Trauma history and risk of the irritable bowel syndrome in women veterans

Vitamin D Deficiency (VDD) and Benefits of Supplementation in Veterans with IBS-D

Many veterans deployed to Gulf War areas suffer from persistent chronic diarrhea that is disabling and affects their quality of life. The causes for this condition have eluded investigators until recently and recent literature has shed light on the effect of vitamin D on the brain-gut axis. This study focused on determining clinical causes contributing to diarrhea and assessed whether reversing the identified causes, specifically vitamin D deficiency (VDD), could reduce the incidence of diarrhea in Gulf War veterans (GWVs). All patients completed a workup that included serologies (IBD, celiac), routine laboratory tests (CBC, chemistry panels, TSH, T4, CRP), cultures for enteric pathogens (C diff, bacteria, viruses, small intestinal bacterial overgrowth (SIBO)), and upper and lower endoscopies with histology and a trial of cholestyramine to exclude choleretic diarrhea and rifaximin for dysbiosis. A total of 4221 veterans were screened for chronic diarrhea, yielding 105 GWVs, of which 69 GWVs had irritable bowel syndrome with diarrhea (IBS-D). Paired t-tests demonstrated that all GWVs had VDD (t-11.62, df68 and sig(2-tailed) 0.0001) (defined as a vitamin D level less than 30 ng/mL with normal ranges of 30-100 ng/mL) but no positive serologies, inflammatory markers, abnormal endoscopies, cultures, or histology to explain their persistent diarrhea. There was no correlation with age, BMI, or inflammation. Some zip codes had a higher frequency of GWVs with VDD, but the number of deployments had no impact. Treatment with vitamin D supplementation (3000-5000 units), given in the morning, based on weight, reduced the number of bowel movements per day (p < 0.0001) without causing hypercalcemia. We suggest that VDD is important in the etiology of IBS-D in GWVs and that vitamin D supplementation significantly reduces diarrhea.

The Prevalence, Humanistic Burden, and Health Care Impact of Irritable Bowel Syndrome Among United States Veterans

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) in veterans is understudied. This study sought to investigate (1) prevalence of IBS; (2) phenotypic, environmental, and psychosocial factors associated with IBS; and (3) associations of IBS with health-related quality of life and health care use.

METHODS

From June 2018 to April 2020, we invited veterans to complete the Rome IV IBS questionnaire; Short Form-12; posttraumatic stress disorder (PTSD) checklist; Hospital Anxiety and Depression Scale; and questionnaires on general health, antibiotic use, infectious enteritis (IE), and health care use.

RESULTS

Among 858 veteran respondents, 244 (28.4%) met Rome IV IBS criteria (47.5% IBS with diarrhea, 16.8% IBS with constipation, 33.6% mixed IBS). IBS was associated with greater anxiety and depression and lower quality of life (all P < .001). Provisional PTSD, IE, and bowel problems after antibiotics were more common in IBS (all P < .001) as were multiple doctor visits (P < .01) and hospitalizations (P = .04). Comparisons across non-IBS and IBS subgroups revealed overall associations of psychological comorbidities (P < .01), multiple doctor visits (P < .01), hospitalizations (P = .03), IE (P < .01), and bowel problems after IE (P = .03) or antibiotics (P < .01) with subgroup. Highest anxiety and depression scores, PTSD, multiple doctor visits, hospitalizations, and bowel problems after IE were observed in IBS with constipation. In adjusted analyses, IBS was associated (all P < .001) with anxiety (odds ratio [OR], 3.47), depression (OR, 2.88), lower quality of life, PTSD (OR, 3.09), IE (OR, 4.44), bowel problems after antibiotics (OR, 1.84), multiple doctor visits (OR, 2.08), and hospitalizations (OR, 1.78).

CONCLUSIONS

IBS is prevalent among veterans and has a measurable impact on individuals and health care resources. Veterans with IBS may experience significant psychological impairment.

Irritable Bowel Syndrome and the Gut Microbiome: A Comprehensive Review

Irritable Bowel Syndrome (IBS) is a functional disorder of the gastrointestinal tract characterized by abdominal pain and altered bowel habits. It has a prevalence of 10 to 25% in the United States and has a high disease burden, as evidenced by reduced quality of life, decreased work productivity and increased healthcare utilization and costs. IBS has been associated with several intra-intestinal and extra-intestinal conditions, including psychiatric comorbidities. Although the pathophysiology of IBS has not been fully elucidated, it involves dysregulation of communication between the brain and gut (brain–gut axis) which is associated with alterations in intestinal motility, gut permeability, visceral hypersensitivity and gut microbiota composition. The purpose of this article is to review the role the gut microbiota plays in the pathophysiology of IBS, understand factors that affect the gut microbiome and explore the microbiome as a target of treatment.

Prevalence of Gastrointestinal Symptoms and Irritable Bowel Syndrome Among Individuals With Symptomatic Posttraumatic Stress Disorder

GOALS

Our aim was to describe the prevalence of irritable bowel syndrome (IBS) and other gastrointestinal symptoms in a sample of veterans with posttraumatic stress disorder (PTSD) and to examine the relationship between gastrointestinal symptoms, PTSD severity, depression severity, and number of prior traumatic events reported.

BACKGROUND

IBS and PTSD can co-occur; yet, little research has focused on describing the gastrointestinal symptoms and prevalence of IBS among veterans with PTSD.

MATERIALS AND METHODS

We examined baseline data from a randomized clinical trial of behavioral interventions for veterans with PTSD. Veterans completed questionnaires assessing gastrointestinal symptoms (Gastrointestinal Patient-Reported Outcome Measures Information Systems; PROMIS) and lifetime traumatic events. Multivariable regression analyses were performed to examine associations between gastrointestinal symptoms and the number of prior traumas reported PTSD severity, and depression symptom severity.

RESULTS

One hundred eighty-four veterans with a diagnosis of PTSD were included. Twenty-five percent met the Rome III criteria for IBS. Veterans reported gastrointestinal symptoms including abdominal/belly pain (36%), diarrhea (21%), constipation (18%), and bloating/gas (17%). In multivariable analyses, greater PTSD severity was associated with worse constipation ( P =0.008), diarrhea ( P =0.005), and gas/bloating ( P =0.001) when controlling for age and sex. Higher levels of depressive symptoms severity were associated with greater abdominal/belly pain ( P =0.04).

CONCLUSIONS

Among a sample of veterans with PTSD, rates of IBS and abdominal/belly pain are greater than general US population reference values. Although levels of constipation and bloating/gas are lower than general US population reference values, increased severity of PTSD was associated with increased gastrointestinal symptoms.

Early adverse life events and post-traumatic stress disorder in patients with constipation and suspected disordered defecation

BACKGROUND

Early adverse life events (EALs) and post-traumatic stress disorder (PTSD) are associated with irritable bowel syndrome (IBS). Disordered defecation (DD) presents with symptoms of IBS or functional constipation (FC) and is associated with psychological distress. However, the role of trauma and stress in chronic constipation is poorly defined. We aimed to examine EALS, PTSD, and psychological symptoms in patients with constipation and suspected DD.

METHODS

We conducted a survey study among adults with constipation who completed anorectal manometry (ARM) and balloon expulsion testing (BET). Data were collected on socio-demographics, EALs, PTSD, bowel symptoms, quality of life, and anxiety and depression. We performed comparisons between individuals with normal versus abnormal ARM or BET, subgroup analysis by detailed ARM and BET findings, and latent class analysis using individual EAL domains.

KEY RESULTS

Among 712 eligible patients, 69 completed the study. EALs and provisional PTSD were present in 75.4% and 27.5%, respectively; rates did not differ between those with normal versus abnormal ARM or BET. Normal testing was associated with higher rates of specific EAL domains (emotional abuse and mental illness), higher depression scores, and poorer mental component scores in both primary and subgroup comparisons (all p < 0.05). Normal testing was associated with a lower likelihood of high-EAL latent class (p = 0.01) membership. Presence of IBS or FC did not influence associations.

CONCLUSIONS & INFERENCES

Early adverse life events and PTSD are prevalent in patients with constipation and suspected DD. Those with normal ARM and BET have higher rates of prior emotional abuse and poorer mental health.

Prevalence and Impact of Post-traumatic Stress Disorder in Gastrointestinal Conditions: A Systematic Review

Psychological distress is often observed in patients with gastrointestinal illness. To date, there has been limited research conducted to assess the prevalence and impact of post-traumatic stress disorder (PTSD) in gastrointestinal cohorts. The aim of this systematic review is to review the evidence for the prevalence of PTSD in gastrointestinal cohorts versus comparator groups (healthy controls and chronic illness groups), predictive factors associated with the development and management of PTSD and the impact on patient outcomes. Adult studies were identified through systematic searches of eight databases (MEDLINE, Embase, Emcare, PsycINFO, Ovid Nursing, CINAHL, Informit Health Collection, and Cochrane Library) in February 2020. The overall pooled prevalence rate of PTSD in GI cohorts was 36%; however, the prevalence rate in non-veteran-specific gastrointestinal cohorts of 18% across all GI classification groups is likely to be the more representative rate. The non-gastrointestinal chronic illness cohort PTSD prevalence rate was 11%. Predictors identified in the development of post-traumatic stress in gastrointestinal cohorts include: female gender, poor social support, life adversity, subjective pain, and dietary choices. Post-traumatic stress was found to exacerbate gastrointestinal symptoms in a Crohn's Disease sample, whereby disease exacerbation was four times in those who met the criteria for probable PTSD. Post-traumatic stress symptoms affect around one in five individuals (non-veteran status) with a gastrointestinal condition. Further research is needed to understand the psychological and biological mechanisms by which PTSD increases the risk of developing and exacerbating gastrointestinal symptoms.

Strides Toward Recovery From Intimate Partner Violence: Elucidating Patient-Centered Outcomes to Optimize a Brief Counseling Intervention for Women

Women in the United States continue to experience intimate partner violence (IPV) at unprecedented rates, necessitating the development and implementation of personalized, effective healthcare-based interventions. Methods of developing patient-centered interventions for IPV should elicit the voice of the target population (i.e., women who experience IPV) while assuring that outcomes identified as important are incorporated into the refined intervention. This pilot study is part of a multiphase, larger study aiming to refine an IPV intervention and clinical outcome measurements prior to formal evaluation of the effectiveness of the intervention. Specifically, this study elucidates patient-centered outcomes identified by women who have experienced IPV. Women patients of the Veterans Health Administration (VHA) in New England participated in focus groups to provide feedback and desired outcomes of a new IPV intervention. Patient-centered outcomes were defined by the participants. Focus groups were transcribed and analyzed using conventional content analysis and matrix analysis. A total of 25 women participated in focus groups (n = 5) at two large VHA facilities. Participant feedback revealed five common themes related to desired outcomes. Women opined increased feelings of empowerment as a key outcome of engaging in an IPV intervention. Women desired increased social connectedness and support to be gained during treatment, citing providers and other survivors of IPV as exemplary sources. Self-esteem was viewed as critical to enhancing recovery, as was increased knowledge across domains of IPV (e.g., warning signs, the link between mental and physical health for self and children). Finally, women identified valued action and goal setting, such as achieving more independence, as an optimal outcome. Addressing IPV against women requires patient-centered interventions that specifically target the types of outcomes deemed important by the end users: women who experience IPV. Findings have implications for tailoring treatments for IPV and selecting measures that tap into women's desired outcomes.

Clinical Complexity in Women Veterans: A Systematic Review of the Recent Evidence on Mental Health and Physical Health Comorbidities

A recent evidence map focused on women veterans underscored the limited number of articles published on mental health comorbid with physical health conditions in this population. The quality of this small body of research has yet to be evaluated. The aim of this systematic review was to evaluate and synthesize research published between 2008 and 2015 and identified in the Women Veterans' Health Research Evidence Map as related to mental and physical health comorbidities among women veterans. Following PRISMA guidelines, 23 published studies were identified and 21 were included in the review. In general, significant associations between several mental health conditions (e.g., depression, posttraumatic stress disorder, substance use disorders) and physical health disorders (e.g., cardiovascular disease, diabetes, gastrointestinal disorders, hypertension, obesity, pain, and urinary symptoms) and health behaviors (e.g., preventative care and treatment adherence) were noted. The majority of studies were rated as low risk of bias, with selection and detection bias most frequently observed across studies. Additionally, gaps in the recent literature were observed, including the need for further investigation of the role of medical conditions in complicating mental health symptoms and care provision. Results underscore the importance of healthcare providers attending to women veterans' mental and physical health simultaneously and irrespective of setting. Further, while the Department of Veterans Affairs continues to make sizable gains in its focus on women veterans' health, continued research on several health domains is needed to ensure adequate understanding of the health needs of women veterans.

Impact of occupational stress on irritable bowel syndrome pathophysiology and potential management in active duty noncombat Greek military personnel: a multicenter prospective survey

INTRODUCTION

Irritable bowel syndrome (IBS) is one of the gut-brain axis interaction disorders. It has global distribution with varying prevalence and particular financial and psychological consequences. IBS has been associated with stress and anxiety, conditions that are usually prevalent in the army. There are scarce data investigating the impact of IBS on noncombat active duty military without reports of Greek military or stress in the occupational environment.

MATERIALS AND METHODS

The main exclusion criteria in our noncombat military multicenter prospective survey were gastrointestinal pathologies, malignancies, hematochezia, recent infections and antibiotics prescription, and pregnancy. Questionnaires included a synthesis of baseline information, lifestyle, and diet, psychological and stress-investigating scales and the IBS diagnosis checklist. Hospital Anxiety and Depression Scale and Rome IV criteria were utilized.

RESULTS

Among 1605 participants included finally, the prevalence of IBS was 8% and 131 cases were identified. Women were more vulnerable to IBS, although male sex was prevalent at a ratio of 3.5 : 1 (male:female) in the entire sample. The mean age of all participants was 23.85 years; most of the IBS patients were older than thirty. Abnormal anxiety scores and high levels of occupational stress were related to an IBS diagnosis.

DISCUSSION

This prospective multicenter survey showed, for the first time, the potential impact of occupational stress on IBS in active duty noncombat Greek Military personnel. The diagnosis of IBS by questionnaire is a quick, affordable way that can upgrade, by its management, the quality of life and relieve from the military burden. Our results are comparable with previous studies, although large-scale epidemiological studies are required for the confirmation of a possible causative relationship.

Systematic review with meta-analysis: The association between post-traumatic stress disorder and irritable bowel syndrome

BACKGROUND AND AIM

Post-traumatic stress disorder (PTSD) is a psychiatric condition characterized by symptoms of hyperarousal and hypervigilance. Increasing research on the "gut-brain" axis (bidirectional signaling between the gut and the brain) has drawn links between PTSD and irritable bowel syndrome (IBS), an exceedingly common yet incompletely understood gastrointestinal condition. This meta-analysis thus aimed to examine the body of evidence and extent of association of PTSD with IBS.

METHODS

Using the keywords [early abuse OR childhood abuse OR violence OR trauma OR PTSD] AND [irritable bowel syndrome or IBS], a preliminary search on the PubMed, Medline, Embase, ScienceDirect, PsychINFO, Web of Science, and Google Scholar databases yielded 11,257 papers published in English between January 1, 1988, and May 1, 2018. Of these, only eight studies were included in the final meta-analysis.

RESULTS

The eight studies (four cross-sectional and four cohort) contained a total of 648,375 subjects. Most studies were from the USA and conducted on army veterans. The funnel plot revealed a roughly symmetrical distribution of studies, and Egger test was not significant for publication bias (P = 0.583). Random-effects meta-analysis found PTSD to be a significant risk factor for IBS (pooled odds ratio 2.80, 95% confidence interval: 2.06 to 3.54, P < 0.001).

CONCLUSIONS

Overall, PTSD is associated with an increased likelihood of IBS. This is the first meta-analysis to specifically examine the association between PTSD and IBS, and it provides insights into the probable (patho)physiology and management of IBS, supporting a holistic consideration of the psychosocial aspects of IBS and further research into effective multi-modal therapeutics.

The Prevalence of Military Sexual Trauma: A Meta-Analysis

Due to methodological heterogeneity, the exact prevalence of military sexual trauma (MST) is unknown. To elucidate our understanding of the pervasiveness of this important social issue, a meta-analysis was conducted. A computerized database search in PsycINFO, PubMed, and PILOTS revealed 584 unique citations for review. Of these identified studies, 69 met the inclusion criteria for the meta-analysis. The results revealed that 15.7% of military personnel and veterans report MST (3.9% of men, 38.4% of women) when the measure includes both harassment and assault. Additionally, 13.9% report MST (1.9% of men, 23.6% of women) when the measure assesses only assault and 31.2% report MST (8.9% of men, 52.5% of women) when the measure assesses only harassment. Regardless of the type of victimization incident (i.e., harassment or assault), women evidenced significantly larger prevalence rates compared to men. Self-report measure and interviews were associated with higher prevalence rates than the review of veterans affair (VA) medical records when measuring both harassment and assault and only harassment. No significant differences were observed among prevalence rates based on VA, non-VA, or both VA and non-VA recruitment. Ultimately, the findings suggest that MST is a pervasive problem, among both men and women in the military, highlighting the importance of this line of research.

Medically unexplained syndromes: irritable bowel syndrome, fibromyalgia and chronic fatigue

This is a review of three of the more common medically unexplained syndromes that present for treatment to liaison psychiatry services in general medical hospitals: chronic fatigue syndrome, fibromyalgia and irritable bowel syndrome. The three are interrelated, extremely disabling and comorbid mood disorders are frequent. In general, treatment, whether psychological or medical, has very modest impact. The disputed classification of medically unexplained syndromes is also reviewed. There is a clear gulf between the views and experiences of patients with these syndromes and the medical establishment. In this article I summarise give the evidence for pharmacological, psychosocial and ‘alternative’ or ‘complementary’ interventions for a range of disorders, about which there is some dispute. I leave it to the reader to decide which interventions hold the most promise.

LEARNING OBJECTIVES

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DECLARATION OF INTEREST

None.

Mechanisms of Stress-induced Visceral Pain

Evidence suggests that long-term stress facilitates visceral pain through sensitization of pain pathways and promotes chronic visceral pain disorders such as the irritable bowel syndrome (IBS). This review will describe the importance of stress in exacerbating IBS-induced abdominal pain. Additionally, we will briefly review our understanding of the activation of the hypothalamic-pituitary-adrenal axis by both chronic adult stress and following early life stress in the pathogenesis of IBS. The review will focus on the glucocorticoid receptor and corticotropin-releasing hormone-mediated mechanisms in the amygdala involved in stress-induced visceral hypersensitivity. One potential mechanism underlying persistent effects of stress on visceral sensitivity could be epigenetic modulation of gene expression. While there are relatively few studies examining epigenetically mediated mechanisms involved in stress-induced visceral nociception, alterations in DNA methylation and histone acetylation patterns within the brain, have been linked to alterations in nociceptive signaling via increased expression of pro-nociceptive neurotransmitters. This review will discuss the latest studies investigating the long-term effects of stress on visceral sensitivity. Additionally, we will critically review the importance of experimental models of adult stress and early life stress in enhancing our understanding of the basic molecular mechanisms of nociceptive processing.

An Evidence Map of the Women Veterans' Health Research Literature (2008-2015)

BACKGROUND

Women comprise a growing proportion of Veterans seeking care at Veterans Affairs (VA) healthcare facilities. VA initiatives have accelerated changes in services for female Veterans, yet the corresponding literature has not been systematically reviewed since 2008. In 2015, VA Women's Health Services and the VA Women's Health Research Network requested an updated literature review to facilitate policy and research planning.

METHODS

The Minneapolis VA Evidence-based Synthesis Program performed a systematic search of research related to female Veterans' health published from 2008 through 2015. We extracted study characteristics including healthcare topic, design, sample size and proportion female, research setting, and funding source. We created an evidence map by organizing and presenting results within and across healthcare topics, and describing patterns, strengths, and gaps.

RESULTS

We identified 2276 abstracts and assessed each for relevance. We excluded 1092 abstracts and reviewed 1184 full-text articles; 750 were excluded. Of 440 included articles, 208 (47%) were related to mental health, particularly post-traumatic stress disorder (71 articles), military sexual trauma (37 articles), and substance abuse (20 articles). The number of articles addressing VA priority topic areas increased over time, including reproductive health, healthcare organization and delivery, access and utilization, and post-deployment health. Three or fewer articles addressed each of the common chronic diseases: diabetes, hypertension, depression, or anxiety. Nearly 400 articles (90%) used an observational design. Eight articles (2%) described randomized trials.

CONCLUSIONS

Our evidence map summarizes patterns, progress, and growth in the female Veterans' health and healthcare literature. Observational studies in mental health make up the majority of research. A focus on primary care delivery over clinical topics in primary care and a lack of sex-specific results for studies that include men and women have contributed to research gaps in addressing common chronic diseases. Interventional research using randomized trials is needed.

Factors Associated with Severity of Irritable Bowel Syndrome Symptoms in Patients with Endometriosis

OBJECTIVE

This study sought to examine factors associated with severity of irritable bowel syndrome (IBS) by using the Birmingham IBS symptom scale in patients presenting with endometriosis to a tertiary referral centre.

METHODS

A prospective research cohort of patients presenting to a tertiary referral centre for endometriosis was evaluated for the presence and severity of IBS between December 2013 and April 2015. Patients with endometriosis had a diagnosis of IBS by using the Rome III criteria and were evaluated for severity of IBS symptoms by using the Birmingham IBS symptom scale. Multifactorial variables, including stage of endometriosis at the time of previous surgery, clinical examination findings, mood disorder questionnaire scores, and lifestyle factors, were evaluated using the t test and Spearman rank correlation test.

RESULTS

A total of 194 of 373 (52%) women with confirmed endometriosis had a diagnosis of IBS. Factors associated with severity of IBS symptoms in patients with endometriosis included lower-stage endometriosis (P = 0.004), presence of mood disorders (P <0.001), tenderness on physical examination (P ≤ 0.001), a history of sexual assault (P ≤ 0.02), and presence of sleep disturbance (P ≤ 0.01). Evaluation of the subscales of the Birmingham IBS symptom scale revealed a strong association between the previously identified factors and the pain subscale.

CONCLUSION

Using the Birmingham IBS symptom scale, our study revealed more severe IBS symptoms in patients with lower-stage endometriosis and identified other variables highly associated with severity of IBS. Continued research is required to characterize further the clinical importance of IBS symptoms in patients with endometriosis-associated pelvic pain.

Physical comorbidities of post-traumatic stress disorder in Australian Vietnam War veterans

OBJECTIVE

To determine whether the prevalence of physical comorbidities in Australian Vietnam War veterans with post-traumatic stress disorder (PTSD) is higher than in trauma-exposed veterans without PTSD.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional analysis of the health status (based on self-reported and objective clinical assessments) of 298 Australian Vietnam War veterans enrolled by the Gallipoli Medical Research Institute (Brisbane) during February 2014 - July 2015, of whom 108 were confirmed as having had PTSD and 106 served as trauma-exposed control participants.Main outcomes and measures: Diagnostic psychiatric interview and psychological assessments determined PTSD status, trauma exposure, and comorbid psychological symptoms. Demographic data, and medical and sleep history were collected; comprehensive clinical examination, electrocardiography, spirometry, liver transient elastography, and selected pathology assessments and diagnostic imaging were performed. Outcomes associated with PTSD were identified; regression analysis excluded the effects of potentially confounding demographic and risk factors and comorbid symptoms of depression and anxiety.

RESULTS

The mean total number of comorbidities was higher among those with PTSD (17.7; SD, 6.1) than in trauma-exposed controls (14.1; SD, 5.2; P < 0.001). For 24 of 171 assessed clinical outcomes, morbidity was greater in the PTSD group, including for conditions of the gastrointestinal, hepatic, cardiovascular, and respiratory systems, sleep disorders, and laboratory pathology measures. In regression analyses including demographic factors, PTSD remained positively associated with 17 adverse outcomes; after adjusting for the severity of depressive symptoms, it remained significantly associated with ten.

CONCLUSION

PTSD in Australian Vietnam veterans is associated with comorbidities in several organ systems, independent of trauma exposure. A comprehensive approach to the health care of veterans with PTSD is needed.

P2X3 receptor-mediated visceral hyperalgesia and neuronal sensitization following exposure to PTSD-like stress in the dorsal root ganglia of rats

BACKGROUND

Patients with posttraumatic stress disorder (PTSD) often share co-morbidity with chronic pain conditions. Recent studies suggest a role of P2X3 receptors and ATP signaling in pain conditions. However, the underlying mechanisms of visceral hyperalgesia following exposure to PTSD-like stress conditions remain unclarified.

METHODS

The behavior and hormones relevant for PTSD were studied. Visceromotor responses (VMR) and the abdominal withdrawal reflexes (AWR) to colorectal distention (CRD) were recorded to determine P2X3-receptor-mediated alteration of hyperalgesia following single-prolonged stress (SPS) exposure. Immunofluorescence, Western blotting, and patch-clamp were used.

KEY RESULTS

The escape latency, adrenocorticotropic hormone and cortisol were increased on days 7-14. Visceromotor responses and AWR was reduced at day 1 in SPS rats but increased to higher levels than in controls after exposure to day 7. Intrathecal administration of the P2X3-receptor antagonist TNP-ATP abolished the CRD response. Based on immunofluorescence and Western blotting analysis, SPS-treated rats exhibited reduced P2X3 expression in dorsal root ganglia (DRG) after day 1 compared with controls. P2X3 expression in DRG was enhanced on day 7 after SPS and the increase of the P2X3 expression was maintained on day 14 and 21 compared with controls. The P2X3-receptor agonist α,β-me ATP (10 μM) induced a fast desensitizing inward current in DRG neurons of both control and SPS-treated rats. The average peak current densities in SPS-treated group were increased 3.6-fold. TNP-ATP (100 nM) markedly blocked all fast α,β-me ATP-induced inward currents in the DRG neurons both in control and SPS-treated rats.

CONCLUSIONS & INFERENCES

The data indicate an important role of P2X3 signaling in visceral hyperalgesia following PTSD-like stress.

Adverse childhood experiences are associated with irritable bowel syndrome and gastrointestinal symptom severity

BACKGROUND

Early adverse life events (EALs) are associated with irritable bowel syndrome (IBS). Exposure to EALs as assessed by the Adverse Childhood Experiences (ACE) questionnaire is associated with greater disease prevalence, but ACE has not been studied in gastrointestinal disorders. Study aims were to: (i) Estimate the prevalence of EALs in the IBS patients using the ACE questionnaire; (ii) Determine correlations between ACE and Early Trauma Inventory Self Report-Short Form (ETI-SR) scores to confirm its validity in IBS; and (iii) Correlate ACE scores with IBS symptom severity.

METHODS

A total of 148 IBS (73% women, mean age = 31 years) and 154 HCs (59% women, mean age = 30 years) completed the ACE and ETI-SR between June 2010 and April 2015. These surveys measured EALs before age 18 in the domains of physical, sexual, and emotional abuse, and general trauma. IBS and abdominal pain severity was measured by a 20-point scale (0 = none, 20 = worst symptoms).

KEY RESULTS

The ACE score increased the odds of having IBS (odds ratio [OR] = 2.05, 95% confidence interval [CI]: 1.21-3.48, p = 0.008). Household mental illness (p < 0.001), emotional abuse (p = 0.004), and incarcerated household member (p = 0.019) were significant predictors of IBS. Adverse childhood experiences and ETI-SR scores were strongly correlated (r = 0.59, p < 0.001). ACE, but not ETI-SR, modestly correlated with IBS severity (r = 0.17, p = 0.036) and abdominal pain (r = 0.20, p = 0.015).

CONCLUSIONS & INFERENCES

The ACE questionnaire is a useful instrument to measure EALs in IBS based on its use in large studies, its ability to measure prevalence across different EAL domains, and its correlation with symptom severity.

Serotonin 5-HT7 Receptor in the Ventral Hippocampus Modulates the Retrieval of Fear Memory and Stress-Induced Defecation

BACKGROUND

Patients with posttraumatic stress disorder or panic disorder are often troubled by inappropriate retrieval of fear memory. Moreover, these disorders are often comorbid with irritable bowel syndrome. The main aim of the present study is to elucidate the involvement of hippocampal serotonergic systems in fear memory retrieval and stress-induced defecation.

METHODS AND RESULTS

Microinjection of serotonin7 receptor antagonist, but not other serotonin receptor antagonists (serotonin 1A, 2A, 2C, 3, 4, and 6), into the rat ventral hippocampus significantly suppressed the expression of freezing behavior, an index of fear memory retrieval, and decreased the amount of feces, an index of stress-induced defecation, in the contextual fear conditioning test. Electrophysiological data indicated that the serotonin7 receptor agonist increased the frequency of action potentials in the ventral hippocampal CA3 pyramidal neuron via the activation of the hyperpolarization-activated nonselective cation current Ih. Moreover, in situ hybridization demonstrated that Htr7 mRNA was abundantly expressed in the CA3 compared with other subregions of the hippocampus and that these Htr7 mRNA-positive cells coexpressed hyperpolarization-activated cyclic nucleotide-gated channel 2 and 4 mRNAs, which are components of the Ih channel.

CONCLUSIONS

These results indicated that the released serotonin activates the serotonin7 receptor in the CA3 ventral hippocampus subregion, enhances the sensitivity to inputs via hyperpolarization-activated cyclic nucleotide 2 and 4 channels, and thereby facilitates fear memory retrieval. The serotonin7 receptor might be a target of drug development for the treatment of mental disorders involving fear memory and gastrointestinal problems.

The Epidemiology of Irritable Bowel Syndrome in the US Military: Findings from the Millennium Cohort Study

OBJECTIVES

Functional gastrointestinal disorders occur more frequently among deployed veterans, although studies evaluating the relative impact of risk factors, including stress and antecedent infectious gastroenteritis (IGE), are limited. We examined risk factors for new-onset irritable bowel syndrome (IBS) among active duty participants in the military's Millennium Cohort Study.

METHODS

Medical encounter data from 2001 to 2009, limited to Cohort members on active duty, were used to identify incident IBS cases (any and highly probable). IGE was identified using medical encounter or self-report. Covariate data were obtained from the Millennium Cohort Study surveys and analyzed using Cox proportional hazards methods.

RESULTS

Overall, 41,175 Cohort members met the eligibility criteria for inclusion and 314 new-onset cases of IBS were identified among these. Significant risk factors (adjusted hazard ratio, 95% confidence interval) included antecedent IGE (2.05, 1.53-2.75), female gender (1.96, 1.53-2.52), number of life stressors (1: 1.82, 1.37-2.41; 2: 2.86, 2.01-4.06; 3+: 6.69, 4.59-9.77), and anxiety syndrome (1.74, 1.17-2.58). Limited to highly probable IBS, a stronger association with antecedent IGE was observed, particularly when based on medical encounter records (any IGE: 2.20, 1.10-4.43; medical encounter IGE only: 2.84, 1.33-6.09). Precedent anxiety or depression and IGE interacted with increased IBS risk compared with IGE alone.

CONCLUSIONS

These results confirm previous studies on the association between sociodemographic or life stressors and IBS. IGE was significantly associated with IBS risk. Whether deployed or not, US service members often encounter repeated exposure to high levels of stress, which, combined with other environmental factors such as IGE, may result in long-term debilitating functional gastrointestinal disorders.

Irritable bowel syndrome: Is it "irritable brain" or "irritable bowel"?

Irritable bowel syndrome (IBS) has been recognized as one of the most common and best studied disorders among the group of functional gastrointestinal disorders. It is a functional bowel disorder in which abdominal pain or discomfort is associated with defecation or a change in bowel habit. In the Western world, IBS appears to affect up to 20% of the population at any given time but in Asian countries, the median value of IBS prevalence defined by various criteria ranges between 6.5% and 10.1%, and community prevalence of 4% is found in North India. Those attending gastroenterology clinics represent only the tip of the iceberg. The disorder substantially impairs the quality of life, and the overall health-care costs are high. IBS has therefore gained increased attention from clinicians, researchers, and pharmaceutical industries. It is often frustrating to both patients and physicians as the disease is usually chronic in nature and difficult to treat. However, the understanding of IBS has been changing from time to time and still most of its concepts are unknown. In this review we have discussed, debated, and synthesized the evidence base, focusing on underlying mechanisms in the brain and bowel. We conclude that it is both brain and bowel mechanisms that are responsible. The clinical implication of such mechanisms is discussed.

Chronic multisymptom illness among female Veterans deployed to Iraq and Afghanistan

BACKGROUND

Chronic multisymptom illness (CMI) may be more prevalent among female Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) deployed Veterans due to deployment-related experiences.

OBJECTIVES

To investigate CMI-related diagnoses among female OEF/OIF/OND Veterans.

RESEARCH DESIGN

We estimated the prevalence of the International Classification of Disease-9th edition-Clinical Modification coded CMI-related diagnoses of chronic fatigue syndrome, fibromyalgia (FM), and irritable bowel syndrome (IBS) among female OEF/OIF/OND Veterans with Veterans Health Administration (VHA) visits, FY2002-2012 (n=78,435). We described the characteristics of female Veterans with and without CMI-related diagnoses and VHA settings of first CMI-related diagnoses.

RESULTS

The prevalence of CMI-related diagnoses among female OEF/OIF/OND Veterans was 6397 (8.2%), over twice as high as the prevalence 95,424 (3.9%) among the totality of female Veterans currently accessing VHA (P<0.01). There were statistically significant differences in age, education, marital status, military component, service branch, and proportions of those with depression and/or post-traumatic stress disorder diagnoses across females with and without CMI-related diagnoses. Diagnoses were mainly from primary care, women's health, and physical medicine and rehabilitation clinics.

CONCLUSIONS

CMI-related diagnoses were more prevalent among female OEF/OIF/OND Veterans compared with all female Veterans who currently access VHA. Future studies of the role of mental health diagnoses as confounders or mediators of the association of OEF/OIF/OND deployment and CMI are warranted. These and other factors associated with CMI may provide a basis for enhanced screening to facilitate recognition of these conditions. Further work should evaluate models of care and healthcare utilization related to CMI in female Veterans.

Care of women veterans

As more women have joined the US military, there has been a shift in the overall veteran population. Those who served in the US military, especially women, have undergone experiences that will impact their overall health and wellbeing. It is therefore critical for providers to better understand US military culture and be prepared on how to ask patients about their military experience. Health care providers need to be aware of the unique medical, psychiatric, and psychosocial needs of women veterans in order to best serve this patient population.

Stress-induced visceral pain: toward animal models of irritable-bowel syndrome and associated comorbidities

Visceral pain is a global term used to describe pain originating from the internal organs, which is distinct from somatic pain. It is a hallmark of functional gastrointestinal disorders such as irritable-bowel syndrome (IBS). Currently, the treatment strategies targeting visceral pain are unsatisfactory, with development of novel therapeutics hindered by a lack of detailed knowledge of the underlying mechanisms. Stress has long been implicated in the pathophysiology of visceral pain in both preclinical and clinical studies. Here, we discuss the complex etiology of visceral pain reviewing our current understanding in the context of the role of stress, gender, gut microbiota alterations, and immune functioning. Furthermore, we review the role of glutamate, GABA, and epigenetic mechanisms as possible therapeutic strategies for the treatment of visceral pain for which there is an unmet medical need. Moreover, we discuss the most widely described rodent models used to model visceral pain in the preclinical setting. The theory behind, and application of, animal models is key for both the understanding of underlying mechanisms and design of future therapeutic interventions. Taken together, it is apparent that stress-induced visceral pain and its psychiatric comorbidities, as typified by IBS, has a multifaceted etiology. Moreover, treatment strategies still lag far behind when compared to other pain modalities. The development of novel, effective, and specific therapeutics for the treatment of visceral pain has never been more pertinent.

Gastrointestinal problems in modern wars: clinical features and possible mechanisms

Gastrointestinal problems are common during wars, and they have exerted significant adverse effects on the health of service members involved in warfare. The spectrum of digestive diseases has varied during wars of different eras. At the end of the 20th century, new frontiers of military medical research emerged due to the occurrence of high-tech wars such as the Gulf War and the Kosovo War, in which ground combat was no longer the primary method of field operations. The risk to the military personnel who face trauma has been greatly reduced, but disease and non-battle injuries (DNBIs) such as neuropsychological disorders and digestive diseases seemed to be increased. Data revealed that gastrointestinal symptoms such as constipation, diarrhea, dyspepsia, and noncardiac chest pain are common among military personnel during modern wars. In addition, a large number of deployed soldiers and veterans who participated in recent wars presented with chronic gastrointestinal complaints, which fulfilled with the Rome III criteria for functional gastrointestinal disorders (FGIDs). It was also noted that many veterans who returned from the Gulf War suffered not only from chronic digestive symptoms but also from neuropsychological dysfunction; however, they also showed symptoms of other systems. Presently, this broad range of unexplained symptoms is known as "Gulf War syndrome". The mechanism that underlies Gulf War syndrome remains unclear, but many factors have been associated with this syndrome such as war trauma, stress, infections, immune dysfunction, radiological factors, anthrax vaccination and so on. Some have questioned if the diagnosis of FGIDs can be reached given the complexity of the military situation. As a result, further studies are needed to elucidate the pathogenesis of gastrointestinal disease among military personnel.

The relationship between irritable bowel syndrome and psychiatric disorders: from molecular changes to clinical manifestations

Irritable bowel syndrome (IBS) is a functional syndrome characterized by chronic abdominal pain accompanied by altered bowel habits. Although generally considered a functional disorder, there is now substantial evidence that IBS is associated with a poor quality of life and significant negative impact on work and social domains. Neuroimaging studies documented changes in the prefrontal cortex, ventro-lateral and posterior parietal cortex and thalami, and implicate alteration of brain circuits involved in attention, emotion and pain modulation. Emerging data reveals the interaction between psychiatric disorders including generalized anxiety disorder, panic disorder, major depressive disorder, bipolar disorder, and schizophrenia and IBS, which suggests that this association should not be ignored when developing strategies for screening and treatment. Psychological, social and genetic factors appear to be important in the development of IBS symptomatology through several mechanisms: alteration of HPA axis modulation, enhanced perception of visceral stimuli or psychological vulnerability. Elucidating the molecular mechanisms of IBS with or without psychiatric comorbidities is crucial for elucidating the pathophysiology and for the identification of new therapeutical targets in IBS.

Association of mental health problems with gastrointestinal disorders in Iraq and Afghanistan veterans

BACKGROUND

Gastrointestinal disorders (GIDs) represent a large public health burden, affecting an estimated 60-70 million Americans annually. Our goal was to examine the relationship between GID and the most common mental health disorders in a national group of newly returning veterans. We also evaluated gender differences in the association of mental health disorders and GID.

METHODS

We utilized a retrospective, longitudinal cohort analysis of veterans' health records. Participants were 603,221 Iraq and Afghanistan veterans who were new users of VA healthcare from October 7, 2001 (start of the war in Afghanistan) to December 31, 2010.

RESULTS

The prevalence of GID in newly returning veterans was nearly 20%, and veterans with a mental health disorder were at least twice as likely to have a GID as those without mental health disorders. For women, the increased risk of all GIDs was greatest among those with depression. Among men, the increased risk of irritable bowel syndrome (IBS) was greatest among those with posttraumatic stress disorder. IBS was the GID most strongly associated with mental health conditions among both genders.

CONCLUSIONS

The large proportion of newly returning veterans with GIDs and comorbid mental health diagnoses is concerning. Successful detection and treatment of GIDs associated with mental health disorders will require integrated efforts from primary care and mental health.

Psychological trauma and functional somatic syndromes: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis systematically examined the association of reported psychological trauma and posttraumatic stress disorder (PTSD) with functional somatic syndromes including fibromyalgia, chronic widespread pain, chronic fatigue syndrome, temporomandibular disorder, and irritable bowel syndrome. Our goals were to determine the overall effect size of the association and to examine moderators of the relationship.

METHODS

Literature searches identified 71 studies with a control or comparison group and examined the association of the syndromes with traumatic events including abuse of a psychological, emotional, sexual, or physical nature sustained during childhood or adulthood, combat exposure, or PTSD. A random-effects model was used to estimate the pooled odds ratio and 95% confidence interval. Planned subgroup analyses and meta-regression examined potential moderators.

RESULTS

Individuals who reported exposure to trauma were 2.7 (95% confidence interval = 2.27-3.10) times more likely to have a functional somatic syndrome. This association was robust against both publication bias and the generally low quality of the literature. The magnitude of the association with PTSD was significantly larger than that with sexual or physical abuse. The association of reported trauma with chronic fatigue syndrome was larger than the association with either irritable bowel syndrome or fibromyalgia. Studies using nonvalidated questionnaires or self-report of trauma reported larger associations than did those using validated questionnaires.

CONCLUSIONS

Findings are consistent with the hypothesis that traumatic events are associated with an increased prevalence of functional somatic syndromes. The analyses also highlight limitations of the existing literature and emphasize the importance of prospective studies, examining the potential similarities and differences of these conditions, and pursuing hypothesis-driven studies of the mechanisms underlying the link between trauma, PTSD, and functional somatic syndromes.

Psychological disorders in gastrointestinal disease: epiphenomenon, cause or consequence?

BACKGROUND

Psychological disorders have been associated with irritable bowel syndrome (IBS) for decades in the absence of other objective etiology. However, such associations are also evident in other chronic diseases with more clearly defined pathogenesis such as ulcerative colitis. In this study, we examined the prevalence and severity of psychological disorders among IBS and ulcerative colitis (UC) patients relative to healthy controls.

METHODS

A review was conducted of English-language literature to identify case-control studies reporting the prevalence of depression or anxiety in IBS and UC populations relative to healthy controls. Our primary endpoint was the pooled prevalence or average score of depression or anxiety in an IBS or UC population relative to healthy control.

RESULTS

Seven case-control studies evaluating IBS and three evaluating UC were included. All IBS and UC studies reported excess prevalence and severity of depression as well as anxiety, relative to healthy controls. The prevalence of depression in excess of healthy controls was 39% in UC case-control trials and 33% in IBS studies, and excess anxiety was present in UC (42%) and IBS (19%) case-control trials as well. Anxiety and depression scores were higher (representing more severe symptoms) in both UC and IBS patients compared to healthy controls.

CONCLUSIONS

Anxiety and depressive disorders are associated with both IBS and UC. The non-specific association between these psychological and gastrointestinal disorders could suggest that chronic gastrointestinal illness might affect psychosocial behavior.

The role of borderline personality disorder and depression in the relationship between sexual assault and body mass index among women veterans

This article examines lifetime sexual assault (LSA) and mental health history as risk factors associated with body mass index (BMI) in a population of women veterans. This cross-sectional study of a retrospective cohort of 948 Veterans Affairs (VA)-enrolled midwestern enlisted rank women veterans included computer-assisted telephone interviews. Findings show that 33.4% of the participants had a BMI of 30.0 or more meeting the criteria for obesity and 62.5% reported lifetime attempted or completed sexual assault. Greater BMI was positively associated with older age, less education, LSA, depression, and borderline personality disorder (BPD) and negatively associated with current substance use disorder in multivariate models. Mediation analysis found that the relationship between sexual assault and BMI was completely mediated by BPD and depression. Interventions should combine physical and mental health care in gender-specific services for overweight women veterans with trauma histories and mental health conditions.

Cognitive-behavioral therapy for the management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common disorder, reported to be found in 5%-20% of the general population. Its management accounts for up to 25% of a gastroenterologist’s workload in the outpatient department, and the main symptoms are abdominal pain, bloating, and altered bowel habits. Despite a great amount of available pharmacological treatments aimed at a wide variety of gastrointestinal and brain targets, many patients have not shown adequate symptom relief. In recent years, there has been increasing evidence to suggest that psychological treatments, in particular cognitive-behavioral therapy (CBT), are effective for the management of IBS. This review discusses CBT for the management of IBS. CBT has proved to be effective in alleviating the physical and psychological symptoms of IBS and has thus been recommended as a treatment option for the syndrome.

Irritable bowel syndrome in the UK military after deployment to Iraq: what are the risk factors?

PURPOSE

Diarrhoea and vomiting (D & V) was common in military personnel during deployment to the initial phases of the Iraq war. D & V is an established risk factor for irritable bowel syndrome (IBS). This study examined the prevalence of IBS in a military sample with a history of deployment to Iraq and the association between D & V and common mental disorder (CMD) with IBS.

METHODS

The study used data from a two-phase cohort study of military/personnel. The sample was restricted to individuals who had been deployed to Iraq before phase 1 of the study and who had completed the self-report D & V question. A measure of probable IBS was derived at both phases of the study based on self-reported symptoms in the previous month. CMD was assessed by the General Health Questionnaire (GHQ-12).

RESULTS

Fifty-nine percent of the sample reported a D & V event and 6.6 % met the criteria for probable IBS at phase 1. Reporting D & V, thinking one might be killed on deployment, poor physical health and CMD were associated with probable IBS at phase 1. CMD at phase 1 was strongly associated with chronic symptoms of IBS.

CONCLUSIONS

There was a high prevalence of D & V during deployment to the early stages of the Iraq war, yet the prevalence of probable IBS on return from deployment was relatively low. D & V was strongly associated with IBS after deployment, and CMD was a risk factor for chronic symptoms of IBS.

PKCγ receptor mediates visceral nociception and hyperalgesia following exposure to PTSD-like stress in the spinal cord of rats

BACKGROUND

Clinical studies indicate that patients with post-traumatic stress disorder (PTSD) frequently share comorbidity with numerous chronic pain conditions. However, the sustained effects of PTSD-like stress over time on visceral nociception and hyperalgesia have been rarely studied, and the underlying mechanisms of stress-induced modulation of visceral hyperalgesia remain elusive. The purpose of this study was to investigate the characterization of visceral nociception and hyperalgesia over time in rats exposed to PTSD-like stress, and to explore the potential role of protein kinase C gamma (PKCγ) in mediating visceral hyperalgesia following exposure to PTSD-like stress.

RESULTS

On day 1, the rats exposed to single-prolonged stress (SPS, an established animal model for PTSD) exhibited an analgesic response and its visceromotor response (VMR) to graded colorectal distention (CRD) at 40 and 60 mmHg was reduced compared with the control group (all P < 0.05). On day 6, the VMR returned to the baseline value. However, as early as 7 days after SPS, VMR dramatically increased compared with its baseline value and that in the controls (all P < 0.001) and this increase persisted for 28 days, with the peak on day 9. Abdominal withdrawal reflex (AWR) scores were higher in SPS rats than in controls on days 7, 9, 14, 21 and 28 (all P < 0.001). Intrathecal administration of GF109203X (an inhibitor of PKC gamma), attenuated the SPS-induced increase in both VMR and AWR scores on days 7, 14, 21 and 28 (all P < 0.05). PKCγ protein expression determined by immunofluorescence was reduced in the spinal cord within 3 days after the exposure to SPS (P < 0.01), which returned to normal levels between days 4 and 6, and significantly increased from day 7, and this increase was maintained on days 14, 21, and 28 (all P < 0.001), with the peak on day 9. In addition, Western blotting showed a consistent trend in the changes of PKCγ protein expression.

CONCLUSIONS

The modified SPS alters visceral sensitivity to CRD, and contributes to the maintenance of visceral hyperalgesia, which is associated with enhanced PKCγ expression in the spinal cord. Functional blockade of the PKCγ receptors attenuates SPS-induced visceral hyperalgesia. Thus, the present study identifies a specific molecular mechanism for visceral hyperalgesia which may pave the way for novel therapeutic strategies for PTSD-like conditions.

[Childhood sexual abuse: how important is the diagnosis to understand and manage sexual, anorectal and lower urinary tract symptoms]

OBJECTIVE

To understand and manage the sequels of childhood sexual abuse on sexual, anorectal and lower urinary tract functions.

MATERIAL AND METHODS

Review of articles published in the Medline database, selected according to their scientific relevance and published guidelines on this subject together with our own experience.

RESULTS

A history of sexual abuse is frequently found when assessing dysfunction or symptoms of the lower urinary tract. In this context, urinary stress incontinence is rarely involved but it can be linked by epidemiological factors. Dysuria with urgency is the most frequent expressed symptom. When associated with anorectal disorders and pelvic pain or a sexual disorder in particular dyspareunia, a sexual abuse should be evoked and specific questions asked to the patient. Although these symptoms are frequently encountered in 12 to 33% of women, and 8 to 16% of men, few practitioners, whatever their speciality ask about them as routine. It is important that the physician diagnose the existence of sexual abuse, in particular when the symptoms mentioned by the patient are not conclusive, in spite of thorough urological assessment. Patients finding the initial examination difficult and painful and the failure of the initial treatment should lead to questions concerning abuse, if neglected by the initial medical inquiry.

CONCLUSIONS

Clinicians involved in perineal functional pathology are able to acquire standardized modalities of inquiry about child sexual abuse for a better time management and efficacy in the therapeutic approach. The interest of a multidisciplinary diagnostic and therapeutic approach is primordial, associating psychological therapy and if necessary perineal re-education. This can avoid unnecessary tests and out-patient visits. Directing patients towards a multidisciplinary approach is highly advisable.

Canadian Digestive Health Foundation Public Impact Series 3: irritable bowel syndrome in Canada. Incidence, prevalence, and direct and indirect economic impact

The Canadian Digestive Health Foundation initiated a scientific program to assess the incidence, prevalence, mortality and economic impact of digestive disorders across Canada in 2009. The current article presents the updated findings from the study concerning irritable bowel syndrome.

Psychosocial determinants of irritable bowel syndrome

From a pure motor disorder of the bowel, in the past few years, irritable bowel syndrome (IBS) has become a multifactorial disease that implies visceral hypersensitivity, alterations at the level of nervous and humoral communications between the enteric nervous system and the central nervous system, alteration of the gut microflora, an increased intestinal permeability and minimum intestinal inflammation. Psychological and social factors can interfere with the communication between the central and enteric nervous systems, and there is proof that they are involved in the onset of IBS and influence the response to treatment and outcome. There is evidence that abuse history and stressful life events are involved in the onset of functional gastrointestinal disorders. In order to explain clustering of IBS in families, genetic factors and social learning mechanisms have been proposed. The psychological features, such as anxiety, depression as well as the comorbid psychiatric disorders, health beliefs and coping of patients with IBS are discussed in relation to the symptoms and outcome.

Stress and visceral pain: from animal models to clinical therapies

Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain.

Stress-related alterations of visceral sensation: animal models for irritable bowel syndrome study

Stressors of different psychological, physical or immune origin play a critical role in the pathophysiology of irritable bowel syndrome participating in symptoms onset, clinical presentation as well as treatment outcome. Experimental stress models applying a variety of acute and chronic exteroceptive or interoceptive stressors have been developed to target different periods throughout the lifespan of animals to assess the vulnerability, the trigger and perpetuating factors determining stress influence on visceral sensitivity and interactions within the brain-gut axis. Recent evidence points towards adequate construct and face validity of experimental models developed with respect to animals' age, sex, strain differences and specific methodological aspects such as non-invasive monitoring of visceromotor response to colorectal distension as being essential in successful identification and evaluation of novel therapeutic targets aimed at reducing stress-related alterations in visceral sensitivity. Underlying mechanisms of stress-induced modulation of visceral pain involve a combination of peripheral, spinal and supraspinal sensitization based on the nature of the stressors and dysregulation of descending pathways that modulate nociceptive transmission or stress-related analgesic response.

Need for a comprehensive medical approach to the neuro-immuno-gastroenterology of irritable bowel syndrome

Irritable bowel syndrome (IBS) is defined by the Rome III criteria as symptoms of recurrent abdominal pain or discomfort with the onset of a marked change in bowel habits with no evidence of an inflammatory, anatomic, metabolic, or neoplastic process. As such, many clinicians regard IBS as a central nervous system problem of altered pain perception. Here, we review the recent literature and discuss the evidence that supports an organic based model, which views IBS as a complex, heterogeneous, inter-dependent, and multi-variable inflammatory process along the neuronal-gut axis. We delineate the organic pathophysiology of IBS, demonstrate the role of inflammation in IBS, review the possible differences between adult and pediatric IBS, discuss the merits of a comprehensive treatment model as taught by the Institute of Functional Medicine, and describe the potential for future research for this syndrome.

Stress and visceral pain: from animal models to clinical therapies

Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain.