Irritable bowel syndrome is significantly associated with somatisation in 840 patients, which may drive bloating

Prevalence of extra-intestinal symptoms according to irritable bowel syndrome subtype

BACKGROUND

Irritable bowel syndrome (IBS) is a functional disorder commonly associated with extra-intestinal symptoms. However, the prevalence of these symptoms according to IBS subtype is not well established.

AIM

To compare the prevalence of extra-intestinal symptoms among patients with different subtypes of IBS.

METHODS

A descriptive cross-sectional study including patients with IBS according to Rome IV criteria was performed between July 2022 and April 2023. Patients were classified according their subtype of IBS: IBS-D (diarrhea-predominant), IBS-C (constipation-predominant), and IBS-M (mixed bowel habits). Patients completed the IBS severity scoring system questionnaire (IBS-SSS) to determine severity of IBS symptoms and patient health questionnaire- 9 (PHQ-9) to define presence and severity of depressive symptoms. The prevalence of reported extra-intestinal symptoms was also assessed and compared between groups.

KEY RESULTS

A total of 4862 patients with IBS were included; 608 IBS-D (12.5%), 1978 IBS-C (40.7%), and 2276 IBS-M (46.8%). Patients with IBS-C had significantly lower IBS-symptoms severity (mean IBS-SSS 290 vs. 310 and 320 for IBS-D and IBS-M, respectively, p = 0.03). The prevalence of obesity was also significantly lower in these patients (17.1% vs. 30.9% IBS-D and 27.9% IBS-M, p = 0.0001). Patients with IBS-D showed a significantly higher prevalence of food intolerance perception (9.5%, p = 0.03), history of cholecystectomy (17.8%, p = 0.03), and fecal incontinence (36.2%, p = 0.0001) as compared to the other groups. Patients with IBS-M had significantly higher mean PHQ-9 score (12.7 vs. 11.1 IBS-D and 10.5 IBS-C, p = 0.001) and prevalence of depressive symptoms (80.0%, p = 0.01). Patients with IBS-M also had higher prevalence of extra-intestinal symptoms such as arthralgia (62.4%, p = 0.0001), extremity numbness (64.5%, p = 0.0001), atopic dermatitis (28.2%, p = 0.02), and chronic cervicalgia (81.0%, p = 0.01).

CONCLUSIONS & INFERENCES

The prevalence of most extra-intestinal symptoms is higher among patients with IBS-M. Further research is needed to better characterize IBS subtypes, which could potentially help refining tailored therapeutic strategies.

Journal of Clinical Gastroenterology Lectureship Dubai 2022 : Management of Irritable Bowel Syndrome With Diarrhea

Irritable bowel syndrome (IBS) with diarrhea (IBS-D) affects ~1% of the general population and is characterized by abdominal pain associated with diarrhea. IBS-D symptoms significantly impact the quality of life of patients. Major uncertainties remain regarding the optimal management of these patients. Several therapies have been investigated over the years for the treatment of IBS-D. In the initial management, commonly prescribed approaches with an effect on global IBS symptoms include a low Fermentable Oligo-, Di-, Mono-Saccharides and Polyols diet and probiotics, while antispasmodics are used for targeting abdominal pain and loperamide for diarrhea only. Additional therapeutic options for the relief of global IBS symptoms include rifaximin, 5-HT 3 antagonists, gut-directed psychological therapies, and eluxadoline, while tricyclic antidepressants can target abdominal pain and bile acid sequestrants diarrhea. Promising evidence exists for the use of mesalazine and fecal microbiota transplantation in IBS-D, although further evidence is needed for definitive conclusions regarding their efficacy.

Novel Symptom Subgroups in Individuals With Irritable Bowel Syndrome Predict Disease Impact and Burden

BACKGROUND & AIMS

Current classification systems based on bowel habit fail to capture the multidimensional nature of irritable bowel syndrome (IBS). We previously derived and validated a classification system, using latent class analysis, incorporating factors beyond bowel habit. We applied this in another cohort of people with IBS to assess its ability to capture the impact of IBS on the individual, the health care system, and society.

METHODS

We collected demographic, symptom, and psychological health data from adults in the community self-identifying as having IBS, and meeting Rome IV criteria. We applied our latent class analysis model to identify the 7 subgroups (clusters) described previously, based on overall gastrointestinal symptom severity and psychological burden. We assessed quality of life, health care costs (£1 = $1.20), employment status, annual income, work productivity, and ability to perform work duties in each cluster.

RESULTS

Of 1278 responders, 752 (58.8%) met Rome IV criteria. The 7-cluster model fit the data well. The patients in the 4 clusters with the highest psychological burden, and particularly those in cluster 6 with high overall gastrointestinal symptom severity and high psychological burden, showed lower educational levels, higher gastrointestinal symptom-specific anxiety, were more likely to have consulted a gastroenterologist, and used more drugs for IBS. IBS-related and generic quality of life were impaired significantly in these 4 clusters and significantly fewer individuals reported earning ≥£30,000 per year. Productivity and the ability to work, manage at home, engage in social and private leisure activities, and maintain close relationships all were impacted significantly, and IBS-related health care costs over the previous 12 months were highest in these 4 clusters. In those in cluster 6, costs were more than £1000 per person per year.

CONCLUSIONS

Our clusters identify groups of individuals with significant impairments in quality of life, earning potential, and ability to work and function socially, who are high utilizers of health care.

Somatization Mediates the Relationship Between Childhood Trauma and Pain Ratings in Patients with Irritable Bowel Syndrome

GOALS

To identify potential mechanisms by which childhood trauma may lead to the adult development of abdominal symptoms in patients with irritable bowel syndrome (IBS).

BACKGROUND

Patients with IBS frequently report a history of childhood trauma. The pathophysiology by which abdominal pain arises in patients with IBS is multidimensional, consisting of both peripheral factors, such as altered motility, inflammation, and bacterial overgrowth, as well as central factors, such as psychological distress and neuro-hormonal dysregulation.

STUDY

Adult psychological factors (anxiety, depression, and somatization) were examined to determine if they mediate the relationship between retrospective reports of childhood trauma and current adult IBS abdominal symptoms in a study of 436 patients (M age=41.6, 79% F) meeting Rome III diagnosis criteria. Childhood trauma was measured using retrospective questions assessing physical and sexual abuse. Psychological factors in adulthood were measured with the subscales of the Brief Symptom Inventory-18. Outcome variables included adult IBS symptoms of abdominal pain, bloating, and satisfaction with bowel habits from the IBS Symptoms Severity Scale.

RESULTS

Results indicated that somatization mediated the relationship between childhood abuse and abdominal pain and bloating but not bowel satisfaction.

CONCLUSIONS

This study provides insight into the multifactorial nature of IBS-associated abdominal pain in patients with a history of childhood trauma, elucidating the need for a trauma-informed treatment approach for patients with histories of abuse.

Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment in primary care (ATLANTIS): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Most patients with irritable bowel syndrome (IBS) are managed in primary care. When first-line therapies for IBS are ineffective, the UK National Institute for Health and Care Excellence guideline suggests considering low- dose tricyclic antidepressants as second-line treatment, but their effectiveness in primary care is unknown, and they are infrequently prescribed in this setting.

METHODS

This randomised, double-blind, placebo-controlled trial (Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment [ATLANTIS]) was conducted at 55 general practices in England. Eligible participants were aged 18 years or older, with Rome IV IBS of any subtype, and ongoing symptoms (IBS Severity Scoring System [IBS-SSS] score ≥75 points) despite dietary changes and first-line therapies, a normal full blood count and C-reactive protein, negative coeliac serology, and no evidence of suicidal ideation. Participants were randomly assigned (1:1) to low-dose oral amitriptyline (10 mg once daily) or placebo for 6 months, with dose titration over 3 weeks (up to 30 mg once daily), according to symptoms and tolerability. Participants, their general practitioners, investigators, and the analysis team were all masked to allocation throughout the trial. The primary outcome was the IBS-SSS score at 6 months. Effectiveness analyses were according to intention-to-treat; safety analyses were on all participants who took at least one dose of the trial medication. This trial is registered with the ISRCTN Registry (ISRCTN48075063) and is closed to new participants.

FINDINGS

Between Oct 18, 2019, and April 11, 2022, 463 participants (mean age 48·5 years [SD 16·1], 315 [68%] female to 148 [32%] male) were randomly allocated to receive low-dose amitriptyline (232) or placebo (231). Intention-to-treat analysis of the primary outcome showed a significant difference in favour of low-dose amitriptyline in IBS-SSS score between groups at 6 months (-27·0, 95% CI -46·9 to -7·10; p=0·0079). 46 (20%) participants discontinued low-dose amitriptyline (30 [13%] due to adverse events), and 59 (26%) discontinued placebo (20 [9%] due to adverse events) before 6 months. There were five serious adverse reactions (two in the amitriptyline group and three in the placebo group), and five serious adverse events unrelated to trial medication.

INTERPRETATION

To our knowledge, this is the largest trial of a tricyclic antidepressant in IBS ever conducted. Titrated low-dose amitriptyline was superior to placebo as a second-line treatment for IBS in primary care across multiple outcomes, and was safe and well tolerated. General practitioners should offer low-dose amitriptyline to patients with IBS whose symptoms do not improve with first-line therapies, with appropriate support to guide patient-led dose titration, such as the self-titration document developed for this trial.

FUNDING

National Institute for Health and Care Research Health Technology Assessment Programme (grant reference 16/162/01).

Clinical Characteristics of Patients Presenting With Bloating as a Predominant Symptom

BACKGROUND

The estimated prevalence of bloating is 15 to 30% in the adult US population and is even higher in patients with disorders of gut-brain interaction (DGBIs). Despite this frequency, there is little research into patients who endorse bloating as a predominant symptom. The aim of this study was to better characterize these patients.

MATERIALS AND METHODS

New patients with DGBIs were asked to identify their 3 most predominant symptoms over the preceding 3 months; those who reported bloating were classified as "bloating predominant." Rome IV and symptom-specific questionnaires were administered to assess for the frequency of DGBIs and other predominant symptoms in this patient population. Using univariable and multivariable modeling, we analyzed the associations between bloating predominance, DGBI subtype, and clinical characteristics.

RESULTS

Of the 586 patients surveyed, 242 (41%) reported predominant bloating. Bloating-predominant patients were more likely to be female, younger, and meet the criteria for IBS-mixed (IBS-M), functional constipation, and functional dyspepsia compared with nonbloating-predominant patients. Bloating-predominant patients were also more likely to endorse concurrently predominant constipation, incomplete evacuation, abdominal pain, belching, and/or nausea. On multivariable logistic regression, constipation and abdominal pain severity were positively associated, although depression was negatively associated with predominant bloating.

CONCLUSIONS

Patients with predominant bloating are more likely to have constipation-related symptoms than diarrhea-related symptoms. They are also more likely to have more severe abdominal pain than patients without predominant bloating. These findings help characterize patients with bloating as a predominant symptom and suggest that diagnosing and treating constipation should be considered as first-line treatment.

Effectiveness of Osteopathic Manipulative Treatment in Adults with Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the effectiveness of the osteopathic manipulative treatment (OMT) in adults with irritable bowel syndrome (IBS). A literature resview was carried out on the following databases: PubMed, Embase, Cochrane, Cinahl, Scopus, PEDro and ClinicalTrials.gov. 350 articles were recovered. Eligibility criteria were evaluated by two independent reviewers, including randomized controlled trials (RCTs), quasi-RCTs, or ongoing RCTs with OMT compared to any kind of control in patients diagnosed with IBS. Six studies (five RCTs and one ongoing RCT) were considered eligible. Four RCTs were classified as some concerns and one as high risk of bias. In the meta-analysis, OMT compared to sham/no intervention showed statistically significant results for abdominal pain (effect size ES = -1.14 [-1.66, -0.62]; p < 0.0001) and constipation (ES = -0.66 [-1.12, -0.20]; p = 0.005). Instead, OMT was not superior to the control for the IBS symptoms measured with the IBS Severity Score and the Likert scale (ES = -0.34 [-0.83, 0.16]; p = 0.19), and diarrhea (ES = -1.20 [-2.84, 0.43]; p = 0.15). The quality of evidence was "low" for IBS symptoms in general for abdominal pain and constipation, while it was judged as "very low" for diarrhea. OMT turns out to be safe in the treatment of IBS without major adverse effects. OMT may be effective in IBS patients, however the results must be interpreted carefully due to the low methodological quality of the studies.

Systematic review and meta-analysis of calculating degree of comorbidity of irritable bowel syndrome with migraine

BACKGROUND

Irritable bowel syndrome (IBS) and migraines are often comorbid each other. These disorders are likely to be bidirectionally linked through the gut-brain axis and share several underlying mechanisms including central nervous system sensitization. However, quantitative analysis of comorbidity was not reported enough. The aim of this systematic review and meta-analysis was to calculate the present degree of comorbidity of these two disorders.

METHODS

A literature search was performed searching for articles describing IBS or migraine patients with the same inverse comorbidity. Pooled odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) were then extracted. The total effect estimates were determined and presented by random effect forest plots for the group of articles with IBS patients with migraine and the group of articles on migraine sufferers with comorbid IBS separately. The average results of these plots were compared.

RESULTS

The literature search resulted in initial 358 articles and final 22 articles for the meta-analysis. The total OR values obtained were 2.09 [1.79 - 2.43] in IBS with comorbid migraine or headache, 2.51 [1.76 - 3.58] for migraineurs with comorbid IBS and an overall HR of 1 .62 [1.29 - 2.03] was found for cohort studies of migraine sufferers with comorbid IBS. A similar expression of a selection of other comorbidities was found in IBS and migraine patients, especially for depression and fibromyalgia a strong similarity was found in their expression rate.

CONCLUSIONS

This systematic review with meta-analysis was the first to combine data on IBS patients with comorbid migraine and migraineurs with comorbid IBS. The fact that closely related existential rates were observed between these two groups should be used as motivation for future research to further investigate these disorders for why this similarity occurs. Mechanisms involved in central hypersensitivity such as genetic risk factors, mitochondrial dysfunction and microbiota are particularly good candidates. Experimental designs in which therapeutic methods for these conditions can be exchanged or combined may also lead to the discovery of more efficient treatment methods.

Antibiotics and Probiotics for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a disorder of a gut-brain interaction characterised by abdominal pain and a change in stool form or frequency. Current symptom-based definitions and the classification of IBS promote heterogeneity amongst patients, meaning that there may be several different pathophysiological abnormalities leading to similar symptoms. Although our understanding of IBS is incomplete, there are several indicators that the microbiome may be involved in a subset of patients. Techniques including a faecal sample analysis, colonic biopsies, duodenal aspirates or surrogate markers, such as breath testing, have been used to examine the gut microbiota in individuals with IBS. Because of a lack of a clear definition of what constitutes a healthy gut microbiota, and the fact that alterations in gut microbiota have only been shown to be associated with IBS, a causal relationship is yet to be established. We discuss several hypotheses as to how dysbiosis may be responsible for IBS symptoms, as well as potential treatment strategies. We review the current evidence for the use of antibiotics and probiotics to alter the microbiome in an attempt to improve IBS symptoms. Rifaximin, a non-absorbable antibiotic, is the most studied antibiotic and has now been licensed for use in IBS with diarrhoea in the USA, but the drug remains unavailable in many countries for this indication. Current evidence also suggests that certain probiotics, including Lactobacillus plantarum DSM 9843 and Bifidobacterium bifidum MIMBb75, may be efficacious in some patients with IBS. Finally, we describe the future challenges facing us in our attempt to modulate the microbiome to treat IBS.

Experiencing multiple concurrent functional gastrointestinal disorders is associated with greater symptom severity and worse quality of life in chronic constipation and defecation disorders

BACKGROUND

Recent community-based studies have demonstrated that experiencing multiple concurrent functional gastrointestinal disorders (FGIDs) is associated with increased somatization, worse quality of life (QoL), and greater health care utilization. However, the presence of multiple overlapping FGIDs is unstudied specifically in chronic constipation and functional defecation disorders (FDD). We investigated the prevalence and impact of additional nonconstipation FGIDs on constipation severity, anorectal physiology, anxiety and depression, and QoL, in patients with chronic constipation and FDD.

METHODS

One-hundred and forty-six consecutive patients with functional constipation or irritable bowel syndrome (IBS-C/IBS-M) presenting to a tertiary referral Neurogastroenterology Clinic were studied. In addition, 90/146 (62%) qualified for FDD due to abnormal defecatory physiology. Patients underwent comprehensive baseline assessment comprising anorectal physiology, Bristol Stool Chart, Rome questionnaire, Knowles-Eccersley-Scott-Symptom (KESS) constipation score, Hospital Anxiety, and Depression Scale, and modified 36-Item Short Form Health Survey (SF-36) for QoL. Additional FGIDs were diagnosed using Rome III criteria.

KEY RESULTS

Additional nonconstipation FGIDs occurred in 85% of patients, with a mean of 2.1 (SD 1.6) additional FGIDs. Patients with four or more additional FGIDs experienced greater constipation severity compared to those with no additional FGIDs (p = 0.004). Comorbid FGIDs were associated with worse SF-36 scores for physical functioning (p < 0.001), role-physical (p = 0.005), bodily pain (p < 0.001), vitality (p = 0.008), social functioning (p = 0.004), and mental health index (p = 0.031).

CONCLUSIONS AND INFERENCES

Functional gastrointestinal disorders comorbidity is highly prevalent in chronic constipation and defecatory disorders, and this is associated with greater symptom severity and worse QoL. Multimodal treatments targeting comorbid FGIDs may lead to superior outcomes.

Factors associated with lower disease-specific and generic health-related quality of life in Rome IV irritable bowel syndrome

BACKGROUND

Little is known about associations with reduced quality of life in irritable bowel syndrome (IBS) or impact of IBS on quality of life compared with other chronic conditions.

METHODS

We collected demographic, gastrointestinal and psychological symptoms, healthcare usage, direct healthcare costs, impact on work and activities of daily living data from 752 individuals with Rome IV-defined IBS. We used the irritable bowel syndrome quality of life (IBS-QOL) and the EQ-5D-5L questionnaires to examine characteristics associated with lower quality of life.

RESULTS

The mean IBS-QOL among all 752 individuals with Rome IV IBS was 48.4 (SD 22.3) and the mean EQ-5D score was 0.570 (SD 0.283), the latter being comparable to people with stroke, leg ulcers or chronic obstructive pulmonary disease. Lower levels of both disease-specific and generic quality of life were associated with severe IBS symptom scores, abnormal anxiety or depression scores, and higher somatoform symptom-reporting and gastrointestinal symptom-specific anxiety scores (p < 0.001 for all analyses). Those with lower quality of life had significantly higher healthcare usage and direct healthcare costs and more impairment in work and activities of daily living (p < 0.01 for all analyses). Avoidance of alcohol, lower educational level, abnormal anxiety, depression or somatoform symptom-reporting scores, and impairment in social leisure activities, home management or maintaining close relationships were all independently associated with lower quality of life.

CONCLUSION

IBS has a substantial impact on the quality of life of those affected, and worse than observed in some severe chronic organic conditions.

Interactions between symptoms and psychological status in irritable bowel syndrome: An exploratory study of the impact of a probiotic combination

BACKGROUND

Stress is an exacerbator of irritable bowel syndrome (IBS) symptoms, and anxiety and depression are co-morbidities. Bifidobacterium longum strains 1714® and 35642® attenuate stress responses in healthy people and reduce symptoms in IBS, respectively. Here, we explore relationships between the psychological and visceral effects of the two strains (COMBO) in IBS subjects and biomarkers of stress and inflammation.

METHODS

We recruited 40 patients with IBS (Rome III) and mild to moderate anxiety (HADS-A) and/or depression (HADS-D) and 57 asymptomatic female controls with low or moderate stress. IBS patients were fed COMBO (1 × 10⁹ cfu/day) for 8 weeks with an 8-week washout. IBS symptoms, psychometric measures, salivary cortisol awakening response (CAR), and plasma inflammatory biomarkers were assessed every 4 weeks.

KEY RESULTS

Compared to healthy controls, IBS subjects had a blunted CAR. Treatment with COMBO restored CAR and improved IBS symptoms compared to baseline during the treatment phase. The COMBO reduced HADS-D, HADS-A score, and TNF-α, while sleep quality improved significantly from baseline to the end of the intervention. Surprisingly, these parameters improved further once treatment ended and maintained this improvement by Week 16.

CONCLUSIONS AND INFERENCES

These findings suggest that the stress response is a major driver of IBS symptoms. The time course of the beneficial effect of COMBO on IBS symptoms suggests that this is achieved through a restoration of the stress response. In contrast, the time course of the effects of COMBO on anxiety and depression in IBS paralleled an anti-inflammatory effect as indicated by a reduction in circulating levels of TNF-α.

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.

Factors related to irritable bowel syndrome and differences among subtypes: A cross-sectional study in the UK Biobank

Background: Irritable bowel syndrome (IBS) reduces patients' quality of life and causes great burdens due to its unclear pathogenesis and criteria for diagnosis. This study aimed to explore the differences in prevalence and the influencing factors for IBS and its subtypes. Methods: The UK Biobank surveyed 174,771 adult participants who completed the Digestive Health Questionnaire (DHQ) through emails and websites. DHQ included the Rome III criteria, IBS symptom severity score, and Patient Health Questionnaire 12 Somatic Symptom score. The UK Biobank also asked regarding previous IBS diagnosis, diagnosis for post-infectious IBS (PI-IBS), and environmental exposures and associated conditions (including anxiety or depression, based on treatment sought or offered). Pearson's Chi-squared test or Wilcoxon's rank-sum test was used for potential associations. Binary logic regression based on sex stratification was used to examine associations between selected factors and IBS and its subtypes. Results: This study included 31,918 participants who met the Rome III criteria for IBS. The pooled prevalence of IBS in the UK Biobank was 18.3%, with mixed IBS as the predominant subtype (59.0%), followed by diarrhea-predominant IBS (25.1%), constipation-predominant IBS (14.7%), and untyped IBS (1.1%). IBS was significantly associated with somatization (male: OR = 5.326, 95% CI = 4.863-5.832; female: OR = 4.738, 95% CI = 4.498-4.992) and coeliac disease (male: OR = 4.107, 95% CI = 3.132-5.385; female: OR = 3.783, 95% CI = 3.310-4.323). Differences in antibiotics and mental status were presented among subtypes and sex. Furthermore, 1,787 individuals were diagnosed with PI-IBS in the group of patients with IBS. The prevalence of PI-IBS in IBS was 16.6% in the UK Biobank, and it was characterized by diarrhea, fever, bloody diarrhea, and vomiting. Conclusion: Somatization and coeliac disease are primary risk factors for IBS. Distinguishing differential risk factors is critical for the precise diagnosis and treatment of IBS subtypes, particularly sex-specific differences in mental health status. General practitioners should focus on the treatment according to IBS subtypes.

Extraintestinal manifestations in irritable bowel syndrome: A systematic review

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by abdominal pain and altered bowel habits. Further, IBS patients experience a high degree of extraintestinal symptoms.

OBJECTIVES

The aim of this review was to describe the relation between IBS and extraintestinal manifestations and mechanisms and treatments of these extraintestinal manifestations.

DESIGN

The study was performed as a systematic review.

DATA SOURCES AND METHODS

Search terms including extraintestinal manifestations or somatization and IBS were used to scrutinize for publications in Pubmed. In total, 630 publications were identified and 80 were finally included in this review.

RESULTS

About 50% of all IBS patients have extraintestinal manifestations in addition to gastrointestinal symptoms. Somatic pain, fatigue, and sleeping disturbances are most common, and most often described in women. Both extraintestinal manifestations and psychological distress are associated with exaggerated gastrointestinal symptoms, impaired quality of life, and difficulties to treat IBS symptoms. The extraintestinal manifestations render an excess of healthcare costs. Varying etiology and pathophysiology to IBS are discussed, and many patients express a general hypersensitivity. Extraintestinal symptoms are seldom documented at clinical healthcare or included in the assessment of treatment outcomes. A good patient-physician relationship and strengthening of coping mechanisms have rendered less gastrointestinal symptoms, psychological distress, and somatization. Altered lifestyle habits may improve both gastrointestinal and extraintestinal symptoms. Pharmacological treatment, including antidepressant drugs, should be considered when lifestyle advice fails. Teamwork between different specialists and healthcare providers may be of importance in the wide range of symptoms and extraintestinal manifestations.

CONCLUSION

Extraintestinal manifestations are common in IBS patients and is associated with worse suffering and difficulties to treat symptoms. Evaluation and treatment of IBS patients should consider also extraintestinal manifestations and their treatment outcome. Establishment of good relationship, strengthening of coping mechanisms, and education in healthier lifestyle habits are crucial in the management of these patients.

Willingness to accept risk with medication in return for cure of symptoms among patients with Rome IV irritable bowel syndrome

BACKGROUND

Some drugs for irritable bowel syndrome (IBS) have serious side effects.

AIMS

To examine the willingness of individuals with IBS to accept risks with medication in return for symptom cure.

METHODS

We collected demographic, gastrointestinal symptoms, psychological health, quality of life and impact on work and daily activities data from 752 adults with Rome IV-defined IBS. We examined median willingness to accept death in return for cure with a hypothetical medication using a standard gamble, according to these variables.

RESULTS

Participants would accept a median 2.0% (IQR 0.0%-9.0%) risk of death in return for a 98.0% (IQR 91.0%-100.0%) chance of permanent symptom cure. The median accepted risk of death was higher in men (5.0% vs 2.0%, P < 0.001), those with continuous abdominal pain (4.0% vs 1.0%, P < 0.001), more severe symptoms (P = 0.005 for trend), abnormal depression scores (P < 0.001 for trend), higher gastrointestinal symptom-specific anxiety (P < 0.001 for trend), and lower IBS-related quality of life (P < 0.001 for trend). Those willing to accept above median risk of death were more likely to be male (17.1% vs 9.1%, P < 0.001), take higher levels of risks in their daily life (P = 0.008 for trend), and report continuous abdominal pain (53.1% vs 39.4%, P < 0.001), and had higher depression (P = 0.004 for trend) and lower quality of life (P < 0.001 for trend) scores.

CONCLUSION

Patients are willing to accept significant risks in return for cure of their IBS symptoms.

Characteristics of, and natural history among, individuals with Rome IV functional bowel disorders

BACKGROUND

Little is known about the natural history of functional bowel disorders using Rome IV criteria. We examined these issues in a longitudinal follow-up study.

METHODS

We collected complete demographic, gastrointestinal symptom, and psychological comorbidity data at baseline from 1372 adults who met Rome IV criteria for one of the five functional bowel disorders. At 12 months, we collected data regarding gastrointestinal symptoms, psychological comorbidity, consultation behavior, and treatment commenced. We examined prognosis and stability of all five functional bowel disorders.

KEY RESULTS

At baseline, 811 (59.1%) individuals met Rome IV criteria for irritable bowel syndrome (IBS), 76 (5.5%) functional constipation (FC), 199 (14.5%) functional diarrhea (FDr), 130 (9.5%) functional abdominal bloating or distension (FABD), and 156 (11.4%) unspecified functional bowel disorder (UFBD). In total, 782 (57.0%) were successfully followed up. Individuals with IBS at baseline were significantly more likely to report symptoms compatible with anxiety, depression, or somatoform-type behavior (p < 0.001 for all analyses) at baseline and follow-up compared with those with the other four functional bowel disorders. IBS was the most stable functional bowel disorder; 319 (70.6%) of 452 participants still met criteria for IBS at 12 months, compared with 14 (34.1%) of 41, 43 (35.5%) of 121, 26 (33.8%) of 77, and 37 (40.7%) of 91 for FC, FDr, FABD, and UFBD, respectively (p < 0.001).

CONCLUSIONS AND INFERENCES

Individuals with Rome IV-defined IBS exhibited higher levels of anxiety, depression, or somatoform-type symptom reporting. IBS was the most stable and the likeliest disorder that the other four functional bowel disorders would fluctuate to.

Cross-lagged analyses between gastrointestinal symptoms, psychological distress, and disability in emerging adults

The gut-brain connection refers to communication between the brain and gastrointestinal (GI) system. Disorders of gut-brain interaction (DGBI) are characterized by GI symptoms that accompany distress and disability. Epidemiological research has suggested DGBI rates in emerging adults are increasing. This study investigated the relationship between GI health, distress, and disability in emerging adults across time. Emerging adults were recruited. A repeated-measure design with a 1-month time lag was used to collect data via an online survey (N = 861) across five academic semesters (Spring 2019 to Summer 2020). Measurement equivalence across time was established and a cross-lagged panel model (CLPM) was specified. Distress at Time 1 predicted GI symptoms at Time 2 (β = .206, SE = .084, p < .05). GI symptoms at Time 1 predicted disability at Time 2 (β = .117, SE = .039, p < .01). Higher disability at Time 1 predicted distress at Time 2 (β = .092, SE = .027, p < .01). The cross-lagged design offers stronger causal inferences than cross-sectional studies used to study the effects of GI symptoms. Findings provide initial evidence of a directional pathway between brain and gut rather than a bidirectional network. Findings highlight the importance of psychogastroenterology.

Gut microbiota signatures and modulation in irritable bowel syndrome

Irritable bowel syndrome (IBS) affects approximately one tenth of the general population and is characterized by abdominal pain associated with abnormalities in bowel habits. Visceral hypersensitivity, abnormal intestinal motor function, mucosal immune activation, and increased intestinal permeability concur to its pathophysiology. Psychological factors can influence symptom perception at the central nervous system level. In addition, recent evidence suggests that dysbiosis may be a key pathophysiological factor in patients with IBS. Increasing understanding of the pathophysiological mechanisms translates into new and more effective therapeutic approaches. Indeed, in line with this evidence, IBS therapies nowadays include agents able to modulate gut microbiota function and composition, such as diet, prebiotics, probiotics, and antibiotics. In addition, in the last decade, an increasing interest in fecal microbiota transplantation has been paid. An in-depth understanding of the intestinal microenvironment through accurate faucal microbiota and metabolite analysis may provide valuable insights into the pathophysiology of IBS, finally shaping new tailored IBS therapies.

Symptom severity and clinical characteristics of patients with bloating

BACKGROUND

Abdominal bloating is common in functional gastrointestinal disorders (FGID). To better characterize this patient population, we evaluated clinical and psychological characteristics of bloating and analyzed their differences by bloating severity.

METHODS

Patients with FGIDs evaluated at a single academic outpatient referral gastroenterology clinic were surveyed. Bloating severity was classified as minimal, moderate or severe. Symptom-specific questionnaires were used to evaluate bowel habits, abdominal bloating, depression, anxiety, somatization and sleep disturbance. Associations between bloating severity, clinical characteristics and FGID subtypes were analyzed in univariate and multivariate modeling.

KEY RESULTS

Of 612 FGID patients included (78% female, mean age of 44 ± 16.5 years), bloating was reported as minimal in 231(37.8%), moderate in 217(35.4%), or severe in 164(26.8%). Patients with severe bloating were more likely to be female, younger, and have co-existing functional dyspepsia than those with minimal bloating (p < 0.05). Bloating severity and severity of abdominal distension were significantly correlated (p < 0.05). On multivariable regression, patients who met criteria for functional constipation and functional dyspepsia had 80% and 125% higher odds, respectively, of severe bloating compared to minimal to moderate bloating. Younger age, abdominal pain and constipation severity, and somatization scores were also independently associated with severity of bloating.

CONCLUSIONS & INFERENCES

Severe bloating is associated with younger age, and with more severe abdominal pain, constipation, and somatization. Patients who met criteria for functional constipation and functional dyspepsia are more likely to experience severe bloating.

The Intestinal Gas Questionnaire (IGQ): Psychometric validation of a new instrument for measuring gas-related symptoms and their impact on daily life among general population and irritable bowel syndrome

BACKGROUND

Gas-related symptoms (GRS) are common in the general population (GPop) and among patients with disorders of gut-brain interactions but there is no patient-reported outcome evaluating these symptoms and their impact on daily life. We have previously developed a 43-item intestinal gas questionnaire (IGQ). The aim of the present study is to perform a psychometric validation of this instrument.

METHODS

Participants (119 from the GPop and 186 irritable bowel syndrome (IBS) patients) were recruited from 3 countries (UK, Spain, France). IBS patients fulfilled ROME IV criteria with an IBS severity score between 150 and 300. Participants completed the IGQ, the functional Digestive Disorders Quality of Life (FDDQL), and the EQ-5D. A subgroup (n = 90) repeated the IGQ completion after 7 days on paper or electronically.

RESULTS

From the original IGQ questionnaire, 26 items were deleted because of poor performance. Confirmatory factorial analysis on the remaining 17 items (7 symptom and 10 impact items) yielded a 6-factor structure accounting for 67% of the variance for bloating (6 items), flatulence (3), belching (2), bad breath (2), stomach rumbling (2), and difficult gas evacuation (2). Global score (0-100) was worse among IBS vs GPop (40 ± 15 vs 33 ± 17; p = 0.0016). At the second visit, the intraclass correlation coefficient of IGQ scores was between 0.71 and 0.86 (n = 67) for test-retest reliability and 0.61-0.87 (n = 64) for equivalence between electronic and paper versions of IGQ.

CONCLUSION

The IGQ available in paper and electronic versions in 3 languages is a robust instrument for capturing and measuring GRS and their impact on daily life.

Irritable bowel syndrome in women: Association between decreased insular subregion volumes and gastrointestinal symptoms

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All insular subregions are smaller in IBS compared to healthy women.

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Insular volume associates with GI symptoms independent of psychiatric comorbidity.

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GI symptoms associate with anterior but not posterior insular volume.

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More nausea associated with smaller dorsal anterior insula bilaterally.

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Insula in major depression is not significantly smaller than in healthy women.

Objective

Irritable bowel syndrome (IBS) is a chronic pain disorder characterized by disturbed interactions between the gut and the brain with depression as a common comorbidity. In both IBS and depression, structural brain alterations of the insular cortices, key structures for pain processing and interoception, have been demonstrated but the specificity of these findings remains unclear. We compared the gray matter volume (GMV) of insular cortex (IC) subregions in IBS women and healthy controls (HC) and examined relations to gastrointestinal (GI) symptoms and glutamate + glutamine (Glx) concentrations. We further analyzed GMV of IC subregions in women with major depression (MDD) compared to HC and addressed possible differences between depression, IBS, IBS with depression and HC.

Design

Women with IBS (n = 75), MDD (n = 41) and their respective HC (n = 39 and n = 43) underwent structural brain MRI. IC subregion volumes were estimated using statistical parametric mapping software. General linear model approaches were applied to IC volumetric data and FDR-corrected partial correlation analyses assessed relations between GMV, GI symptoms and Glx concentrations.

Results

IBS patients had significantly smaller IC subregions than HC in both hemispheres but there was no significant difference between MDD compared with IBS and HC for any insular subregion. In IBS, the dorsal anterior insular volumes were negatively correlated with symptoms of nausea and pain, and the left ventral subregion showed a positive correlation with straining to defecate, while the posterior subregion volumes showed no relation to symptoms. In the anterior insula, concentration of Glx showed positive correlations with GMV bilaterally in HC and with GMV of the right anterior insula in IBS.

Conclusion

As the interoceptive cortex, the insula shows substantial and disease-specific structural differences in patients with chronic interoceptive visceral pain. Particularly changes in the anterior proportions might be related to chronic exposure to or enhanced salience towards adverse interoceptive visceral signals and could be linked to biochemical changes, calling for further multimodal and longitudinal work.

Review article: Physical and psychological comorbidities associated with irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders encountered by physicians in primary and secondary care. Patients with IBS commonly present with various extraintestinal complaints, which account for a substantial clinical and economic burden. The common extraintestinal comorbidities associated with IBS include anxiety, depression, somatisation, fibromyalgia, chronic fatigue syndrome, chronic pelvic pain, interstitial cystitis, sexual dysfunction and sleep disturbance. The presence of comorbidity in IBS poses a diagnostic and therapeutic challenge with patients frequently undergoing unnecessary investigations and interventions, including surgery. This review discusses the different physical and psychological comorbidities associated with IBS, the shared pathophysiological mechanisms and potential management strategies.

Altered Structural Covariance of Insula, Cerebellum and Prefrontal Cortex Is Associated with Somatic Symptom Levels in Irritable Bowel Syndrome (IBS)

Somatization, defined as the presence of multiple somatic symptoms, frequently occurs in irritable bowel syndrome (IBS) and may constitute the clinical manifestation of a neurobiological sensitization process. Brain imaging data was acquired with T1 weighted 3 tesla MRI, and gray matter morphometry were analyzed using FreeSurfer. We investigated differences in networks of structural covariance, based on graph analysis, between regional gray matter volumes in IBS-related brain regions between IBS patients with high and low somatization levels, and compared them to healthy controls (HCs). When comparing IBS low somatization (N = 31), IBS high somatization (N = 35), and HCs (N = 31), we found: (1) higher centrality and neighbourhood connectivity of prefrontal cortex subregions in IBS high somatization compared to healthy controls; (2) higher centrality of left cerebellum in IBS low somatization compared to both IBS high somatization and healthy controls; (3) higher centrality of the anterior insula in healthy controls compared to both IBS groups, and in IBS low compared to IBS high somatization. The altered structural covariance of prefrontal cortex and anterior insula in IBS high somatization implicates that prefrontal processes may be more important than insular in the neurobiological sensitization process associated with IBS high somatization.

British Society of Gastroenterology guidelines on the management of irritable bowel syndrome

Irritable bowel syndrome (IBS) remains one of the most common gastrointestinal disorders seen by clinicians in both primary and secondary care. Since publication of the last British Society of Gastroenterology (BSG) guideline in 2007, substantial advances have been made in understanding its complex pathophysiology, resulting in its re-classification as a disorder of gut-brain interaction, rather than a functional gastrointestinal disorder. Moreover, there has been a considerable amount of new evidence published concerning the diagnosis, investigation and management of IBS. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based management of patients. One of the strengths of this guideline is that the recommendations for treatment are based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of trial-based and network meta-analyses assessing the efficacy of dietary, pharmacological and psychological therapies in treating IBS. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system, summarising both the strength of the recommendations and the overall quality of evidence. Finally, this guideline identifies novel treatments that are in development, as well as highlighting areas of unmet need for future research.

Impact of Psychological Comorbidity on the Prognosis of Irritable Bowel Syndrome

INTRODUCTION

Psychological comorbidities are associated with irritable bowel syndrome (IBS), but little is known about their cumulative effect on its prognosis. We examined this issue in a longitudinal 12-month follow-up study.

METHODS

We collected complete demographic, symptom, and psychological comorbidity data (anxiety, depression, somatic symptom disorder, perceived stress, and gastrointestinal symptom-specific anxiety) at baseline from 807 adults who met Rome IV criteria for IBS. At 12 months, we collected data regarding IBS symptom severity and impact, consultation behavior, and treatments commenced from 452 individuals successfully followed up. We examined the cumulative effects of psychological comorbidities at baseline on subsequent IBS disease behavior.

RESULTS

At baseline, among the 807 participants, 177 (21.9%) had 1, 139 (17.2%) 2, 103 (12.8%) 3, 89 (11.0%) 4, and 54 (6.7%) 5 psychological comorbidities. IBS symptom severity at baseline increased significantly with the number of psychological comorbidities (72.2% of those with 5 psychological comorbidities reported severe symptoms, vs 29.1% of those with none, P < 0.001). Among 452 (56.0%) participants followed up at 12 months, those with a higher number of psychological comorbidities at baseline were significantly more likely to have seen a gastroenterologist (33.3% of those with 5 psychological comorbidities, vs 21.4% of those with none, P = 0.001), cycle through more treatments (P < 0.0001), to report more severe IBS symptoms (66.7% with 5, vs 24.4% with none, P < 0.001) and continuous abdominal pain (22.1% with none, vs 61.9% with 5, P < 0.001), and to report that symptoms impacted on daily activities ≥50% of the time (90.5% with 5, vs 41.2% with none, P < 0.001).

DISCUSSION

The prognosis of individuals with Rome IV-defined IBS worsens according to incremental increases in psychological comorbidity. This has important clinical and research implications.

Comparison of the Rome IV criteria with the Rome III criteria for the diagnosis of irritable bowel syndrome in secondary care

OBJECTIVES

Despite being proposed 4 years ago, there has been no independent validation study of the Rome IV criteria for IBS. We assessed their performance for the diagnosis of IBS in secondary care and compared them with the previous iteration, the Rome III criteria.

DESIGN

We collected complete symptom data from consecutive adult patients with suspected IBS referred to a single UK clinic. All subjects underwent relatively standardised workup, with assessors blinded to symptom status. The reference standard used to confirm IBS was the presence of lower abdominal pain or discomfort in association with altered stool form or frequency, in a patient with no evidence of organic gastrointestinal disease after investigation. Sensitivity, specificity and positive and negative likelihood ratios (LRs), with 95% CIs, were calculated for each of the diagnostic criteria.

RESULTS

The level of agreement between the Rome IV and Rome III criteria was good (kappa=0.65). Compared with the reference standard, sensitivity and specificity of the Rome IV criteria in 572 patients (431 (75.3%) women, mean age 36.5 years) were 82.4% and 82.9%, respectively. Positive and negative LRs for the Rome IV criteria were 4.82 (95% CI 3.30 to 7.28) and 0.21 (95% CI 0.17 to 0.26), respectively. The Rome IV criteria performed best in those with IBS with constipation or mixed bowel habits. In 471 patients (350 (74.3%) women, mean age 36.7 years), compared with the reference standard, the sensitivity and specificity of the Rome III criteria were 85.8% and 65.0%; positive and negative LRs were 2.45 (95% CI 1.90 to 3.27) and 0.22 (0.16 to 0.29), respectively. Incorporating mood and extraintestinal symptom reporting into diagnostic criteria did not improve their performance significantly.

CONCLUSIONS

The Rome IV criteria performed significantly better than the Rome III criteria in diagnosing IBS in this single centre secondary care study, although the clinical relevance of this is uncertain.

Psychological comorbidity in gastrointestinal diseases: Update on the brain-gut-microbiome axis

The high comorbidity of psychological disorders in both functional and organic gastrointestinal diseases suggests the intimate and complex link between the brain and the gut. Termed the brain-gut axis, this bidirectional communication between the central nervous system and enteric nervous system relies on immune, endocrine, neural, and metabolic pathways. There is increasing evidence that the gut microbiome is a key part of this system, and dysregulation of the brain-gut-microbiome axis (BGMA) has been implicated in disorders of brain-gut interaction, including irritable bowel syndrome, and in neuropsychiatric disorders, including depression, Alzheimer's disease, and autism spectrum disorder. Further, alterations in the gut microbiome have been implicated in the pathogenesis of organic gastrointestinal diseases, including inflammatory bowel disease. The BGMA is an attractive therapeutic target, as using prebiotics, probiotics, or postbiotics to modify the gut microbiome or mimic gut microbial signals could provide novel treatment options to address these debilitating diseases. However, despite significant advancements in our understanding of the BGMA, clinical data is lacking. In this article, we will review current understanding of the comorbidity of gastrointestinal diseases and psychological disorders. We will also review the current evidence supporting the key role of the BGMA in this pathology. Finally, we will discuss the clinical implications of the BGMA in the evaluation and management of psychological and gastrointestinal disorders.

Cumulative Effect of Psychological Alterations on Gastrointestinal Symptom Severity in Irritable Bowel Syndrome

INTRODUCTION

Psychological alterations are common and considered important for symptom generation in irritable bowel syndrome (IBS). However, the possible cumulative effect of having multiple psychological alterations on gastrointestinal (GI) symptom severity in IBS is largely unknown.

METHODS

Patients with IBS (Rome IV) completed validated questionnaires assessing GI symptoms (Gastrointestinal Symptom Rating Scale, IBS version and IBS Severity Scoring System), personality traits (Big Five), posttraumatic stress and psychological alterations, anxiety (Generalized Anxiety Disorder 7-item scale and State-Trait Anxiety Inventory), depression (Patient Health Questionnaire, 9-item version), fatigue (Multidimensional Fatigue Inventory), pain catastrophizing, somatization (Patient Health Questionnaire, 12-item version), stress (Perceived Stress Scale), and GI-specific anxiety (Visceral Sensitivity Index). Of the 18 possible psychological factors, those with significant associations with GI symptom severity, corrected for multiple comparisons, were identified. The associations between increasing number of psychological alterations (validated cutoff values or uppermost tertile) and the severity of GI symptoms were analyzed with linear trend analyses.

RESULTS

In total, 106 patients with IBS (Rome IV criteria) were included (72 [68%] women, median age of 35 [interquartile range: 26-45] years). Psychological alterations were common and overlap among these factors were frequently seen. Five psychological factors (physical fatigue, GI-specific anxiety, perceived stress, pain catastrophizing, and trait anxiety) demonstrated significant, noncollinear associations with GI symptom severity. With increasing number of these psychological alterations, a gradual increase was seen in the overall severity of GI symptoms (Gastrointestinal Symptom Rating Scale, IBS version: partial η = 0.268, P < 0.001; IBS Severity Scoring System: partial η = 0.219, P < 0.001, both large effect sizes).

DISCUSSION

Distinct associations were seen between the severity of GI symptoms and individual, as well as an increasing number of psychological alterations. This highlights the importance of understanding different psychological alterations for the disease burden in IBS (visual abstract, Supplementary Digital Content 1, http://links.lww.com/AJG/B756).

Irritable bowel syndrome

Irritable bowel syndrome is a functional gastrointestinal disorder with symptoms including abdominal pain associated with a change in stool form or frequency. The condition affects between 5% and 10% of otherwise healthy individuals at any one point in time and, in most people, runs a relapsing and remitting course. The best described risk factor is acute enteric infection, but irritable bowel syndrome is also more common in people with psychological comorbidity and in young adult women than in the rest of the general population. The pathophysiology of irritable bowel syndrome is incompletely understood, but it is well established that there is disordered communication between the gut and the brain, leading to motility disturbances, visceral hypersensitivity, and altered CNS processing. Other less reproducible mechanisms might include genetic associations, alterations in gastrointestinal microbiota, and disturbances in mucosal and immune function. In most people, diagnosis can be made on the basis of clinical history with limited and judicious use of investigations, unless alarm symptoms such as weight loss or rectal bleeding are present, or there is a family history of inflammatory bowel disease or coeliac disease. Once the diagnosis is made, an empathetic approach is key and can improve quality of life and symptoms, and reduce health-care expenditure. The mainstays of treatment include patient education about the condition, dietary changes, soluble fibre, and antispasmodic drugs. Other treatments tend to be reserved for people with severe symptoms and include central neuromodulators, intestinal secretagogues, drugs acting on opioid or 5-HT receptors, or minimally absorbed antibiotics (all of which are selected according to predominant bowel habit), as well as psychological therapies. Increased understanding of the pathophysiology of irritable bowel syndrome in the past 10 years has led to a healthy pipeline of novel drugs in development.

Psychological profiles of irritable bowel syndrome patients with different phenotypes

BACKGROUND/AIMS

Abnormal psychological profiles are frequently found in patients with functional gastrointestinal disorders (FGIDs). The present study aimed to evaluate the psychological profiles of FGID patients with irritable bowel syndrome (IBS), and IBS phenotypes.

METHODS

In 608 FGID patients, including 235 with IBS, have filled a Rome III questionnaire and the French version of the Minnesota Multiphasic Personality Inventory 2. Data analysis was performed using univariate analysis and multivariate logistic regression.

RESULTS

This study shows that IBS patients have abnormal psychological profiles with more significant symptom exaggeration and decreased test defensiveness than non-IBS patients. They have a significantly higher score for all clinical scales. Logistic regression analysis showed in IBS patients a decrease of body mass index (P= 0.002), and test defensiveness score K (P= 0.001) and an increase of Hypochondriasis (P< 0.001) and Masculinity-Femininity scale (P= 0.018). By comparison with non-IBS patients, IBS-constipation, IBS-diarrhea, and mixed IBS patients have increased Hypochondriasis value and Depression score, mixed IBS patients have higher Psychasthenia score and higher Hypomania score. No item was significantly different in the IBS-unspecified group.

CONCLUSIONS

This study shows that IBS patients have different psychological profiles than other FGID patients and that psychological characteristics are associated with IBS phenotypes except for patients with unsubtyped IBS.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

None.

Irritable Bowel Syndrome: News from an Old Disorder

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, which can affect all members of a society, regardless of age, sex, race or socioeconomic status. Because of its high prevalence and chronic nature, it represents a significant economic burden. In fact, these patients have a relevant impairment of their quality of life, which limits their work productivity and daily social activities, especially when it is associated with other disorders, such as anxiety and depression. The diagnosis of IBS relies on symptom-based diagnostic criteria with normal results on a limited number of complementary tests that rule out other possible diagnoses. The aetiology of this condition is incompletely established. However, evidence suggests that it is a multifactorial disorder with several different mechanisms that have been implicated as responsible for the symptoms. Since the treatment strategy is usually based on predominant symptoms and their severity, it is important to recognise the underlying mechanisms in order to successfully relief the visceral pain and altered bowel habits. The aim of this non-systematic review of the literature was to explore the pathophysiology and treatment options of IBS, highlighting the most recent evidence, from the new Rome IV criteria to the new drug armamentarium.

Distinct associations of DSM-5 Somatic Symptom Disorder, the Diagnostic Criteria for Psychosomatic Research-Revised (DCPR-R) and symptom severity in patients with irritable bowel syndrome

OBJECTIVE

The clinical management of high symptom severity is a challenging task with patients with functional somatic disorders. We investigated the extent to which DCPR-revised (DCPR-R) syndromes and the DSM-5 category of Somatic Symptom Disorder (SSD) were able to predict symptom severity in 203 consecutive tertiary care patients with irritable bowel syndrome (IBS).

METHOD

Semistructured interview were used for assessing DCPR-R and validated scales for SSD (combining PHQ-12 and WI-7), severity of symptoms (IBS-SSS), psychological distress (HADS), and psychosocial functioning (SF-12).

RESULTS

Compared to moderate severity (IBS-SSS = 175-300), patients in the high range of severity (IBS-SSS > 300) had significantly more DCPR-R syndromes (particularly alexithymia and persistent somatization), higher psychological distress, and poorer psychosocial functioning, but showed no difference for SSD. DCPR-R, particularly alexithymia and persistent somatization, significantly and independently predicted IBS severity by explaining 18.5% of the IBS-SSS variance with large effect size (d = 1.18), after controlling for covariables. Conversely, SSD was not able to significantly predict IBS severity.

CONCLUSIONS

This study highlights the need of an integrative approach in the medical setting. Psychosomatic factors play a relevant role in the individual perception of symptom severity and should be carefully evaluated for clinical management of functional syndromes.

Patients with Multiple Functional Gastrointestinal Disorders (FGIDs) Show Increased Illness Severity: A Cross-Sectional Study in a Tertiary Care FGID Specialty Clinic

OBJECTIVES

Overlaps between different functional gastrointestinal disorders (FGIDs) are common. However, little is known about the impact of this overlap on patients' health status. This study is aimed at analyzing the differences between patients with multiple as compared to one single FGID.

METHODS

A retrospective, cross-sectional study was conducted with patients presenting to a tertiary care FGID specialty clinic between 06/2012 and 01/2015 (n = 294). They were characterized primarily according to their GI symptom severity (IBS-SSS) and secondarily to their physical as well as psychosocial symptom burden, quality of life, health care utilization, and work-related impairment. Differences between patients with >1 vs. 1 FGID were analyzed.

RESULTS

Of the 294 patients, 92.2% fulfilled the Rome III criteria for any FGID, and 48.0% had >1 FGIDs. FGID patients had a median age of 38 [23.0] years; 72.0% were female. Median GI symptom severity (IBS-SSS) scores were 339 [126] and 232 [163] in patients with >1 and 1 FGID, respectively (p < .001). Furthermore, patients with >1 FGIDs had higher general somatic symptom severity, higher illness anxiety, lower quality of life, and more work-related impairment. Almost no differences were found regarding their somatic as well as mental comorbidities.

CONCLUSIONS

Multiple FGIDs are associated with an increased risk for complicated courses of illness as reflected in higher GI and somatic symptom severity, as well as stronger psychosocial and diet- and work-related impairment. Stepped and interdisciplinary models of care including psychosocial expertise and dietary advice are needed, especially for patients with multiple FGIDs.

Anxiety and depression in irritable bowel syndrome: Exploring the interaction with other symptoms and pathophysiology using multivariate analyses

BACKGROUND

Anxiety or depression, in other words, psychological distress, are common comorbidities in patients with irritable bowel syndrome (IBS), but their interaction with pathophysiological factors and other symptoms are unclear.

METHODS

Patients with IBS (Rome III criteria), thoroughly characterized regarding pathophysiology (colonic transit time, visceral sensitivity, and autonomic nervous system [ANS] function), symptom profile (IBS severity, somatic symptoms, gastrointestinal [GI]-specific anxiety and fatigue), and quality of life, were explored for differences regarding pathophysiology and symptoms between patients with and without reported psychological distress in univariate and multivariate analyses (Principal Component Analysis [PCA] with Hotelling's T² and Orthogonal Partial Least Squares-Discriminant Analysis [OPLS-DA]).

KEY RESULTS

When using Hospital Anxiety and Depression Scale score ≥8 as cut-off score, including both borderline and clinically significant cases, 345 (44.9%) out of 769 IBS patients reported anxiety, and 198 (25.7%) depression. In univariate analyses, patients reporting psychological distress demonstrated more severe GI and non-GI symptoms, fatigue, GI-specific anxiety and lower quality of life, and differences for some pathophysiological measures. IBS patients with and without reported psychological distress showed significant differences between the multivariate means in symptom reporting (PCA; both P < 0.001), and in pathophysiological measures in patients with and without anxiety (P = 0.018). Visceral hypersensitivity, altered ANS function, more severe GI-specific anxiety, fatigue, and higher somatic non-GI symptoms were the factors that most strongly separated patients with and without psychological distress (OPLS-DA).

CONCLUSIONS AND INFERENCES

Reported anxiety and depression are common in IBS patients, and our study demonstrates that they are interwoven in the complex pathophysiological and clinical picture of IBS.

Systematic review with meta-analysis: the prevalence of anxiety and depression in patients with irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common and potential disabling functional gastrointestinal disorder. Studies have revealed a possible association between IBS and psychological problems, such as anxiety and depression. Existing systematic reviews have addressed only the levels of anxiety or depression in patients with IBS.

AIM

To investigate systematically the prevalence of anxiety or depression in IBS patients METHODS: A literature search was conducted using the related keywords from the bibliographic databases of Embase, PubMed, Scopus, Web of Science and POPLINE published until 1 January 2019 with no language restriction. Studies reporting the prevalence of anxiety/depressive symptoms/disorders in adult (≥15 years) IBS patients were evaluated. The pooled prevalence, odds ratio (OR) and 95% CI were calculated using stata software.

RESULTS

A total of 14 926 articles were initially screened, and finally 73 papers were included. The prevalence rates of anxiety symptoms and disorders in IBS patients were 39.1% (95% CI: 32.4-45.8) and 23% (95% CI: 17.2-28.8) respectively. The ORs for anxiety symptoms and disorders in IBS patients compared with healthy subjects were 3.11 (95% CI: 2.43-3.98) and 2.52 (95% CI: 1.99-3.20) respectively. The prevalence estimates of depressive symptoms and disorders in IBS patients were 28.8% (95% CI: 23.6-34) and 23.3% (95% CI: 17.2-29.4) respectively. The ORs for depressive symptoms and disorders in IBS patients compared to healthy subjects were 3.04 (95% CI: 2.37-3.91) and 2.72 (95% CI: 2.45-3.02) respectively.

CONCLUSION

Patients with IBS have a three-fold increased odds of either anxiety or depression, compared to healthy subjects.

The Microbiome and Irritable Bowel Syndrome - A Review on the Pathophysiology, Current Research and Future Therapy

Irritable bowel syndrome (IBS) is a functional disorder which affects a large proportion of the population globally. The precise etiology of IBS is still unknown, although consensus understanding proposes IBS to be of multifactorial origin with yet undefined subtypes. Genetic and epigenetic factors, stress-related nervous and endocrine systems, immune dysregulation and the brain-gut axis seem to be contributing factors that predispose individuals to IBS. In addition to food hypersensitivity, toxins and adverse life events, chronic infections and dysbiotic gut microbiota have been suggested to trigger IBS symptoms in tandem with the predisposing factors. This review will summarize the pathophysiology of IBS and the role of gut microbiota in relation to IBS. Current methodologies for microbiome studies in IBS such as genome sequencing, metagenomics, culturomics and animal models will be discussed. The myriad of therapy options such as immunoglobulins (immune-based therapy), probiotics and prebiotics, dietary modifications including FODMAP restriction diet and gluten-free diet, as well as fecal transplantation will be reviewed. Finally this review will highlight future directions in IBS therapy research, including identification of new molecular targets, application of 3-D gut model, gut-on-a-chip and personalized therapy.

Health problems associated with irritable bowel syndrome: analysis of a primary care registry

BACKGROUND

Associations between irritable bowel syndrome and other health problems have been described, but comprehensive reports are missing, especially in primary care.

AIMS

To investigate which health problems are associated with irritable bowel syndrome, how they cluster together and when they are typically diagnosed relative to irritable bowel syndrome.

METHODS

We used Intego, a general practice registry in Flanders, Belgium. Patients with an irritable bowel syndrome diagnosis (n = 13 701) were matched with controls without gastrointestinal diagnosis and controls with organic gastrointestinal disease. Long-term prevalences of 680 symptoms and diagnoses were compared between patients and controls. Results were summarised using functional enrichment analysis and visualised in a network and we calculated incidence rate ratios in the 10 years before and after the irritable bowel syndrome diagnosis for the network's key components.

RESULTS

Various symptoms and infections, but not neoplasms, were enriched in irritable bowel syndrome patients compared to both control groups. We characterised the comorbidities of irritable bowel syndrome as psychosocial health problems, urogenital symptoms and infections, musculoskeletal symptoms and other somatic symptoms. These had a uniform incidence in the years around the irritable bowel syndrome diagnosis, and did not structurally precede or follow irritable bowel syndrome.

CONCLUSIONS

Irritable bowel syndrome shares long-term associations with psychosocial health problems, urogenital symptoms and infections, musculoskeletal symptoms and other somatic symptoms in primary care. Clinicians are encouraged to take comorbidities into account when diagnosing and managing irritable bowel syndrome, as this may have important treatment implications.

Pathophysiology of Functional Gastrointestinal Disorders: A Holistic Overview

Background and Summary: Traditionally, functional gastrointestinal disorders (FGID), including functional dyspepsia or irritable bowel syndrome (IBS), are defined by more or less specific symptoms and the absence of structural or biochemical abnormalities that cause these symptoms. This concept is now considered to be outdated; if appropriate tests are applied, structural or biochemical abnormalities that explain or cause the symptoms may be found in many patients. Another feature of FGID are the highly prevalent psychiatric comorbidities, such as depression and anxiety. It is implied that mood disorders "cause" gastrointestinal symptoms. In fact, epidemiological data now provide strong evidence that in subsets of cases, gastrointestinal (GI) symptoms arise first and mood disorders occur later, while in other patients the reverse appears to happen. Possible mechanisms for gut-brain dysfunction have been identified, with systemic minimal inflammation as a causal factor in at least some subjects. Other mechanisms that play a role in FGID include chronic infections, intestinal microbiota, low-grade mucosal inflammation including the increase of eosinophils, systemic immune activation, altered intestinal permeability, in diarrhea predominant IBS altered bile salt metabolism, abnormalities in the serotonin metabolism and genetic factors. All these factors might be modulated by environmental factors such as diet. Key Messages: While a number of factors can be linked to specific symptoms (e.g., pain or diarrhea), it is evident that the symptom-based categorization of patients will not allow targeted treatments that specifically address the underlying pathophysiology.

The Prevalence and Impact of Overlapping Rome IV-Diagnosed Functional Gastrointestinal Disorders on Somatization, Quality of Life, and Healthcare Utilization: A Cross-Sectional General Population Study in Three Countries

OBJECTIVES

The population prevalence of Rome IV-diagnosed functional gastrointestinal disorders (FGIDs) and their cumulative effect on health impairment is unknown.

METHODS

An internet-based cross-sectional health survey was completed by 5,931 of 6,300 general population adults from three English-speaking countries (2100 each from USA, Canada, and UK). Quota-based sampling was used to generate demographically balanced and population representative samples with regards to age, sex, and education level. The survey enquired for demographics, medication, surgical history, somatization, quality of life (QOL), doctor-diagnosed organic GI disease, and criteria for the Rome IV FGIDs. Comparisons were made between those with Rome IV-diagnosed FGIDs against non-GI (healthy) and organic GI disease controls.

RESULTS

The number of subjects having symptoms compatible with a FGID was 2,083 (35%) compared with 3,421 (57.7%) non-GI and 427 (7.2%) organic GI disease controls. The most frequently met diagnostic criteria for FGIDs was bowel disorders (n=1,665, 28.1%), followed by gastroduodenal (n=627, 10.6%), anorectal (n=440, 7.4%), esophageal (n=414, 7%), and gallbladder disorders (n=10, 0.2%). On average, the 2,083 individuals who met FGID criteria qualified for 1.5 FGID diagnoses, and 742 of them (36%) qualified for FGID diagnoses in more than one anatomic region. The presence of FGIDs in multiple regions was associated with increasing somatization, worse mental/physical QOL, more medical therapies, and a higher prevalence of abdominal surgeries; all P<0.001. Notably, individuals with FGIDs in multiple regions had greater somatization and worse QOL than organic GI disease controls.

CONCLUSIONS

Roughly a third of the general adult population fulfils diagnostic criteria for a Rome IV FGID. In a third of this subset multiple GI regions are involved and this overlap is associated with increased health impairment.

The role of incongruence between the perceived functioning by patients and clinicians in the detection of psychological distress among functional and motor digestive disorders

OBJECTIVES

Previous research on gastrointestinal and other medical conditions has shown the presence of incongruence between self- and clinician-reported functioning and its relation with psychopathology. The main objective of this study was to test whether inconsistencies between clinician- and self-assessed functionality can be used to detect psychopathology among patients diagnosed of motor or functional gastrointestinal disorders.

METHODS

One hundred and three patients from a gastroenterology inpatient unit were included in this study. All patients underwent clinical assessment, including intestinal manometry, Rome III criteria for functional gastrointestinal disorders, and psychological and psychiatric evaluation. Patients with suspected gastroparesis underwent a scintigraphic gastric emptying test. Definitive diagnoses were made at discharge.

RESULTS

Patients with higher levels of incongruence differed in various sociodemographic (age, educational level, work activity and having children) and psychopathological (all SCL-90-R subscales except anxiety and hostility) characteristics. Using general lineal models, incongruence was found to be the variable with stronger relations with psychopathology even when controlling for diagnosis. Interactions were found between incongruence and diagnosis reflecting a pattern in which patients with functional disorders whose subjective evaluation of functioning is not congruent with that of the clinician, have higher levels of psychopathology than patients with motor disorders.

CONCLUSIONS

Incongruence between clinician and self-reported functionality seems to be related to higher levels of psychopathology in patients with functional disorders. These findings underscore the need for routine psychosocial assessment among these patients. Gastroenterologists could use the concept of incongruence and its clinical implications, as a screening tool for psychopathology, facilitating consultation-liaison processes.

Irritable Bowel Syndrome

: Irritable bowel syndrome (IBS) is a common, chronic gastrointestinal (GI) condition characterized by disturbances in bowel habits and abdominal pain in the absence of known organic pathology. IBS reduces quality of life and is costly to treat. It is diagnosed using the symptom-based Rome criteria for functional GI disorders, which was recently updated and released as Rome IV. Both physiologic and psychological variables play a role in the etiology of IBS and perpetuate symptoms. Although research has shed light on IBS pathophysiology, therapeutic interventions remain symptom driven, employing both pharmacologic and nonpharmacologic approaches. Here, the authors review the epidemiology and pathophysiology of IBS, summarize diagnostic and treatment strategies, and discuss implications for nursing practice.

Editorial: latent class analysis to improve confidence in the diagnosis of IBS

Linked Content

This article is linked to Sood et al papers. To view these articles visit https://doi.org/10.1111/apt.14012 and https://doi.org/10.1111/apt.13949.

Early response predicts a sustained response to eluxadoline in patients with irritable bowel syndrome with diarrhoea in two Phase 3 studies

BACKGROUND

The mixed μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist, eluxadoline, is licensed in the USA for the treatment of irritable bowel syndrome with diarrhoea (IBS-D), based on the results of two large Phase 3 clinical trials.

AIM

To understand the time course of treatment benefits with eluxadoline by comparing responder rates over the first month of treatment with responder rates over longer treatment intervals.

METHODS

In this post hoc analysis of two Phase 3 studies, composite and adequate relief (AR) responder rates were calculated over month 1 and patients were stratified by their responder status. Cumulative counts over subsequent intervals (months 1-3, months 1-6, months 2 through 6) were tallied.

RESULTS

The studies randomised 2428 patients. Over month 1, 24.6%, 22.8% and 12.5% of patients were composite responders with eluxadoline 100 mg, eluxadoline 75 mg and placebo respectively. For month 1 responders, 77.8% and 81.5% (over months 1-3) and 70.7% and 73.9% (over months 1-6) showed a continuous response with eluxadoline 100 mg and 75 mg respectively. [Correction added on 5 April 2017, after first online publication: The percentage for the responders over months 1-3 was previously wrong and has been corrected.] Of the month 1 nonresponders, <20% showed a response over months 1-3 or months 1-6. Similar results were seen for the analysis of proportions of AR responders over these time intervals.

CONCLUSIONS

Over two-thirds of patients who respond over the first month retain a positive response over 6 months of treatment with eluxadoline, indicating that early clinical response to eluxadoline is associated with sustained benefits for up to 6 months in patients with IBS-D.

Derivation and validation of a diagnostic test for irritable bowel syndrome using latent class analysis

BACKGROUND

The accuracy of symptom-based diagnostic criteria for irritable bowel syndrome (IBS) is modest.

AIMS

To derive and validate a new test that utilises latent class analysis.

METHODS

Symptom, colonoscopy, and histology data were collected from 1981 patients and 360 patients in two cohorts referred to secondary care for investigation of their gastrointestinal symptoms in Canada and the UK, respectively. Latent class analysis was used to identify naturally occurring clusters in patient-reported symptoms in the Canadian dataset, and the latent class model derived from this was then applied to the UK dataset in order to validate it. Sensitivity, specificity, and positive and negative likelihood ratios (LRs) were calculated for the latent class models.

RESULTS

In the Canadian cohort, the model had a sensitivity of 44.7% (95% CI 40.0-50.0) and a specificity of 85.3% (95% CI 83.4-87.0). Positive and negative LRs were 3.03 (95% CI 2.57-3.56) and 0.65 (95% CI 0.59-0.71) respectively. A maximum positive LR of 3.93 was achieved following construction of a receiver operating characteristic curve. The performance in the UK cohort was similar, with a sensitivity and specificity of 52.5% (95% CI 42.2-62.7) and 84.3% (95% CI 79.3-88.6), respectively. Positive and negative LRs were 3.35 (95% CI 2.38-4.70) and 0.56 (95% CI 0.45-0.68), respectively, with a maximum positive LR of 4.15.

CONCLUSIONS

A diagnostic test for IBS, utilising patient-reported symptoms incorporated into a latent class model, performs as accurately as symptom-based criteria. It has potential for improvement via addition of clinical markers, such as coeliac serology and faecal calprotectin.