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

Global trends in research on irritable bowel syndrome and the brain–gut axis: Bibliometrics and visualization analysis

Irritable bowel syndrome (IBS) is a gastrointestinal disorder with no structural damage, and its pathogenesis remains unclear. Studies have shown that the brain–gut axis is closely related to the occurrence of IBS. However, studies of IBS related to the brain–gut axis have not been systematically analyzed by bibliometrics and visual analysis. This study is based on 631 publications in the Web of Science Core Collection (WoSCC) to analyze hot spots and trends in this field. The collaborations between different authors, institutions, countries, and keywords were bibliometrically analyzed by CiteSpace software. Meanwhile, VOSviewer analyzed the references. The results show that since 2012, the number of publications has been growing rapidly. According to the collaborative network analysis, the United States, the National University of Ireland, Cork, and J.F. Cryan are the countries, institutions, and authors contributing the most, respectively. Through keywords and literature analysis, mechanisms and therapy associated with IBS and the brain–gut axis have still been a research focus in recent years. Furthermore, the physiological and pathological mechanisms of the brain–gut axis influencing IBS (related to gastrointestinal dysfunction, vagus nerve, visceral pain, intestinal flora, serotonin, tryptophan metabolism, stress, brain-derived neurotrophic factor (BDNF), and malonyldialdehyde) are the future research trends, especially the mechanisms related to intestinal flora. This is the first bibliometric and visualization analysis of IBS and brain–gut axis-related literature to explore research hotspots and trends.

Impact of Rome IV irritable bowel syndrome on work and activities of daily living

BACKGROUND

Few studies have demonstrated the impact of irritable bowel syndrome (IBS) on work and activities of daily living.

METHODS

We collected demographic, gastrointestinal symptom, psychological health and quality of life data from 752 adults with Rome IV-defined IBS. We used the work productivity and activity impairment questionnaire for irritable bowel syndrome and the work and social adjustment scale to examine the degree of both impairment at work and in activities of daily living, as well as factors associated with these.

RESULTS

Of 467 individuals who were employed, 133 (28.5%) reported absenteeism, 373 (85.6%) presenteeism and 382 (81.8%) overall work impairment. A mean of 1.97 hours of work per week was lost due to IBS. Extrapolating this across the entire UK, we estimate that between 72 and 188 million hours of work are lost per year due to IBS in individuals of working age. Among all 752 participants, 684 (91.0%) reported any activity impairment with 220 (29.3%) reporting impairment in home management, 423 (56.3%) in social leisure activities, 207 (27.5%) in private leisure activities, and 203 (27.0%) in maintaining close relationships. Severe IBS, higher levels of anxiety, depression, somatization and gastrointestinal symptom-specific anxiety, and lower levels of IBS-related quality of life were associated with impairment in both work and activities of daily living.

CONCLUSION

Patients with IBS experience a substantial impact on their work and activities of daily living because of their IBS. Future studies should assess the impact of medical interventions on the ability to work and participate in social activities.

British Society of Gastroenterology guidelines on the management of functional dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, affecting approximately 7% of individuals in the community, with most patients managed in primary care. The last British Society of Gastroenterology (BSG) guideline for the management of dyspepsia was published in 1996. In the interim, substantial advances have been made in understanding the complex pathophysiology of FD, and there has been a considerable amount of new evidence published concerning its diagnosis and classification, with the advent of the Rome IV criteria, and management. 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 diagnosis and treatment of patients. The approach to investigating the patient presenting with dyspepsia is discussed, and efficacy of drugs in FD summarised based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of pairwise and network meta-analyses. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system. These provide both the strength of the recommendations and the overall quality of evidence. Finally, in this guideline, we consider novel treatments that are in development, as well as highlighting areas of unmet need and priorities for future research.

Transcutaneous Electrical Acustimulation Improves Irritable Bowel Syndrome With Constipation by Accelerating Colon Transit and Reducing Rectal Sensation Using Autonomic Mechanisms

INTRODUCTION

Slow colon transit and visceral hypersensitivity are recognized as major pathophysiological mechanisms in irritable bowel syndrome with constipation (IBS-C). However, there is a lack of therapies targeting both abdominal pain and colonic motility. This study was designed to investigate the long-term effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) in patients with IBS-C.

METHODS

Fifty-two patients with IBS-C were randomized into 2 groups: daily TEA for 4 weeks (n = 26) and daily sham-TEA for 4 weeks (n = 26). The number of complete spontaneous bowel movements per week (CSBMs/week, primary outcome), Irritable Bowel Syndrome Severity Scoring System, Patient Assessment of Constipation Quality of Life, visual analog scale (VAS) pain score, colonic transit time, and anorectal physiology were evaluated before treatment and at the end of the treatment. Colonic transit was assessed with radiopaque markers. Electrocardiograms were recorded for assessing autonomic functions.

RESULTS

(i) TEA improved constipation and abdominal pain. After the treatment, the number of CSBMs/week during the last week in the TEA group was higher than that in the sham-TEA group (3.5 ± 1.6 vs 2.3 ± 0.6, P = 0.002). Similar effects were also noted in the visual analog scale pain score ( P = 0.002) and Irritable Bowel Syndrome Severity Scoring System score ( P = 0.025). In addition, there was a significant improvement in the quality of life of patients with constipation. The Patient Assessment of Constipation Quality of Life total score was significantly decreased in the TEA group ( P = 0.004). (ii) Compared with sham-TEA, TEA improved colon transit ( P = 0.002) and increased the threshold of rectal sensation (desire to defecate, P = 0.004; maximum tolerability, P < 0.001). (iii) TEA increased vagal activity, compared with sham-TEA ( P < 0.05); at the end of the treatment, the vagal activity was significantly correlated with colon transit and the CSBMs/week.

DISCUSSION

TEA improves constipation and symptoms of IBS by accelerating colon transit and reducing rectal sensation, possibly mediated by using the autonomic mechanisms.

Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction, with a complex pathophysiology. Antispasmodics are prescribed as first-line therapy because of their action on gut dysmotility. In this regard, peppermint oil also has antispasmodic properties.

AIM

To update our previous meta-analysis to assess efficacy and safety of peppermint oil, particularly as recent studies have cast doubt on its role in the treatment of IBS METHODS: We searched the medical literature up to 2nd April 2022 to identify randomised controlled trials (RCTs) of peppermint oil in IBS. Efficacy and safety were judged using dichotomous assessments of effect on global IBS symptoms or abdominal pain, and occurrence of any adverse event or of gastro-oesophageal reflux. Data were pooled using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified 10 eligible RCTs (1030 patients). Peppermint oil was more efficacious than placebo for global IBS symptoms (RR of not improving = 0.65; 95% CI 0.43-0.98, number needed to treat [NNT] = 4; 95% CI 2.5-71), and abdominal pain (RR of abdominal pain not improving = 0.76; 95% CI 0.62-0.93, NNT = 7; 95% CI 4-24). Adverse event rates were significantly higher with peppermint oil (RR of any adverse event = 1.57; 95% CI 1.04-2.37).

CONCLUSIONS

Peppermint oil was superior to placebo for the treatment of IBS, but adverse events were more frequent, and quality of evidence was very low. Adequately powered RCTs of peppermint oil as first-line treatment for IBS are needed.

Probiotics in the Management of Mental and Gastrointestinal Post-COVID Symptomes

Patients with “post-COVID” syndrome manifest with a variety of signs and symptoms that continue/develop after acute COVID-19. Among the most common are gastrointestinal (GI) and mental symptoms. The reason for symptom occurrence lies in the SARS-CoV-2 capability of binding to exact receptors, among other angiotensin converting enzyme 2 (ACE2) receptors in gastrointestinal lining and neuropilin-1 (NRP-1) in the nervous system, which leads to loss of gastrointestinal and blood-brain barriers integrity and function. The data are mounting that SARS-CoV-2 can trigger systemic inflammation and lead to disruption of gut-brain axis (GBA) and the development of disorders of gut brain interaction (DGBIs). Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are the most common DGBIs syndromes. On the other hand, emotional disorders have also been demonstrated as DGBIs. Currently, there are no official recommendations or recommended procedures for the use of probiotics in patients with COVID-19. However, it can be assumed that many doctors, pharmacists, and patients will want to use a probiotic in the treatment of this disease. In such cases, strains with documented activity should be used. There is a constant need to plan and conduct new trials on the role of probiotics and verify their clinical efficacy for counteracting the negative consequences of COVID-19 pandemic. Quality control is another important but often neglected aspect in trials utilizing probiotics in various clinical entities. It determines the safety and efficacy of probiotics, which is of utmost importance in patients with post-acute COVID-19 syndrome.

Gut Non-Bacterial Microbiota: Emerging Link to Irritable Bowel Syndrome

As a common functional gastrointestinal disorder, irritable bowel syndrome (IBS) significantly affects personal health and imposes a substantial economic burden on society, but the current understanding of its occurrence and treatment is still inadequate. Emerging evidence suggests that IBS is associated with gut microbial dysbiosis, but most studies focus on the bacteria and neglect other communities of the microbiota, including fungi, viruses, archaea, and other parasitic microorganisms. This review summarizes the latest findings that link the nonbacterial microbiota with IBS. IBS patients show less fungal and viral diversity but some alterations in mycobiome, virome, and archaeome, such as an increased abundance of Candida albicans. Moreover, fungi and methanogens can aid in diagnosis. Fungi are related to distinct IBS symptoms and induce immune responses, intestinal barrier disruption, and visceral hypersensitivity via specific receptors, cells, and metabolites. Novel therapeutic methods for IBS include fungicides, inhibitors targeting fungal pathogenic pathways, probiotic fungi, prebiotics, and fecal microbiota transplantation. Additionally, viruses, methanogens, and parasitic microorganisms are also involved in the pathophysiology and treatment. Therefore, the gut nonbacterial microbiota is involved in the pathogenesis of IBS, which provides a novel perspective on the noninvasive diagnosis and precise treatment of this disease.

Modulating the gut microenvironment as a treatment strategy for irritable bowel syndrome: a narrative review

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction with a complex pathophysiology. Growing evidence suggests that alterations of the gut microenvironment, including microbiota composition and function, may be involved in symptom generation. Therefore, attempts to modulate the gut microenvironment have provided promising results as an indirect approach for IBS management. Antibiotics, probiotics, prebiotics, food and faecal microbiota transplantation are the main strategies for alleviating IBS symptom severity by modulating gut microbiota composition and function (eg. metabolism), gut barrier integrity and immune activity, although with varying efficacy. In this narrative review, we aim to provide an overview of the current approaches targeting the gut microenvironment in order to indirectly manage IBS symptoms.

Effect of a Multistrain Probiotic on Leaky Gut in Patients with Diarrhea-Predominant Irritable Bowel Syndrome: A Pilot Study

BACKGROUND

A probiotic mixture prevented epithelial barrier impairment in various experimental models. The objective was to evaluate its effects in patients suffering from IBS with diarrhea (IBS-D) with confirmed leaky gut.

METHODS

IBS-D patients with increased intestinal permeability measured by radionuclide tracers were enrolled in this pilot, open-label, prospective, interventional, single-center, Phase IV study. Patients received two capsules of a multistrain probiotic a day for 30 days and were evaluated by repeated intestinal permeability tests, the Bristol Stool Scale, and patient-perceived quality of life and satisfaction.

RESULTS

Of the 30 enrolled patients (mean age: 42.1 [SD: 13.1] years; female: 60%), 27 completed the study (full analysis set [FAS]), and 18 had no major protocol violation (per protocol set [PPS]). On D30, an improvement of intestinal permeability was observed in 81.5% of patients in FAS, normalization being observed in 37% of the participants (44% in PPS). The mean intestinal permeability was significantly decreased: baseline minus D30, 3.4 (95% CI: 1.7, 5.2); the IBS-QOL total score was significantly increased: D30 minus baseline, 8.0 (95% CI: 3.0, 12.9); and stool consistency was significantly improved. On D15 and D30, 96.3% of patients claimed that their IBS symptoms had been satisfactory alleviated, and a significant improvement was reported for the following VAS-IBS items: abdominal pain, diarrhea, and impact of gastrointestinal problems in daily life. Compliance and tolerance were satisfactory.

CONCLUSION

The multistrain probiotic tested may reduce intestinal permeability in a considerable proportion of patients and may improve abdominal pain, stool consistency, and quality of life. These results pave the way for larger, placebo-controlled clinical studies.

Efficacy of an Irritable Bowel Syndrome Diet in the Treatment of Small Intestinal Bacterial Overgrowth: A Narrative Review

Small intestinal bacterial overgrowth (SIBO) is highly prevalent in irritable bowel syndrome (IBS). The eradication of bacterial overgrowth with antibiotics is the first-line treatment. However, focusing only on the antimicrobial effects without taking care to improve lifestyle factors, especially dietary patterns, may predispose patients to intestinal microbiota dysfunction. The objective of this study is to determine whether the current recommendations regarding nutrition in IBS are suitable for patients with SIBO. A narrative literature review was carried out using databases, including PubMed, ScienceDirect and Google Scholar. Recent studies indicate that dietary manipulation may have a role in alleviating SIBO gastrointestinal symptoms. A low FODMAP diet proposed for IBS may promote a negative shift in the gut microbiota and deepen the existing state of dysbiosis in SIBO patients. Supplementation with soluble fiber can lessen the symptoms in IBS and SIBO. Targeted probiotic therapy may also increase the effectiveness of antibiotic treatment and regulate bowel movements. Therefore, optimal dietary patterns play a key role in the treatment of SIBO. Based on currently available literature, the potential efficacy of the IBS diet in SIBO is largely hypothetical. Future research is needed to characterize a specific diet for the treatment of SIBO.

Alleviating insomnia should decrease the risk of irritable bowel syndrome: Evidence from Mendelian randomization

Background: Associations have been reported between sleep and irritable bowel syndrome (IBS). However, whether there exists a causation between them is still unknown.

Methods: We employed the Mendelian randomization (MR) design to explore the causal relationship between sleep and IBS. All genetic associations with sleep-related traits reached genome-wide significance (p-value < 5 × 10-8). The genetic associations with IBS were obtained from two independent large genome-wide association studies (GWAS), where non-FinnGen GWAS was in the discovery stage and FinnGen GWAS was in the validation stage. Primarily, the inverse-variance weighted method was employed to estimate the causal effects, and a meta-analysis was performed to combine the MR estimates.

Results: In the discovery, we observed that genetic liability to the “morning” chronotype could lower the risk of IBS [OR = 0.81 (0.76, 0.86)]. Also, the genetic liability to insomnia can increase the risk of IBS [OR = 2.86 (1.94, 4.23)] and such causation was supported by short sleep duration. In the validation stage, only insomnia displayed statistical significance [OR = 2.22 (1.09, 4.51)]. The meta-analysis suggested two genetically-determined sleep exposures can increase the risk of IBS, including insomnia [OR = 2.70 (1.92, 3.80)] and short sleep duration [OR = 2.46 (1.25, 4.86)]. Furthermore, the multivariable MR analysis suggested insomnia is an independent risk factor for IBS after adjusting for chronotype [OR = 2.32 (1.57, 3.43)] and short sleep duration [OR = 1.45 (1.13, 1.85)]. IBS cannot increase the risk of insomnia in the reverse MR analysis.

Conclusion: Genetic susceptibility to insomnia can increase the risk of IBS, and improving sleep quality, especially targeting insomnia, can help to prevent IBS.

Update on gut microbiota in gastrointestinal diseases

The human gut is a complex microbial ecosystem comprising approximately 100 trillion microbes collectively known as the "gut microbiota". At a rough estimate, the human gut microbiome contains almost 3.3 million genes, which are about 150 times more than the total human genes present in the human genome. The vast amount of genetic information produces various enzymes and physiologically active substances. Thus, the gut microbiota contributes to the maintenance of host health; however, when healthy microbial composition is perturbed, a condition termed "dysbiosis", the altered gut microbiota can trigger the development of various gastrointestinal diseases. The gut microbiota has consequently become an extremely important research area in gastroenterology. It is also expected that the results of research into the gut microbiota will be applied to the prevention and treatment of human gastrointestinal diseases. A randomized controlled trial conducted by a Dutch research group in 2013 showed the positive effect of fecal microbiota transplantation (FMT) on recurrent Clostridioides difficile infection (CDI). These findings have led to the development of treatments targeting the gut microbiota, such as probiotics and FMT for inflammatory bowel diseases (IBD) and other diseases. This review focuses on the association of the gut microbiota with human gastrointestinal diseases, including CDI, IBD, and irritable bowel syndrome. We also summarize the therapeutic options for targeting the altered gut microbiota, such as probiotics and FMT.

Practical approach to irritable bowel syndrome-diarrhea beyond low-FODMAP diet

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain and altered defecation, usually accompanied by abdominal bloating or distension. The integrated model of bidirectional interaction between the central, autonomic, enteric nervous system, the microbiome, and the gut barrier allows a better understanding of the pathophysiology of IBS, as well as consideration of potential therapeutic strategies. IBS with predominant diarrhea (IBS-D) represents a therapeutic challenge. Dietary changes or restrictions are most commonly used by patients in an attempt at symptom control. Therefore, a number of diets, especially low-FODMAP diet, have increasingly gained interest as a therapy for IBS-D or mixed IBS. However, this kind of diet, while effective, is not exempt of problems. It is therefore necessary that other therapeutic options be considered while bearing pathophysiological mechanisms and general symptom management in mind.

The effect of self-management online modules plus nurse-led support on pain and quality of life among young adults with irritable bowel syndrome: A randomized controlled trial

BACKGROUND

Irritable bowel syndrome is a chronic pain condition that needs life-long self-management. However, the effect of self-management among young adults with irritable bowel syndrome is limited.

OBJECTIVES

This study aimed to examine the effect of a nurse-led self-management program on pain, symptoms, and quality of life among young adults with irritable bowel syndrome.

DESIGN

A randomized controlled trial.

SETTINGS AND PARTICIPANTS

Eighty young adults with irritable bowel syndrome recruited from two campuses of a public university and two gastrointestinal clinics were randomly assigned into a self-management online education and learning modules alone group (Online Modules, n = 41) or a nurse-led one-to-one consultation plus self-management online education and learning modules group (Nurse-Led Online Modules, n = 39). Twenty-one healthy controls were also recruited from these two campuses.

METHODS

Both the intervention groups received ten online modules after baseline data collection. Participants in the Nurse-Led Online Modules group received additional three nurse-led one-to-one consultations at baseline, 6- and 12-week follow-ups. Self-reported pain, symptoms, quality of life, self-efficacy for managing chronic disease, and coping were measured at baseline, and 6- and 12-week follow-ups among the participants with irritable bowel syndrome. The healthy controls completed data collection of pain and symptoms at baseline and the 12-week follow-up. The intervention effects across study time points and the comparisons between the two interventional groups were analyzed using linear mixed models. A longitudinal mediation analysis was also conducted to explore the mediation effects of self-management mechanisms of the interventions.

RESULTS

Both the intervention groups showed significant interventional effects on decreasing pain intensity and pain interference and increasing quality of life at the 12-week follow-up (all p < 0.05). At the 12-week follow-up, the Nurse-Led Online Modules significantly reduced anxiety (p = 0.016) and had a significant greater improvement in quality of life than the Online Modules (p = 0.040). Increased self-efficacy mediated the intervention effect of the Nurse-Led Online Modules group on reducing pain interference and improving quality of life, while the effect of the Online Modules was mediated through decreasing inefficient coping strategy-catastrophizing.

CONCLUSIONS

This study showed that both the pain self-management online education and nurse-led intervention were effective for alleviating pain and improving quality of life among young adults with irritable bowel syndrome by targeting the self-management process. The nurse-led intervention had a better outcome than the online education alone in improving quality of life.

REGISTRATION NUMBER

NCT03332537.

How to Implement the 3-Phase FODMAP Diet Into Gastroenterological Practice

BACKGROUND/AIMS

The 3-phase fermentable oligo-, di-, mono-saccharides, and polyols (FODMAP) diet has shown a high level of efficacy in irritable bowel syndrome, largely based on dietitian delivered education. However, access to dietitians can be limited, and challenges exist when applying the diet to a wide range of cultures, such as limited FODMAP analysis of local foods. This review aims to discuss ways to optimally use the FODMAP diet in practice in a wide range of cultures, directed at gastroenterologists from a dietitian's perspective.

METHODS

Recent literature was analysed via search databases including Medline, CINAHL, PubMed and Scopus.

RESULTS

The dietetic process involves detailed assessment and follow-up through the 3 stages of the FODMAP diet (restriction, re-introduction, and long-term maintenance). Emerging evidence suggests the diet can be delivered by other health professionals such as the gastroenterologist or nurse, but training on how to do so successfully would be needed. Self-guided approaches through use of technology or specialised food delivery services may be an alternative when dietitians are not available, but efficacy data is limited. Regardless of delivery mode, nutritional and psychological risks of the diet must be mitigated. Additionally, culturally appropriate education must be provided, with accommodations necessary when the FODMAP content of local foods are unknown.

CONCLUSION

While the diet has shown improved irritable bowel syndrome outcomes across studies, it is important to acknowledge the essential role of dietitians in implementing, tailoring, and managing the diet to achieve the best outcome for each individual.

Aetiology, diagnosis and management of small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth is a small bowel disorder characterised by excessive amounts of bacteria populating the small intestine leading to symptoms of abdominal pain, bloating and change in bowel habit. This creates some degree of diagnostic uncertainty due to the overlap of these symptoms with numerous other gastrointestinal conditions. Quantitative culture of jejunal aspirates is the gold standard diagnostic test but has largely been replaced by glucose and lactulose breath tests due to their relative ease and accessibility. The approach to treatment centres around reducing bacterial numbers through antibiotic therapy and managing any predisposing factors. Further research is required in order to define the optimum antibiotic choice and duration of therapy as well as the potential diagnostic utility of home breath testing and capsule-based technology.

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

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

Direct healthcare costs of Rome IV or Rome III-defined irritable bowel syndrome in the United Kingdom

BACKGROUND

Previous studies have demonstrated a substantial economic impact of irritable bowel syndrome (IBS).

AIMS

To provide contemporaneous estimates of direct healthcare costs of IBS in the United Kingdom.

METHODS

We collected demographic, gastrointestinal and psychological symptoms, quality of life and healthcare usage data from adults with Rome IV or Rome III IBS in the United Kingdom. We calculated the mean annual direct healthcare costs of IBS per person and used contemporaneous IBS prevalence data, together with census data, to estimate annual direct costs of IBS. We also examined predictors of higher costs.

RESULTS

The mean annual direct cost of IBS per person among 752 individuals with Rome IV IBS was £556.65 (SD £1023.92) and £474.16 (SD £897.86) for 995 individuals with Rome III IBS. We estimate the annual direct healthcare cost of IBS in the United Kingdom is £1.27 billion if the Rome IV criteria are used to define IBS, and £2.07 billion using Rome III. Among individuals with Rome IV IBS, mean annual costs were higher in those with opiate use (£907.90 vs £470.58, p < 0.001), more severe symptoms (p < 0.001 for trend), a shorter duration of IBS (1 year, £1227.14 vs >5 years £501.60, p = 0.002), lower quality of life (p < 0.001 for trend), and higher depression, somatisation and gastrointestinal symptom-specific anxiety scores (P < 0.001 for trend for all).

CONCLUSION

We estimate annual direct healthcare costs of IBS of between £1.3 and £2 billion in the United Kingdom.

Gut Microbiota Manipulation in Irritable Bowel Syndrome

Increased knowledge suggests that disturbed gut microbiota, termed dysbiosis, might promote the development of irritable bowel syndrome (IBS) symptoms. Accordingly, gut microbiota manipulation has evolved in the last decade as a novel treatment strategy in order to improve IBS symptoms. In using different approaches, dietary management stands first in line, including dietary fiber supplements, prebiotics, and probiotics that are shown to change the composition of gut microbiota, fecal short-chain fatty acids and enteroendocrine cells densities and improve IBS symptoms. However, the exact mixture of beneficial bacteria for each individual remains to be identified. Prescribing nonabsorbable antibiotics still needs confirmation, although using rifaximin has been approved for diarrhea-predominant IBS. Fecal microbiota transplantation (FMT) has recently gained a lot of attention, and five out of seven placebo-controlled trials investigating FMT in IBS obtain promising results regarding symptom reduction and gut microbiota manipulation. However, more data, including larger cohorts and studying long-term effects, are needed before FMT can be regarded as a treatment for IBS in clinical practice.

Effects of a low FODMAP diet on the colonic microbiome in irritable bowel syndrome: a systematic review with meta-analysis

BACKGROUND

A low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet is increasingly used to manage symptoms in irritable bowel syndrome (IBS). Although this approach may alter the colonic microbiome, the nature of these changes has not been comprehensively synthesized.

OBJECTIVES

The aim of this study was to conduct a systematic review with meta-analysis of randomized controlled trials examining the impact of a low FODMAP diet on the composition and function of the microbiome in patients with IBS.

METHODS

A systematic search was conducted for randomized controlled trials evaluating the effects of a low FODMAP diet on the colonic microbiome in patients with IBS in MEDLINE, EMBASE, CENTRAL, and Web of Science from inception to April 2022. Outcomes included diversity of the microbiome, specific bacterial abundances, fecal SCFA concentration, and fecal pH. For fecal SCFA concentrations and pH, meta-analyses were performed via a random-effects model.

RESULTS

Nine trials involving 403 patients were included. There were no clear effects of the low FODMAP diet on diversity of the microbiome. A low FODMAP diet consistently led to lower abundance of Bifidobacteria, but there were no clear effects on diversity of the microbiome or abundances of other specific taxa. There were no differences in total fecal SCFA concentration between the low FODMAP diet and control diets (standardized mean difference: -0.25; 95% CI: -0.63, 0.13; P = 0.20), nor were there differences for fecal concentrations of specific SCFAs or fecal pH.

CONCLUSIONS

In patients with IBS, the effects of a low FODMAP diet on the colonic microbiome appear to be specific to Bifidobacteria with no consistent impacts on other microbiome metrics, including diversity, fecal SCFA concentrations, and fecal pH. Further, adequately powered trials are needed to confirm these findings.This review was registered at https://www.crd.york.ac.uk/prospero/ as CRD42020192243.

Gastrointestinal symptoms and nutritional issues in patients with hypermobility disorders: assessment, diagnosis and management

Patients diagnosed with hypermobile Ehlers-Danlos syndrome and hypermobile spectrum disorders are increasingly presenting to secondary and tertiary care centres with gastrointestinal (GI) symptoms and nutritional issues. Due to the absence of specific guidance, these patients are investigated, diagnosed and managed heterogeneously, resulting in a growing concern that they are at increased risk of iatrogenic harm. This review aims to collate the evidence for the causes of GI symptoms, nutritional issues and associated conditions as well as the burden of polypharmacy in this group of patients. We also describe evidence-based strategies for management, with an emphasis on reducing the risk of iatrogenic harm and improving multidisciplinary team care.

Adverse events in trials of licensed drugs for irritable bowel syndrome with constipation or diarrhea: Systematic review and meta-analysis

BACKGROUND

Nocebo effects occurring in patients receiving placebo frequently impact on adverse events reported in randomized controlled trials (RCTs) in irritable bowel syndrome (IBS). Therefore, we conducted a systematic review and meta-analysis to assess the proportion of patients randomized to placebo or active drug experiencing any adverse event in trials of licensed drugs for IBS with constipation (IBS-C) or diarrhea (IBS-D), and to estimate the risk of developing adverse events among patients randomized to placebo.

METHODS

We searched MEDLINE, EMBASE CLASSIC and EMBASE, and the Cochrane central register of controlled trials (through June 2021) to identify RCTs comparing licensed drugs with placebo in adults with IBS-C or IBS-D. We generated Forest plots of pooled adverse event rates in both active drug and placebo arms and pooled risk differences (RDs) with 95% confidence intervals (CIs).

KEY RESULTS

There were 21 RCTs of licensed drugs versus placebo in IBS-C (5953 patients placebo) and 17 in IBS-D (3854 patients placebo). Overall, 34.9% and 46.9% of placebo patients in IBS-C and IBS-D trials, respectively, developed at least one adverse event, with a statistically significantly higher risk of any adverse event and withdrawal due to an adverse event with active drug. In IBS-C and IBS-D trials, rates of each individual adverse event were generally higher with active drug. However, in IBS-C trials, only diarrhea or headache was significantly more common with active drug (RD 0.066 (95% CI 0.043-0.088) and RD 0.011 (95% CI 0.002-0.021), respectively), and in IBS-D trials only constipation, nausea, or abdominal pain (RD 0.096 (95% CI 0.054-0.138), 0.014 (95% CI 0.002-0.027), and 0.018 (95% CI 0.002-0.034), respectively).

CONCLUSIONS & INFERENCES

Patients with IBS randomized to placebo have a high risk of reporting adverse events, which might relate to both nocebo and non-nocebo factors. Although patients' expectations and psychosocial factors may be involved, further understanding of the mechanisms are important to control or optimize these effects in RCTs, as well as in clinical practice.

Prognosis of patients with Rome IV-defined versus physician-diagnosed irritable bowel syndrome: Longitudinal follow-up study

INTRODUCTION

Little is known about the differences between patients diagnosed with irritable bowel syndrome (IBS) by a physician who meet the Rome IV criteria for IBS and those who do not. We conducted a longitudinal follow-up study examining this.

METHODS

We collected complete gastrointestinal, extraintestinal, and psychological symptom data from 577 consecutive adult patients with suspected IBS in a single UK gastroenterology clinic. We compared baseline characteristics between patients who met Rome IV criteria for IBS, and those who had IBS according to a physician's diagnosis but who did not meet Rome IV criteria, as well as examining whether meeting Rome IV criteria at baseline influenced evolution of symptoms under therapy.

KEY RESULTS

Of 455 patients diagnosed with IBS by a physician, 375 (82.4%) met Rome IV criteria and 80 (17.4%) did not. Those who met Rome IV criteria were more likely to report severe symptoms (67.6%, vs. 30.0%, p < 0.001) and that symptoms limited activities ≥50% of the time (63.0%, vs. 37.5%, p < 0.001). Patients with Rome IV IBS were more likely to have abnormal anxiety scores (50.8%, vs. 35.9%, p = 0.007) and higher levels of somatoform symptom-reporting (29.4%, vs. 12.5%, p < 0.001). Despite this, during longitudinal follow-up, there was no significant difference in mean number of appointments required subsequently, or IBS symptom severity.

CONCLUSIONS AND INFERENCES

Although patients who met the Rome IV criteria had more severe symptoms at baseline and were more likely to exhibit psychological comorbidity, they did not appear to have a worse prognosis than those with physician-diagnosed IBS.

Developing sensor materials for screening intestinal diseases

Intestinal diseases that have high mortality and morbidity rates and bring huge encumbrance to the public medical system and economy worldwide, have always been the focus of clinicians and scientific researchers. Early diagnosis and intervention are valuable in the progression of many intestinal diseases. Fortunately, the emergence of sensor materials can effectively assist clinical early diagnosis and health monitoring. By accurately locating the lesion and sensitively analyzing the level of disease markers, these sensor materials can help to precisely diagnose the stage and state of lesions, thereby avoiding delayed treatment. In this review, we provide comprehensive and in-depth knowledge of diagnosing and monitoring intestinal diseases with the assistance of sensor materials, particularly emphasizing their design and application in bioimaging and biodetection. This review is dedicated to conveying practical applications of sensor materials in the intestine, critical analysis of their mechanisms and applications and discussion of their future roles in medicine. We believe that this review will promote multidisciplinary communication between material science, medicine and relevant engineering fields, thus improving the clinical translation of sensor materials.

Efficacy of a low FODMAP diet in irritable bowel syndrome: systematic review and network meta-analysis

OBJECTIVE

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is recommended for irritable bowel syndrome (IBS), if general lifestyle and dietary advice fails. However, although the impact of a low FODMAP diet on individual IBS symptoms has been examined in some randomised controlled trials (RCTs), there has been no recent systematic assessment, and individual trials have studied numerous alternative or control interventions, meaning the best comparator is unclear. We performed a network meta-analysis addressing these uncertainties.

DESIGN

We searched the medical literature through to 2 April 2021 to identify RCTs of a low FODMAP diet in IBS. Efficacy was judged using dichotomous assessment of improvement in global IBS symptoms or improvement in individual IBS symptoms, including abdominal pain, abdominal bloating or distension, and bowel habit. Data were pooled using a random effects model, with efficacy reported as pooled relative risks (RRs) with 95% CIs, and interventions ranked according to their P-score.

RESULTS

We identified 13 eligible RCTs (944 patients). Based on failure to achieve an improvement in global IBS symptoms, a low FODMAP diet ranked first vs habitual diet (RR of symptoms not improving=0.67; 95% CI 0.48 to 0.91, P-score=0.99), and was superior to all other interventions. Low FODMAP diet ranked first for abdominal pain severity, abdominal bloating or distension severity and bowel habit, although for the latter it was not superior to any other intervention. A low FODMAP diet was superior to British Dietetic Association (BDA)/National Institute for Health and Care Excellence (NICE) dietary advice for abdominal bloating or distension (RR=0.72; 95% CI 0.55 to 0.94). BDA/NICE dietary advice was not superior to any other intervention in any analysis.

CONCLUSION

In a network analysis, low FODMAP diet ranked first for all endpoints studied. However, most trials were based in secondary or tertiary care and did not study effects of FODMAP reintroduction and personalisation on symptoms.

Experience and clinical efficacy of gut‐directed hypnotherapy in an Asian population with refractory irritable bowel syndrome

Background and Aim

Recent studies have highlighted the high worldwide prevalence of irritable bowel syndrome (IBS) and disparities in its management between ethnic groups. For instance, gut‐directed hypnotherapy (GDH), one of the most effective evidence‐based treatments for IBS, is not recommended in Asian countries partly due to lack of population‐specific outcome data. In this context, we evaluated the outcomes of GDH in an Asian population.

Methods

Consecutive British Asian patients with refractory IBS who received 12‐sessions of GDH using the Manchester protocol were included. Patients were treated by a team including a therapist able to speak several Asian languages. All patients prospectively completed the following questionnaires before and after GDH: IBS symptom severity score (IBS‐SSS), hospital anxiety and depression scale (HADS), non‐colonic symptom score, and the quality‐of‐life (QOL) score. The primary outcome measure was response to GDH defined by ≥50‐point reduction in IBS‐SSS. Pre‐ and post‐treatment data were compared statistically.

Results

Forty‐four Asian patients with IBS (age 49 ± 13 years; 29 [66%] female; baseline IBS‐SSS: 332.8 ± 94.6) completed GDH. Overall, 37 of 44 (84%) achieved a ≥50‐point reduction in IBS‐SSS and 25 of 44 (57%) achieved ≥30% reduction in abdominal pain scores. Following GDH, there were also significant mean improvements in IBS‐SSS (−132.1, P < 0.0001), non‐colonic symptom score (P < 0.0001), QOL score (P < 0.0001), HADS‐anxiety (P < 0.0001), and HADS‐depression (P < 0.0001), compared with baseline.

Conclusion

Regardless of the ethnicity of the therapist, GDH was highly effective with similar response rates to outcomes in other IBS populations, supporting the development of GDH in Asian countries.

Carbohydrate Maldigestion and Intolerance

This review summarizes dietary carbohydrate intolerance conditions and recent advances on the possible role of carbohydrate maldigestion and dietary outcomes in patients with functional bowel disease. When malabsorbed carbohydrates reach the colon, they are fermented by colonic bacteria, with the production of short-chain fatty acids and gas lowering colonic pH. The appearance of diarrhoea or symptoms of flatulence depends in part on the balance between the production and elimination of these fermentation products. Different studies have shown that there are no differences in the frequency of sugar malabsorption between patients with irritable bowel disease (IBS) and healthy controls; however, the severity of symptoms after a sugar challenge is higher in patients than in controls. A diet low in 'Fermentable, Oligo-Di- and Monosaccharides and Polyols' (FODMAPs) is an effective treatment for global symptoms and abdominal pain in IBS, but its implementation should be supervised by a trained dietitian. A 'bottom-up' approach to the low-FODMAP diet has been suggested to avoid an alteration of gut microbiota and nutritional status. Two approaches have been suggested in this regard: starting with only certain subgroups of the low-FODMAP diet based on dietary history or with a gluten-free diet.

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.

Pelvic floor biofeedback is an effective treatment for severe bloating in disorders of gut-brain interaction with outlet dysfunction

BACKGROUND

The pathophysiology of bloating is partially understood. We investigated in patients with disorders of gut-brain interaction (DGBI) the relationship between severity of bloating, abdominal girth changes and defecation pattern, and the efficacy of pelvic floor biofeedback treatment on bloating.

METHODS

Disorders of gut-brain interaction patients with severe bloating as the main complaint were prescribed 2 weeks dietary advice and underwent abdominal girth measurements. At the first visit, all patients underwent a questionnaire on the subjective improvement of bloating, a (0-100) VAS abdominal bloating, and abdominal girth measurement. Patients reporting inadequate bloating relief underwent a standardized balloon expulsion test. Furthermore, they were invited to undergo pelvic floor electromyography and biofeedback treatment previously used for constipation due to dyssynergic defecation. The primary outcome was bloating improvement on a 5-point Likert scale. The secondary outcomes were the effect of diet intervention and pelvic floor biofeedback treatment on bloating severity and quality of life changes as well as the effect of pelvic floor biofeedback treatment on BET and EMG on straining.

KEY RESULTS

One hundred and fifty six patients (129 F, 39.3 ± 11.7 mean age) completed the 2-week run-in period. 105 patients were diet non-responder and underwent balloon expulsion test, with the vast majority (64%) failing the test. Patients who scored higher bloating on VAS had a significant association with failed balloon expulsion test (adjusted B 0.4 [95% CI 10.8-25.7], p < 0.0001). 63% agreed to perform pelvic floor biofeedback treatment at Verona center, 54% became responders reporting fair or major improvement/cure (ITT analysis, McNemar test, p < 0.0001), and all of them showed a 50% decrease in bloating severity.

CONCLUSIONS AND INFERENCES

Disordered defecation is a prevalent etiology in DGBI patients with bloating unresponsive to conservative measures; pelvic floor biofeedback treatment to improve the defecation effort significantly relieved bloating (http://www.isrctn.com, ISRCTN17004079).

Efficacy of Probiotics for Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Background

Irritable bowel syndrome (IBS) is a common gastrointestinal condition. Studies regarding the treatment of IBS with probiotics have not yielded consistent results, and the best probiotics has not yet been confirmed. Therefore, we performed a network meta-analysis (NMA) to assess the relative rank order of different probiotics for IBS.

Method

We searched for RCTs on the efficacy of probiotics for IBS until August 25, 2021. The primary outcome was the symptom relief rate, as well as global symptoms, abdominal pain, bloating, and straining scores. The NMA was conducted using Stata 15.0. We also used meta-regression to explore whether the treatment length and dose influenced the efficacy.

Results

Forty-three RCTs, with 5,531 IBS patients, were included in this analysis. Firstly, we compared the efficacy of different probiotic species. B.coagulans exhibited the highest probability to be the optimal probiotic specie in improving IBS symptom relief rate, as well as global symptom, abdominal pain, bloating, and straining scores. In regard to the secondary outcomes, L.plantarum ranked first in ameliorating the QOL of IBS patients, but without any significant differences compared with other probiotic species in standardized mean differences (SMD) estimates. Moreover, patients received L.acidophilus had lowest incidence of adverse events. The meta-regression revealed that no significant differences were found between participants using different doses of probiotics in all outcomes, while the treatment length, as a confounder, can significantly influence the efficacy of probiotics in ameliorating abdominal pain (Coef = -2.30; p = 0.035) and straining (Coef = -3.15; p = 0.020) in IBS patients. Thus, we performed the subgroup analysis on treatment length subsequently in these two outcomes, which showed that efficacy of B.coagulans using 8 weeks ranked first both in improving the abdominal pain and straining scores. Additionally, B. coagulans still had significant efficacy compared to different types of probiotic combinations in present study.

Conclusions

The findings of this NMA suggested that B.coagulans had prominent efficacy in treating IBS patients, and incorporating B.coagulans into a probiotic combination, or genetically engineering it to amplify its biological function may be a future research target to treat IBS patients. With few direct comparisons available between individual therapies today, this NMA may have utility in forming treatment guideline for IBS with probiotics.

Diet as a therapeutic tool in chronic gastrointestinal disorders: Lessons from the FODMAP journey

BACKGROUND AND AIM

Diet is a powerful tool in the management of gastrointestinal disorders, but developing diet therapies is fraught with challenge. This review discusses key lessons from the FODMAP diet journey.

METHODS

Published literature and clinical experience were reviewed.

RESULTS

Key to designing a varied, nutritionally adequate low-FODMAP diet was our accurate and comprehensive database of FODMAP composition, made universally accessible via our user-friendly, digital application. Our discovery that FODMAPs coexist with gluten in cereal products and subsequent gluten/fructan challenge studies in nonceliac gluten-sensitive populations highlighted issues of collinearity in the nutrient composition of food and confirmation bias in the interpretation of dietary studies. Despite numerous challenges in designing, funding, and executing dietary randomized controlled trials, efficacy of the low-FODMAP diet has been repeatedly demonstrated, and confirmed by real-world experience, giving this therapy credibility in the eyes of clinicians and researchers. Furthermore, real-world application of this diet saw the evolution of a safe and effective three-phased approach. Specialist dietitians must deliver this diet to optimize outcomes as they can target and tailor the therapy and to mitigate the key risks of compromising nutritional adequacy and precipitating disordered eating behaviors, skills outside the gastroenterologist's standard tool kit. While concurrent probiotics are ineffective, specific fiber supplements may improve short-term and long-term outcomes.

CONCLUSIONS

The FODMAP diet is highly effective, but optimal outcomes are contingent on the involvement of a gastroenterological dietitian who can assess, educate, and monitor patients and manage risks associated with implementation of this restrictive diet.

Role of Traditional Chinese Herbal Medicines in Functional Gastrointestinal and Motility Disorders

PURPOSE OF REVIEW

Traditional Chinese medicine (TCM) has been in use for thousands of years in Asian countries and is rapidly gaining popularity in the Western world. Among different forms of TCM, the traditional Chinese herbal therapy and acupuncture are the most popular modalities. Here, we review the fundamentals of TCMs for clinicians practicing in the West and will also detail the evidence-based utility of Chinese herbal medicine in the management of functional gastrointestinal disorders (FGIDs).

RECENT FINDINGS

In the recent decades, the popularity and usage of traditional Chinese herbal medicine in FGIDs is increasing in the West. TCMs are commonly utilized by many patients with FGIDs as the conventional therapies do have limitations such as cost, inadequate symptom control and adverse effects. The unfamiliarity of TCM philosophy among clinicians in the West, and shortage of traditional Chinese herbalists remain. The philosophy of TCM is complex and entirely different from the Western medical concepts and is difficult to understand for a clinician trained in the West. Further traditional Chinese herbal therapies are often viewed skeptically by the clinicians in the West for various reasons such as lack of scientific rigor, inconsistencies in the constituents of herbal products, and also concerns due to adverse herb effects. Future clinical trials in FGIDs should focus on herb product quality, herb-drug interactions, and standardized criteria for diagnosis and management outcomes.

Pre-diagnostic faecal calprotectin levels in patients with colorectal cancer: a retrospective study

BACKGROUND

Faecal calprotectin (FC) is a potential biomarker for colorectal cancer (CRC) screening. There is uncertainty if tumor characteristics are associated with FC levels. We investigated how tumor stage and tumor localization influence the extent of FC levels in patients with CRC in clinical practice.

METHODS

In two cohorts of patients with CRC, we retrospectively analyzed FC tests (CALPRO®) performed within three months prior to diagnosis. One hundred twenty-four patients with CRC were included (mean age 68 years, 44% women).

RESULTS

Ninety-eight patients with CRC (79%) had a FC ≥ 50 µg/g. FC correlated positively with tumor stage (UICC based on WHO TNM classification) (r_s 0.24; p = 0.007) and with CRP levels (r_s 0.31, p = 001), and a negatively with B-haemoglobin (r_s -0.21; p = 0.019). The patients with right-sided CRC had significantly more often a FC ≥ 50 µg/g than patients with left-sided CRC (92% vs 74% p = 0.027). In a binary logistic regression analysis, tumor stage III/IV (adjusted OR 3.47; CI 1.27-9.42) and right-sided tumor localization (adjusted OR 3.80; CI 1.01-14.3) were associated with FC ≥ 50 µg/g. Tumor stage III/IV (adjusted OR 2.30; CI 1.04-5.10) and acetylsalicylic use (adjusted OR 3.54; CI 1.03-12.2) were associated with FC ≥ 100 µg/g. In a cox regression analysis, a FC ≥ 100 µg/g was not associated with survival (Hazard OR 0.61; CI 0.24-1.52).

CONCLUSIONS

Elevated pre-diagnostic FC levels were common in patients with CRC in close proximity to diagnosis. Right-sided localization and tumor stage were significantly associated with a rise in FC levels.

Potential Roles of Enterochromaffin Cells in Early Life Stress-Induced Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, also known as disorders of the gut–brain interaction; however, the pathophysiology of IBS remains unclear. Early life stress (ELS) is one of the most common risk factors for IBS development. However, the molecular mechanisms by which ELS induces IBS remain unclear. Enterochromaffin cells (ECs), as a prime source of peripheral serotonin (5-HT), play a pivotal role in intestinal motility, secretion, proinflammatory and anti-inflammatory effects, and visceral sensation. ECs can sense various stimuli and microbiota metabolites such as short-chain fatty acids (SCFAs) and secondary bile acids. ECs can sense the luminal environment and transmit signals to the brain via exogenous vagal and spinal nerve afferents. Increasing evidence suggests that an ECs-5-HT signaling imbalance plays a crucial role in the pathogenesis of ELS-induced IBS. A recent study using a maternal separation (MS) animal model mimicking ELS showed that MS induced expansion of intestinal stem cells and their differentiation toward secretory lineages, including ECs, leading to ECs hyperplasia, increased 5-HT production, and visceral hyperalgesia. This suggests that ELS-induced IBS may be associated with increased ECs-5-HT signaling. Furthermore, ECs are closely related to corticotropin-releasing hormone, mast cells, neuron growth factor, bile acids, and SCFAs, all of which contribute to the pathogenesis of IBS. Collectively, ECs may play a role in the pathogenesis of ELS-induced IBS. Therefore, this review summarizes the physiological function of ECs and focuses on their potential role in the pathogenesis of IBS based on clinical and pre-clinical evidence.

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.

The symptom burden of Irritable Bowel Syndrome in tertiary care during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic caused unprecedented disruption to healthcare services worldwide with well-documented detrimental effects on mental health. Patients with refractory disorders of gut-brain interaction such as Irritable Bowel Syndrome (IBS) seen in tertiary care tend to exhibit higher levels of psychological comorbidity, but the impact of the pandemic on IBS symptom severity in tertiary care is unknown.

METHODS

As part of routine clinical care, consecutive tertiary referrals with refractory IBS patients prospectively completed a series of baseline questionnaires including IBS symptom severity score (IBS-SSS), non-colonic symptom score, Hospital Anxiety and Depression (HAD), and Illness impact scores. The symptom severity questionnaire data were compared for consecutive patients seen in tertiary care 12 months before and after the onset of COVID-19 pandemic restrictions.

KEY RESULTS

Of 190 consecutive tertiary referrals with IBS, those seen during the pandemic had greater IBS severity (IBS-SSS: 352 vs. 318, p = 0.03), more severe extra-intestinal symptoms (non-colonic score: 269 vs. 225, p = 0.03), sleep difficulties (p = 0.03), helplessness and loss of control (p = 0.02), but similar HAD-Anxiety (p = 0.96) and HAD-Depression (p = 0.84) scores. During the pandemic, unmarried patients (p = 0.03), and keyworkers (p = 0.0038) had greater IBS severity.

CONCLUSIONS AND INFERENCES

This study has shown for the first time that patients seen in tertiary care with refractory IBS during the COVID-19 pandemic had a significantly higher symptom burden emphasizing the importance of gut-brain axis in IBS. Furthermore, lack of support and perceived loss of control appear to be contributory factors.

COVID-19 infection causing residual gastrointestinal symptoms - a single UK centre case series

Although COVID-19 was first recognised as an acute respiratory illness, extra-pulmonary manifestations are increasingly being recognised. Acute gastrointestinal side effects have been well reported with COVID-19 infection and are estimated to affect around 17% of patients. With COVID-19 still being a relatively new illness, the chronic gastrointestinal symptoms are less well characterised. Post-infectious irritable bowel syndrome (IBS) can occur following bacterial and viral infections, and with ACE-2 receptors being shown to be present in the gastrointestinal tract and SARS-Cov-2 RNA being present in stool, SARS-CoV-2 is now appreciated as an enteric pathogen. In our study, we survey acute and chronic gastrointestinal symptoms after COVID-19 infection. We have conducted one of the few UK studies on gastrointestinal symptoms, with the longest follow-up duration of 6 months. We have found that gastrointestinal symptoms are common at 6 months, affecting 43.8% of our patients. Further research is needed to explore whether this represents a new post-COVID-19 IBS, which has not previous been described in the literature, including its clinical course and response to any potential medical therapies.

Commonly used biomarkers do not contribute to diagnosing irritable bowel syndrome

OBJECTIVE

The aim of this article was to examine the costs and effectiveness of standardized blood and fecal investigations in patients fulfilling the Rome criteria for irritable bowel syndrome (IBS).

METHODS

We conducted a real-life cohort study in patients fulfilling the Rome III criteria for IBS without red flag signs or symptoms, in a center of excellence for IBS patients from 1 January 2015 till 1 January 2019. Standardized blood and fecal investigations [hemoglobin (Hb), thyroid-stimulating hormone (TSH), coeliac serology, and fecal calprotectin (FCP)] were performed during the first consultation. Patients were followed for at least 1 year. Primary outcome was the probability of another diagnosis than IBS with subsequent overall costs.

RESULTS

A total of 218 patients were included. In approximately 200 patients blood and fecal investigations were performed and 47 patients underwent a colonoscopy. Two-hundred ten patients were diagnosed with IBS, 5 with inflammatory bowel disease (IBD), 1 with nonspecific acute ileitis, 1 with hyperthyroidism, and 1 with coeliac disease. The number needed to diagnose all included laboratory tests was 34, and for the individual test: TSH 197, coeliac serology 199, and FCP 50. The total costs were approximately €4900 to diagnose one patient with another diagnosis than IBS.

CONCLUSION

In our real-life cohort of adult patients under the age of 50 years fulfilling the Rome criteria for IBS without red flag symptoms, standardized blood, and fecal investigations have a very low diagnostic yield accompanied by high additional costs. Colonoscopy is not indicated in patients with Rome III positive IBS and normal FCP.

Oral and parenteral anti-neuropathic agents for the management of pain and discomfort in irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a highly prevalent and economically burdensome condition; and pain is often the most unpleasant, disruptive, and difficult-to-treat symptom. Visceral hypersensitivity is a common feature driving pain in IBS, suggesting that neuropathic mechanisms may be implicated. We conducted a systematic review of available evidence to examine the role of anti-neuropathic medicines in the management of pain in IBS.

METHODS

We systematically searched scientific repositories for trials investigating conventional oral, and/or parenteral, pharmaceutical antineuropathic treatments in patients with IBS. We summarized key participant characteristics, outcomes related to pain (primary outcome), and selected secondary outcomes.

KEY RESULTS

We included 13 studies (n = 629 participants): six investigated amitriptyline, three duloxetine, three pregabalin, and one gabapentin. There was considerable methodological and statistical heterogeneity, so we performed a narrative synthesis and limited meta-analysis. Amitriptyline was most extensively studied, though only in diarrhea-predominant patients. In individual trials, amitriptyline, pregabalin and gabapentin generally appeared beneficial for pain outcomes. While duloxetine studies tended to report improvements in pain, all were un-controlled trials with high risk of bias. Meta-analysis of three studies (n = 278) yielded a pooled relative-risk of 0.50 (95%CI 0.38-0.66) for not improving with anti-neuropathic agent vs control. We did not identify any eligible studies investigating the role of parenteral anti-neuropathics.

CONCLUSIONS AND INFERENCES

Anti-neuropathic analgesics may improve pain in IBS, and deserve further, high-quality investigation, potentially considering parenteral administration and agents with minimal gastrointestinal motility effects. Investigation of amitriptyline's efficacy in non-diarrhea-predominant subtypes is currently lacking, and we recommend particular caution for its use in IBS-C.

Probiotics in irritable bowel syndrome - is the quest for the right strain over? Rapid review of existing guidelines and recommendations

Irritable bowel syndrome (IBS) - functional gastrointestinal disorder (FGIDs) and disorder of gut-brain interaction (DGBIs) - has emerged as an important medical problem with an impact on health care systems, affecting patients' quality of life. The management of IBS consists of pharmacological and non-pharmacological treatments; however, the data of their long-term efficacy are scarce. Modulation of gastrointestinal microbiota, by means of probiotics and prebiotics, is often sought and advertised as a popular treatment modality in IBS. Faecal microbiota transplantation (FMT) awaits recommendations for IBS treatment and requires more methodological assessments. To date, numerous guidelines and recommendations have been published on the role of probiotics in IBS. Because no probiotic claim for probiotics in foods has yet been granted by the European Food and Safety Authority (EFSA), medical practitioners still recommend probiotics on the basis of available literature and recommendations released by independent health authorities. We aimed to summarize published formal recommendations and guidelines regarding the clinical effectiveness of available probiotic strains and conduct a random-effects meta-analysis of outcomes for which ≥ 2 studies contributed data on the same probiotic strain recommended to adults with IBS. Based on available and most recent guidelines, we report that probiotics, as a group, may be an effective treatment for global symptoms and abdominal pain in IBS, with the strongest effect for genus Lactobacillus. Our current and updated meta-analysis is in line with several reports documenting significant effects of Lactobacillus plantarum (Lp299v) in reducing the risk of global symptoms and their persistence, which could assist clinicians in making the choice for the right probiotic strain in IBS patients.

Review article: the effectiveness of group and self-help hypnotherapy for irritable bowel syndrome and the implications for improving patients' choice and access to treatment

BACKGROUND

Individual hypnotherapy (IH) is a recognised treatment for irritable bowel syndrome (IBS). However, it is not widely available to patients due to its resource-intensive nature, lack of adequately trained therapists, and scepticism about hypnosis. Non-individualised hypnotherapy approaches, such as group and self-help hypnotherapy, could maximise existing therapist resources by treating more patients at the same time, thus widening patient access to treatment without incurring additional expenditure.

AIMS

To investigate the research literature for non-individualised approaches to hypnotherapy for IBS and to determine their effectiveness for reducing symptom severity and/or providing adequate relief.

METHODS

A literature review of published peer-reviewed studies was conducted. Quantitative research was selected to determine the effectiveness of the interventions.

RESULTS

Ten studies were eligible for inclusion. Three delivered group hypnotherapy, three integrated hypnosis within a group concept, and four utilised a self-help home hypnotherapy treatment using audio recordings. Both group hypnotherapy for adults and the self-help home hypnotherapy treatment for children were effective interventions that may be non-inferior to IH for patients with mild-to-moderate symptoms. Treatment benefits were long-lasting. The evidence for the integrative group concept and home treatment for adults was less compelling.

CONCLUSIONS

Group hypnotherapy for adults, and self-help hypnotherapy for children, may be cost-effective treatments that can widen access for patients with milder IBS in primary care settings. Further research is needed to determine the effectiveness of group hypnotherapy for patients with severe, refractory IBS.

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.