Smoking in Irritable Bowel Syndrome: A Systematic Review

Risk factors for developing irritable bowel syndrome: systematic umbrella review of reviews

BACKGROUND

Irritable bowel syndrome (IBS) is a debilitating disorder affecting 4-9% of the global population. It is a multifaceted disorder with complex and varied causes. This review aims to consolidate the evidence regarding IBS risk factors by examining existing systematic reviews and meta-analyses, covering potential genetic, immunological, psychological, and dietary causes.

METHODS

Systematic literature searches were conducted in MEDLINE, Embase and Cochrane library databases. Study selection and data extraction were conducted independently by four authors, with discrepancies resolved by consensus with a senior author. Systematic reviews examining risk factors of IBS development were eligible for review. Results were narratively synthesized. Quality of reviews were analysed using AMSTAR 2, and evidence were appraised using GRADE methodology.

RESULTS

A total of 69 systematic reviews were included in this study. Most reviews were of "critically low" quality, while the remaining were "low" quality. Common shortcomings included the absence of a list of excluded studies with justifications for their exclusion and inadequate consideration of the risk of bias in individual studies. Eight major categories of risk factors for IBS identified were as follows: dietary, genetic, environmental, psychological, gut microbiome, socio-economic, physiological, and pathological, albeit overlaps exist. The most frequently reported risk factors for IBS development were female gender and anxiety disorders, with overall GRADE evaluation of "low"; depression and gastroenteritis, with overall GRADE evaluation of "moderate".

CONCLUSIONS

Clinical practice should prioritize recognition of these risk factors. Future reviews should improve their reporting of results based on the PRISMA guidelines, to enhance the quality of research in this field.

PROTOCOL REGISTRATION

PROSPERO CRD42023493739.

Irritable Bowel Syndrome (IBS) and Smoking: An Evaluation of IBS symptom severity and anxiety sensitivity among adults in the United States

INTRODUCTION

Irritable bowel syndrome (IBS) is a prevalent disorder of gut-brain function associated with psychological distress as well as work and quality of life impairment. Smoking has been linked to gastrointestinal dysfunction, however, research focused on the prevalence of IBS and smoking is limited. Previous research has shown that anxiety sensitivity is linked to increased risk of aversive bodily experiences and subsequent coping-oriented regulation efforts. Higher anxiety sensitivity has also been associated with processes linked to tobacco cigarette smoking lapse and relapse. There is a need to clarify the explanatory roles of anxiety sensitivity in the context of more severe IBS symptoms among persons with IBS who are current smokers.

METHOD

The present investigation evaluated the main and interactive effects of IBS symptom severity and anxiety sensitivity in relation to processes related to the maintenance and relapse of tobacco smoking among adults with IBS. The sample consisted of 263 (52.1 % female; Mage = 44.13 years, SD = 12.71) adults who met criteria for IBS and smoke at least 5 cigarettes per day.

RESULTS

Hierarchical regression results indicated that both anxiety sensitivity and IBS symptom severity independently predicted greater perceived barriers to smoking cessation, severity of problems experienced during quitting, and negative reinforcement smoking expectancies. A statistically significant interaction further indicated that IBS symptom severity was more strongly associated with negative reinforcement smoking expectancies among participants with higher, relative to lower, anxiety sensitivity.

CONCLUSIONS

This study is the first to show that both IBS symptom severity and anxiety sensitivity are related to greater perceived barriers to smoking cessation, previous difficulty quitting, and negative reinforcement expectancies among adults with IBS. There is a continued need to further scientific understanding of interrelations between anxiety sensitivity, IBS symptom severity, and smoking cessation-related beliefs and processes to identify novel approaches that can best support quitting among this understudied population.

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.

Factors associated with irritable bowel syndrome and Helicobacter pylori infection: public knowledge and awareness of signs and symptoms

OBJECTIVE

To investigate factors related to the risk of developing irritable bowel syndrome (IBS) or Helicobacter pylori infection.

METHODS

This cross-sectional, questionnaire-based study analysed the responses from participants that completed an online questionnaire, which asked about their knowledge of the causes and risk factors associated with IBS and H. pylori infection.

RESULTS

The study analysed responses from 230 participants: 181 females (of 227 participants; 79.7%) and 190 aged 18-40 years (of 228; 83.3%). Of the 230 participants, 40 (17.4%) had been diagnosed by a physician with IBS and 57 (24.8%) had been diagnosed with H. pylori infection. Of 226 participants, 93 (41.2%) had self-medicated with antibiotics in the past 6 months for various reasons. The overall mean ± SD knowledge score about IBS and H. pylori infection for the study cohort (n = 230) was 35.8 ± 19.2%. Wald χ2-test analysis demonstrated that chronic diseases, antibiotic use and having an endoscopy were significantly associated with developing IBS. Male sex and chronic diseases were significantly associated with H. pylori infection. Logistic regression analysis showed no relationship between IBS and H. Pylori infection.

CONCLUSION

Chronic diseases was the only risk factor common for IBS and H. pylori infection.

Letter: Antibiotics prescription and new-onset irritable bowel syndrome-Authors' reply

This article is linked to Staller et al papers. To view these articles, visit https://doi.org/10.1111/apt.17736 and https://doi.org/10.1111/apt.17820

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.

Irritable bowel syndrome (IBS) among Lebanese adults: unidentified IBS and associated factors

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most frequent functional gastrointestinal disorders, but the condition is still underdiagnosed. The high of rate of unidentified IBS by patients can be related to different factors. The aim of this study is to assess the rate of unidentified IBS among Lebanese adults and investigate the role of socio-demographic factors, anxiety, depression, insomnia and eating attitudes on IBS diagnosis.

METHODS

A cross-sectional study was conducted among Lebanese adults older than 18 years between June 2022 and December 2022, using a self-reporting questionnaire distributed via social media.

RESULTS

A total of 425 participants was enrolled in the study with around 184 (46.8%) having a possible unidentified IBS. Higher psychological distress (aOR = 1.07) and insomnia severity (aOR = 1.08) were significantly associated with higher odds of having possible unidentified IBS whereas a higher household crowding index (aOR = 0.67) was significantly associated with lower odds of having possible IBS. The correlation of eating attitudes with cigarette smoking (aOR = 1.33; p = .025; 95% CI 1.04; 1.70) and insomnia severity with cigarette smoking (aOR = .89; p = .023; 95% CI .80; .98) were significantly associated with the presence of possible IBS. In nonsmokers, higher psychological distress (aOR = 1.07) and insomnia severity (aOR = 1.10) were significantly associated with higher odds of having possible IBS. In smokers, higher BMI (aOR = .78) was significantly associated with lower odds of having possible IBS, whereas higher eating attitudes scores (more inappropriate eating) (aOR = 1.40) were significantly associated with higher odds of having possible IBS.

CONCLUSION

The study highlighted the implication of raising awareness about IBS among the Lebanese population to promote early diagnosis and minimize the rate of unidentified IBS by patients. Initiation of appropriate treatment plans, tailored symptomatic management approach, and diet programs should be highly encouraged.

Gastroesophageal reflux disease incidence among male patients with irritable bowel syndrome: A single-center cross-sectional study in southern Iran

Background and Aim

Gastrointestinal reflux disease (GERD) and irritable bowel syndrome (IBS) are among the most common gastrointestinal disorders in which the overlap of these diseases and their syndromes has been frequently reported. In this study, we aimed to evaluate GERD incidence among IBS patients and the related risk factors.

Methods

Male patients aged 18-60 years with an impression of IBS and referred to the gastrointestinal clinic from March 2019 to 2020 in Shiraz, Iran, were included in this study.

Results

Among the 163 enrolled patients with an average age of 31.53 ± 9.38 years, 64 (39.3%) were diagnosed with GERD. Based on statistical analysis, there was a significant association between GERD and the IBS patients' age (P = 0.006), smoking (P = 0.011), and alcohol consumption (P = 0.043). Also, GERD among IBS patients was significantly associated with the type of IBS (P < 0.001), with IBS-D having the lowest incidence (19.4%) and IBS-M the highest incidence of GERD (66.7%). Based on multivariate analysis, smoking had a reverse and significant correlation with lower incidence of GERD (OR = -1.364; P = 0.002).

Conclusion

Our results demonstrate that among male IBS patients, younger age, smoking, and alcohol consumption were among the risk factors for GERD. These findings may provide further insight into the best approach to treating these diseases.

Predictors of abdominal pain severity in patients with constipation-prevalent irritable bowel syndrome

BACKGROUND

Symptoms of irritable bowel syndrome (IBS) have been associated to altered colonic motility and sensation. Smoking affects pain perception and is a risk factor in the development of post-infectious IBS, but its effect on abdominal pain and colonic transit remains to be elucidated in IBS.

METHODS

Forty patients with IBS-C and 28 with IBS-M were selected based on Rome IV criteria. Colonic transit time was studied and smoking habit was recorded. Presence of mild or severe abdominal pain and the prevalent pain characteristics (diffuse or localized, chronic or acute, with cramps or gradually distending) were recorded. Data were analyzed by univariate and stepwise multiple logistic regression analysis to verify the risk association between pain and all other variables.

RESULTS

IBS-C patients had a longer transit time in the right colon and scored more chronic pain than IBS-M patients. When severity of abdominal pain was used as discriminating factor, a significant number of subjects reporting severe pain were males and smokers (16/30 vs. 4/38 and 20/30 vs. 4/38, both ƿ<0.001). Multivariate analysis confirmed that smoking was an independent factor associated with severe abdominal pain (OR 14.3, CI 2-99, p=0.007). Smoking was not associated with colonic transit times and colonic transit was not associated with IBS symptoms' severity (both ƿ=N.S.).

CONCLUSIONS

Smoking was the only factor independently associated with severe abdominal pain. As smoking does not seem to affect colonic transit time, we suggest that smoking may influence visceral perception and symptoms severity in IBS patients.

The changes in prevalence and risk of irritable bowel syndrome over time in a population-based cohort, the HUNT study, Norway

OBJECTIVE

To study the changes in prevalence of irritable bowel syndrome (IBS), the distribution between the sexes and age groups, and risk factors for the disease and its subtypes.

MATERIAL AND METHODS

Every inhabitant of Nord-Trøndelag county, Norway, over 20 years of age was invited to participate in the Trøndelag Health Study (HUNT). In HUNT3 (2006-2008) and HUNT4 (2017-2019), IBS was assessed by a questionnaire. The standardized prevalence was calculated, and risk factors were assessed by multivariable logistic regression, reporting odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

In HUNT3 and HUNT4, 41,198 and 42,669 individuals were included, respectively. The prevalence of IBS was 7.5% in HUNT3 and 9.5% in HUNT4. Both surveys showed higher prevalence among women and among young adults. In HUNT4, the most prevalent subtype was mixed IBS (46.1%). Women had increased risk of IBS compared to men (OR 1.82, 95% CI 1.69-1.96). Age ≥40 years decreased the risk of IBS compared to age <40 years (OR 0.82, 95% CI 0.75-0.90). Being unmarried increased the risk for IBS compared to being married (OR 1.21, 95% CI 1.11-1.32). Both previous (OR 1.28, 95% CI 1.20-1.38) and current (OR 1.35, 95% CI 1.20-1.51) smokers had increased risk of IBS compared to never smokers.

CONCLUSIONS

IBS is a prevalent disease, and the prevalence has increased between 2006-2008 and 2017-2019. Risk of IBS was increased among women, young adults, smokers and unmarried participants.

Frequency and severity of irritable bowel syndrome in cigarette smokers, Turkey 2019

INTRODUCTION

Cigarette smoking has recently been associated with several gastrointestinal symptoms, and smoking cessation has been recommended as a lifestyle change strategy for irritable bowel syndrome (IBS). This study assessed the prevalence of IBS in cigarette smokers based on the Rome IV criteria, the severity of nicotine dependence, and the effect of smoking cessation in smokers with IBS.

METHODS

This prospective study included 371 smokers who attended smoking cessation treatment at family medicine clinics in a tertiary hospital between January and April 2019, in Turkey. Data on demographic characteristics, IBS status according to the Rome IV criteria, and Fagerström test for nicotine dependence (FTND) scores were collected during face-to-face interviews.

RESULTS

The mean patient age was 40.7 ± 11.96 years. Out of the total patients, 29.4% were heavy smokers, and 18.1% had IBS. There was a significant difference in age (p=0.03), duration of smoking (p=0.05), FTND score (p=0.02), and sex (p<0.001) between those with and without IBS. Logistic regression analyses identified female sex as a predictor of IBS in smokers (adjusted odds ratio, AOR=1.78; 95% CI: 1.18-2.69; p=0.006). At follow-up at 1 year, IBS(+) smokers who had quit smoking showed decreased gastrointestinal symptoms (p=0.035).

CONCLUSIONS

FTND score was higher in IBS(+) smokers than in IBS(-) smokers. Smoking cessation ameliorated gastrointestinal symptoms but did not affect IBS status.

Review article: irritable bowel syndrome: natural history, bowel habit stability and overlap with other gastrointestinal disorders

Symptoms of irritable bowel syndrome (IBS) characteristically fluctuate over time. We aimed to review the natural history of IBS and IBS subgroups including bowel habit disturbances, and the overlap of IBS with other gastrointestinal disorders. The community incidence of IBS is approximately 67 per 1000 person years. The prevalence of IBS is stable over time because symptoms fluctuate and there is a portion who experience resolution of their GI symptoms similar in number to those developing new-onset IBS. The proportion who report resolution of symptoms varies amongst population-based studies from 17% to 55%. There is evidence of substantial movement between subtypes of IBS. For example in a clinical trial cohort, only one in four patients retained their baseline classification throughout the study periods, two in three moved between IBS-C (constipation) and IBS-M (mixed), while over half switched between IBS-D (diarrhoea) and IBS-M. The least stable group was IBS-M. There are very limited data on drivers of bowel habit change in IBS. There are emerging evidence fluctuations in intestinal immune activity might account for symptom variability over time. It is of clinical importance to recognise the substantial overlap of IBS symptoms with other gastrointestinal syndromes including gastro-oesophageal reflux disease. This is important to ensure the correct clinical diagnosis of IBS is made and patients are not over investigated. Knowledge of the natural history, stability of subgroups and overlap of IBS with other gastrointestinal conditions should be considered in therapeutic decision making.

Irritable Bowel Syndrome: Prevalence and Risk Factors in Jazan Region, Saudi Arabia

Background The prevalence of irritable bowel syndrome (IBS) worldwide remains heterogeneous. In Saudi Arabia, there are insufficient studies on the prevalence of IBS among the general population, yet the prevalence of IBS in certain professional groups has been reported. This study was conducted to determine the prevalence of IBS and its associated risk factors in the Jazan Region of Saudi Arabia. Methods An online cross-sectional study was conducted from January to March 2020 in the Jazan Region of Saudi Arabia, using a multi-stage stratified sampling technique. The data were collected using a web-based validated Rome IV questionnaire. The Rome IV criteria are used to diagnose functional gut disorders, including IBS. Logistic regression analysis was used to determine the odds ratio (OR) with 95% confidence intervals (95% CI) for the selected risk factors. Results The survey included 1554 participants with an overall IBS prevalence of 16%. Women had a higher incidence of IBS than men (55.3% and 44.7%, respectively). IBS-mixed (32.66%) and constipation-predominant (32.25%) were the most common subtypes. In multiple regression analysis, female gender (OR = 1.503, p-value = 0.037), stress (OR = 2.386, p-value = 0.000), anxiety (OR = 1.943, p-value = 0.000), and tobacco smoking (OR = 2.093, p-value = 0.001) showed a statistically significant association with IBS. Conclusions The prevalence of IBS in the southwest region of Saudi Arabia is high. Female sex, tobacco smoking, stress, and anxiety are the major risk factors associated with IBS.

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.

NUTRITIONAL STATUS, QUALITY OF LIFE AND LIFE HABITS OF WOMEN WITH IRRITABLE BOWEL SYNDROME: A CASE-CONTROL STUDY

BACKGROUND

Irritable bowel syndrome is a functional and chronic gastrointestinal disorder that may cause abdominal pain and altered bowel habits, affecting the nutritional status and quality of life of its carriers. Its prevalence is high, affecting about 10% to 15% of the general population in developed countries, being more prevalent in women than in men in the proportion 2:1.

OBJECTIVE

The aim of our study was to compare the profile of body adiposity, life habits, and the quality of life of women with irritable bowel syndrome with a healthy control group.

METHODS

Case-control study on 70 women, 34 with irritable bowel syndrome and 36 healthy. We applied the "Irritable Bowel Syndrome Quality of Life Questionnaire"to assess quality of life. Body adiposity was assessed from body mass index, waist circumference, and waist-to-hip ratio. We investigated the self-reporting of gastrointestinal symptoms with food deemed as problematic for carriers of irritable bowel syndrome and the presence of typical comorbidities. Assessment of life habits included: practice of physical activities, alcoholism, smoking, daytime sleepiness, and exclusion of foods from the feeding routine. For statistical analysis we used the IBM SPSS program, with a significance level at 5%.

RESULTS

There was higher volume of central and general adiposity in the case group compared with the control group (P<0.05). Cases presented a higher chance of developing IBS-related comorbidities (P<0.05). About of 80% of patients with irritable bowel syndrome have excluded some food from the diet (P<0.01) and the total amount of troublesome foods varied from 7 to 21 (P<0.01). The case group featured worse quality of life compared with the control (P<0.05).

CONCLUSION

Compared to the control group, women with irritable bowel syndrome showed greater body adiposity, higher frequency of comorbidities, greater restriction on the consumption of problematic foods and worse quality of life.

Cohort Profile: The Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT)

BACKGROUND AND AIMS

This cross-sectional observational case-control study was initiated in July 2016 with the aim of increasing an understanding of the underlying disease mechanisms in functional gastrointestinal disorders (FGIDs) including irritable bowel syndrome (IBS), functional diarrhoea (FD), and functional constipation (FC). Specific areas of interest include the effect of food, microbiome, host and microbial genetics, metabolome, and psychological variables on unexplained chronic gastrointestinal (GI) symptoms.

METHODS

This study recruited consecutive patients who were attending one of two endoscopy centres in Christchurch, New Zealand, for colonoscopy and a subgroup of participants from the general public who did not undergo colonoscopy. Participants with known GI disease other than an FGID were excluded. Those with symptoms were recruited as cases, whilst those without symptoms were recruited as controls. In the days prior to preparation for colonoscopy, or an agreeable time for those not undergoing colonoscopy, demographic, symptom, psychological, dietary, and health data were collected in addition to biological samples (breath, faeces, blood, and urine). Colonic biopsies were taken at the time of colonoscopy from participants in the colonoscopy subgroup.

RESULTS

Between July 2016 and December 2018, 349 participants were recruited, 315 of whom completed the study, 220 participants were from the colonoscopy subgroup, and 95 from the non-colonoscopy subgroup. This included 129 controls and 186 cases (57 IBS-diarrhoea predominant, 30 IBS-constipation predominant, 41 IBS-mixed, 42 FC, and 16 FD). The mean age of FGID cases was 53.4 years and controls 54.4 years. Cases (149/186, 80.1%) and controls (57/72, 55.8%) were predominantly female. Education levels were similar across the cohort. Smoking and alcohol rates were also similar. Biological samples were collected as planned from participants.

CONCLUSIONS

The COMFORT cohort is a unique clinical cohort of FGID cases and controls with a wide range of demographic, dietary, clinical, psychological, and health data in addition to biological samples. Future research will aim to use a systems biology approach to establish the potential role of diet, host-microbiome interactions, and other factors in the pathogenesis of FGIDs.

The association between irritable bowel syndrome and osteoporosis: a systematic review and meta-analysis

BACKGROUND

Recent studies have suggested that irritable bowel syndrome (IBS) could be a risk factor for osteoporosis although the evidence is still limited. The current study aimed to comprehensively examine the risk of osteoporosis among patients with IBS using systematic review and meta-analysis technique.

METHODOLOGY

Literature search was independently conducted by two investigators using MEDLINE, EMBASE, and Google Scholar database up to October 2019. Eligible study must evaluate whether patients with IBS have a higher risk of osteoporosis and/or osteoporotic fracture. It could be either cross-sectional study, case-control study, or cohort study. Point estimates and standard errors from each eligible study were combined together using the generic inverse variance method of DerSimonian and Laird.

RESULTS

Of the 320 articles identified from the three databases, four cohort and one cross-sectional study with 526,633 participants met the eligibility criteria and were included into the meta-analysis. All five studies investigated the risk of osteoporosis among patients with IBS, and the pooled analysis found that patients with IBS had a significantly higher risk of osteoporosis than individuals without IBS with the pooled risk ratio of 1.95 (95% CI, 1.04-3.64; I² 100%). Sensitivity analysis including only cohort studies found a lower RR (pooled RR 1.55; 95% CI, 1.39-1.72) with a lower I² (59%). Three studies investigated the risk of osteoporotic fracture, and the pooled analysis found that patients with IBS also had a higher risk of osteoporotic fracture than individuals without IBS with the pooled risk ratio of 1.58 although statistical significance was not reached (95% CI, 0.95-2.62; I² 99%). Sensitivity analysis including only cohort studies found a lower RR (pooled RR 1.27; 95% CI, 1.20-1.39) with a dramatically lower I² (0%). Limitations included high heterogeneity and reliance on diagnostic codes.

CONCLUSION

A significantly increased risk of osteoporosis among IBS patients was observed in this study. Early intervention to prevent the development of osteoporosis, such as weight-bearing exercise, adequate intake of vitamin D and calcium, and early screening for osteoporosis, may be beneficial to these patients although further studies are still required to confirm the efficacy and cost-effectiveness of this approach.

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.

The association between smoking and both types of microscopic colitis: A systematic review and meta-analysis

BACKGROUND AND STUDY AIMS

It has been suggested that smoking may be associated with microscopic colitis (MC) in some studies; however, there are conflicting results in the current literature with many of these studies having significant limitations. Our study aims to offer a meta-analysis evaluating the association between MC, including both its subtypes, and smoking.

PATIENTS AND METHODS

A systemic review was conducted in PUBMED, Embase, PubMed Central, and ScienceDirect databases from inception through December 2019. Effect estimates from the individual studies were extracted and combined using the random effect, generic inverse variance method of DerSimonian and Laird and a pooled odds ratio (OR) was calculated. Forest plots were generated, and publication bias was assessed for using conventional techniques.

RESULTS

Eight observation studies with a total of 1461 patients with MC were included in this study, 383 of whom were active smokers (26.2%). Current smoking was significantly associated with MC (OR 3.58, 95% CI, 2.51-5.11), lymphocytic colitis (LC) (OR 3.64, 95% CI, 2.46-5.38), and collagenous colitis (CC) (OR 4.43, 95% CI, 2.68-7.32). Gender-specific subgroup analysis showed a significant association with smoking was found for CC in men (OR 4.53, 95% CI, 1.59-12.85), CC in women (OR 3.27, 95% CI, 2.35-4.54), LC in women (OR 2.27, 95% CI, 1.27-4.06) and MC in women (OR 2.93, 95% CI, 2.09-4.10). We found no publication bias as assessed by the funnel plots and Egger's regression asymmetry test.

CONCLUSION

Our meta-analysis found a statistically significant association between smoking and both subtypes of MC.

Association of irritable bowel syndrome and venous thromboembolism

OBJECTIVE

Inflammatory bowel disease (IBD) is associated with venous thromboembolism (VTE). Whether functional gastrointestinal disorders, such as irritable bowel syndrome (IBS), are associated with VTE has not been determined. This nationwide study aimed to determine the risk of VTE in IBS outpatients in primary and specialist care.

DESIGN

We performed two matched case-control studies. Cases (n = 90,502) were individuals in Sweden aged 18-80 years with a first hospital diagnosis of VTE between 2001 and 2010. Five controls (n = 452,510) from the Swedish Total Population Register were matched to each case for birth, sex, country of birth, and education level. Diagnosis of IBS was determined in the Swedish hospital outpatient register. This procedure was replicated for the primary care population. As the Primary Care data did not have nationwide coverage, we only included individuals that were registered in the Primary Care database. A total of 9766 cases of hospital diagnosed VTE individuals could be found in the Primary Care population and they were matched to 48,830 controls also from the Primary health care population. Conditional logistic regression was used to determine odds ratio (OR) for first VTE diagnosis. Results The adjusted OR for VTE when IBS was diagnosed in hospital outpatient care was 1.49 (95% confidence interval 1.33-1.67). The crude OR for VTE was 1.18 (0.94-1.48) when IBS was diagnosed in primary care.

CONCLUSIONS

This is the first study describing an association between VTE and IBS. The results suggest that specialist treated IBS patients have increased risk of VTE.