Improvement in Gastrointestinal Symptoms After Cognitive Behavior Therapy for Refractory Irritable Bowel Syndrome

The impact of depression-mediated gut microbiota composition on Irritable Bowel Syndrome: A Mendelian study

OBJECTIVE

This study uses a two-sample Mendelian randomization (MR) analysis to delineate the causal influence of gut microbiota on the occurrence of irritable bowel syndrome (IBS), concurrently assessing the potential mediating function of depression within this framework.

METHODS

Several two-sample MR methods were used to assess the causal repercussions of gut microbiota on the onset of both IBS and depression. Following this, gut microbiota and depression, which demonstrated notable causal associations, were integrated as exposure variables in a multivariable Mendelian randomization (MVMR) framework to construct a model encompassing gut microbiota, depression, and IBS. Mediation effects were assessed by examining the indirect pathway of gut microbiota → depression → IBS.

RESULTS

Two-sample MR analysis unveiled a statistically significant causal association (P < 0.05) between specific bacterial group within the gut microbiota, notably p_Actinobacteria(OR = 0.829225), c_Clostridia(OR = 0.798897), s_Desulfovibrio_piger(OR = 1.163912), g_Streptococcus(OR = 1.132735), c_Actinobacteria(OR = 0.829224), and the onset of IBS. In the MVMR analysis, the relationship between depression and IBS was significant across Model 3, Model 7, Model 8, and Model 13 (P < 0.05). Assessment of mediation effects revealed that c_Clostridia and o_Clostridiales indirectly impacted IBS through depression, with masking effect ratios of 168.46 % and 168.44 %, respectively.

CONCLUSION

These findings underscore a resilient causal association between the composition of gut microbiota and the initiation of IBS. Furthermore, depression serves as a mediator for particular groups of gut bacteria, thereby contributing to the development of IBS. These observations imply that interventions targeting mental health may potentially alleviate the risk of IBS onset attributable to adverse configurations of gut microbiota.

The Use of Psychotherapy for Refractory Irritable Bowel Syndrome: A Systematic Review

Irritable bowel syndrome (IBS) is a common yet debilitating and chronic condition that consists of disturbances in bowel habits and abdominal pain that is frequently relieved with defecation. While the first line of treatment for IBS is pharmacological treatment, this has been shown to fail, leading to the patient being classified as having refractory IBS. The quality of life (QOL) of these patients is greatly hindered; in this case, there are rarely moments of relief. Additional modalities of treatment have been employed in classical cases of IBS, such as psychotherapy, and research has started to evaluate its effectiveness with refractory IBS. Both cognitive behavioral therapy (CBT) and gut-directed hypnotherapy (GDH) are effective in treating classical IBS as they restructure and bring a state of meditation to the patient, allowing them to work through the symptoms. The question is whether it remains successful in refractory cases. This systematic review was conducted with strict adherence to PRISMA guidelines with an initial inquiry resulting in 28,978 publications through PubMed, ScienceDirect, and ProQuest databases. Through automatic and manual screening processes, articles that were peer-reviewed experimental or observation publications done between 2003 and 2023 were included in this study, resulting in 21 publications. Across all studies evaluating CBT, it was consistently found to be successful in improving symptom severity and frequency, QOL, and extracolonic symptoms such as anxiety and depression. When broken down into delivery methods, minimal contact CBT was found to be just as, if not superior, to standard contact. Within this, telephone-delivered CBT was superior to web-delivered CBT. GDH and biofeedback therapy were found to also significantly improve all domains of IBS with no difference between them. Acceptance and commitment therapy were found only to improve associated symptoms. However, there was no significant improvement in their QOL, whereas integrative group therapy found no significant improvement in any domain. Because IBS is so common and crippling to those affected, its crucial to continuously improve QOL through advancement in treatment modalities. Further research should focus more on other modes of therapy as success has been shown in standard therapeutic techniques.

Development and Current State of Digital Therapeutics for Irritable Bowel Syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is a common, debilitating disorder characterized by abdominal pain and disordered bowel habits. Current pharmacologic treatments often provide incomplete symptom relief and may be poorly tolerated. Furthermore, alleviation of gastrointestinal symptoms does not always translate into improved quality of life for IBS patients. Current treatment guidelines recommend brain-gut behavior therapy (BGBT) in conjunction with other IBS therapies, and, in randomized controlled trials, BGBT has been shown to improve symptoms, patient satisfaction, functioning, and quality of life. Access to BGBT is limited by lack of adequately trained gastrointestinal psychologists, patient time constraints, and cost. Furthermore, clinician knowledge that BGBT is specific, and different from psychotherapy approaches for common mental health disorders, may limit referrals even where available. This review provides an overview of the pathophysiology of IBS, disease burden, unmet therapeutic needs, evidence base of novel digital therapeutics for IBS, and guidance on the introduction and appropriateness of these interventions for patients.

METHODS

We searched the literature for available published data relating to the use of novel digital therapeutics to provide cognitive behavioral therapy and gut-directed hypnotherapy in the treatment of irritable bowel syndrome.

RESULTS

Clinical trial data support the development and utility of digital therapeutics designed to deliver self-guided cognitive behavioral therapy and hypnotherapy for the treatment of IBS.

CONCLUSIONS

BGBTs are effective, guideline-recommended treatments for IBS. Digital therapeutic devices offer accessible, cost-effective treatment options for delivery of adjunctive BGBT for the treatment of IBS. The decision to recommend digital BGBTs should be guided by careful patient assessment that includes mental health screening and risk assessment.

Formative Evaluation of a Comprehensive Self-Management Intervention for Irritable Bowel Syndrome, Comorbid Anxiety, and Depression: Mixed Methods Study

BACKGROUND

Irritable bowel syndrome (IBS) is a disorder of the gut-brain interaction that is associated with abdominal pain, altered bowel patterns, and reduced quality of life. Up to 50% of patients with IBS also report anxiety or depressive symptoms. Although effective self-management interventions exist for individuals with IBS, few have been effectively implemented, and most do not consider the unique needs of patients with comorbid IBS and anxiety or depression.

OBJECTIVE

This study aimed to determine the anticipated acceptability, appropriateness, feasibility, and usability of a comprehensive self-management intervention using an implementation science and human-centered design approach among individuals with comorbid IBS and anxiety or depression and health care providers.

METHODS

A convergent mixed methods design was used to elicit feedback on the comprehensive self-management intervention outline and content to identify refinement needs before testing. Patients with IBS and moderate to severe anxiety or depression and health care providers were purposefully sampled from primary care and gastroenterology settings. Participants completed semistructured interviews and surveys on anticipated acceptability, appropriateness, feasibility, and usability.

RESULTS

Patient participants (n=12) were on average 36.8 (SD 12.2) years of age, and 42% (5/12) were currently receiving psychological therapy. Health care providers (n=14) were from primary care (n=7) and gastroenterology (n=7) settings. The mean usability scores (out of 100) were 52.5 (SD 14.5) for patients and 45.6 (SD 11.6) for providers. For patients and providers, qualitative data expanded the quantitative findings for acceptability and appropriateness. Acceptability findings were the comprehensive nature of the intervention and discussion of the gut-brain interaction. For appropriateness, participants reported that the intervention provided structure, accountability, and support. Feasibility was confirmed for patients, but there was a divergence of findings between quantitative and qualitative measures for providers. Patients focused on intervention feasibility, while providers focused on implementation feasibility in the clinic. Identified usability issues to address before implementation included the intervention delivery format, length, and lack of integration into health care settings that, if not addressed, may limit the reach of the intervention.

CONCLUSIONS

Patients and health care providers found the intervention acceptable and appropriate. Several feasibility and usability issues were identified, including intervention delivery methods, length of intervention, and the best methods to implement in the clinic setting. The next steps are to refine the intervention to address the identified issues and test in a pilot study whether addressing usability issues leads to the anticipated improvements in implementation and uptake.

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.

Efficacy of an eHealth self-management program in reducing irritable bowel syndrome symptom severity: a randomized controlled trial

This study aimed to verify whether an eHealth-based self-management program can reduce irritable bowel syndrome (IBS) symptom severity. An open-label simple randomized controlled trial was conducted that compared an intervention group (n = 21) participating in an eHealth self-management program, which involved studying IBS-related information from an established self-help guide followed by in-built quizzes, with a treatment-as-usual group (n = 19) that, except for pharmacotherapy, had no treatment restrictions. Participants were female Japanese university students. The eHealth group received unlimited access to the self-management program for 8 weeks on computers and mobile devices. The primary outcome, participants' severity of IBS symptoms assessed using the IBS-severity index (IBS-SI), and the secondary outcomes of participants' quality of life, gut bacteria, and electroencephalography alpha and beta power percentages were measured at baseline and 8 weeks. A significant difference was found in the net change in IBS-SI scores between the eHealth and treatment-as-usual groups, and the former had significantly lower IBS-SI scores following the 8-week intervention than at baseline. Moreover, there was a significant difference in the net change in phylum Cyanobacteria between the eHealth and treatment-as-usual groups. Thus, the eHealth-based self-management program successfully reduced the severity of IBS symptoms.

Environmental enrichment reverses stress-induced changes in the brain-gut axis to ameliorate chronic visceral and somatic hypersensitivity

Introduction

Behavioral therapies, including cognitive behavioral therapy, hypnotherapy and stress management activities, have emerged as effective treatments for irritable bowel syndrome (IBS), a female predominant disorder of the brain-gut axis. IBS, affecting over 10% of the global population, typically presents with abnormal bowel habits and abdominal pain due to visceral hypersensitivity. While the mechanisms underlying how behavioral therapies treat IBS are still elusive, we had previously shown that chronic stress alters gene expression in brain regions critical for stress processing and nociception. We found that exposure to an enriched environment (EE), the rodent analogue of behavioral therapies, prior to and during the stressor was sufficient to prevent stress-induced changes in glucocorticoid receptor (GR) expression in the central nucleus of the amygdala (CeA) and hippocampus. Pre-exposure to EE also inhibited stress-induced increased colonic permeability and was able to block the induction of stress-induced visceral and somatic hypersensitivity. However, it remains unknown if EE can reverse chronic viscerosomatic hypersensitivity that persists following exposure to stress. We hypothesized that EE after chronic stress would be sufficient to reverse stress-induced changes in i) GR expression in the CeA and hippocampus, ii) ameliorate stress-induced colonic hyperpermeability and iii) restore normal visceral and somatic sensitivity in male and female rats.

Methods

Male and female rats were exposed to daily water avoidance stress (WAS). After confirming the rats had developed visceral hypersensitivity, 50% of the animals were housed in EE for 2 weeks while the other 50% remained in standard housing (SH). At the end of this period, we assessed visceral and somatic sensitivity. We also collected colon tissue to measure colonic permeability. Micro-punches of tissue from the CeA and hippocampus were isolated to measure GR expression. Control animals not exposed to WAS were kept in SH for the duration of the study (n = 8 per group).

Results

In both male and female rats, EE reversed stress-induced visceral (p < 0.001) and somatic (p < 0.01) hypersensitivity when compared to WAS animals housed in SH to levels comparable to control animals. EE exposure also reversed changes in GR expression in both the hippocampus (p < 0.01) and CeA (p < 0.01), normalizing GR expression to control levels. EE exposure ameliorated stress-induced colonic hyperpermeability in both male (p < 0.01) and female (p < 0.01) rats compared to WAS rats in SH.

Conclusion

Our findings suggest that behavioral therapies are viable therapeutic options for IBS as they can counter the stress-induced pathophysiology underlying IBS symptoms including visceral hypersensitivity, increased colonic permeability and altered gene expression.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Psychological treatments for irritable bowel syndrome: a comprehensive systematic review and meta-analysis

A wide range of psychological treatments have been found to reduce the symptoms of irritable bowel syndrome (IBS) but their relative effects are unclear. In this systematic review and meta-analysis, we determined the effects of psychological treatments for IBS, including subtypes of cognitive behavior therapy, versus attention controls. We searched 11 databases (March 2022) for studies of psychological treatments for IBS, reported in journal articles, books, dissertations, and conference abstracts. The resulting database comprised 9 outcome domains from 118 studies published in 1983-2022. Using data from 62 studies and 6496 participants, we estimated the effect of treatment type on improvement in composite IBS severity using random-effects meta-regression. In comparison with the attention controls, there was a significant added effect of exposure therapy (g = 0.52, 95% CI = 0.17-0.88) and hypnotherapy (g = 0.36, 95% CI = 0.06-0.67) when controlling for the pre- to post-assessment duration. When additional potential confounders were included, exposure therapy but not hypnotherapy retained a significant added effect. Effects were also larger with a longer duration, individual treatment, questionnaire (non-diary) outcomes, and recruitment outside of routine care. Heterogeneity was substantial. Tentatively, exposure therapy appears to be a particularly promising treatment for IBS. More direct comparisons in randomized controlled trials are needed. OSF.io identifier: 5yh9a.

Brief cognitive-behavioral treatment for avoidant/restrictive food intake disorder in the context of functional dyspepsia: Study protocol for a feasibility randomized controlled trial

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) symptoms are common (up to 40%) among adults with functional dyspepsia (FD), a disorder of gut-brain interaction characterized by early satiation, post-prandial fullness, epigastric pain, and/or epigastric burning. Using an 8-session exposure-based cognitive-behavioral treatment (CBT) for adults with FD + ARFID compared to usual care (UC) alone, we aim to: (1) determine feasibility, (2) evaluate change in clinical outcomes in, and (3) explore possible mechanisms of action.

METHODS

We will randomize adults with FD who meet criteria for ARFID with ≥5% weight loss (N = 50) in a 1:1 ratio to CBT (with continued UC) or to UC alone. A priori primary benchmarks will be: ≥75% eligible participants enroll; ≥75% participants complete assessments; ≥70% participants attend 6/8 sessions; ≥70% of sessions have all content delivered; ≥70% participants rate Client Satisfaction Questionnaire scores above scale midpoint. We will also examine the size of changes in FD symptom severity and related quality of life within and between groups, and explore possible mechanisms of action.

CONCLUSIONS

Findings from this trial will inform next steps with treatment development or evaluation-either for further refinement or for next-step efficacy testing with a fully-powered clinical trial.

Factors That Predict Magnitude, Timing, and Persistence of Placebo-Like Response in Patients With Irritable Bowel Syndrome

BACKGROUND AND AIMS

Placebo response impedes the development of novel irritable bowel syndrome (IBS) therapies and the interpretability of randomized clinical trials. This study sought to characterize the magnitude, timing, and durability of IBS symptom relief in patients undergoing a non-drug placebo-like control.

METHODS

One hundred forty-five Rome III-diagnosed patients (80% F, M age = 42 years) were assigned to education/nondirective support delivered over a 10-week acute phase. Treatment response was based on the IBS version of the Clinical Global Improvement Scale completed 2 weeks after treatment ended. Candidate predictors were assessed at baseline (eg, emotion regulation, pain catastrophizing, distress, neuroticism, stress, somatization, gastrointestinal-specific anxiety) or clinically relevant points during treatment (patient-provider relationship, treatment expectancy/credibility).

RESULTS

Midtreatment response was associated with lower levels of stress and somatization at baseline and greater patient-provider agreement on treatment tasks (P < .001). Treatment response was associated with baseline gastroenterologist-rated IBS severity, anxiety, ability to reappraise emotions to reduce their impact [cognitive reappraisal], and agreement that provider and patient shared goals from provider perspective (P < .001). The day-to-day ability to reappraise emotions at baseline distinguished rapid from delayed placebo responders (P = .011).

CONCLUSION

Patient beliefs (eg, perceived stress, cognitive reappraisal) impacted the magnitude, timing, and persistence of placebo response measured at midway point of acute phase and 2 weeks after treatment discontinuation. Baseline beliefs that patients could alter the impact of stressful events by rethinking their unpleasantness distinguished rapid vs delayed placebo responders. Collaborative agreement between doctor and patient around shared tasks/goals from the clinician perspective predicted placebo response.

Irritable Bowel Syndrome: Treating the Gut and Brain/Mind at the Same Time

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal (GI) disorders in the world. Although IBS does not affect a person's life span, it can significantly influence their quality of life. The treatment of IBS should be tailored to each patient's specific symptomatology because it can often be difficult to manage. Given that the pathogenesis of IBS is not well understood, it places a tremendous load on healthcare resources. Over the years, IBS has been described as either a simple GI disorder or a more complex multi-symptomatic gut-brain axis disorder. Many persons with IBS have psychological issues in addition to gastrointestinal symptoms, offering the door to non-pharmacological therapies such as cognitive behavioral therapy, gut-directed hypnosis, or psychodynamic interpersonal therapy. Non-pharmacological therapies with no side effects should be used as first-line therapy. Diet, exercise, microbiota-targeted therapies, and psychological treatments are among the most significant interventions. This review goes into the details of all the non-pharmacological interventions that can be used to treat IBS.

Clinical efficacy of cognitive behavioral therapy combined with pinaverium bromide tablets on irritable bowel syndrome

Objective

To investigate the clinical efficacy of cognitive behavioral therapy combined with pinaverium bromide tablets in admitted patients with irritable bowel syndrome (IBS).

Methods

This is a retrospective study. A total of 60 patients with IBS admitted to Beijing Hospital of Integrated Traditional Chinese and Western Medicine between June 2021 and June 2022 were selected and randomly divided into two groups. Patients in the control group were treated with pinaverium bromide tablets, and those in the observation group were treated with cognitive behavior therapy combined with pinaverium bromide tablets. The improvement of clinical symptoms and quality of life before and after treatment was compared for the two groups, IBS-SSS scale and IBS-QOL scale were used to compare the improvement of clinical symptoms and quality of life between the two groups of patients before and after treatment. SAS score and SDS score were used to evaluate the psychology of the two groups. Adverse reactions occurring during the treatment were recorded, such as nausea and vomiting, dizziness and headache, etc.

Results

The efficacy of the observation group was higher than that of the control group and the difference was significant (P<0.05). After treatment, the IBS-SSS score in the observation group and the control group decreased and the IBS-QOL score increased. The SDS score and SAS score in the observation group were better than those in the control group (P< 0.05). After treatment, there was no significant difference in adverse reactions between the observation group and the control group (P > 0.05).

Conclusion

Cognitive behavioral therapy combined with pinaverium bromide tablets is significantly effective in the treatment of patients with IBS, which can effectively relieve symptoms such as diarrhea and abdominal pain, and reduce irritable bowel reactions.

Pain Catastrophizing and Clinical Outcomes Among Patients Receiving a Novel Cognitive-Behavioral Therapy for Irritable Bowel Syndrome: An Experimental Therapeutics Approach

Irritable bowel syndrome (IBS) is the most common gastrointestinal (GI) condition treated by GI and primary care physicians. Although IBS symptoms (abdominal pain, bowel problems) are generally refractory to medical therapies, consistent research has shown that they improve following cognitive-behavioral therapy (CBT). Notwithstanding empirical support for CBT, there is less research explicating the reasons for why or how it works. Like other pain disorders, the focus on change mechanisms for behavioral pain treatments has focused on pain-specific cognitive-affective processes that modulate pain experience, few of which are more important than pain catastrophizing (PC). The fact that PC changes are seen across treatments of differing theoretical and technical orientation, including CBT, yoga, and physical therapy, suggests that it may be a nonspecific (vs. theory-based) change mechanism akin to therapeutic alliance and treatment expectancy. Therefore, the current study examined change in PC as a concurrent mediator of IBS symptoms severity, global GI symptom improvement, and quality of life among 436 Rome III-diagnosed IBS patients enrolled in a clinical trial undergoing two dosages of CBT versus a nonspecific comparator emphasizing education and support. Results from structural equation modeling parallel process mediation analyses suggest that reduction in PC during treatment are significantly associated with improvement in IBS clinical outcomes through 3-month follow-up. Results from the current study provide evidence that PC may be an important, albeit nonspecific change mechanism, during CBT for IBS. Overall, reducing the emotional unpleasantness of pain through cognitive processes is associated with improved outcomes for IBS.

The role of gut microbiota on cognitive development in rodents: a meta-analysis

Cognitive function includes learning, remembering and using acquired information. Emerging studies indicate the correlation between microbiota and cognitive function. Higher abundance of a specific gut microbiota, such as Bacteroidetes may improve cognitive abilities. However, another study reported different result. These results suggest that further systematic analysis is required to determine the effect of the gut microbiota abundance on cognitive development. The aim of this study is to summarize the abundance of the specific gut microbiota and cognitive development using meta-analysis. PubMed, ScienceDirect, and Clinical-Key were used as data bases to perform the literature search. Phylum Bacteroidetes, and family Lactobacillaceae were more abundant in cognitive-behavioral enhancement (CBE), whereas Firmicutes, Proteobacteria, Actinobacteria, and family Ruminococcaceae were less abundant in CBE. Differences in gut microbiota abundance are influenced by differences in stage of cognitive dysfunction, intervention, and strain of gut microbiota.

Approach to Disorders of Gut-Brain Interaction

Disorders of gut-brain interaction, previously known as functional gastrointestinal disorders (eg, functional dyspepsia and irritable bowel syndrome), are commonly encountered in both the primary care and gastroenterology clinics. These disorders are often associated with high morbidity and poor patient quality of life and often lead to increased health care use. The management of these disorders can be challenging, as patients often present after having undergone an extensive workup without a definite etiology. In this review, we provide a practical five-step approach to the clinical assessment and management of disorders of gut-brain interaction. The five-step approach includes (1) excluding organic etiologies of the patient's symptoms and using Rome IV criteria for diagnosis, (2) empathizing with the patient to develop trust and a therapeutic relationship, (3) educating the patient about the pathophysiology of these gastrointestinal disorders, (4) expectation setting with a focus on improving function and quality of life, and (5) establishing a treatment plan with central and peripherally acting medications and nonpharmacological modalities. We discuss the pathophysiology of disorders of gut-brain interaction (eg, visceral hypersensitivity), initial assessment and risk stratification, as well as treatment for a variety of diseases with a focus on irritable bowel syndrome and functional dyspepsia.

Development of a brief cognitive-behavioral treatment for avoidant/restrictive food intake disorder in the context of disorders of gut-brain interaction: Initial feasibility, acceptability, and clinical outcomes

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) symptoms are common (up to 40%) among adults with disorders of gut-brain interaction (DGBI), but treatments for this population (DGBI + ARFID) have yet to be evaluated. We aimed to identify initial feasibility, acceptability, and clinical effects of an exposure-based cognitive-behavioral treatment (CBT) for adults with DGBI + ARFID.

METHODS

Patients (N = 14) received CBT as part of routine care in an outpatient gastroenterology clinic. A two-part investigation of the CBT included a retrospective evaluation of patients who were offered a flexible (8-10) session length and an observational prospective study of patients who were offered eight sessions. Feasibility benchmarks were ≥75% completion of sessions, quantitative measures (for treatment completers), and qualitative interviews. Acceptability was assessed with a benchmark of ≥70% patients reporting a posttreatment satisfaction scores ≥3 on 1-4 scale and with posttreatment qualitative interviews. Mixed model analysis explored signals of improvement in clinical outcomes.

RESULTS

All feasibility and acceptability benchmarks were achieved (and qualitative feedback revealed high satisfaction with the treatment and outcomes). There were improvements in clinical outcomes across treatment (all p's < .0001) with large effects for ARFID fear (-52%; Hedge's g = 1.5; 95% CI = 0.6, 2.5) and gastrointestinal-specific anxiety (-42%; Hedge's g = 1.0; 95% CI = 0.5, 16). Among those who needed to gain weight (n = 10), 94%-103% of expected weight gain goals were achieved.

DISCUSSION

Initial development and testing of a brief 8-session CBT protocol for DGBI + ARFID showed high feasibility, acceptability, and promising clinical improvements. Findings will inform an NIH Stage 1B randomized control trial.

PUBLIC SIGNIFICANCE

While cognitive-behavioral treatments (CBTs) for ARFID have been created in outpatient feeding and eating disorder clinics, they have yet to be developed and refined for other clinic settings or populations. In line with the recommendations for behavioral treatment development, we conducted a two-part investigation of an exposure-based CBT for a patient population with high rates of ARFID-adults with disorders of gut-brain interaction (also known as functional gastrointestinal disorders). We found patients had high satisfaction with treatment and there were promising improvements for both gastrointestinal and ARFID outcomes. The refined treatment includes eight sessions delivered by a behavioral health care provider and the findings reported in this article will be studied next in an NIH Stage 1B randomized controlled trial.

The neurobiology of irritable bowel syndrome

Irritable bowel syndrome (IBS) is the most prevalent disorder of brain-gut interactions that affects between 5 and 10% of the general population worldwide. The current symptom criteria restrict the diagnosis to recurrent abdominal pain associated with altered bowel habits, but the majority of patients also report non-painful abdominal discomfort, associated psychiatric conditions (anxiety and depression), as well as other visceral and somatic pain-related symptoms. For decades, IBS was considered an intestinal motility disorder, and more recently a gut disorder. However, based on an extensive body of reported information about central, peripheral mechanisms and genetic factors involved in the pathophysiology of IBS symptoms, a comprehensive disease model of brain-gut-microbiome interactions has emerged, which can explain altered bowel habits, chronic abdominal pain, and psychiatric comorbidities. In this review, we will first describe novel insights into several key components of brain-gut microbiome interactions, starting with reported alterations in the gut connectome and enteric nervous system, and a list of distinct functional and structural brain signatures, and comparing them to the proposed brain alterations in anxiety disorders. We will then point out the emerging correlations between the brain networks with the genomic, gastrointestinal, immune, and gut microbiome-related parameters. We will incorporate this new information into a systems-based disease model of IBS. Finally, we will discuss the implications of such a model for the improved understanding of the disorder and the development of more effective treatment approaches in the future.

Symptom management needs of patients with irritable bowel syndrome and concurrent anxiety and/or depression: A qualitative study

AIMS

To understand the experiences and needs of symptom management among individuals with irritable bowel syndrome and concurrent symptoms of anxiety and/or depression.

DESIGN

This study used a qualitative descriptive research design.

METHODS

Individuals with a diagnosis of irritable bowel syndrome and concurrent symptoms of anxiety and/or depression participated were recruited through an online ResearchMatch and a listserv. Semi-structured interviews focused on symptoms and experiences with symptom management interventions conducted from June to August 2020. Interviews were transcribed and data were analysed based on thematic analysis.

RESULTS

Twelve individuals participated in this study; all reported current irritable bowel syndrome and anxiety/depression symptoms. The data analysis cumulated with three themes related to symptom management: (a) irritable bowel syndrome negatively impacts physical and mental well-being; (b) a trial and error approach to symptom management; and (c) challenges with healthcare professionals supporting symptom management including negative interactions with healthcare professionals and lack of nutritional expertize and support.

CONCLUSION

There is a need for individualized approaches which consider patients' current symptoms of anxiety and depression, previous experiences with the trial-and-error process and consideration for intervention delivery methods.

IMPACT

There is a limited qualitative research focusing on the experiences of individuals with irritable bowel syndrome and concurrent symptoms of anxiety and/or depression. This research highlights the need for individualized approaches to enhance symptom management that acknowledges patients' psychological state and past negative experiences with providers and prior dietary regimens.

Digital health for functional gastrointestinal disorders

BACKGROUND

Functional gastrointestinal disorders are a common but challenging set of conditions to treat. Gastroenterology practices often struggle to meet the needs of patients with functional disorders given the need for careful monitoring, frequent communication, and management of stressors that occur outside of the clinical setting. In recent years, applications in digital health have created a new set of tools that can improve the care of these patients, including through improved symptom tracking, physiologic monitoring, direct provision of care, and patient support.

PURPOSE

The purpose of this review is to evaluate how digital applications are being used to manage functional gastrointestinal disorders today, with several examples of relevant technologies and organizations. It also the shortcomings of current treatment strategies and how they can be overcome.

New multimodal intervention to reduce irritable bowel syndrome (IBS) severity symptoms-Pilot study with a 12 month follow-up

INTRODUCTION

Irritable bowel syndrome (IBS) is characterized by patients' high level of suffering. Up to 60% of patients with IBS have symptoms of anxiety or depression and only little attention has been paid to their specific requirements. Anthroposophical multimodal therapy (AMT) has been shown to significantly improve health-related quality of life of patients with high symptomatic burden.

OBJECTIVE

The aim of this pilot study was to find out whether AMT meets the needs of IBS patients and the interactions of AMT with IBS, depression and anxiety.

METHODS

Patients with diagnosed IBS were included in a feasibility study and received 12 sessions of AMT over 8 weeks (drks.de, DRKS00016890). The primary endpoint was the change of the IBS severity score (IBS-SSS) and changes were calculated by linear mixed effects analyses. The secondary endpoints were changes of self-reported PHQ-9 and GAD-7 for mental comorbidity as well as self-valued effectiveness and satisfaction of AMT.

RESULTS

Thirty-six patients, 89% female, were included in the study. AMT was successfully applied to IBS patients (-45 points in the IBS-SSS, p < .05). AMT had a large positive effect (-84 points in IBS-SSS, p < .003) on patients without anxiety or depression. Over time, patients with higher anxiety scores worsened with regard to their IBS compared to patients with depression and without mental comorbidity. The AMT effect was maintained at a 12 month follow up and both mentally affected and unaffected patients, had even lower IBS severity than shortly after AMT. AMT modules were rated by IBS patients as very effective.

CONCLUSION

Our findings suggest that an 8-week program of AMT improves the severity of IBS with an ongoing effect at a 12 month follow-up. Especially for patients without psychological comorbidities, AMT is very successful. Future IBS therapies should incorporate a modified multimodal concept with stronger psychological therapy modules in parallel for patients with depression and anxiety.

Study protocol and methods for Easing Pelvic Pain Interventions Clinical Research Program (EPPIC): a randomized clinical trial of brief, low-intensity, transdiagnostic cognitive behavioral therapy vs education/support for urologic chronic pelvic pain syndrome (UCPPS)

Background

Urologic chronic pelvic pain syndrome (UCPPS) encompasses several common, costly, diagnoses including interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome that are poorly understood and inadequately treated with conventional medical therapies. Behavioral strategies, recommended as a first-line treatment for managing symptoms, are largely inaccessible, time and labor intensive, and technically complex. The Easing Pelvic Pain Interventions Clinical Research Program (EPPIC) is a clinical trial examining the efficacy of low-intensity cognitive behavioral therapy (Minimal Contact CBT or MC-CBT) for UCPPS and its durability 3 and 6 months post treatment. Additional aims include characterizing the operative processes (e.g., cognitive distancing, context sensitivity, coping flexibility, repetitive negative thought) that drive MC-CBT-induced symptom relief and pre-treatment patient variables that moderate differential response.

Methods

UCPPS patients (240) ages 18–70 years, any gender, ethnicity, and race, will be randomized to 4-session MC-CBT or a credible, non-specific education comparator (EDU) that controls for the generic effects from simply going to treatment. Efficacy assessments will be administered at pre-treatment, 2 weeks, and 3 and 6 months post treatment-week acute phase. A novel statistical approach applied to micro-analytic mediator assessment schedule will permit the specification of the most effective CBT component(s) that drive symptom relief.

Discussion

Empirical validation of a low-intensity self-management therapy transdiagnostic in scope has the potential to improve the health of chronic pelvic pain patients refractory to medical therapies, reduce social and economic costs, conserve health care resources, as well as inform evidence-based practice guidelines. Identification of change mechanisms and moderators of treatment effects can provide proactive patient-treatment matching fundamental to goals of personalized medicine.

Trial Registration

Clinicaltrials.gov NCT05127616. Registered on 9/19/21.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06554-9.

Quality of life in irritable bowel syndrome: Exploring mediating factors through structural equation modelling

BACKGROUND

Irritable Bowel Syndrome (IBS) negatively influences mental and physical quality of life (QoL), but factors that explain this impact are still unclear. Increasing evidence has associated IBS severity, psychological distress, somatic symptoms, and gastrointestinal (GI)-specific anxiety with QoL in IBS. The aim of this study is to further explore these associations and to analyze potential mediating factors.

METHOD

A total of 1017 IBS patients (69.3% female, mean age 40.6 years) who completed a QoL measure (SF-36) were included in this study. A proportion of these participants (N = 183; 72.7% female, mean age 41.7), who additionally completed psychological distress, somatic symptoms, and GI-specific anxiety measures, was included in the mediation analysis. This analysis was conducted via structural equation modelling to identify factors of importance for generic QoL, using a cross-sectional design.

RESULTS

IBS patients reported lower QoL than what is observed in the general population, in particular regarding role limitations caused by health and emotional functioning, vitality, and social functioning. Female patients scored lower than male patients on most QoL dimensions. The effects of IBS severity on mental and physical QoL were mediated by GI-specific anxiety. In addition to GI-specific anxiety, depressive symptoms were also of importance for mental QoL, and somatic symptom severity for physical QoL.

CONCLUSION

QoL is reduced in patients with IBS and GI-specific anxiety, depressive symptoms, and somatic complaints are particularly important for this outcome. Future trials should test the efficacy of psychological interventions specifically targeting these factors in improving QoL in IBS.

Enriched environment alleviates adolescent visceral pain, anxiety- and depression-like behaviors induced by neonatal maternal separation

BACKGROUND

Neonatal maternal separation (NMS), a major kind of early life stress, increases the risk of visceral pain, anxiety- and depression-like behaviors in adulthood. An enriched environment (EE) has been shown to successfully rescue the brain from various early life psychological stressors. Therefore, this study aimed to investigate whether NMS induces visceral pain, anxiety- and depression-like behaviors in adolescents and to evaluate the impact of EE in infancy on these symptoms.

METHODS

Male C57BL/6 J mice that had been subjected to NMS were used in this study. The visceral pain threshold test (PTT), open field test (OFT), and sucrose preference test (SPT) were conducted to evaluate visceral pain, anxiety- and depression-like behaviors in mice, respectively. An enzyme linked immunosorbent assay (ELISA) for tumor necrosis factor-α (TNF-α), interleukin-1β, (IL-1β), and interleukin-10 (IL-10) was performed to assess neuroinflammatory responses. Then, the effects of EE (free-turning running wheels, pipes, stairs, and various colored ocean balls, etc.) on NMS-induced behaviors and neuroinflammatory factors were examined.

RESULTS

The impacts of NMS included adolescent visceral pain, anxiety- and depression-like behaviors. The medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and paraventricular nucleus (PVN) were biased towards pro-inflammatory features. Further, EE alleviated adolescent visceral pain, anxiety- and depression-like behaviors. The application of EE up-regulated the expression of IL-10, and down-regulated the expression of IL-1β and TNF-α in mPFC, BLA, and PVN.

CONCLUSIONS

The effects of NMS include adolescent visceral pain, anxiety- and depression-like behaviors, accompanied by an imbalance of neuroinflammation. Intervention with EE in pediatric mice relieved these symptoms by reducing neuroinflammation in the central nervous system.

Associations between Abnormal Eating Styles and Irritable Bowel Syndrome: A Cross-Sectional Study among Medical School Students

(1) Background: Few studies have investigated the association between eating styles and IBS. This study aimed to explore the association between abnormal eating styles and irritable bowel syndrome (IBS). (2) Methods: This cross-sectional study investigated students in China Medical University and Shenyang Medical College. Eating styles were evaluated by the Dutch Eating Behavior Questionnaire (DEBQ), and IBS was diagnosed according to Rome III criteria. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). (3) Results: A total of 335 students were diagnosed with IBS. Students with the total scores in tertile 2 and 3 had 1.29 times and 2.75 times higher risk of IBS than students with the total scores in tertile 1, respectively. Simultaneously, the risk of IBS in the tertile 3 of external eating, emotional eating, and restraint eating trends was 3.87 times, 2.71 times, and 3.82 times higher than that of tertile 1, respectively. (4) Conclusions: this study showed that a high score in both total eating styles and each eating style was associated with the odds of having IBS and suggested that the psychological factors behind eating styles may play a critical role in controlling the IBS.

Delivery Methods of Cognitive Behavior Therapy for Patients With Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is the most commonly diagnosed gastrointestinal disorder and negatively impacts individuals' quality of life. Cognitive behavioral therapy appears effective for reducing symptoms in many irritable bowel syndrome patients. However, the optimal methods to deliver cognitive behavioral therapy and the effective treatment dosage for patients with IBS remain unclear. This article aims to provide an update on cognitive behavioral therapy research in IBS, particularly considering the dose of treatment, route of delivery (in-person vs. web- and telephone-based delivery), and outcome measures. A systematic literature review was conducted using databases of PubMed, CINAHL Complete, and Web of Science from 2008 through 2021. Twelve studies reporting randomized clinical trials comparing cognitive behavioral therapy delivered with in-person, telephone, and web for the management of IBS symptoms among adults with irritable bowel syndrome were found. The dose of treatment varied from 4 to 10 sessions. Six different scales measured various outcomes. No severe adverse reactions to cognitive behavioral therapy were reported. Cognitive behavioral therapy is an effective treatment for IBS symptoms regardless of the dose and the route of treatment. However, it is difficult to compare the effectiveness of these randomized clinical trials due to the various cognitive behavioral therapy protocols, combined routes of therapy delivery, and different outcome measures used.

Do I really have to do my homework? The role of homework compliance in cognitive behavioral therapy for irritable bowel syndrome

Treatment guidelines identify cognitive behavioral therapy (CBT) as a treatment of choice for irritable bowel syndrome (IBS). As a learning-based treatment, homework assignments are regarded as important for optimizing outcomes for CBT-treated patients. However, their actual benefit for IBS is unknown. This study examined whether homework completion corresponds with immediate and sustained treatment response in IBS patients enrolled in CBT treatment. Subjects were 358 IBS patients receiving clinic-based CBT (10 session), home-based CBT (4 session), or a 4 session, non-specific IBS education comparator as part of a large NIH trial. Homework completion was rated by clinician at each session. IBS symptom improvement was measured with the Clinician Global Improvement Scale at treatment week 5, post-treatment (week 12), and at follow-ups (weeks 22, 34, 46, 62). Homework completion rates over the 10-week acute phase corresponded with greater IBS symptom improvement and patient satisfaction at post-treatment. Early treatment homework completion did not predict early treatment response. Contrary to expectations, homework compliance rates were not greater among in-clinic session patients than home-based patients. Data lend empirical support to the clinical value of homework in teaching patients how to self-manage painful GI symptoms refractory to conventional medical and dietary therapies.

Acupuncture in addition to usual care for patients with irritable bowel syndrome: a component network meta-analysis

OBJECTIVE

The efficacy of acupuncture alone in the treatment of irritable bowel syndrome (IBS) is controversial, but the benefit of acupuncture added to usual care has rarely been studied. We aimed to examine the benefit of acupuncture added to usual care through network meta-analysis (NMA).

METHODS

PubMed, Embase, and the Cochrane Register of Controlled Trials (CENTRAL) were searched from their inception to 1 July 2021, without any language restriction. Randomized controlled trials (RCTs) testing the effect of acupuncture alone or acupuncture combined with usual care for IBS were included. The primary outcome was improvement of global IBS symptoms. Standard NMA was performed to compare differential combinations of acupuncture (including manual acupuncture (MA) and electroacupuncture (EA)), and component network meta-analysis (CNMA) was subsequently performed to determine whether acupuncture provided additional benefits to usual care. The effect size of an intervention was measured using relative ratio (RR).

RESULTS

We included 25 RCTs (n = 3041 participants) after screening 582 retrieved articles. Five RCTs were classified as low risk of bias. The results of standard NMA showed that MA combined with usual care ranked the most effective (sham acupuncture as common comparator; RR = 1.96 (95% confidence interval (CI) 1.23 to 3.12)). The results of CNMA showed that MA was the most effective component (RR = 1.38 (95% CI, 1.12 to 1.70)) when added to usual care.

CONCLUSION

Acupuncture provided additional benefits to usual care, and it might be considered as adjunctive therapy for patients who respond inadequately to usual care.

Brain Network Topology and Structural–Functional Connectivity Coupling Mediate the Association Between Gut Microbiota and Cognition

Increasing evidence indicates that gut microbiota can influence cognition via the gut–brain axis, and brain networks play a critical role during the process. However, little is known about how brain network topology and structural–functional connectivity (SC–FC) coupling contribute to gut microbiota-related cognition. Fecal samples were collected from 157 healthy young adults, and 16S amplicon sequencing was used to assess gut diversity and enterotypes. Topological properties of brain structural and functional networks were acquired by diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (fMRI data), and SC–FC coupling was further calculated. 3-Back, digit span, and Go/No-Go tasks were employed to assess cognition. Then, we tested for potential associations between gut microbiota, complex brain networks, and cognition. The results showed that gut microbiota could affect the global and regional topological properties of structural networks as well as node properties of functional networks. It is worthy of note that causal mediation analysis further validated that gut microbial diversity and enterotypes indirectly influence cognitive performance by mediating the small-worldness (Gamma and Sigma) of structural networks and some nodal metrics of functional networks (mainly distributed in the cingulate gyri and temporal lobe). Moreover, gut microbes could affect the degree of SC–FC coupling in the inferior occipital gyrus, fusiform gyrus, and medial superior frontal gyrus, which in turn influence cognition. Our findings revealed novel insights, which are essential to provide the foundation for previously unexplored network mechanisms in understanding cognitive impairment, particularly with respect to how brain connectivity participates in the complex crosstalk between gut microbiota and cognition.

An enriched environment reduces chronic stress-induced visceral pain through modulating microglial activity in the central nucleus of the amygdala

Cognitive behavioral therapy (CBT) improves the quality of life for patients with brain-gut disorders; however, the underlying mechanisms of CBT remain to be explored. Previously, we showed that environmental enrichment (EE), an experimental paradigm that mirrors positive behavioral intervention, ameliorates chronic stress-induced visceral hypersensitivity in a rodent model via mechanisms involving altered activity in the central nucleus of amygdala (CeA). In the present study, we investigated whether microglia-mediated synaptic plasticity in the CeA is a potential mechanism underlying the protective effects of EE against stress-induced visceral hypersensitivity. We stereotaxically implanted corticosterone (CORT) micropellets onto the dorsal margin of the CeA shown previously to induce colonic hypersensitivity. Animals were housed in EE cages or standard cages for 14 days after CORT implantation. Visceral sensitivity was assessed via visceromotor behavioral response to colorectal distension. Microglial morphology, microglia-mediated synaptic engulfment, and the expression of synaptic pruning-related signals complement component 1q (C1q), complement component 3 (C3), and C3 receptor (C3R) were measured using immunofluorescence and RNAscope assay. We found that housing CORT implanted rats in EE cages for 14 days attenuated visceral hypersensitivity in both male and female rats as compared with control rats maintained in standard housing. EE reduced CORT-induced microglial remodeling and microglia-mediated synaptic pruning with reduced C1q and CR3, but not C3, expression. Our data suggest that exposure to EE is sufficient to ameliorate stress-induced visceral pain via reducing amygdala microglia-modulated neuronal plasticity.NEW & NOTEWORTHY Clinical studies show that cognitive behavioral therapy (CBT) is effective in ameliorating visceral pain in patient with irritable bowel syndrome (IBS), yet the underlying mechanisms remain unexplored. By using environmental enrichment (EE), an experimental paradigm that mirrors positive behavioral intervention, we demonstrated that microglia-mediated synaptic plasticity in the CeA explains, plays a role, at least in part, in the positive effects of EE to reduce visceral hypersensitivity.

Acceptability and efficacy of the Zemedy app versus a relaxation training and meditation app for IBS: protocol for a randomised controlled trial

INTRODUCTION

Irritable bowel syndrome (IBS) has high rates of psychiatric comorbidity, and impairs health-related quality of life (HRQL). Cognitive-behavioural therapy (CBT) is an effective treatment for IBS, but access to treatment remains low. Our proposed solution is a CBT-based smartphone app, Zemedy.

METHODS AND ANALYSIS

This randomised controlled trial of Zemedy (V.2.0) uses an education and relaxation training active control app meant to simulate treatment as usual. A target N of 300 participants complete baseline questionnaires and consent at screening, and are then allocated to either the immediate treatment (Zemedy) or the active control. Treatment lasts 8 weeks, after which both groups complete the same battery used at baseline, and the control group is crossed over to Zemedy. After another 8 weeks, the crossed-over participants will be surveyed once more. Follow-up questionnaires are administered at 3, 6 and 12 months post-treatment. Primary outcomes include gastrointestinal symptom severity and HRQL. Clinically significant change will be defined as post-treatment scores falling within 2 SD of the healthy mean. Analysis will include intent-to-treat between-groups comparisons, controlling for baseline symptom severity, as well as moderation and mediation analyses. We hypothesise that the Zemedy app will outperform the active control app in reducing IBS symptom severity and improving HRQL.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Board at the University of Pennsylvania. Results will provide essential information on the efficacy and acceptability of an app-based CBT treatment for IBS. The data gathered may help establish the Zemedy app as an empirically supported intervention for IBS and will assist funding bodies in deciding whether to invest in its further development and dissemination. The results will be disseminated to patients with IBS via the media and the company website, to healthcare professionals via professional training (e.g. webinars and grand rounds talks) and to researchers via conferences and publications.

TRIAL REGISTRATION NUMBER

NCT04665271 (https://clinicaltrials.gov/ct2/show/NCT04665271).

Comparing Costs and Outcomes of Treatments for Irritable Bowel Syndrome With Diarrhea: Cost-Benefit Analysis

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most expensive gastroenterological conditions and is an ideal target for developing a value-based care model. We assessed the comparative cost-benefit of treatments for IBS with diarrhea (IBS-D), the most common IBS subtype from insurer and patient perspectives.

METHODS

We constructed a decision analytic model assessing trade-offs among guideline-recommended and recently FDA-approved drugs, supplements, low FODMAP diet, cognitive behavioral therapy (CBT). Outcomes and costs were derived from systematic reviews of clinical trials and national databases. Health-gains were represented using quality-adjusted life years (QALY).

RESULTS

From an insurer perspective, on-label prescription drugs (rifaximin, eluxadoline, alosetron) were significantly more expensive than off-label treatments, low FODMAP, or CBT. Insurer treatment preferences were driven by average wholesale prescription drug prices and were not affected by health gains in sensitivity analysis within standard willingness-to-pay ranges up to $150,000/QALY-gained. From a patient perspective, prescription drug therapies and neuromodulators appeared preferable due to a reduction in lost wages due to IBS with effective therapy, and also considering out-of-pocket costs of low FODMAP food and out-of-pocket costs to attend CBT appointments. Comparative health outcomes exerted influence on treatment preferences from a patient perspective in cost-benefit analysis depending on a patients' willingness-to-pay threshold for additional health-gains, but health outcomes were less important than out-of-pocket costs at lower willingness-to-pay thresholds.

CONCLUSIONS

Costs are critical determinants of IBS treatment value to patients and insurers, but different costs drive patient and insurer treatment preferences. Divergent cost drivers appear to explain misalignment between patient and insurer IBS treatment preferences in practice.

A Coached Digital Cognitive Behavioral Intervention Reduces Anxiety and Depression in Adults With Functional Gastrointestinal Disorders

INTRODUCTION

Traditional cognitive behavioral interventions (CBIs) improve mood and gastrointestinal symptom severity in patients with functional gastrointestinal disorders (FGIDs) but face substantial barriers to implementation. Integrating behavioral health technology into medical clinic workflows could overcome these barriers. We evaluated the feasibility and impact of a coached digital CBI (dCBI) as a first-line intervention in a prospective cohort of emotionally distressed patients with FGID.

METHODS

Patients with anxiety and/or depressive symptoms were offered a dCBI (an app called RxWell) during routine clinic visits. RxWell provides cognitive behavioral techniques enhanced by within-app text messaging with a health coach. Both gastroenterology and behavioral health-care providers electronically prescribed RxWell. We tracked patient interactions with RxWell, and patients completed anxiety (General Anxiety Disorder-7) and depression (Personal Health Questionniare Depression Scale) measures through the app. Our primary study outcome was the change in General Anxiety Disorder-7 and Personal Health Questionniare Depression Scale scores.

RESULTS

Of 364 patients with FGID (mean age 43 years [SD 16 years]; 73.1% women) prescribed the dCBI, 48.4% enrolled (median use, 3 techniques [interquartile range 1-14]). About half of RxWell enrollees communicated with health coaches. The mean baseline anxiety score was 11.4 (SD 5.5), and the depression score was 11.5 (SD 6.1). RxWell users experienced improvements in anxiety (mean change 2.71 [t = 3.7, df = 58; P < 0.001]) and depression (mean change 2.9 [t = 4.2, df = 45; P < 0.001]) at 4 months.

DISCUSSION

Patients with FGIDs and moderately severe anxiety and depressive symptoms are willing to use dCBI tools recommended by their providers. Our pilot data demonstrate that dCBI usage is associated with clinically and statistically significant mood symptom reductions.

Overall Impact of Coronavirus Disease 2019 Outbreak in Children With Functional Abdominal Pain Disorders: Results From the First Pandemic Phase

OBJECTIVE

We aimed to assess how the first phase of coronavirus disease 2019 (COVID-19) pandemic influenced symptoms in children with functional abdominal pain disorders (FAPDs) and to characterize their quality of life (QoL), anxiety and global health.

METHODS

This was a multicenter, observational, international study conducted between April and July 2020 at six different referral centers. Children diagnosed with FAPDs between October 2019 and February 2020 were enrolled and prospectively interviewed at 4 months of follow-up during the first pandemic phase (Quarantine group). Patients were asked to complete PedsQL 4.0 Generic Core Scale and PROMIS Anxiety and Global Health questionnaires. A cohort of children diagnosed with FAPDs between October 2018 and February 2019 was used as a Control group.

RESULTS

Three-hundred-fifty-six children were enrolled of whom 180 (mean age at diagnosis: 14 ± 2.8 years) in the Quarantine group and 176 (mean age at diagnosis: 13 ± 2.8 years) in the Control group. At 4 months of follow-up, we observed a significant reduction of children reporting >5 episodes of abdominal pain per month when compared to baseline, in both groups (Quarantine group: 63.9% vs 42.2%, P < 0.001; Control group: 83.5% vs 50%, P < 0.001). The Quarantine group had median QoL values of 84.8 with 16.6% of children showing high anxiety values and 55% having decreased global health score.

CONCLUSIONS

We demonstrated symptoms' improvement at 4 months of follow-up in both cohorts. During the first months of the COVID-19 quarantine children with FAPDs showed satisfactory QoL and anxiety scores, suggesting positive effects of school closure and increased parental attention.

Review Article: Current and future treatment approaches for IBS with diarrhoea (IBS-D) and IBS mixed pattern (IBS-M)

BACKGROUND

Irritable bowel syndrome-diarrhoea (IBS-D) and IBS-mixed stool pattern (IBS-M) are disorders of gut-brain interaction characterised by abdominal pain associated with diarrhoea or both diarrhoea and constipation respectively. The pathophysiology of IBS-D/M is multifactorial and not completely understood; thus, treatment is aimed at multiple mechanisms such as altering gut microbiota, visceral hypersensitivity, intestinal permeability, gut-brain interaction and psychological strategies.

AIM

The goal of this article was to provide an up-to-date review of the current evidence for both non-pharmacological and pharmacological treatment options in IBS-D and IBS-M. Future treatments for IBS-D and IBS-M will also be discussed.

METHODS

Medline and Embase database searches (through April 30 2021) to identify clinical studies in subjects with IBS-D in which dietary modification, alternative treatments (probiotics, acupuncture, exercise) as well as FDA-approved medications were used.

RESULTS

Dietary modification is often the first line of therapy. Furthermore, lifestyle treatments include complementary alternative medications (CAM), probiotics and peppermint oil are useful adjuncts but have not specifically been described in IBS-D/M. Evidence strongly supports psychotherapy in the treatment of IBS. Beyond over-the counter anti-diarrhoeals, anti-spasmodics and anti-depressants, pharmacological treatment now includes treating for bile acid malabsorption and the FDA-approved medications rifaximin, eluxadoline and alosetron.

CONCLUSIONS

The treatment of IBS-D/M ideally involves a multidisciplinary approach of primary care, gastroenterologist and psychologist. Treatment often involves both non-pharmacological and pharmacological therapies. Future therapies may include faecal microbial transplant, Crofelemer and serotonin antagonists, but further studies are needed.

The Role of Resilience in Irritable Bowel Syndrome, Other Chronic Gastrointestinal Conditions, and the General Population

BACKGROUND & AIMS

Resilience is the ability to adapt positively to stress and adversity. It is a potential therapeutic target as it is reduced in irritable bowel syndrome (IBS) compared to healthy controls and associated with worse symptom severity and poorer quality of life. The aim of this study was to examine if these findings are generalizable by comparing resilience between IBS versus the general population and other chronic gastrointestinal (GI) conditions.

METHODS

Participants in the general population completed an online survey containing questionnaires measuring demographics, diagnosis of IBS and other GI conditions, symptom severity, psychological symptoms, resilience, and early adverse life events (EALs). IBS was defined as having a physician diagnosis of IBS and/or meeting Rome criteria without co-morbid GI disease. All others were included in the general population group. The chronic GI conditions group included those with inflammatory bowel disease, celiac disease and/or microscopic colitis.

RESULTS

Resilience was lower in IBS (n = 820) than the general population (n = 1026; p < 0.001) and associated with worse IBS symptom severity (p < 0.05). Global mental health affected resilience differently in IBS compared to the general population (all p's < 0.05). EALs were associated with decreased ability to bounce back from adversity in both IBS and the general population (p < 0.001). Resilience scores were similar in IBS and other chronic GI conditions that present with similar symptoms.

CONCLUSIONS

Resilience is lower compared to the general U.S. population but does not appear to be specific to IBS as it is comparable to other chronic GI conditions. Low resilience negatively affects symptom severity and mental health and thus, may serve as a novel therapeutic target.

Cognitive behavioral therapy for irritable bowel syndrome induces bidirectional alterations in the brain-gut-microbiome axis associated with gastrointestinal symptom improvement

BACKGROUND

There is growing recognition that bidirectional signaling between the digestive tract and the brain contributes to irritable bowel syndrome (IBS). We recently showed in a large randomized controlled trial that cognitive behavioral therapy (CBT) reduces IBS symptom severity. This study investigated whether baseline brain and gut microbiome parameters predict CBT response and whether response is associated with changes in the brain-gut-microbiome (BGM) axis.

METHODS

Eighty-four Rome III-diagnosed IBS patients receiving CBT were drawn from the Irritable Bowel Syndrome Outcome Study (IBSOS; ClinicalTrials.gov NCT00738920) for multimodal brain imaging and psychological assessments at baseline and after study completion. Fecal samples were collected at baseline and post-treatment from 34 CBT recipients for 16S rRNA gene sequencing, untargeted metabolomics, and measurement of short-chain fatty acids. Clinical measures, brain functional connectivity and microstructure, and microbiome features associated with CBT response were identified by multivariate linear and negative binomial models.

RESULTS

At baseline, CBT responders had increased fecal serotonin levels, and increased Clostridiales and decreased Bacteroides compared to non-responders. A random forests classifier containing 11 microbial genera predicted CBT response with high accuracy (AUROC 0.96). Following treatment, CBT responders demonstrated reduced functional connectivity in regions of the sensorimotor, brainstem, salience, and default mode networks and changes in white matter in the basal ganglia and other structures. Brain changes correlated with microbiome shifts including Bacteroides expansion in responders.

CONCLUSIONS

Pre-treatment intestinal microbiota and serotonin levels were associated with CBT response, suggesting that peripheral signals from the microbiota can modulate central processes affected by CBT that generate abdominal symptoms in IBS. CBT response is characterized by co-correlated shifts in brain networks and gut microbiome that may reflect top-down effects of the brain on the microbiome during CBT. Video abstract.

Minimal-Contact Versus Standard Cognitive Behavioral Therapy for Irritable Bowel Syndrome: Cost-Effectiveness Results of a Multisite Trial

BACKGROUND

Irritable bowel syndrome (IBS) is a common, often disabling gastrointestinal (GI) disorder for which there is no satisfactory medical treatment but is responsive to cognitive behavior therapy (CBT).

PURPOSE

To evaluate the costs and cost-effectiveness of a minimal contact version of CBT (MC-CBT) condition for N = 145 for IBS relative to a standard, clinic-based CBT (S-CBT; N = 146) and a nonspecific comparator emphasizing education/support (EDU; N = 145).

METHOD

We estimated the per-patient cost of each treatment condition using an activity-based costing approach that allowed us to identify and estimate costs for specific components of each intervention as well as the overall total costs. Using simple means analysis and multiple regression models, we estimated the incremental effectiveness of MC-CBT relative to S-CBT and EDU. We then evaluated the cost-effectiveness of MC-CBT relative to these alternatives for selected outcomes at immediate posttreatment and 6 months posttreatment, using both an intent-to-treatment and per-protocol methodology. Key outcomes included scores on the Clinical Global Impressions-Improvement Scale and the percentage of patients who positively responded to treatment.

RESULTS

The average per-patient cost of delivering MC-CBT was $348, which was significantly less than the cost of S-CBT ($644) and EDU ($457) (p < .01). Furthermore, MC-CBT produced better average patient outcomes at immediate and 6 months posttreatment relative to S-CBT and EDU (p < .01). The current findings indicated that MC-CBT is a cost-effective option relative to S-CBT and EDU.

CONCLUSION

As predicted, MC-CBT was delivered at a lower cost per patient than S-CBT and performed better over time on the primary outcome of global IBS symptom improvement.

Comprehensive Cognitive-Behavioral Interventions Augment Diaphragmatic Breathing for Rumination Syndrome: A Proof-of-Concept Trial

BACKGROUND

Rumination syndrome (RS) is often treated in medical settings with 1-2 sessions of diaphragmatic breathing to target reflexive abdominal wall contraction in response to conditioned cues (e.g., food). However, many patients remain symptomatic and require additional behavioral interventions.

AIMS

In an attempt to augment diaphragmatic breathing with additional interventions, we tested the proof-of-concept of a comprehensive Cognitive-Behavioral Therapy (CBT) for RS.

METHODS

In an uncontrolled trial, adults with RS completed a 5-8 session CBT protocol, delivered by one of two psychology behavioral health providers. CBT included two main phases: awareness training and diaphragmatic breathing (Phase 1) and modularized interventions chosen by the therapist and patient to target secondary maintenance mechanisms (Phase 2). At pre-treatment, post-treatment, and 3-month follow-up, participants completed a semi-structured interview on RS symptoms with an independent evaluator.

RESULTS

Of 10 eligible individuals (ages 20-67 years, 50% female) offered treatment, all 10 initiated treatment and eight completed it. All participants endorsed high treatment credibility at Session 1. Permutation-based repeated measures ANOVA showed participants achieved large reductions in regurgitations across treatment [F(1,7) = 17.7, p = .007, η _p²  = .69]. Although participants reduced regurgitations with diaphragmatic breathing during Phase 1, addition of other CBT strategies in Phase 2 produced further large reductions [F(1,7) = 6.3, p = .04, η _p²  = .47]. Of eight treatment completers, treatment gains were maintained at 3-month follow-up for n = 6.

CONCLUSIONS

Findings provide evidence of feasibility, acceptability, and proof-of-concept for a comprehensive CBT for RS that includes interventions in addition to diaphragmatic breathing to target secondary maintenance mechanisms. Randomized controlled trials are needed.

Environmental enrichment prevents stress-induced epigenetic changes in the expression of glucocorticoid receptor and corticotrophin releasing hormone in the central nucleus of the amygdala to inhibit visceral hypersensitivity

INTRODUCTION

Stress is a known trigger for the symptoms of irritable bowel syndrome (IBS), a gastrointestinal (GI) disorder that presents with abnormal bowel habits and abdominal pain due to visceral hypersensitivity. While behavioral therapies have been used to attenuate IBS symptoms, the underlying mechanisms by which these therapies interact with stress-induced pathology remains to be delineated. Here we use a rat model to test the hypothesis that exposure to environmental enrichment (EE) inhibits stress-induced changes within the brain-gut axis to prevent visceral and somatic hypersensitivity and colonic hyperpermeability.

METHODS

Female rats (n = 8/group) were housed in EE one week before and one week during exposure to water avoidance stress (WAS) while controls were housed in standard cages (SH). One day after the final WAS exposure, colonic and somatic sensitivity were assessed by the visceromotor response (VMR) to colorectal distension (CRD) and withdrawal threshold elicited by an electronic von Frey on the hind paw of the rats respectively. All rats were returned to SH for 3 weeks before colonic and somatic sensitivity were reassessed on day 28. The rats were then immediately euthanized and the spinal cord was collected to assess changes in neuronal activation (assessed via ERK phosphorylation) in response to noxious CRD. A separate cohort of animals (n = 8/group) that did not undergo behavioral assessments was euthanized the day after the final WAS exposure and the central nucleus of the amygdala (CeA) was collected to investigate WAS and EE induced epigenetic changes at the glucocorticoid receptor (GR) and corticotrophin releasing hormone (CRH) promoter. The colon from these rats was also collected to assess colonic permeability via changes in transepithelial electrical resistance (TEER) in vitro.

RESULTS

Exposure to stress persistently increased VMR to CRD (P < 0.01) and decreased the hind paw withdrawal threshold (P < 0.001) in female rats. WAS also decreased TEER in the colon tissue of female rats (p = 0.05). In the CeA, WAS induced a decrease in histone acetylation at the GR promoter but increased histone acetylation at the CRH promoter and reduced GR-CRH interactions in the CeA. Analysis of the spinal cord showed that WAS increased CRD-evoked ERK phosphorylation in the dorsal horn. Exposure to EE prevented WAS-induced changes in the CeA, dorsal horn and colon respectively to prevent visceral and somatic hypersensitivity.

CONCLUSION

Our data reveals that behavioral therapies can produce long lasting molecular and epigenetic changes that can prevent stress-induced pathologies even after completion of the therapy. These results highlight the potential mechanisms by which behavioral therapies may ameliorate visceral pain associated stress-related pathologies such as the irritable bowel syndrome.

Supported online self-management versus care as usual for symptoms of fatigue, pain and urgency/incontinence in adults with inflammatory bowel disease (IBD-BOOST): study protocol for a randomised controlled trial

BACKGROUND

Despite being in clinical remission, many people with inflammatory bowel disease (IBD) live with fatigue, chronic abdominal pain and bowel urgency or incontinence that limit their quality of life. We aim to test the effectiveness of an online self-management programme (BOOST), developed using cognitive behavioural principles and a theoretically informed logic model, and delivered with facilitator support.

PRIMARY RESEARCH QUESTION

In people with IBD who report symptoms of fatigue, pain or urgency and express a desire for intervention, does a facilitator-supported tailored (to patient needs) online self-management programme for fatigue, pain and faecal urgency/incontinence improve IBD-related quality of life (measured using the UK-IBDQ) and global rating of symptom relief (0-10 scale) compared with care as usual?

METHODS

A pragmatic two-arm, parallel group randomised controlled trial (RCT), of a 12-session facilitator-supported online cognitive behavioural self-management programme versus care as usual to manage symptoms of fatigue, pain and faecal urgency/incontinence in IBD. Patients will be recruited through a previous large-scale survey of unselected people with inflammatory bowel disease. The UK Inflammatory Bowel Disease Questionnaire and global rating of symptom relief at 6 months are the co-primary outcomes, with multiple secondary outcomes measured also at 6 and 12 months post randomisation to assess maintenance. The RCT has an embedded pilot study, health economics evaluation and process evaluation. We will randomise 680 patients, 340 in each group. Demographic characteristics and outcome measures will be presented for both study groups at baseline. The UK-IBDQ and global rating of symptom relief at 6 and 12 months post randomisation will be compared between the study groups.

DISCUSSION

The BOOST online self-management programme for people with IBD-related symptoms of fatigue, pain and urgency has been designed to be easily scalable and implemented. If it is shown to improve patients' quality of life, this trial will enable clinicians and patients to make informed management decisions. This is the first trial, to our knowledge, focused on multiple symptoms prioritised by both people with IBD and health professionals.

TRIAL REGISTRATION

ISRCTN71618461 . Registered on 9 September 2019.

Potential Benefit With Complementary and Alternative Medicine in Irritable Bowel Syndrome: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Patients with irritable bowel syndrome (IBS) may pursue complementary and alternative medicine (CAM). We conducted a comprehensive systematic review and meta-analysis examining efficacy of CAM vs. placebo or sham in adults with IBS.

METHODS

Publication databases were searched for randomized controlled trials of CAM therapies (herbal therapy, dietary supplements, mind-body based, body-based, and energy-healing) in adults with IBS. Data were extracted to obtain pooled estimates of mean improvement in abdominal pain (standardized mean difference [SMD]) and relative risk (RR) of overall response using random effects models. Sensitivity and subgroup analyses along with quality assessments were completed.

RESULTS

Among 2825 articles identified, 66 were included. Herbal therapy (SMD=0.47, 95% CI: 0.20 to 0.75, I²=82%) demonstrated significant benefit over placebo for abdominal pain (low confidence in estimates). Benefit with mind-body based therapy for abdominal pain was of borderline significance (SMD=0.29, 95% CI: -0.01 to 0.59, I²=78%). Herbal therapy (RR=1.57, 95% CI: 1.31 to 1.88, I²=77%), dietary supplements (RR=1.95, 95% CI: 1.02 to 3.73, I²=75%), and mind-body based therapy (RR=1.67, 95% CI: 1.13 to 2.49, I²=63%) showed benefit for overall response compared to placebo (low confidence in estimates). Body-based and energy healing therapies demonstrated no significant benefit over placebo or sham for abdominal pain or overall response.

CONCLUSIONS

CAM therapies such as herbal or dietary supplements and mind-body based approaches may be beneficial for abdominal pain and overall response in IBS. However, overall quality of evidence is low. Rigorous, high quality clinical trials are warranted to investigate CAM in IBS.

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.

Pediatric allergic rhinitis with functional gastrointestinal disease: Associations with the intestinal microbiota and gastrointestinal peptides and therapeutic effects of interventions

Children are susceptible to allergic rhinitis (caused by external allergens) accompanied by functional gastrointestinal disease, which seriously affects physical and mental health. Antihistamines and nasal spray hormones are commonly used in clinical treatment, but these drugs often have unsatisfactory efficacy and result in high recurrence rates. Therefore, understanding the pathogenesis of allergic rhinitis with functional gastrointestinal disease and seeking safer treatment and prevention methods is essential. Herein, molecular ecology and immunoassays were used to analyze correlations between pediatric allergic rhinitis with functional gastrointestinal disease and both the intestinal microbiota and gastrointestinal peptide levels. Fifty healthy children (healthy group) and 80 children with allergic rhinitis with functional gastrointestinal disease (case group: evenly divided into a control group (conventional drug therapy) and an intervention group (conventional drug therapy + glutamine+probiotics)), were enrolled. Bifidobacterium and Lactobacillus counts and the gastrin and motilin levels were lower in the case group than in the healthy group, whereas Enterobacter, yeast, and Enterococcus counts and the somatostatin, serotonin, and vasoactive intestinal peptide levels were higher. Post treatment, intestinal microbiota indices, gastrointestinal peptide levels, and intestinal barrier function were better in the intervention group than in the control group (p < 0.05). The intervention group had a significantly higher total therapeutic response rate (95.00%) than the control group (77.50%). The intestinal microbiota was closely associated with gastrointestinal peptide levels. Treatment with glutamine and probiotics regulated these levels, re-established balance in the intestinal microbiota, and restored intestinal barrier function.

Specific and common mediators of gastrointestinal symptom improvement in patients undergoing education/support vs. cognitive behavioral therapy for irritable bowel syndrome

Objective: This study sought to characterize change mechanisms that underlie gastrointestinal (GI) symptom improvement in IBS patients undergoing two dosages of CBT for IBS as compared to a nondirective education/support (EDU) condition. Method: Data were collected in the context of a large clinical trial that randomized 436 Rome III-diagnosed IBS patients (Mage = 41, 80 % female) to standard, clinic-based CBT (S-CBT), a largely home-based version with minimal therapist contact (MC-CBT) or Education/Support that controlled for nonspecific effects. Outcome was measured with the IBS-version of the Clinical Global Improvement scale that was administered at Week 5 and 2-week posttreatment (Week 12). Potential mediators (IBS Self-efficacy (IBS-SE), pain catastrophizing, fear of GI symptoms, and treatment alliance were assessed at Weeks 3, 5, and 8 during treatment with the exception of treatment expectancy that was measured at the end of Session 1. Results: IBS-SE, a positive treatment expectancy for symptom improvement, and patient-therapist agreement on tasks for achieving goals mediated effects of CBT early in treatment (rapid response, RR) and at posttreatment. Notwithstanding their different intensities, both CBT conditions had comparable RR rates (43%-45%) and significantly greater than the EDU RR rate of 22%. While pain catastrophizing, fear of GI symptoms, and patient-therapist emotional bonding related to posttreatment symptom improvement, none of these hypothesized mediators explained differences between CBT and EDU, thereby lacking the mechanistic specificity of IBS-SE, task agreement, and treatment expectancy. Conclusion: Findings suggest that CBT-induced GI symptom improvement may be mediated by a constellation of CBT-specific (IBS-SE) and nonspecific (task agreement, treatment expectancy) processes that reciprocally influence each other in complex ways to catalyze, improve, and sustain IBS symptom relief. (PsycInfo Database Record (c) 2021 APA, all rights reserved).