Risk factors for upper and lower functional gastrointestinal disorders in Persian Gulf War Veterans during and post-deployment

SARS-CoV-2 Infection, Vaccination, and Irritable Bowel Syndrome in Veterans: A Cross-Sectional Study

Background

The association and interaction between SARS-CoV-2 (COVID-19) infection and irritable bowel syndrome (IBS) has not been adequately explored. We sought to determine whether a mechanistic relationship exists and whether vaccination against COVID-19 plays a role in this relationship.

Methods

Using the Veterans Affairs (VA) electronic healthcare database, we obtained a random sample of veterans in October 2022 for this cross-sectional study. Demographic characteristics of the participants (e.g., age, sex, race), prior COVID infection, COVID vaccination status, and IBS diagnosis were extracted from the VA medical records. Univariate and multivariate logistic regression analyses were performed to determine potential associations between the listed factors and IBS diagnosis.

Results

A total of 9,112 veterans were analyzed. In univariate analysis, race, COVID infection, and vaccination were significantly associated with IBS. In multivariate regression analysis, only the effects of COVID infection and vaccination were statistically significant. The odds ratios for development of IBS among veterans with COVID infection versus those without was 1.94 (95% CI: 1.53-2.45), and for vaccinated versus unvaccinated, was 1.49 (95% CI: 1.18-1.89). Further analysis showed that vaccinated veterans who did not contract COVID infection had a lower risk of developing IBS compared to unvaccinated veterans who contracted COVID.

Conclusions

The results of this study suggest that veterans with COVID infection are almost twice as likely to develop IBS compared to those who have never had COVID infection. Vaccinated veterans have a lower risk of contracting COVID and subsequently, a diminished chance of developing IBS. Overall, vaccination of veterans with protection against COVID diminishes the risk of IBS development.

Irritable Bowel Syndrome in Veterans With Gulf War Illness Evaluated at VA's War-Related Illness and Injury Study Center

INTRODUCTION

Excess rates of Gulf War illness (GWI) and irritable bowel syndrome (IBS), two chronic multisymptom illnesses, have long been documented among nearly 700,000 veterans who served in the 1990-1991 Persian Gulf War. We sought to report the prevalence, characteristics, and association of GWI and IBS decades after the war in a clinical cohort of deployed Gulf War veterans (GWVs) who were evaluated at the Department of Veterans Affairs' War Related Illness and Injury Study Center (WRIISC) for unexplained chronic symptoms.

MATERIALS AND METHODS

We analyzed data gathered from clinical intake questionnaires of deployed GWVs who were evaluated at WRIISC clinics between 2008 and 2020. We applied Centers for Disease Control (CDC) criteria to determine the prevalence of severe GWI. IBS was identified using Rome IV diagnostic criteria (current IBS) and veterans' self-reported "history of physician-diagnosed IBS." We examined associations between IBS and GWI using bivariate analyses and multivariable logistic regression.

RESULTS

Among the N = 578 GWVs evaluated by the WRIISC, severe GWI (71.8%), history of physician-diagnosed IBS (50.3%) and current IBS (42.2%) were all highly prevalent. Nearly half of GWVs with severe GWI met Rome criteria for IBS (45.8%), and over half reported a history of physician-diagnosed IBS (56.1%). In multivariable models, severe GWI was significantly associated both with current IBS (adjusted odds ratio (aOR): 1.68, 95% CI: 1.11, 2.54) and with veteran-reported history of physician-diagnosed IBS (aOR: 2.15, 95% CI: 1.43, 2.23). IBS with diarrhea (IBS-D) was the most common subtype among GWVs with current IBS (61.1%). However, IBS-mixed affected a significantly greater proportion of veterans with severe GWI, compared to veterans who did not have severe GWI (P = .03).

CONCLUSIONS

More than 20 years after the Persian Gulf War, our findings indicate a high degree of comorbidity between severe GWI and IBS among deployed GWVs seeking care for unexplained illnesses. Our results suggest GWVs with GWI should be screened for IBS for which evidence-based treatments are available and could potentially reduce symptom burden. Conversely, symptoms of IBS should trigger additional evaluation for non-gastrointestinal symptoms in deployed Gulf War veterans to identify possible GWI and ensure a comprehensive approach to care.

Randomized double-blind placebo-controlled study to evaluate the effect of long-acting mesalamine on postinfectious irritable bowel syndrome with diarrhea

BACKGROUND

A subset of patients with irritable bowel syndrome (IBS) develop their symptoms after gastroenteritis, referred to as postinfectious IBS (PI-IBS). PI-IBS is associated with low-grade intestinal inflammation. Previous studies have evaluated mesalamine, an anti-inflammatory drug, in patients with IBS. We evaluated the efficacy of long-acting mesalamine in patients with PI-IBS.

METHODS

Sixty-one patients who developed diarrhea-predominant IBS (IBS-D) after gastroenteritis were randomized to receive either 2.4 g of long-acting mesalamine or placebo daily for 8-weeks. The symptoms assessed were abdominal pain, bloating, stool frequency, stool consistency, severity of diarrhea and constipation, satisfaction with bowel habits, and IBS affecting or interfering with life. Quality-of-life (QOL) was assessed using the IBS-QOL questionnaire. The prespecified primary outcome variable was the overall bowel symptom score (BSS) after 8-weeks of treatment. Effect sizes were expressed as standardized mean differences (Cohen's d).

RESULTS

Fifty-four patients completed the 8-week treatment (n = 28 mesalamine, n = 26 placebo), 49 (91%) were male, and age range 23-71 years (mean ± SD 43 ± 13). Mesalamine demonstrated superior efficacy compared to placebo on the primary outcome variable, overall BSS (Cohen's d = 0.57, p = 0.042). Mesalamine was also superior for the secondary outcome of how much IBS affects your life in general (d = 0.72, p = 0.01). For the secondary outcomes of IBS symptoms, 7 of the 7 symptoms had trends of mesalamine superiority. For the secondary outcomes of IBS-QOL subscales, 8 of 9 had trends of mesalamine superiority.

CONCLUSION

In patients with PI-IBS, long-acting mesalamine demonstrated to be effective in reducing IBS symptoms and improving QOL.

Enduring association between irritable bowel syndrome and war trauma during the Nicaragua civil war period: A population-based study

BACKGROUND

Psychosocial and physical trauma are known risk factors for irritable bowel syndrome (IBS), including in war veterans, whereas war exposure in civilians is unclear. Nicaragua experienced two wars, 1970-1990: The Sandinistas Revolution (1970s) and The Contra War (1980s). Our aim was to investigate the role of exposure to war trauma in the subsequent development of IBS in the context of an established health surveillance system (11000 households).

AIM

To investigate in a civilian population the relationship between exposure to war trauma and events and the subsequent development of IBS in the context of an established public health and demographic surveillance system in western Nicaragua.

METHODS

We conducted a nested population-based, cross-sectional study focused on functional gastrointestinal disorders based on Rome II criteria. 1617 adults were randomly selected. The Spanish Rome II Modular Questionnaire and Harvard Trauma Questionnaire were validated in Nicaragua. War exposure was assessed with 10 measures of direct and indirect war trauma and post-war effects. Multiple exposures were defined by ≥ 3 measures.

RESULTS

The prevalence of IBS was 15.2% [Female (F) 17.1%, Male (M) 12.0%], war exposure 19.3% (F 9.3%, M 36.7%), and post-traumatic stress disorder (PTSD) 5.6% (F 6.4%, M 4.3%). Significant associations with IBS in the civilian population were observed (adjusted by gender, age, socioeconomic status, education): physical and psychological abuse [adjusted odds ratio (aOR): 2.25; 95% confidence interval: 1.1-4.5], witnessed execution (aOR: 2.4; 1.1-5.2), family member death (aOR: 2.2; 1.2-4.2), and multiple exposures (aOR: 2.7; 1.4-5.1). PTSD was independently associated with IBS (aOR: 2.6; 1.2-5.7).

CONCLUSION

An enduring association was observed in the Nicaragua civilian population between specific civil war-related events and subsequent IBS. Civilian populations in regions with extended armed conflict may warrant provider education and targeted interventions for patients.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Self-reported gastrointestinal disorders among veterans with gulf war illness with and without posttraumatic stress disorder

BACKGROUND

Gulf War Illness (GWI) is a chronic, multi-symptom disorder affecting 25%-32% of Gulf War veterans. Veterans with GWI disproportionately suffer from gastrointestinal (GI) disorders. Given the increasing evidence supporting a gut-brain axis, we explore the relationship between post-traumatic stress disorder (PTSD), GWI, and self-reported GI disorders among GW veterans.

METHODS

Veterans from the Gulf War Era Cohort and Biorepository responded to a mail-based survey (N = 1058). They were stratified by GWI (Centers for Disease Control definition) and PTSD status. This yielded three groups: GWI-, GWI+/PTSD-, and GWI+/PTSD+. Multivariable logistic regression adjusting for demographic and military characteristics examined associations between GWI/PTSD groups and GI disorders. Results were expressed as adjusted odds ratios (aOR) with 95% confidence intervals (95% CI).

KEY RESULTS

The most frequently reported GI disorders were irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD), and colon polyps (CP). The GWI+/PTSD+ group had a higher odds of these disorders than the GWI+/PTSD- group (aOR_IBS  = 3.12, 95% CI: 1.93-5.05; aOR_GERD  = 2.04, 95% CI: 1.44-2.90; aOR_CP  = 1.85, 95% CI: 1.23-2.80), which had a higher odds of these disorders than the GWI- group (aOR_IBS  = 4.38, 95% CI: 1.55-12.36; aOR_GERD  = 2.51 95% CI: 1.63-3.87; aOR_CP  = 2.57, 95% CI: 1.53-4.32).

CONCLUSIONS & INFERENCES

GW veterans with GWI and PTSD have significantly higher odds of specific self-reported GI disorders than the other groups. Given the known bidirectional influences of the gut and brain, these veterans may benefit from a holistic healthcare approach that considers biopsychosocial contributors to the assessment and management of disease.

Autonomic dysfunction and gastroparesis in Gulf War veterans

Over 25% of veterans with Gulf War illness developed chronic gastrointestinal (GI) symptoms of unknown etiology after they returned from deployment to the Persian Gulf. To determine the prevalence of delayed gastric emptying and its association with autonomic dysfunction in returning Gulf War (GW) veterans with chronic GI symptoms, we prospectively studied 35 veterans who were deployed to the Persian Gulf and developed chronic nausea, vomiting, postprandial abdominal pain, and bloating during their tour of duty and 15 asymptomatic controls. All veterans underwent 5 standardized cardiovascular tests to assess autonomic function. Each test was scored from 0 (normal) to 5 (severe disease) and the mean was calculated. A composite score >1.5 was considered abnormal, with 5 representing severe autonomic dysfunction. A standardized gastric emptying test with a solid phase was performed in each veteran. A gastric retention of >50% at 100 minutes was considered abnormal. The composite autonomic score was 3.7 in veterans with GI symptoms (vs 1.3 in controls) (p<0.01). The mean solid phase retention at 100 minutes was 72.6% in the symptomatic veterans versus 24.6% in controls (p<0.001). Our results suggest that autonomic dysfunction and delayed gastric emptying are common in returning GW veterans with GI symptoms. Autonomic dysfunction was positively correlated with the severity of delayed gastric emptying and may account for the GI symptoms of nausea, vomiting, postprandial abdominal pain, and bloating. These new findings are important for an increasing number of veterans who are serving in the Persian Gulf and are at a high risk of developing GI disorders while deployed.

High-Dose Opioid Use Among Veterans with Unexplained Gastrointestinal Symptoms Versus Structural Gastrointestinal Diagnoses

BACKGROUND

In a cohort of Veterans dually enrolled in the Department of Veterans Affairs (VA) and Medicare Part D, we sought to describe high-dose daily opioid use among Veterans with unexplained gastrointestinal (GI) symptoms and structural GI diagnoses and examine factors associated with high-dose use.

METHODS

We used linked national patient-level data from the VA and Centers for Medicare and Medicaid Services (CMS). We grouped patients into 3 subsets: those with unexplained GI symptoms (e.g., chronic abdominal pain); structural GI diagnoses (e.g., chronic pancreatitis); and those with a concurrent unexplained GI symptom and structural GI diagnosis. High-dose daily opioid use levels were examined as a binary variable [≥ 100 morphine milligram equivalents (MME)/day] and as an ordinal variable (50-99 MME/day, 100-119 MME/day, or ≥ 120 MME/day).

RESULTS

We identified 141,805 chronic GI patients dually enrolled in VA and Part D. High-dose opioid use was present in 11% of Veterans with unexplained GI symptoms, 10% of Veterans with structural GI diagnoses, and 15% of Veterans in the concurrent GI group. Compared to Veterans with only an unexplained GI symptom or structural diagnosis, concurrent GI patients were more likely to have higher daily opioid doses, more opioid days ≥ 100 MME, and higher risk of chronic use. Factors associated with high-dose use included opioid receipt from both VA and Part D, younger age, and benzodiazepine use.

CONCLUSIONS

A significant subset of chronic GI patients in the VA are high-dose opioid users. Efforts are needed to reduce high-dose use among Veterans with concurrent GI symptoms and diagnoses.

Small Intestinal Bacterial Overgrowth in Functional Dyspepsia: A Systematic Review and Meta-Analysis

INTRODUCTION

This systematic review and meta-analysis aimed to determine the role of small intestinal bacterial overgrowth (SIBO) in patients with functional dyspepsia (FD).

METHODS

Electronic databases were searched until July 2020 for studies reporting prevalence of SIBO in FD. The prevalence rates, odds ratio, and 95% confidence intervals (CIs) of SIBO in FD and controls were calculated.

RESULTS

Seven studies with 263 patients with FD and 84 controls were identified. The odds for SIBO in patients with FD were significantly higher as compared to that in controls (odds ratio = 4.3, 95% CI, 1.1-17.5, 4 studies, 234 participants); however, there was moderate heterogeneity in this analysis. Including high-quality, case-control studies (all using glucose breath tests [GBTs]), the risk of SIBO in patients with FD as compared to controls was 2.8 higher (95% CI 0.8-10.0, 3 studies, 200 participants) with minimal heterogeneity in this analysis. Using the lactulose breath test, SIBO prevalence in FD was significantly higher (53.4%, 95% CI 33.9-71.9, 3 studies, 110 participants) as compared to that with GBT (17.2%, 95% CI 8.6-31.6, 4 studies, 153 participants). Substantial heterogeneity was found in studies using the lactulose breath test but not in studies using GBT. There was no significant difference in SIBO prevalence in patients with FD according to FD subtype.

DISCUSSION

This meta-analysis suggests a link between FD and SIBO. The quality of evidence is low and can be largely attributed to the type of breath test for SIBO diagnosis and clinical heterogeneity. More appropriately designed studies are required to confirm the link between SIBO and FD.

Management of functional dyspepsia in 2020: a clinical point of view

Dyspepsia is a disorder that refers mainly to central upper abdominal pain or discomfort. When a cause of this symptom is not identified the condition is termed functional dyspepsia (FD), that affects a large part of the general population. The relevance of FD is due to its high prevalence, but also to its chronic or intermittent course. This induces a significant burden for each national healthcare system. The pathogenesis of FD is complex and multifactorial, depending on cultural, environmental, and biological factors. Although considered of main importance in the pathophysiology of several gastroduodenal diseases, in the context of FD Helicobacter pylori (H. pylori) infection plays a limited role. The diagnosis of FD requires the exclusion of organic gastroduodenal diseases as well as H. pylori infection. Thus, the diagnostic workup includes a complete anamnesis, biochemical tests, and endoscopy with biopsy (when requested), and the satisfaction of clinic criteria recommended by the Rome IV consensus. The treatment of FD is also challenging, in fact more and more studies focused on a wide range of different therapies, with a multitude of results. The aim of this literature review is to provide an update of the new evidences useful for diagnosis and management of FD.