The results of the inverse variance weighted method did not reveal any causal relationship between the genetically predisposed calcium (OR = 0.92, 95% CI: 0.80-1.06, p = 0.25) and Vit-D (OR = 0.99, 95% CI: 0.83-1.19, p = 0.94) level and the risk of IBS. The bidirectional analysis demonstrated that genetic predisposition to IBS was associated with a decreased level of PTH (beta: -0.19, 95%CI: -0.34 to -0.04, p = 0.01). In conclusion, the present study indicates no causal relationship between the serum calcium and Vit-D concentrations and the risk of IBS. The potential mechanisms via which IBS affects serum PTH need to be further investigated.

Internet-based emotional awareness and expression therapy for somatic symptom disorder: A randomized controlled trial

OBJECTIVE

Somatic symptom disorder (SSD) is commonly encountered in health care settings. Cognitive-behavioural treatments have been most extensively studied, but they tend to have small effects of temporary duration. Emotional awareness and expression therapy (EAET) is a newly developed treatment for SSD, targeting emotional processing of trauma and conflict as a mechanism of symptom change. In an earlier uncontrolled study of self-guided, internet-administrated EAET (I-EAET), we found substantial reductions in somatic symptoms, prompting the need for a randomized controlled trial of I-EAET.

METHODS

We conducted a 2-arm RCT, comparing 10-week I-EAET (n = 37) to a waitlist control (WL; n = 37). Primary outcomes were reductions of somatic symptoms (PHQ-15) and pain intensity (BPI-4) at post-treatment, with a 4-month evaluation of effect duration. We also analysed emotional processing (EPS-25) and depression (PHQ-9) as possible mediators of I-EAET's effects.

RESULTS

Compared to controls, I-EAET significantly reduced somatic symptoms at both post-treatment and follow-up. I-EAET also reduced pain, depression, insomnia, and anxiety at post-treatment, but these effects were not retained at follow-up. As hypothesized, a facet of emotional processing partially mediated the treatment effect on somatic symptoms, even when controlling for depression.

CONCLUSIONS

Although treatment effects were smaller than in the previous uncontrolled trial, I-EAET is a promising treatment for SSD, with a minority of patients (around 20%) experiencing substantial clinical improvement. The benefits of I-EAET are partially mediated by improved emotional processing. Future research should identify and target patients who respond best to I-EAET and develop tailored treatment to enhance treatment effects. (Preregistered at clinicaltrials.gov: NCT04751825.).

Association between infections and functional somatic disorders: a cross-sectional population-based cohort study

OBJECTIVES

It has been suggested that infections can trigger functional somatic disorders (FSD). However, current evidence is limited by inconsistent findings in smaller studies conducted in clinical settings within selected populations and short follow-up times. We aimed to test the hypothesis that former infections are associated with FSD using data from nationwide registries and a large population-based cohort study, the Danish Study of Functional Disorders study.

DESIGN

FSD cases were identified in a cross-sectional population-based cohort and linked retrospectively to former hospital contacts with infections identified in the Danish National Patient Registry. The associations between FSD and former infections within 17 years were analysed using logistic regressions to calculate ORs and 95% CIs adjusted for age, sex and subjective social status.

SETTING

A population-based cohort in Denmark examined between 2011 and 2015.

PARTICIPANTS

A total of 9656 men and women aged 18-76 years.

MAIN OUTCOME MEASURES

FSD measured by various delimitations, including bodily distress syndrome (BDS), irritable bowel (IB), chronic fatigue (CF), chronic widespread pain (CWP), and multiple chemical sensitivity (MCS).

RESULTS

Overall, infections were associated with increased risk of all delimitations of FSD. The associations were more pronounced for multisystemic FSD. The number of prior infections increased the risk in a dose-response manner (p<0.0001). Bacterial but not viral infections were significantly associated with BDS (OR 1.69 (95% CI 1.46 to 1.96)), IB (OR 1.41 (95% CI 1.06 to 1.88)), CWP (OR 1.47 (95% CI 1.13 to 1.90)) and CF (OR 1.62 (95% CI 1.34 to 1.96)), but not MCS.

CONCLUSION

Former infections leading to hospital contacts were associated with a higher risk of having FSD. These associations were more pronounced for bacterial than viral infections, and more infections increased the risk in a dose-response manner. These results tend to support the idea that severe infections could play a role in FSD.

Association between body mass index and irritable bowel syndrome in the young Japanese population: a cross-sectional study

PURPOSE

The association between body mass index (BMI) and irritable bowel syndrome (IBS) has been inconsistent in the Asian population. Also, no evidence regarding this issue in the young population exists. The aim of the present study is to investigate the association between BMI and IBS based on the Rome III criteria in young Japanese people.

METHODS

This study was a cross-sectional study consisted of 8923 Japanese university students. The definition of IBS was based on the Rome III criteria. BMI was divided into four categories (quartiles) on the basis of the study subjects' distribution (lowest, low, moderate, and high [reference]). The definition of lean, normal, and overweight was BMI < 18.5 kg/m², 18.5 ≤ BMI < 25 kg/m² (reference), and 25 ≤ BMI kg/m², respectively. Age, sex, drinking, smoking, exercise habit, anemia, and sports injury were selected a priori as potential confounding factors.

RESULTS

The prevalence of IBS was 6.5%, with females having a significantly higher prevalence than males (6.0% vs. 7.2%, p = 0.029). In females, being overweight was independently positively associated with IBS after adjustment (adjusted odds ratio [OR]: 1.81 [95% confidence interval (CI): 1.13-2.79]). In contrast, in males, no association between being lean or overweight and IBS was found.

CONCLUSIONS

Among the young Japanese population, being overweight might be independently positively associated with prevalence of IBS in females but not in males.

Risk factors for worsening of somatic symptom burden in a prospective cohort during the COVID-19 pandemic

Introduction

Little is known about risk factors for both Long COVID and somatic symptoms that develop in individuals without a history of COVID-19 in response to the pandemic. There is reason to assume an interplay between pathophysiological mechanisms and psychosocial factors in the etiology of symptom persistence.

Objective

Therefore, this study investigates specific risk factors for somatic symptom deterioration in a cohort of German adults with and without prior SARS-CoV-2 infection.

Methods

German healthcare professionals underwent SARS-CoV-2 IgG antibody testing and completed self-rating questionnaires at baseline and 21 months later between April 2020 and February 2022. Differences in variables between the time points were analyzed and a regression analysis was performed to predict somatic symptom deterioration at follow-up.

Results

Seven hundred fifty-one adults completed both assessments. Until follow-up, n = 58 had contracted SARS-CoV-2 confirmed by serology. Between baseline and follow-up, signs of mental and physical strain increased significantly in the sample. Symptom expectations associated with COVID-19 and a self-reported history of COVID-19, but not serologically confirmed SARS-CoV-2 infection, significantly predicted somatic symptom deterioration at follow-up. A further predictor was baseline psychological symptom burden.

Conclusions

This study supports a disease-overarching biopsychosocial model for the development of burdensome somatic symptoms during the COVID-19 pandemic and supports research findings that symptom burden may be more related to the psychosocial effects of the pandemic than to infection itself. Future studies on Long COVID should include SARS-CoV-2 negative control groups and consider symptom burden prior to infection in order to avoid an overestimation of prevalence rates.

A Discussion of Whether Various Lifestyle Changes can Alleviate the Symptoms of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) causes abdominal pain during bowel movements and is diagnosed according to the Rome IV international diagnostic criteria. Patients diagnosed as having IBS experience abdominal pain at least 1 day/week, on average, over a 3-month period and not 3 days per month. A diagnosis of IBS is confirmed if symptoms have persisted for more than 6 months. IBS symptoms negatively affect daily life. First, improving daily habits are important to ameliorating IBS symptoms. IBS symptoms can be alleviated by staying active, sleeping, resting and staying stress-free. In addition, it is important to eat three, balanced meals a day on a regular basis and avoid overeating, especially at night. Spicy foods, high-fat foods, and alcohol can exacerbate symptoms. Researchers found, in a literature review, that IBS symptoms can be ameliorated by improving daily habits, thus relieving abdominal pain and the defecation symptoms of IBS.

Efficacy of evidence-based comprehensive psycho-social intervention in patients with irritable bowel syndrome

BACKGROUND

With the rapid development of society, the incidence of irritable bowel syndrome (IBS) in China is increasing year by year. IBS is a chronic physical and mental disease for which there is no specific drug to cure; however, the efficacy of the drugs can be strengthened through psychological cognition and social intervention. However, there are few reports on the psycho-social intervention of IBS patients in China.

AIM

To explore the efficacy of comprehensive evidence-based psycho-social intervention in patients with IBS.

METHODS

A total of 140 patients with IBS who were admitted to Beijing Rehabilitation Hospital of Capital Medical University from March 2019 to September 2021 were included as the research subjects, and they were randomly divided into either a control group or a research group, with 70 cases in each. The control group was given routine outpatient follow-up and nursing intervention, while the research group was given comprehensive evidence-based psycho-social intervention. Both groups were followed for 3 mo. The gastrointestinal symptom rating scale (GSRS), irritable bowel syndrome-quality of life questionnaire (IBS-QOL), multi-gastrointestinal function tester, medication compliance scale, self-rating anxiety scale (SAS), and self-rating depression scale (SDS) were used to evaluate and compare gastrointestinal symptoms, rectal function, medication compliance, quality of life, and negative psychology in the two groups before and after intervention to evaluate the intervention effect.

RESULTS

There were five dropout cases in the control group and three in the research group. Finally, 65 cases in the control group and 67 in the research group completed the study. Before intervention, there were no significant differences in GSRS score, rectal sensation threshold, rectal defecation threshold, rectal pain threshold, rectal motor index, medication compliance scale score, IBS-QOL score, SAS score, or SDS score between the two groups (P > 0.05). After intervention, the GSRS scores, SAS scores, and SDS scores of the two groups were significantly lower than those before intervention, and these scores were significantly lower in the research group than in the control group (P < 0.05). After intervention, rectal sensory threshold, rectal defecation threshold, rectal pain threshold, and rectal motor index were significantly improved in both groups (P < 0.05); the improvements were significantly better in the research group than in the control group (P < 0.05). After intervention, the medication compliance score and IBS-QOL score of the control group were not significantly different from those before intervention (P > 0.05), and the medication compliance score, IBS-QOL score, and curative effect of the research group were significantly higher than those of the control group.

CONCLUSION

Evidence-based comprehensive psycho-social intervention program can effectively improve medication compliance of IBS patients, reduce patients' negative psychology, and improve patients' gastrointestinal function and quality of life.

Risk Factors for Abdominal Pain-Related Disorders of Gut-Brain Interaction in Adults and Children: A Systematic Review

BACKGROUND & AIMS

Many studies have assessed risk factors of irritable bowel syndrome (IBS) and other abdominal pain-related disorders of gut-brain interaction (AP-DGBI); however, the role of these factors is unclear due to heterogeneous study designs. The aim of this systematic review was to extensively evaluate the literature and determine clinical risk and protective factors for the presence and persistence of AP-DGBI in children and adults.

METHODS

A PubMed search identified studies investigating potential risk and protective factors for AP-DGBI in adults and children. Inclusion criteria included fully published studies with a control group; exclusion criteria included poor-quality studies (using a validated scale). For each factor, the proportion of studies that found the factor to be a risk factor, protective factor, or neither was summarized. The number of studies, diagnostic criteria, number of subjects, and average study quality rating provided further context. Whenever possible, a meta-analysis generated pooled odds ratios or mean difference.

RESULTS

The systematic review included 348 studies. Female sex, gastroenteritis, abuse, stress, psychological disorders, somatic symptoms, and poor sleep were consistent risk factors for developing AP-DGBI in adults and children. In adults, additional risk factors included obesity, smoking, and increased use of medical resources. Protective AP-DGBI factors in adults included social support and optimism; no studies for protective factors were found for children.

CONCLUSIONS

There are multiple risk factors for AP-DGBI in adults and children. These include female sex, gastroenteritis, abuse, stress, poor sleep, obesity, psychological disorders, and somatic symptoms. Additional studies are needed in children, on protective factors, and on factors associated with persistence of AP-DGBI.

Molecular and in vivo studies of a glutamate-class prolyl-endopeptidase for coeliac disease therapy

The digestion of gluten generates toxic peptides, among which a highly immunogenic proline-rich 33-mer from wheat α-gliadin, that trigger coeliac disease. Neprosin from the pitcher plant is a reported prolyl endopeptidase. Here, we produce recombinant neprosin and its mutants, and find that full-length neprosin is a zymogen, which is self-activated at gastric pH by the release of an all-β pro-domain via a pH-switch mechanism featuring a lysine plug. The catalytic domain is an atypical 7+8-stranded β-sandwich with an extended active-site cleft containing an unprecedented pair of catalytic glutamates. Neprosin efficiently degrades both gliadin and the 33-mer in vitro under gastric conditions and is reversibly inactivated at pH > 5. Moreover, co-administration of gliadin and the neprosin zymogen at the ratio 500:1 reduces the abundance of the 33-mer in the small intestine of mice by up to 90%. Neprosin therefore founds a family of eukaryotic glutamate endopeptidases that fulfils requisites for a therapeutic glutenase.

Celiac disease is characterized by intolerance to gluten, a cereal protein. Here, the authors show that neprosin, a glutamate peptidase from the pitcher plant, efficiently cleaves gluten components under physiological conditions in vitro and in the gut of mice.

Risk Factors for Self-reported Irritable Bowel Syndrome With Prior Psychiatric Disorder: The Lifelines Cohort Study

Background/Aims

The role of psychiatric disorder in irritable bowel syndrome (IBS) is not clear. This study aims to assess whether individuals who have psychiatric disorder prior to IBS onset differ in their risk factors from the remainder.

Methods

The prospective, population-based Lifelines cohort study includes 132 922 adults without prior IBS or taking IBS medication at baseline. Baseline data included socio-demographic status, physical and psychiatric disorders, psycho-social and behavioral variables. At follow-up (mean 2.4 years later) new onsets of IBS were recorded by self-report. The predictors of new onsets of IBS were assessed using logistic regression; participants with and without prior psychiatric disorders were analyzed separately.

Results

At follow-up 1507 (1.1%) participants reported new onset IBS. Of these, 27% reported prior psychiatric disorder. Predictors of IBS in this group were 2 or more psychiatric disorders (OR, 2.74; 95% CI, 1.3-5.6), female sex, proton pump inhibitors, numerous bodily symptoms, impaired sleep, low BMI and negative health perception. These variables, except psychiatric disorders and BMI, also predicted IBS in those without prior psychiatric disorder but, in this group, gallstones, asthma, fibromyalgia, reported allergies, impairment through bodily pain, and frequent healthcare were also predictors.

Conclusions

Despite its limitations this study suggests that prior psychiatric disorder is an important risk factor in a quarter of IBS onsets. Negative health perception and multiple bodily symptoms are associated with all IBS onsets in line with the cognitive-behavior model of IBS. Prior psychiatric disorder may predict an optimal response to psychiatric treatment. Further studies could usefully study mechanisms linking IBS to prior psychiatric disorder.

Translational Gap between Guidelines and Clinical Medicine: The Viewpoint of Italian General Practitioners in the Management of IBS

Irritable bowel syndrome (IBS) guidelines are generally developed by experts, with the possibility of a translational gap in clinical medicine. The aim of our study was to assess an Italian group of general practitioners (GPs) for their awareness and use of criteria for the diagnosis and management of IBS. For this purpose, a survey was carried out involving 235 GPs, divided into two groups according to their years of activity: 65 “junior general practitioners” (JGPs) (≤10 years) and 170 “senior general practitioners” (SGPs) (>10 years). JGPs were more familiar with the Rome IV Criteria and Bristol Scale than SGPs. Abdominal pain, bowel movement frequency and bloating were the symptoms most frequently used to make a diagnosis. The most probable causes of IBS were reported to be abnormal gastrointestinal motility and psychological triggers. SGPs reported more frequently than JGPs that challenging management and patient’s request were motivations for a gastroenterological consultation. The practice of clinical medicine is still far from the guidelines provided by the specialists. Abdominal pain related to defecation and changes in bowel frequency are considered to be the more important symptoms for IBS diagnosis, but most GPs, both JGPs and SGPs, like to consider abdominal bloating as another useful symptom. Involving both gastroenterologists and GPs in developing shared guidelines would be highly desirable in order to improve IBS management strategies in everyday clinical practice.

Post-Infectious Irritable Bowel Syndrome after an Epidemic of Gastroenteritis in South of Iran

Background: Irritable bowel syndrome (IBS) is a chronic disabling condition without a well-defined etiology. Infectious gastroenteritis (IGE) has been linked to this syndrome. There are few data from Iran on this association. Methods: In August 2018, an epidemic of IGE caused by Escherichia coli occurred in a village in the west of Shiraz in southern Iran. One year after this epidemic, the occurrence of IBS was surveyed in those who suffered from IGE based on Rome IV criteria in that village. Results: Of 179 patients included in the present study, 17 patients (9.5%) had post-infectious (PI)-IBS. There was no difference in age, sex, antibiotic use, hematochezia, duration of infectious diarrhea, fever, and weight loss at the time of IGE between those with and without PI-IBS. Conclusion: PI-IBS is common after IGE, but no risk factor for its development was found in this study.

Zinc nutritional status, mood states and quality of life in diarrhea-predominant irritable bowel syndrome: a case-control study

Zinc is an important trace element for structure, and regulation in the central nervous system, as well as the gut homeostasis. There are several mental disorders associated with zinc deficiency. The relationship between zinc nutritional status with mood states and quality of life (QoL) in diarrhea-predominant irritable bowel syndrome (IBS-D) has not been studied yet. This case–control study aimed to investigate the association between zinc nutritional status with mood states and QoL in IBS-D patients. Sixty-one newly diagnosed patients with IBS-D and 61 matched healthy controls were enrolled. Dietary zinc intakes and serum zinc levels were measured. Mood states and QoL were evaluated by validated questionnaires. Logistic regression was used to estimate the odds of IBS-D in relation to zinc deficiency. Decreased serum zinc levels were observed in the IBS-D group than in the controls (p = 0.001). There were higher scores of depression (p = 0.014), anxiety (p = 0.005), and stress (p = 0.001) among IBS-D patients. Moreover, overall QoL, physical and psychological health were lower in IBS-D patients compared to the controls (p < 0.001). “Food avoidance” had the lowest, while the “relationship” had the highest score among the patients (51.09 ± 26.80 and 78.14 ± 23.30, respectively). Dietary zinc intake was positively correlated with psychological health in the controls (r = 0.295, p = 0.022) and with body image in the patients (r = 0.266, p = 0.044). According to the logistic regression, zinc deficiency was not significantly associated with odds of IBS-D. Findings show that zinc deficiency may be associated with some parameters of IBS-D. Further clinical studies are needed to explore the causal relationship between zinc status and IBS pathogenesis.

Estrogens Play a Critical Role in Stress-Related Gastrointestinal Dysfunction in a Spontaneous Model of Disorders of Gut-Brain Interaction

BACKGROUND

Disorders of the gut-brain interaction (DGBI), such as irritable bowel syndrome and functional dyspepsia, are more prevalent in women than in men, with a ratio of 2:1. Furthermore, stressful life events have been reported as one of the triggers for symptoms in DGBI patients.

METHODS

Here, we studied the effect of an early-life stressor (maternal separation (MS)) on jejunal and colonic alterations, including colonic sensitivity and immune cells infiltration and activation in a validated spontaneous model of DGBI (BBDP-N), and investigated the involvement of β-estradiol on stress-worsened intestinal alterations.

RESULTS

We found that maternal separation exacerbated colonic sensitivity and mast cell and eosinophil infiltration and activation in females only. Ovariectomy partially rescued the stress phenotype by decreasing colonic sensitivity, which was restored by β-estradiol injections and did not impact immune cells infiltration and activation. Stressed males exposed to β-estradiol demonstrated similar intestinal alterations as MS females.

CONCLUSION

Estrogen plays a direct critical role in colonic hypersensitivity in a spontaneous animal model of DGBI, while for immune activation, estrogen seems to be involved in the first step of their recruitment and activation. Our data point towards a complex interaction between stress and β-estradiol in DGBI.

Can the French version of the short Örebro Musculoskeletal Pain Screening Questionnaire or its subsets predict the evolution of patients with acute, (sub) acute and chronic pain?

Background

Prevention of chronic pain relies on accurate detection of at-risk patients. Screening tools have been validated mainly in (sub) acute spinal pain and the need of more generic tools is high. We assessed the validity of the French version of the short Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) in patients with a large range of pain duration and localization.

Methods

First, we re-analyzed data from a 6-month longitudinal study of 73 patients with (sub) acute spinal pain consulting in secondary line settings. Secondly, we performed a new 12-month longitudinal study of 542 primary care patients with (sub) acute and chronic pain in different localizations (spinal, limbs, “non-musculoskeletal”). The area under the receiver operating characteristic curve and cutoff scores were computed and compared for different subpopulations and ÖMPSQ subscores.

Results

Data from patients suffering from (sub) acute and chronic spinal pain consulting in both primary and secondary care settings confirmed the validity of the short French ÖMPSQ version and its subsets. In the primary care cohort, the performance of the questionnaire and its psychosocial subscore was variable but at least “fair” in most populations ((sub) acute and chronic, spinal and limb pain). Cutoff scores showed quite large variability depending on the outcome and the subpopulation considered.

Conclusions

These results confirm the usefulness of the short French ÖMPSQ for prediction of the evolution of (sub) acute and chronic patients with spinal and limb pain, whatever its duration. However, increasing population heterogeneity results in slightly worse predictive performance and largely variable cutoff scores. Consequently, it might be difficult to choose universal cutoff scores and other criteria, such as patients’ values and the available resources for patient management, should be taken into account.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04944-9.

The Prevalence and Incidence of Irritable Bowel Syndrome and Inflammatory Bowel Disease in Depression and Bipolar Disorder: A Systematic Review and Meta-Analysis

OBJECTIVE

The increased prevalence and incidence of affective disorders among patients with gastrointestinal disease have been well established. However, few studies have investigated the inverse relationship. We aimed to identify all pieces of evidence of the prevalence and incidence of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) in people with depression and bipolar disorder.

METHODS

We conducted a systematic review of studies reporting the association between affective disorders (exposure) and IBS or IBD (outcome) in adults. Evidence was evaluated for quality using Joanna Briggs Institute Critical Appraisal tools. Where suitable data were available, meta-analyses were performed.

RESULTS

We identified 18 studies that met the selection criteria, of which 11 provided data on IBS, 5 on IBD, and 2 on both. Overall, people with depression were significantly more likely to have comorbid IBS (risk ratio = 2.42, 95% confidence interval = 1.98-2.96) and to develop new-onset IBS (risk ratio = 1.90, 95% confidence interval = 1.41-2.56) compared with people without depression. They were also more likely to have and develop IBD, and among patients with IBD, significantly increased rates of depression were observed as early as 5 years before diagnosis. Bipolar disorder was not consistently associated with risk of either condition.

CONCLUSIONS

People with depression are at an increased risk of both having and developing lower gastrointestinal disorders. These findings have important implications for how we understand, manage, and prevent this comorbidity in clinical practice. Further studies are needed to improve our understanding of the relationship between bipolar disorder and bowel disease as well as the role of psychotropic medication, particularly selective serotonin reuptake inhibitors.

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.

Neuronal-enriched extracellular vesicles in individuals with IBS: A pilot study of COMT and BDNF

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by abdominal pain, bowel habit alterations, and psychiatric comorbidities. Although pathophysiology remains incompletely understood, prior work demonstrates associations with brain-derived neurotrophic factor (BDNF) and catechol-O-methyltransferase (COMT). The purpose of this study was to quantify BDNF and COMT in plasma and in neuronal-enriched extracellular vesicles (nEVs), assess relationships with psychological symptoms, and gain insight on the brain-gut connection in IBS.

METHODS

Clinical data and biorepository samples from a parent investigation were used, including scores on the Perceived Stress Scale (PSS) and Center for Epidemiological Studies Depression Scale (CES-D). Distinct subpopulations of nEVs were isolated using neural cell adhesion molecule L1CAM; levels of COMT, mature BDNF, and pro-BDNF were quantified in plasma and in nEVs using ELISA.

KEY RESULTS

Data from 47 females (28.11 ± 6.85 years) included 18 IBS and 29 healthy control (HC) participants. IBS participants displayed reduced plasma levels of mature BDNF compared with HC (p = 0.024). Levels of COMT plasma and IBS grouping significantly predicted CES-D scores (p = 0.034). Exploratory analyses by IBS subtype and race revealed African American HC display lower levels of COMT EV than Caucasian HC (p = 0.022).

CONCLUSIONS & INFERENCES

Lower levels of mature BDNF in IBS participants, preliminary patterns detected in cargo content of nEVs, and relevance of COMT and IBS status to CES-D scores, offer insight on depressive symptomatology and brain-gut dysregulation in IBS. Lower COMT levels in nEVs of African Americans highlight the relevance of race when conducting such analyses across diverse populations.

Predictors of new onsets of irritable bowel syndrome, chronic fatigue syndrome and fibromyalgia: the lifelines study

BACKGROUND

It has been claimed that functional somatic syndromes share a common etiology. This prospective population-based study assessed whether the same variables predict new onsets of irritable bowel syndrome (IBS), chronic fatigue syndrome (CFS) and fibromyalgia (FM).

METHODS

The study included 152 180 adults in the Dutch Lifelines study who reported the presence/absence of relevant syndromes at baseline and follow-up. They were screened at baseline for physical and psychological disorders, socio-demographic, psycho-social and behavioral variables. At follow-up (mean 2.4 years) new onsets of each syndrome were identified by self-report. We performed separate analyses for the three syndromes including participants free of the relevant syndrome or its key symptom at baseline. LASSO logistic regressions were applied to identify which of the 102 baseline variables predicted new onsets of each syndrome.

RESULTS

There were 1595 (1.2%), 296 (0.2%) and 692 (0.5%) new onsets of IBS, CFS, and FM, respectively. LASSO logistic regression selected 26, 7 and 19 predictors for IBS, CFS and FM, respectively. Four predictors were shared by all three syndromes, four predicted IBS and FM and two predicted IBS and CFS but 28 predictors were specific to a single syndrome. CFS was more distinct from IBS and FM, which predicted each other.

CONCLUSIONS

Syndrome-specific predictors were more common than shared ones and these predictors might form a better starting point to unravel the heterogeneous etiologies of these syndromes than the current approach based on symptom patterns. The close relationship between IBS and FM is striking and requires further research.

Prevalence and risk factors of functional constipation in the Rome IV criteria during a medical check-up in Japan

BACKGROUND AND AIM

Functional constipation (FC) is one of the functional bowel disorders with symptoms of constipation in the Rome IV criteria. This study aimed to examine the epidemiology of FC in a large-scale survey of individuals undergoing a medical check-up in Japan.

METHODS

A total of 13 729 subjects who underwent a medical check-up at MedCity21 between April 2018 and March 2019 were given a questionnaire that inquired about bowel habits. Among them, 10 658 subjects participated in this study, and FC was diagnosed based on the Rome IV criteria.

RESULTS

The number of subjects who fulfilled diagnostic criteria of FC was 220, and the prevalence of FC was 2.1%. Compared with subjects with non-FC, those with FC were more complaining of abdominal bloating and distension, feeling stressed, getting annoyed, lack of motivation, fatigue upon waking, and feeling depressed. The risk of FC was significantly lower among subjects who drank alcohol more than 5 days a week, exercised for more than 30 min at least twice a week for more than 1 year, and were getting enough rest by sleeping, whereas it was significantly higher among women and subjects who were eating faster than other people.

CONCLUSIONS

The prevalence of FC in Japanese subjects during a medical check-up was relatively low compared with that in Western countries. Subjects with FC had troublesome symptoms, and it might be suggested that female sex, lack of regular exercise with moderate activity, insufficient rest by sleeping, and eating faster were a risk of FC.

Role of smoking in functional dyspepsia and irritable bowel syndrome: three random population-based studies

BACKGROUND

It is uncertain if functional dyspepsia (FD) or irritable bowel syndrome (IBS) are linked to smoking, and smoking cessation is not part of the routine advice provided to these patients.

AIM

To assess if smoking is an independent risk factor for FD and IBS.

METHODS

Three population-based endoscopy studies in Sweden with 2560 community individuals in total (mean age 51.5 years, 46% male). IBS (14.9%), FD (33.5%), and associated symptoms were assessed using the validated abdominal symptom questionnaire, and smoking (17.9%) was obtained from standardised questions during a clinic visit. The effect of smoking on symptom status was analysed in an individual person data meta-analysis using mixed effect logistic regression, adjusted for snuffing, age and sex.

RESULTS

Individuals smoking cigarettes reported significantly higher odds of postprandial distress syndrome (FD-PDS) (OR 10-19 cig/day = 1.42, 95% CI 1.04-1.98 P = 0.027, OR ≥20 cig/day = 2.16, 95% CI 1.38-3.38, P = 0.001) but not epigastric pain. Individuals smoking 20 or more cigarettes per day reported significantly higher odds of IBS-diarrhoea (OR = 2.40, 95% CI 1.12-5.16, P = 0.025), diarrhoea (OR = 2.01, 95%CI 1.28-3.16, P = 0.003), urgency (OR = 2.21, 95%CI 1.41-3.47, P = 0.001) and flatus (OR = 1.77, 95%CI 1.14-2.76, P = 0.012) than non-smokers. Smoking was not associated with IBS-constipation or IBS-mixed.

CONCLUSION

Smoking is an important environmental risk factor for postprandial distress syndrome, the most common FD subgroup, with over a twofold increased odds of PDS in heavy smokers. The role of smoking in IBS-diarrhoea, but not constipation, is also likely important.

When gut feelings teach the brain to fear pain: Context-dependent activation of the central fear network in a novel interoceptive conditioning paradigm

The relevance of contextual factors in shaping neural mechanisms underlying visceral pain-related fear learning remains elusive. However, benign interoceptive sensations, which shape patients' clinical reality, may context-dependently become conditioned predictors of impending visceral pain. In a novel context-dependent interoceptive conditioning paradigm, we elucidated the putative role of the central fear network in the acquisition and extinction of pain-related fear induced by interoceptive cues and pain-predictive contexts. In this fMRI study involving rectal distensions as a clinically-relevant model of visceroception, N = 27 healthy men and women underwent differential conditioning. During acquisition training, visceral sensations of low intensity as conditioned stimuli (CS) predicted visceral pain as unconditioned stimulus (US) in one context (Con⁺), or safety from pain in another context (Con^-). During extinction training, interoceptive CS remained unpaired in both contexts, which were operationalized as images of different rooms presented in the MRI scanner. Successful contextual conditioning was supported by increased negative valence of Con⁺ compared to Con^- after acquisition training, which resolved after extinction training. Although interoceptive CS were perceived as comparatively pleasant, they induced significantly greater neural activation of the amygdala, ventromedial PFC, and hippocampus when presented in Con⁺, while contexts alone did not elicit differential responses. During extinction training, a shift from CS to context differentiation was observed, with enhanced responses in the amygdala, ventromedial, and ventrolateral PFC to Con⁺ relative to Con^-, whereas no CS-induced differential activation emerged. Context-dependent interoceptive conditioning can turn benign interoceptive cues into predictors of visceral pain that recruit key regions of the fear network. This first evidence expands knowledge about learning and memory mechanisms underlying interoceptive hypervigilance and maladaptive avoidance behavior, with implications for disorders of the gut-brain axis.

Association Between Psychological Disorders and Irritable Bowel Syndrome

Introduction

Irritable bowel syndrome (IBS) is an idiopathic, functional and chronic relapsing disorder. Physiological and psychological variables have been linked with etiology of IBS. In this study, we will determine the prevalence of IBS in local setting and its association with anxiety and depression.

Materials and methods

This cross-section study was conducted in multiple cities of Pakistan. One thousand and seven hundred and sixty (1,760) participants from general population between the age group 18 to 50 were enrolled in the study after informed consent. Diagnosis of IBS was made by assessing participants via ROME III criteria. Hospital anxiety and depression scale (HADS) was used to determine if the participants had anxiety and depression.

Results

IBS was present in 456 (25.9%) participants. IBS was significantly more prevalent in females compared to males. Anxiety was significantly more common in participants with IBS compared to participants without IBS (53.0% vs. 23.0%; p-value < 0.00001). Similarly, depression was significantly more common in participants with IBS (50.6% vs. 21.5%; p-value < 0.00001).

Conclusion

IBS is very common in Pakistan, but rarely diagnosed. It is important anyone, particularly at young age, presenting with diarrhea or constipation should be evaluated for IBS. Simultaneously, patients diagnosed with IBS should be screened for anxiety and depression, and managed accordingly.

Sex- and Gender-Related Differences in Common Functional Gastroenterologic Disorders

Functional gastrointestinal (GI) disorders (FGIDs) result from central and peripheral mechanisms, cause chronic remitting-relapsing symptoms, and are associated with comorbid conditions and impaired quality of life. This article reviews sex- and gender-based differences in the prevalence, pathophysiologic factors, clinical characteristics, and management of functional dyspepsia (FD) and irritable bowel syndrome (IBS) that together affect approximately 1 in 4 people in the United States. These conditions are more common in women. Among patients with IBS, women are more likely to have severe symptoms and coexistent anxiety or depression; constipation or bloating and diarrhea are more common in women and men, respectively, perhaps partly because defecatory disorders, which cause constipation, are more common in women. Current concepts suggest that biological disturbances (eg, persistent mucosal inflammation after acute gastroenteritis) interact with other environmental factors (eg, abuse) and psychological stressors, which influence the brain and gut to alter GI tract motility or sensation, thereby causing symptoms. By comparison to a considerable understanding of sex-based differences in the pathogenesis of visceral hypersensitivity in animal models, we know less about the contribution of these differences to FGID in humans. Slow gastric emptying and colon transit are more common in healthy women than in men, but effects of gonadal hormones on colon transit are less important than in rodents. Although increased visceral sensation partly explains symptoms, the effects of sex on visceral sensation, colonic permeability, and the gut microbiome are less prominent in humans than rodents. Whether sex or gender affects response to medications or behavioral therapy in FD or IBS is unclear because most patients in these studies are women.

Human Leukocyte Antigen (HLA) Haplotype Does Not Influence the Inflammatory Pattern of Duodenal Lymphocytosis Linked to Irritable Bowel Syndrome

Background and objectives: Duodenal lymphocytosis (DL) is a condition characterized by enhanced infiltration of intraepithelial lymphocytes (IELs) in the duodenal mucosa, and it can be linked to both gluten- and non-gluten-related diseases, such as irritable bowel syndrome (IBS). Materials and methods: We retrospectively selected patients with DL linked to IBS. Formalin-embedded biopsy samples of the duodenum were collected. CD3 lymphocyte immunohistochemistry was used for IELs. The real-time polymerase chain reaction was used to quantify the amount of mRNA coding for tissue transglutaminase 2 (tTG2), interferon-gamma (IFNγ), toll-like receptor 2 (TLR2), and myeloid differentiation primary response 88 (MyD88). All subjects underwent DQ2-8 haplotype analysis. Controls were represented by subjects with IBS without DL. Results: Thirty-two patients with IBS-DL were retrospectively recruited. Fourteen subjects (43.8%) had a DQ2-8 haplotype. DQ2-8 positive subjects had similar levels compared to negative ones for tTG2, IFNγ, TLR2, and MyD88. Cigarette smoke did not influence molecular expression in our study. Smokers had a statistically higher IELs count than non-smokers (54.2 ± 7.7 vs. 36.0 ± 8.8, p < 0.001). A significant, direct correlation between IELs and duodenal expression of IFNγ was found (r = 0.36, p = 0.04). Conclusions: IBS with DL showed higher expression of inflammatory markers than controls, but DQ2-8 haplotype did not seem to affect their expression. Smoking might increase IELs infiltration.

Mast Cell Regulation and Irritable Bowel Syndrome: Effects of Food Components with Potential Nutraceutical Use

Mast cells are key actors in inflammatory reactions. Upon activation, they release histamine, heparin and nerve growth factor, among many other mediators that modulate immune response and neuron sensitization. One important feature of mast cells is that their population is usually increased in animal models and biopsies from patients with irritable bowel syndrome (IBS). Therefore, mast cells and mast cell mediators are regarded as key components in IBS pathophysiology. IBS is a common functional gastrointestinal disorder affecting the quality of life of up to 20% of the population worldwide. It is characterized by abdominal pain and altered bowel habits, with heterogeneous phenotypes ranging from constipation to diarrhea, with a mixed subtype and even an unclassified form. Nutrient intake is one of the triggering factors of IBS. In this respect, certain components of the daily food, such as fatty acids, amino acids or plant-derived substances like flavonoids, have been described to modulate mast cells' activity. In this review, we will focus on the effect of these molecules, either stimulatory or inhibitory, on mast cell degranulation, looking for a nutraceutical capable of decreasing IBS symptoms.