Detection of colorectal tumor and inflammatory bowel disease during follow-up of patients with initial diagnosis of irritable bowel syndrome

Link between irritable bowel syndrome, depression, and colorectal cancer risk in young patients: Age-matched nationwide population-based study

BACKGROUND

There exists a link between irritable bowel syndrome (IBS) and depression. Similarly, chronic depression is known to increase the risk of cancer in general. In this population-based analysis, we investigated the prevalence and the odds of colorectal cancer (CRC) in young-depressed patients with IBS.

AIM

To investigate the relationship between IBS and CRC in young, depressed patients using a nationally representative United States inpatient sample.

METHODS

The 2019 National Inpatient Sample was used to identify young (18-44 years) patients admitted with comorbid depression in the presence vs absence of IBS using relevant International Classification of Diseases, Tenth Revision, Clinical Modification codes. Primary endpoint was the prevalence and odds of CRC in age matched (1:1) young-depressed cohort hospitalized with IBS (IBS+) vs without IBS (IBS-). Multivariable regression analysis was performed adjusting for potential confounders.

RESULTS

Age-matched (1:1) young-depressed IBS+ (83.9% females, median age 36 years) and IBS- (65.8% females, median age 36 years) cohorts consisted of 14370 patients in each group. IBS+ cohort had higher rates of hypertension, uncomplicated diabetes, hyperlipidemia, obesity, peripheral vascular disease, chronic obstructive pulmonary disease, hypothyroidism, prior stroke, prior venous thromboembolism, anxiety, bipolar disorder, and borderline personality disorder (P < 0.005) vs the IBS- cohort. However, prior myocardial infarction, acquired immunodeficiency syndrome, dementia, smoking, alcohol abuse, and drug abuse (P < 0.005) are high in IBS- cohort. The rate of CRC was comparable in both cohorts [IBS+ n = 25 (0.17%) vs IBS- n = 35 (0.24%)]. Compared to the IBS- cohort, the odds ratio (OR) of developing CRC was not significantly higher [OR 0.71, 95% confidence interval (CI) 0.23-2.25)] in IBS+ cohort. Also, adjusting for baseline sociodemographic and hospital characteristics and relevant comorbidities, the OR was found to be non-significant (OR 0.89, 95%CI 0.21-3.83).

CONCLUSION

This nationwide propensity-matched analysis revealed comparable prevalence and risk of CRC in young-depressed patients with vs without IBS. Future large-scale prospective studies are needed to evaluate the long-term effects of depression and its treatment on CRC risk and outcomes in IBS patients.

Metabolic biomarkers in irritable bowel syndrome diagnosis

Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) disorder characterized by altered bowel habits and abdominal discomfort during defecation. It significantly impacts life quality and work productivity for those affected. Global data suggests a slightly higher prevalence in females than in males. Today, unambiguous diagnosis of IBS remains challenging due to the absence of a specific biochemical, histopathological, or radiological test. Current diagnosis relies heavily on thorough symptom evaluation. Efforts by the Rome committees have established standardized diagnostic criteria (Rome I-IV), improving consistency and clinical applicability. Recent studies in this framework, seem to have successfully employed metabolomics techniques to identify distinct metabolite profiles in breath and stool samples of IBS patients, differentiating them from healthy controls and those with other functional GI disorders, such as inflammatory bowel disease (IBD). Building on this success, researchers are investigating the presence of similar metabolites in easily accessible biofluids such as urine, potentially offering a less invasive diagnostic approach. Accordingly, this review focuses on key metabolites specifically detected in IBS patients' biological specimens, with a focus on urinary metabolites, using various methods, particularly mass spectrometry (MS)-based techniques, including gas chromatography-MS (GC-MS), liquid chromatography-tandem MS (LC-MS/MS), and capillary electrophoresis-MS (CE-MS) metabolomics assays. These findings may make provision for a new set of non-invasive biomarkers for IBS diagnosis and management.

Sources of diagnostic delay for people with Crohn's disease and ulcerative colitis: Qualitative research study

OBJECTIVE

An improved understanding of the causes and experience of diagnostic delay in Inflammatory Bowel Disease (IBD).

METHODS

Framework analysis of semi-structured interviews with 20 adults with IBD.

RESULTS

Participants' prior knowledge of normal bowel function/IBD was limited. Symptoms were sometimes misattributed to mild/transient conditions or normalised until intolerable. Family pressures, work, education, mistrust of doctors, fear and embarrassment could exacerbate delays. Poor availability of face-to-face appointments deterred people from seeing a GP. Patients feared that by the time they got to see their GP, their symptoms would have resolved. Patients instead self-managed symptoms, but often regretted not seeking help earlier. Limited time in consultations, language barriers, embarrassment, and delays in test results subsequently delayed specialist referrals. GPs misattributed symptoms to other conditions due to atypical or non-specific presentations, leading to reduced trust in health systems. Patients complained of poor communication, delays in accessing test results, appointments, and onward referrals-all associated with clinical deterioration. GPs were sometimes unable to 'fast-track' patients into specialist care. Consultations and endoscopies were often difficult experiences for patients, especially for non-English speakers who are also less likely to receive information on mental health support and the practicalities of living with IBD.

CONCLUSIONS

The framework analysis demonstrates delay in the diagnosis of IBD at each stage of the patient journey.

RECOMMENDATIONS

Greater awareness of IBD amongst the general population would facilitate presentation to healthcare services through symptom recognition by individuals and community advice. Greater awareness in primary care would help ensure IBD is included in differential diagnosis. In secondary care, greater attention to the wider needs of patients is needed-beyond diagnosis and treatment. All clinicians should consider atypical presentations and the fluctuating nature of IBD. Diagnostic overshadowing is a significant risk-where other diagnoses are already in play the risk of delay is considerable.

Patients' perspectives on irritable bowel syndrome: a qualitative analysis based on social media in China

AIM

To explore the perspectives, experience, and concerns of patients with irritable bowel syndrome (IBS) in China.

METHODS

We used data mining to investigate posts shared in Baidu Tieba concerned with IBS; we collected the data through the crawler code, and mined the cleaned data's themes based on Latent Dirichlet allocation (LDA) and the Grounded theory.

RESULTS

We found 5746 network posts related to IBS. LDA analysis generated 20 topics, and grounded theory analysis established eight topics. Combining the two methods, we finally arranged the topics according to five concepts: difficulty in obtaining disease information; serious psychosocial problems; dissatisfied with the treatment; lack of social support; and low quality of life.

CONCLUSION

Social media research improved patient-centric understanding of patients' experiences and perceptions. Our study may facilitate doctor-patient communication and assist in the formulation of medical policies.

Organic colonic lesions in patients with irritable bowel syndrome: A comparative study

INTRODUCTION AND AIMS

Any alarm symptoms in patients with irritable bowel syndrome (IBS) should be carefully evaluated. Colonoscopy is a standard diagnostic procedure for evaluating the colonic mucosa and ruling out probable diseases responsible for patient symptoms. We analyzed the colonoscopy findings in patients with and without IBS.

MATERIAL AND METHODS

Ninety-six patients with IBS and 101 without IBS were consecutively enrolled in the study. All the patients in the IBS group met the Rome IV criteria, and underwent colonoscopy due to the appearance of red flags. The colonoscopy findings were compared between the 2 groups of patients.

RESULTS

The main indications for colonoscopy in the IBS group were progressive abdominal pain (36.7%), rectal bleeding with fresh blood (17.7%), and occult blood in stool (12.5%). In the non-IBS group, the most prevalent indicators were rectal bleeding with fresh blood (37.6%), colorectal cancer surveillance (21.8%), and abdominal pain (13.9%). The most common macroscopic findings in the 2 groups were hemorrhoids, polyps, and anal fissure. There were no statistically significant differences with respect to the microscopic and macroscopic findings between groups.

CONCLUSIONS

We concluded that the prevalence of organic lesions in the colon of patients with IBS was the same as that in the patients without IBS. The Rome IV criteria accurately predicted IBS. Additional evaluation through colonoscopy in IBS should be based on the presence of alarm features.

Organic colonic lesions in patients with irritable bowel syndrome: A comparative study

INTRODUCTION AND AIMS

Any alarm symptoms in patients with irritable bowel syndrome (IBS) should be carefully evaluated. Colonoscopy is a standard diagnostic procedure for evaluating the colonic mucosa and ruling out probable diseases responsible for patient symptoms. We analyzed the colonoscopy findings in patients with and without IBS.

MATERIAL AND METHODS

Ninety-six patients with IBS and 101 without IBS were consecutively enrolled in the study. All the patients in the IBS group met the Rome IV criteria, and underwent colonoscopy due to the appearance of red flags. The colonoscopy findings were compared between the 2 groups of patients.

RESULTS

The main indications for colonoscopy in the IBS group were progressive abdominal pain (36.7%), rectal bleeding with fresh blood (17.7%), and occult blood in stool (12.5%). In the non-IBS group, the most prevalent indicators were rectal bleeding with fresh blood (37.6%), colorectal cancer surveillance (21.8%), and abdominal pain (13.9%). The most common macroscopic findings in the 2 groups were hemorrhoids, polyps, and anal fissure. There were no statistically significant differences with respect to the microscopic and macroscopic findings between groups.

CONCLUSIONS

We concluded that the prevalence of organic lesions in the colon of patients with IBS was the same as that in the patients without IBS. The Rome IV criteria accurately predicted IBS. Additional evaluation through colonoscopy in IBS should be based on the presence of alarm features.

Irritable Bowel Syndrome Is Not Associated with an Increased Risk of Polyps and Colorectal Cancer: A Systematic Review and Meta-Analysis

OBJECTIVES

Colorectal cancer (CRC) is the third most common malignancy in the US. Several factors are associated with increased/decreased CRC risk and often linked to adenomatous colorectal polyps (CRP). Recent studies suggest a lower risk of neoplastic lesions among irritable bowel syndrome (IBS) patients. We aimed to systematically assess the occurrence of CRC and CRP in IBS patients.

METHODS

Searches of the Medline, Cochrane, and EMBASE databases were performed, blindly and independently, by two investigators. Studies of CRC or CRP incidence in IBS patients (diagnosed by Rome or other symptom-based criteria) were eligible for inclusion. CRC and CRP effect estimates were pooled in meta-analyses using random models.

RESULTS

Of 4941 non-duplicate studies, 14 were included, comprising 654,764 IBS patients and 2,277,195 controls in 8 cohort studies, and 26,641 IBS patients and 87,803 controls in 6 cross-sectional studies. Pooled analysis revealed a significantly decreased prevalence of CRP in IBS subjects vs. controls, with a pooled odds ratio (OR) of 0.29 (95% CI (0.15, 0.54)). There was significant heterogeneity between studies (I2 = 96%, p < 0.01). This finding persisted when studies which did not report pre-cancerous polyps separately were excluded (OR 0.23, 95% CI (0.15, 0.35), I2 = 85%, p < 0.01). CRC prevalence was lower in IBS subjects, but this did not reach statistical significance (OR 0.40, 95% CI (0.09, 1.77]).

CONCLUSION

Our analyses reveal a decreased incidence of colorectal polyps in IBS, although CRC did not reach significance. Mechanistic studies with detailed genotypic analysis and clinical phenotyping are needed to better elucidate the potentially protective effect of IBS on CRC development.

Assessment of Public's Awareness Regarding Irritable Bowel Syndrome in Aseer Region, Saudi Arabia

Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by altered bowel habits, abdominal pain, or discomfort. It is a highly prevalent disorder that affects patients' quality of life. A workup is usually required to diagnose IBS, as its differential diagnosis includes some serious conditions such as carcinoma of the colon. The present study aimed to assess the awareness and beliefs of the general population regarding IBS. This study was conducted in the Aseer Region, in the southwestern part of Saudi Arabia. It followed a cross-sectional research design that was conducted during the period from January to March 2021 using a structured self-administered questionnaire to assess the demographic variables in addition to questions to assess participants' awareness and beliefs related to IBS. Following a convenience sample, the study included 779 participants, with 43.3% being male, mostly in the age group 21-30 years (36.7%), and 68.7% being university graduates. Most participants (70.5%) were aware of IBS, and had the correct knowledge about its etiology, symptoms, risk factors, prognosis, and management. It is recommended to conduct various awareness-raising programs regarding IBS to improve the public's knowledge and to decrease functional disabilities and their impact on life.

Prevalence of irritable bowel syndrome and its association with colorectal cancer: a systematic review and meta-analysis

BACKGROUND

This study evaluates the risk of colorectal cancer (CRC) in patients with Irritable Bowel Syndrome (IBS).

METHODS

A literature search was performed on MEDLINE, EMBASE, SCOPUS, and Google Scholar from inception to 31st January 2020 without any limitations on article type or language for studies reporting data on CRC on patients with IBS. A meta-analysis was performed to estimate the prevalence of CRC among patients with IBS. Data extraction was according to the PRISMA guidelines. The quality of the included studies was assessed according to the Newcastle Ottawa Scale.

RESULTS

Twenty-one articles were eligible for data extraction and quantitative analysis. Of them, 11 were included in the meta-analysis (IBS n = 284 366, no-IBS n = 8 390 509). The pooled prevalence of CRC in patients with IBS was 0.96% (95% CI-0.184%-2.344%). The prevalence was lowest in the constipation-predominant IBS (pooled prevalence 1.126%. Patients with IBS-D and IBS-U had an equal pooled prevalence of CRC (2.49%). Eleven studies compared the prevalence of CRC in patients with IBS with a control population. The pooled OR was 2.8 (CI 2.305-3.294).

CONCLUSIONS

There was an increased risk of CRC among patients diagnosed with IBS, primarily in the first year after IBS diagnosis.

REGISTRATION

The review was registered on PROSPERO (CRD42021236707).

Association between impaired healing after orthognathic surgery and irritable bowel syndrome: A case report and literature review

Introduction

In the disease irritable bowel syndrome (IBS), gastrointestinal function is worsened even though no organic abnormalities are observed in the gastrointestinal mucosa. We report the case of an orthognathic surgery patient with suspected irritable bowel syndrome.

Case

In September 2017, a 15-year-old Japanese female was referred to us with dental crowding, malocclusion, and mandibular protrusion. In June 2019, a disagreement with classmates led to abdominal pain, diarrhea, and hemorrhage; in August 2019, a preoperative blood test showed sudden anemia, and her surgery was thus postponed. Subsequent upper and lower gastrointestinal endoscopy revealed no organic abnormality, and no definitive diagnosis was made. In March 2020, after an improvement in anemia was observed, a segmental Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) were performed under general anesthesia. On the third post-operative day, due to the mucosal dehiscence adjacent to the suture part, the titanium plate was exposed, and irrigation of the wound with normal saline solution and oral hygiene instruction was continued daily for 2 weeks. Two years and eight months have passed since the surgery, and the healing of the oral mucosa and bone has been uneventful.

Discussion

The relationship between IBS and post-operative impaired healing associated with the fragility of the oral mucosa is unknown. However, psychological stress has been reported as a cause of IBS and to be related to oral microorganisms.

Conclusion

Reducing risk factors for IBS and maintaining proper perioperative oral hygiene is essential in managing similar cases.

•

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease with recurrent abdominal pain.

•

It is difficult to diagnose IBS since the clinical symptoms are confusing.

•

IBS and psychological stress affect post-surgical healing.

•

Reducing risk factors for IBS and maintaining proper perioperative oral hygiene is essential in the management.

Risk Factors for Self-reported Irritable Bowel Syndrome With Prior Psychiatric Disorder: The Lifelines Cohort Study

Background/Aims

The role of psychiatric disorder in irritable bowel syndrome (IBS) is not clear. This study aims to assess whether individuals who have psychiatric disorder prior to IBS onset differ in their risk factors from the remainder.

Methods

The prospective, population-based Lifelines cohort study includes 132 922 adults without prior IBS or taking IBS medication at baseline. Baseline data included socio-demographic status, physical and psychiatric disorders, psycho-social and behavioral variables. At follow-up (mean 2.4 years later) new onsets of IBS were recorded by self-report. The predictors of new onsets of IBS were assessed using logistic regression; participants with and without prior psychiatric disorders were analyzed separately.

Results

At follow-up 1507 (1.1%) participants reported new onset IBS. Of these, 27% reported prior psychiatric disorder. Predictors of IBS in this group were 2 or more psychiatric disorders (OR, 2.74; 95% CI, 1.3-5.6), female sex, proton pump inhibitors, numerous bodily symptoms, impaired sleep, low BMI and negative health perception. These variables, except psychiatric disorders and BMI, also predicted IBS in those without prior psychiatric disorder but, in this group, gallstones, asthma, fibromyalgia, reported allergies, impairment through bodily pain, and frequent healthcare were also predictors.

Conclusions

Despite its limitations this study suggests that prior psychiatric disorder is an important risk factor in a quarter of IBS onsets. Negative health perception and multiple bodily symptoms are associated with all IBS onsets in line with the cognitive-behavior model of IBS. Prior psychiatric disorder may predict an optimal response to psychiatric treatment. Further studies could usefully study mechanisms linking IBS to prior psychiatric disorder.

A new therapy against ulcerative colitis via the intestine and brain using the Si-based agent

Ulcerative colitis (UC) is a non-specific inflammatory bowel disease that causes ulcers and erosions in the colonic mucosa and becomes chronic with cycles of amelioration and exacerbation. Because its exact etiology remains largely unclear, and the primary therapy is limited to symptomatic treatment, the development of new therapeutic agent for UC is highly desired. Because one of the disease pathogenesis is involvement of oxidative stress, it is likely that an appropriate antioxidant will be an effective therapeutic agent for UC. Our silicon (Si)-based agent, when ingested, allowed for stable and persistent generation of massive amounts of hydrogen in the gastrointestinal tract. We demonstrated the Si-based agent alleviated the mental symptom as well as the gastrointestinal symptoms, inflammation, and oxidation associated with dextran sodium sulfate-induced UC model through Hydrogen and antioxidant sulfur compounds. As the Si-based agent was effective in treating UC in the brain and large intestine of mice, it was considered to be capable of suppressing exacerbations and sustaining remission of UC.

Irritable Bowel Syndrome and Long-Term Risk of Cancer: A Prospective Cohort Study Among 0.5 Million Adults in UK Biobank

INTRODUCTION

To investigate the prospective association of irritable bowel syndrome (IBS) with long-term risk of overall, site-specific cancer and cancer-specific mortality in general population.

METHODS

Participants free of inflammatory bowel disease, celiac disease, and any cancer at baseline from the UK Biobank were included, with patients with IBS as the exposure group and non-IBS patients as the reference group. The primary outcome was the incidence of overall cancer and cancer-specific mortality. Secondary outcomes included site-specific cancers and types of digestive cancers. The Cox proportional hazard model was used to investigate the associated risk of incident malignancies and related mortality.

RESULTS

Among 449,595 participants, 22,338 (5.0%) were diagnosed with IBS. During a median of 12.2-year follow-up, 2,937 cases of incident cancer were identified in patients with IBS (11.47 per 1,000 person-years), compared with 60,556 cases in reference individuals (12.51 per 1,000 person-years). Of these cases, 512 and 12,282 cancer-specific deaths occurred in IBS and non-IBS groups. Compared with non-IBS, the adjusted hazard ratio for overall cancer and cancer-specific mortality was 0.97 (95% confidence interval: 0.93-1.00, P = 0.062) and 0.83 (0.76-0.91, P < 0.001) among patients with IBS. Specifically, decreased risk of digestive (0.79 [0.71-0.89]), particularly colon (0.75 [0.62-0.90]) and rectal (0.68 [0.49-0.93]), cancers was observed in patients with IBS. Further sensitivity analysis and subgroup analysis by age and sex indicated similar results.

DISCUSSION

Compared with the general population, IBS does not increase the overall risk of cancer. Conversely, IBS is associated with lower risk of incident colorectal cancer and cancer-specific mortality.

Risk of Colorectal Cancer in Patients With Irritable Bowel Syndrome: A Meta-Analysis of Population-Based Observational Studies

Background and Aims

Evidence on the association between irritable bowel syndrome (IBS) and colorectal cancer (CRC) risk is inconsistent. Therefore, we aimed to examine whether IBS leads to an increased risk for CRC using a systematic review and meta-analysis approach.

Methods

PubMed, Embase, and Web of Science were systematically searched to identify all relevant literature published through July 30, 2021. The pooled risk ratios (RRs) and corresponding 95% confidence intervals (CIs) for CRC after diagnosis of IBS were computed using random-and fixed-effects models and stratified by age, follow-up time, gender, and study design. The quality of included studies was assessed by the Newcastle-Ottawa scale.

Results

We included six studies consisting of 1,085,024 participants. Overall, the risk of detecting CRC after the initial IBS diagnosis was significantly higher than non-IBS controls (RR = 1.52, 95% CI: 1.04-2.22, P = 0.032). The peak of elevated risk occurred within the first year of IBS diagnosis (RR = 6.84, 95% CI: 3.70-12.65, P < 0.001), and after 1 year, the risk of CRC was similar to that of the general population (RR = 1.02, 95% CI: 0.88-1.18, P = 0.813). Notably, we found that the RR of CRC was more significant in IBS patients younger than 50 years compared to those older than 50 years (RR = 2.03, 95% CI: 1.17-3.53, P = 0.012 vs. 1.28, 95%CI: 0.94-1.75, P = 0.118, respectively). Gender and study design did not affect the results.

Conclusion

The risk of CRC within one year of the initial IBS diagnosis was increased approximately six-fold, whereas the long-term risk was not increased. However, current evidence does not support that IBS leads to an increased incidence of CRC, and the early excess risk is more likely attributable to misclassification resulting from overlapping symptoms rather than causation. Clinicians must remain vigilant for the CRC risk in patients younger than 50 years with IBS-like symptoms to avoid delaying necessary screening.

Functional gastrointestinal disorders. Overlap syndrome Clinical guidelines of the Russian Scientific Medical Society of Internal Medicine and Gastroenterological Scientific Society of Russia

.

Vagus nerve-mediated intestinal immune regulation: therapeutic implications for inflammatory bowel diseases

The pathophysiology of inflammatory bowel disease (IBD) involves immunological, genetic and environmental factors. Through its ability to sense environmental stimuli, the autonomic nervous system plays a key role in the development and persistence of IBD. The vagus nerve (VN), which contains sensory and motor neurons, travels throughout the body to innervate the gut and other visceral organs in the thoracic and abdominopelvic cavities. Recent studies show that the VN has anti-inflammatory effects via the release of acetylcholine, in what is known as the cholinergic anti-inflammatory pathway (CAIP). In the gut immune system, the CAIP is proposed to be activated directly by signals from the gut and indirectly by signals from the liver, which receives gut-derived bioactive substances via the portal vein and senses the status of the gut. The gut-brain axis and liver-brain-gut reflex arc regulate a wide variety of peripheral immune cells to maintain homeostasis in the gut. Therefore, targeting the neural reflex by methods such as VN stimulation is now under investigation for suppressing intestinal inflammation associated with IBD. In this review, we describe the role of the VN in the regulation of intestinal immunity, and we discuss novel therapeutic approaches for IBD that target neuroimmune interactions.

Evidence-based clinical practice guidelines for irritable bowel syndrome 2020

Managing irritable bowel syndrome (IBS) has attracted international attention because single-agent therapy rarely relieves bothersome symptoms for all patients. The Japanese Society of Gastroenterology (JSGE) published the first edition of evidence-based clinical practice guidelines for IBS in 2015. Much more evidence has accumulated since then, and new pharmacological agents and non-pharmacological methods have been developed. Here, we report the second edition of the JSGE-IBS guidelines comprising 41 questions including 12 background questions on epidemiology, pathophysiology, and diagnostic criteria, 26 clinical questions on diagnosis and treatment, and 3 questions on future research. For each question, statements with or without recommendations and/or evidence level are given and updated diagnostic and therapeutic algorithms are provided based on new evidence. Algorithms for diagnosis are requisite for patients with chronic abdominal pain or associated symptoms and/or abnormal bowel movement. Colonoscopy is indicated for patients with one or more alarm symptoms/signs, risk factors, and/or abnormal routine examination results. The diagnosis is based on the Rome IV criteria. Step 1 therapy consists of diet therapy, behavioral modification, and gut-targeted pharmacotherapy for 4 weeks. For non-responders, management proceeds to step 2 therapy, which includes a combination of different mechanistic gut-targeted agents and/or psychopharmacological agents and basic psychotherapy for 4 weeks. Step 3 therapy is for non-responders to step 2 and comprises a combination of gut-targeted pharmacotherapy, psychopharmacological treatments, and/or specific psychotherapy. These updated JSGE-IBS guidelines present best practice strategies for IBS patients in Japan and we believe these core strategies can be useful for IBS diagnosis and treatment globally.

Sex-Bias in Irritable Bowel Syndrome: Linking Steroids to the Gut-Brain Axis

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that is more common in females. Despite its high global incidence, the disease mechanism is still unclear and therapeutic options remain limited. The sexual dimorphism in IBS incidence suggests that sex steroids play a role in disease onset and symptoms severity. This review considers sex steroids and their involvement in IBS symptoms and the underlying disease mechanisms. Estrogens and androgens play important regulatory roles in IBS symptomology, including visceral sensitivity, gut motility and psychological conditions, possibly through modulating the gut-brain axis. Steroids are regulators of hypothalamic-pituitary-adrenal activity and autonomic nervous system function. They also modulate gut microbiota and enteric nervous systems, impacting serotonin and mast cell signaling. Sex steroids also facilitate bidirectional cross-talk between the microbiota and host following bacterial transformation and recycling of steroids by the intestine. The sex-specific interplay between sex steroids and the host provides neuroendocrinology insight into the pathophysiology, epigenetics and treatment of IBS patients.

The effects of gastrointestinal symptoms on structural grey matter volume in youth

Previous neuroimaging studies have examined the association between changes in brain structure and gastrointestinal symptoms (GIS), seen in disorders such as Irritable Bowel Syndrome and Irritable Bowel Disease. Studies in adults have found changes in white and grey matter volume (GMV) in patients with various gastrointestinal disorders. However, it is unclear whether GIS-related structural changes in the brain are limited to adults or could be present throughout the lifespan. Given that gastrointestinal disorders are typically diagnosed between 4 and 18 years old, we investigated GIS-induced morphological changes in pre-adolescents (8-10), adolescents (12-16 years) and young adults (17-21 years). Using a voxel-based morphometry (VBM) analysis, we compared regional grey matter volume (GMV) between participants with GIS and controls, using structural brain images from the Philadelphia Neurodevelopmental Cohort (PNC) database. A total of 211 participants (107 participants with GISs and 104 control participants) who had undergone structural magnetic resonance imaging were analysed. VBM analysis was used to objectively analyse GMV across the whole brain and compare between participants with GIS and controls. Participants experiencing GIS showed smaller GMV in regions within the limbic system/basal ganglia (bilateral caudate, bilateral ventral hippocampus, bilateral amygdala and bilateral superior orbital frontal cortex), and larger GMV in regions within the pain-matrix (thalamus, bilateral putamen, right mid-frontal gyrus) compared to controls. These differences were most prominent in the adolescent and young adult groups compared to pre-adolescents. In conclusion, the structural differences found in participants with GIS support the need for further research into the neurophysiological impact of these symptoms.

Irritable Bowel Syndrome between Molecular Approach and Clinical Expertise-Searching for Gap Fillers in the Oxidative Stress Way of Thinking

Irritable bowel syndrome (IBS) remains to date an intriguing functional gastrointestinal disorder. Recent studies described a multitude of exogenous factors that work together in IBS, gradually impairing intestinal lining cellular metabolism, including oxidative status balance, with or without a genetic background. Although the current biomarkers support the differentiation between IBS subtypes and other functional gastrointestinal disorder, they are mostly non-specific, referring to clinical, biochemical, and inflammatory imbalances. Since IBS could be also the result of deficient signaling pathways involving both gastrointestinal secretion and neuro-vegetative stimulation, IBS makes no exception from the oxidative hypothesis in the pathological mechanisms. Regarding the oxidative stress implication in IBS, the previous research efforts showed controversial results, with some animal models and patient studies reporting clear oxidative imbalance both on systemic and local levels, but still with no concrete evidence to point to a direct correlation between oxidative stress and IBS. Additionally, it seems that a major role could be also attributed to gut microbiota and their ability to shape our bodies and behaviors. Moreover, the genetic features study in IBS patients showed that several genetic similarities point to a possible correlation of IBS with affective spectrum disorders. Thus, we focus here the discussion on the assumption that IBS could in fact be more likely a stress-related disorder rather than a gastrointestinal one.

Estrogen modulation of visceral pain

It is commonly accepted that females and males differ in their experience of pain. Gender differences have been found in the prevalence and severity of pain in both clinical and animal studies. Sex-related hormones are found to be involved in pain transmission and have critical effects on visceral pain sensitivity. Studies have pointed out the idea that serum estrogen is closely related to visceral nociceptive sensitivity. This review aims to summarize the literature relating to the role of estrogen in modulating visceral pain with emphasis on deciphering the potential central and peripheral mechanisms.

Review article: the incidence and risk factors for irritable bowel syndrome in population-based studies

BACKGROUND

In the absence of prior gastrointestinal infection, the risk factors for irritable bowel syndrome (IBS) are not well established.

AIM

To identify the incidence and risk factors for IBS in general population samples METHODS: Narrative review of population-based studies. Electronic databases were searched using the keywords "incidence," "onset," "epidemiology," "population," "risk factors" with "irritable bowel syndrome" with subsequent hand searching. Inclusion criteria were: population-based, adults, prospective design (including retrospective case cohorts), clinical or research diagnosis of IBS and exclusion of individuals who had IBS prior to recruitment.

RESULTS

Of 1963 papers, 38 were included; all provided data on risk factors, 27 reported incidence. The median incidence of physician-diagnosed IBS in 19 general population cohorts was 38.5 per 10 000 person-years (interquartile range = 20-45.3). In 14 cohorts with specific medical disorders, median incidence was 92 per 10 000 person-years (IQR: 73.9-119). Apart from gastroenteritis, the most common risk factors were other medical disorders, female sex, age (both young and old), anxiety and depression, life events/stress, frequent healthcare use, pain and sleep disorders. The results were conflicting for alcohol consumption, smoking and BMI. Incidence rates were similar in different countries but risk factors differed.

CONCLUSIONS

Incidence rates were generally lower than previous estimates reflecting physician-diagnosed IBS. The results highlight the importance of other medical and psychosocial problems in the onset of IBS in addition to prior gastrointestinal infections. Aetiological research could be enhanced by studying the underlying mechanisms relating to all of these risk factors.

Metabolomics reveals elevated urinary excretion of collagen degradation and epithelial cell turnover products in irritable bowel syndrome patients

INTRODUCTION

Irritable bowel syndrome (IBS), the most commonly diagnosed functional gastrointestinal (GI) disorder in developed countries, is characterized by chronic abdominal pain, and altered bowel habits.

OBJECTIVES

Accurate and timely diagnosis is challenging as it relies on symptoms and an evolving set of exclusion criteria to distinguish it from other related GI disorders reflecting a complex etiology that remains poorly understood. Herein, nontargeted metabolite profiling of repeat urine specimens collected from a cohort of IBS patients (n = 42) was compared to healthy controls (n = 20) to gain insights into the underlying pathophysiology.

METHODS

An integrated data workflow for characterization of the urine metabolome with stringent quality control was developed to authenticate reliably measured (CV < 30%) and frequently detected (> 75%) metabolites using multisegment injection-capillary electrophoresis-mass spectrometry. Complementary statistical methods were then used to rank differentially excreted urinary metabolites after normalization to osmolality that were subsequently identified by high resolution tandem mass spectrometry and their electrophoretic migration behavior.

RESULTS

Our work revealed ten consistently elevated urinary metabolites in repeat samples collected from IBS patients at two different time points (q < 0.05 after age and Benjamini-Hochberg/FDR adjustment), which were associated with greater collagen degradation and intestinal mucosal turn-over processes likely due to low-grade inflammation. IBS-specific metabolites identified in urine included a series of hydroxylysine metabolites (O-glycosylgalactosyl-hydroxylysine, O-galactosyl-hydroxylysine, lysine), mannopyranosy-L-tryptophan, imidazole propionate, glutamine, serine, ornithine, dimethylglycine and dimethylguanosine. A major limitation in this retrospective case-control study was significant co-morbidity of IBS patients with other illnesses, including depression and prescribed medications as compared to healthy controls.

CONCLUSION

This work provides new mechanistic insights into the pathophysiology of IBS while also offering a convenient way to monitor patient disease progression and treatment responses to therapy based on a panel of urinary metabolites that avoids invasive blood sampling, colonoscopy and/or tissue biopsies.

Overlapping irritable bowel syndrome and inflammatory bowel disease

The pathogenesis of irritable bowel-type symptoms occurring in patients with inflammatory bowel disease who are in apparent remission continues to generate scientific controversy and the interpretation and management of these symptoms, so distressing to the sufferer, represent major challenges for the clinician. On the one hand, these symptoms often satisfy Rome IV criteria for IBS and their occurrence correlates highly with anxiety, a known trigger for IBS. On the other hand, recent studies have shown that many of these patients exhibit subtle inflammatory changes. These observations beg the question: are these symptoms "true" IBS superimposed on IBD, or an active but subclinical form of IBD? While it is certain that earlier studies failed to detect subclinical inflammation, it is also evident that even with the use of sensitive biomarkers for inflammation, such as calprotectin and lactoferrin backed up by pan-endoscopy and biopsy to exclude ongoing inflammatory activity in its most subtle form, the prevalence of IBS-type symptoms remains higher than expected in the IBD patient. Pending further definition of its etiology and pathology, we coined the term irritable inflammatory bowel syndrome (IIBS) to refer to this phenomenon. Here we explore the risk factors for this entity, sift through clues to its pathogenesis and attempt to provide, albeit bereft of a robust evidence base, an approach to its management.

Rome Foundation Working Team Report on Post-Infection Irritable Bowel Syndrome

BACKGROUND & AIMS

The existence of postinfection irritable bowel syndrome (PI-IBS) has been substantiated by epidemiology studies conducted in diverse geographic and clinical settings. However, the available evidence has not been well summarized, and there is little guidance for diagnosis and treatment of PI-IBS. The ROME Foundation has produced a working team report to summarize the available evidence on the pathophysiology of PI-IBS and provide guidance for diagnosis and treatment, based on findings reported in the literature and clinical experience.

METHODS

The working team conducted an evidence-based review of publication databases for articles describing the clinical features (diagnosis), pathophysiology (intestinal sensorimotor function, microbiota, immune dysregulation, barrier dysfunction, enteroendocrine pathways, and genetics), and animal models of PI-IBS. We used a Delphi-based consensus system to create guidelines for management of PI-IBS and a developed treatment algorithm based on published findings and experiences of team members.

RESULTS

PI-IBS develops in about 10% of patients with infectious enteritis. Risk factors include female sex, younger age, psychological distress during or before acute gastroenteritis, and severity of the acute episode. The pathogenesis of PI-PBS appears to involve changes in the intestinal microbiome as well as epithelial, serotonergic, and immune system factors. However, these mechanisms are incompletely understood. There are no evidence-based, effective pharmacologic strategies for treatment of PI-IBS. We provide a consensus-based treatment algorithm, based on clinical presentation and potential disease mechanisms.

CONCLUSIONS

Based on a systematic review of the literature and team experience, we summarize the clinical features, pathophysiology (from animal models and human studies), and progression of PI-IBS. Based on these findings, we present an algorithm for diagnosis and treatment of PI-IBS based on team consensus. We also propose areas for future investigation.

Sex-Gender Differences in Irritable Bowel Syndrome

Because of the sex-gender differences that are shown in a diversity of physiological and psychological factors, it can be speculated that the clinical presentation of symptoms as well as treatment strategies in women and men with irritable bowel syndrome (IBS) may differ. Studies have revealed that IBS is more common in women than men. As for the IBS subtype, IBS with constipation is significantly more prevalent among women than men. Sex hormones and gender differences may play important roles in the pathophysiology of IBS. However, its pathophysiologic mechanisms still remain largely unknown, and therapeutic implications are limited. Moreover, women IBS patients have been reported to feel more fatigue, depression, anxiety, and lower quality of life than men IBS patients. Furthermore, there has been evidence of differences in the appropriate treatment efficacy to IBS in men and women, although relatively few men are enrolled in most relevant clinical trials. A more sex-gender-oriented approach in the medical care setting could improve understanding of heterogeneous patients suffering from IBS. An individualized and multicomponent approach including sex and gender issues might help improve the treatment of IBS.

Evidence-based update on rosacea comorbidities and their common physiologic pathways

Rosacea is a common chronic inflammatory disease affecting the facial skin whose etiology and pathophysiology are the subject of much investigation. Risk factors include genetic and environmental elements that may predispose individuals to localized inflammation and abnormal neurovascular responses to stimuli. Recent studies have introduced an array of systemic rosacea comorbidities, such as inflammatory bowel disease and neurologic conditions, that can be challenging to synthesize. We critically review the current data behind reported rosacea comorbidities and identify and highlight underrecognized physiologic mediators shared among rosacea and associated comorbidities. This information may be helpful in addressing patient questions about potential systemic implications of rosacea and can serve as a candidate platform for future research to understand rosacea and improve treatments.

Effect of diet and individual dietary guidance on gastrointestinal endocrine cells in patients with irritable bowel syndrome (Review)

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal (GI) disorder that is characterized by a combination of abdominal pain or discomfort, bloating and alterations in bowel movements. This review presents recent developments concerning the roles of diet and GI endocrine cells in the pathophysiology of IBS and of individual dietary guidance in the management of IBS. Patients with IBS typically report that food aggravates their IBS symptoms. The interactions between specific types of foodstuffs rich in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and GI endocrine cells induce changes in cell densities. Providing individual dietary guidance about a low FODMAP intake, high soluble-fiber intake, and changing the proportions of protein, fat and carbohydrates helps to reduce the symptoms experienced by patients with IBS and to improve their quality of life. These improvements are due to restoring the densities of the GI endocrine cells back to normal. The reported observations emphasize the role of GI endocrine cells in the pathophysiology of IBS and support the provision of dietary guidance as a first-line treatment for managing IBS.

Primary Care Evaluation and Management of Gastroenterologic Issues in Women

Gastrointestinal disorders often present to the primary care setting where initial preventive, diagnostic, and treatment strategies are implemented. This article reviews the presentation and diagnosis of common gastrointestinal disorders, including colorectal cancer, irritable bowel syndrome, peptic ulcer disease, gallbladder disorders, inflammatory bowel disease, gastroesophageal reflux, and Barrett's esophagus. We focus on the evaluation and management of these diseases in women.

The Severity of Symptoms Related to Irritable Bowel Syndrome is a Risk Factor for the Misclassification of Significant Organic Disease

BACKGROUND AND AIMS

The diagnosis of irritable bowel syndrome (IBS) is based mainly on clinical evaluation. The reported incidence of misclassification of significant organic diseases in previously diagnosed IBS patients differs between studies. The aim of this study was to examine the incidence and risk factors for the misclassification of significant organic disease [colon cancer, inflammatory bowel disease (IBD), Celiac disease, and thyroid dysfunction] in a cohort of young patients with symptoms attributed to IBS.

METHODS

In this population-based cohort study, we examined the incidence and risk factors for the diagnosis of a new significant organic diseases in a cohort of 2645 IBS patients.

RESULTS

During follow-up, organic disease was diagnosed in 27 subjects (1.03%): IBD in 23, Celiac disease in 2, IBD and Celiac disease in 1, and hypothyroidism in1. The mean interval from the diagnosis of IBS to the diagnosis of an organic disorder was 13.08±8.51 months. Increased symptom severity was the only significant risk factor for the misclassification of an organic disease (hazard ratio, 2.26; 95% confidence interval, 1.01-5.05; P=0.047). The risk ratio for misclassification of organic diseases in moderate to severe IBS was increased by 2.575 (95% confidence interval, 1.10-6.51; P=0.027) as compared with mild IBS.

CONCLUSIONS

The incidence of misclassification of major organic disease in IBS patients was low. Increased symptoms severity was the only significant risk factor for the misclassification of organic disorders. Further gastrointestinal evaluation should be considered in patients with moderate to severe symptoms attributed to IBS.

Epidemiology of inflammatory bowel disease among participants of the Millennium Cohort: incidence, deployment-related risk factors, and antecedent episodes of infectious gastroenteritis

BACKGROUND

Crohn's disease (CD) and ulcerative colitis (UC) are two pathotypes of inflammatory bowel disease (IBD) with unique pathology, risk factors and significant morbidity.

AIM

To estimate incidence and identify IBD risk factors in a US military population, a healthy subset of the US population, using information from the Millennium Cohort Study.

METHODS

Incident IBD was identified from medical encounters from 2001 to 2009 or by self-report. Our primary risk factor of interest, infectious gastroenteritis, was identified from medical encounters and self-reported post-deployment health assessments. Other potential risk factors were assessed using self-reported survey responses and military personnel files. Hazard ratios were estimated using Cox proportional hazards analysis.

RESULTS

We estimated 23.2 and 21.9 diagnoses per 100 000 person-years, respectively, for CD and UC. For CD, significant risk factors included [adjusted hazard ratio (aHR), 95% confidence interval]: current smoking (aHR: 2.7, 1.4-5.1), two life stressors (aHR: 2.8, 1.4-5.6) and prior irritable bowel syndrome (aHR: 4.7, 1.5-15.2). There was no significant association with prior infectious gastroenteritis. There was an apparent dose-response relationship between UC risk and an increasing number of life stressors. In addition, antecedent infectious gastroenteritis was associated with almost a three-fold increase in UC risk (aHR: 2.9, 1.4-6.0). Moderate alcohol consumption (aHR: 0.4, 0.2-0.6) was associated with lower UC risk.

CONCLUSIONS

Stressful conditions and the high risk of infectious gastroenteritis in deployment operations may play a role in the development of IBD in military populations. However, observed differences in risk factors for UC and CD warrant further investigation.

The epidemiology of irritable bowel syndrome: Symptom development over a 3-year period in Denmark. A prospective, population-based cohort study

BACKGROUND

We aimed to explore the natural history of irritable bowel syndrome (IBS) in Denmark over 3 years by studying development of IBS symptoms and associated factors.

METHODS

A cohort study was carried out using a web panel representative of the Danish general population 18-50 years. The survey, including a questionnaire based on the Rome III criteria for IBS, was conducted in January 2010, January 2011, and March 2013.

KEY RESULTS

The prevalence of IBS was 15.4% (920/5986). The incidence was 10.3%, and was three times higher for persons with unspecific gastrointestinal (GI) symptoms compared to asymptomatic persons. Of respondents with IBS symptoms in both 2010 and 2011, 69% (131/191) also reported symptoms of IBS in 2013, which was significantly more compared to respondents with IBS symptoms in 2010 reporting to be asymptomatic or having unspecific GI symptoms in 2011 (20% and 39%, respectively, P<.001). Being diagnosed with IBS predicted fulfilling the criteria for IBS 3 years later (OR: 2.59, 95% CI: 1.11-6.10). Fulfilling criteria for IBS after 1 year also led to a high risk of IBS symptoms 3 years later in asymptomatic persons and persons with unspecific symptoms at baseline.

CONCLUSIONS & INFERENCES

The vast majority of persons fulfilling criteria for IBS report GI symptoms after one and 3 years. Fulfilling IBS criteria after 1 year led to a high risk of reporting IBS symptoms after 3 years. In the general population having an IBS diagnosis predicts persistently fulfilling the Rome III criteria for IBS 3 years later.

Trends in Irritable Bowel Syndrome Incidence among Taiwanese Adults during 2003-2013: A Population-Based Study of Sex and Age Differences

Background

No population-based irritable bowel syndrome (IBS) incidence data among Taiwanese adults are available. Whether IBS is associated with risk of organic colonic diseases remains unanswered. We investigated 1) the sex- and age-stratified trends in the annual incidence of IBS, and 2) the risk of selected organic diseases in patients with IBS compared with those without IBS among Taiwanese adults during 2003–2013.

Methods

Medical claims data for 1 million randomly selected beneficiaries were obtained and analyzed. Patients with IBS were considered eligible for enrollment if they aged between 20 and 100 and had at least two medical encounters with IBS codes within 1 year. To test whether there was a linear secular trend in IBS incidence over time, multivariate Poisson regression with generalized estimating equation model was conducted. The risk of selected organic diseases associated with IBS was examined using multivariate Cox proportional hazard regression.

Results

From 2003 to 2013, the incidence of IBS significantly decreased over time [adjusted incidence rate ratio (IRR) = 0.97, p< 0.001]; the incidence of IBS significantly increased with age (adjusted IRR = 1.03, p < 0.001) and was significantly higher in women than in men (adjusted IRR = 1.14, p< 0.001). IBS significantly associated with increased risk of microscopic colitis, inflammatory bowel disease, and colorectal cancer during a 10-year follow-up period.

Conclusions

The incidence of IBS increased with age and was slightly higher in women than in men among Taiwanese adults. During 2003–2013, IBS incidence gradually decreased over time. IBS may increase risk of several colonic organic diseases.

Gastrointestinal symptoms related to the irritable bowel syndrome - a longitudinal population-based register study

OBJECTIVE

Functional gastrointestinal (GI) symptoms can develop into persistent states often categorised as the irritable bowel syndrome (IBS). In the severe end of the GI symptom continuum, other coexisting symptoms are common. We aimed to investigate the GI symptom continuum in relation to mortality and development of GI diseases, and to examine if coexisting symptoms had an influence on the outcomes.

MATERIAL AND METHODS

A longitudinal population-based study comprising two 5-year follow-up studies: Dan-Monica1 (1982-1987) and Inter99 (1999-2004). IBS was defined according to a population-based IBS definition. The pooled cohort (n = 7278) was followed until December 2013 in Central Registries.

RESULTS

Fifty-one percent had no GI symptoms, 39% had GI symptoms but never fulfilled the IBS definition, 8% had fluctuating IBS and 2% had persisting IBS. There was no significant association between symptom groups and mortality (p = 0.47). IBS and GI symptoms with abdominal pain were significantly associated with development of GI diseases. Only GI symptoms with abdominal pain were associated with development of severe GI diseases (HR: 1.38; 95% CI: [1.06-1.79]). There were no statistically significant interactions between symptom groups and coexisting symptoms in relation to the two outcomes.

CONCLUSIONS

GI diseases were seen more frequently, but IBS was not associated with severe GI diseases or increased mortality. Clinicians should be more aware when patients do not fulfil the IBS definition, but continue to report frequent abdominal pain. Coexisting symptoms did not influence mortality and development of GI diseases.

Irritable bowel syndrome and inflammatory bowel disease overlap syndrome: pieces of the puzzle are falling into place

Irritable bowel syndrome (IBS), a common gastrointestinal disorder involving the gut-brain axis, and inflammatory bowel disease (IBD), a chronic relapsing inflammatory disorder, are both increasing in incidence and prevalence in Asia. Both have significant overlap in terms of symptoms, pathophysiology, and treatment, suggesting the possibility of IBS and IBD being a single disease entity albeit at opposite ends of the spectrum. We examined the similarities and differences in IBS and IBD, and offer new thoughts and approaches to the disease paradigm.

The joint power of sex and stress to modulate brain-gut-microbiota axis and intestinal barrier homeostasis: implications for irritable bowel syndrome

BACKGROUND

Intestinal homeostasis is a dynamic process that takes place at the interface between the lumen and the mucosa of the gastrointestinal tract, where a constant scrutiny for antigens and toxins derived from food and microorganisms is carried out by the vast gut-associated immune system. Intestinal homeostasis is preserved by the ability of the mucus layer and the mucosal barrier to keep the passage of small-sized and antigenic molecules across the epithelium highly selective. When combined and preserved, immune surveillance and barrier's selective permeability, the host capacity of preventing the development of intestinal inflammation is optimized, and viceversa. In addition, the brain-gut-microbiome axis, a multidirectional communication system that integrates distant and local regulatory networks through neural, immunological, metabolic, and hormonal signaling pathways, also regulates intestinal function. Dysfunction of the brain-gut-microbiome axis may induce the loss of gut mucosal homeostasis, leading to uncontrolled permeation of toxins and immunogenic particles, increasing the risk of appearance of intestinal inflammation, mucosal damage, and gut disorders. Irritable bowel syndrome is prevalent stress-sensitive gastrointestinal disorder that shows a female predominance. Interestingly, the role of stress, sex and gonadal hormones in the regulation of intestinal mucosal and the brain-gut-microbiome axis functioning is being increasingly recognized.

PURPOSE

We aim to critically review the evidence linking sex, and stress to intestinal barrier and brain-gut-microbiome axis dysfunction and the implications for irritable bowel syndrome.

Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye?

Though distinct in terms of pathology, natural history and therapeutic approach, irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have some features in common. These include shared symptomatology and largely similar demographics. However, in most instances, clinical presentation, together with laboratory, imaging and endoscopic findings will readily permit the differentiation of active IBD from IBS. More problematic is the situation where a subject with IBD, in apparent remission, continues to complain of symptoms which, in aggregate, satisfy commonly employed criteria for the diagnosis of IBS. Access to methodologies, such the assay for levels of calprotectin in feces, now allows identification of ongoing inflammation in some such individuals and prompts appropriate therapy. More challenging is the IBD patient with persisting symptoms and no detectable evidence of inflammation; is this coincident IBS, IBS triggered by IBD or an even more subtle level of IBD activity unrecognized by available laboratory or imaging methods? Arguments can be advanced for each of these proposals; lacking definitive data, this issue remains unresolved. The occurrence of IBS-type symptoms in the IBD patient, together with some data suggesting a very subtle level of 'inflammation' or 'immune activation' in IBS, raises other questions: is IBS a prodromal form of IBD; and are IBS and IBD part of the spectrum of the same disease? All of the available evidence indicates that the answer to both these questions should be a resounding 'no'. Indeed, the whole issue of overlap between IBS and IBD should be declared moot given their differing pathophysiologies, contrasting natural histories and divergent treatment paths. The limited symptom repertoire of the gastrointestinal tract may well be fundamental to the apparent confusion that has, of late, bedeviled this area.

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.

Influences of diet and the gut microbiome on epigenetic modulation in cancer and other diseases

Epigenetic modulation of gene activity occurs in response to non-genetic factors such as body weight status, physical activity, dietary factors, and environmental toxins. In addition, each of these factors is thought to affect and be affected by the gut microbiome. A primary mechanism that links these various factors together in mediating control of gene expression is the production of metabolites that serve as critical cofactors and allosteric regulators of epigenetic processes. Here, we review the involvement of the gut microbiota and its interactions with dietary factors, many of which have known cellular bioactivity, focusing on particular epigenetic processes affected and the influence they have on human health and disease, particularly cancer and response to treatment. Advances in DNA sequencing have expanded the capacity for studying the microbiome. Combining this with rapidly improving techniques to measure the metabolome provides opportunities to understand complex relationships that may underlie the development and progression of cancer as well as treatment-related sequelae. Given broad reaching and fundamental biology, both at the cellular and organismal levels, we propose that interactive research programs, which utilize a wide range of mutually informative experimental model systems—each one optimally suited for answering particular questions—provide the best path forward for breaking ground on new knowledge and ultimately understanding the epigenetic significance of the gut microbiome and its response to dietary factors in cancer prevention and therapy.

Chronic subordinate colony housing paradigm: a mouse model to characterize the consequences of insufficient glucocorticoid signaling

Chronic, in particular chronic psychosocial, stress is a burden of modern societies and known to be a risk factor for numerous somatic and affective disorders (in detail referenced below). However, based on the limited existence of appropriate, and clinically relevant, animal models for studying the effects of chronic stress, the detailed behavioral, physiological, neuronal, and immunological mechanisms linking stress and such disorders are insufficiently understood. To date, most chronic stress studies in animals employ intermittent exposure to the same (homotypic) or to different (heterotypic) stressors of varying duration and intensity. Such models are only of limited value, since they do not adequately reflect the chronic and continuous situation that humans typically experience. Furthermore, application of different physical or psychological stimuli renders comparisons to the mainly psychosocial stressors faced by humans, as well as between the different stress studies almost impossible. In contrast, rodent models of chronic psychosocial stress represent situations more akin to those faced by humans and consequently seem to hold more clinical relevance. Our laboratory has developed a model in which mice are exposed to social stress for 19 continuous days, namely the chronic subordinate colony housing (CSC) paradigm, to help bridge this gap. The main aim of the current review article is to provide a detailed summary of the behavioral, physiological, neuronal, and immunological consequences of the CSC paradigm, and wherever possible relate the findings to other stress models and to the human situation.

Evidence-based clinical practice guidelines for irritable bowel syndrome

New strategies for the care of irritable bowel syndrome (IBS) are developing and several novel treatments have been globally produced. New methods of care should be customized geographically because each country has a specific medical system, life style, eating habit, gut microbiota, genes and so on. Several clinical guidelines for IBS have been proposed and the Japanese Society of Gastroenterology (JSGE) subsequently developed evidence-based clinical practice guidelines for IBS. Sixty-two clinical questions (CQs) comprising 1 definition, 6 epidemiology, 6 pathophysiology, 10 diagnosis, 30 treatment, 4 prognosis, and 5 complications were proposed and statements were made to answer to CQs. A diagnosis algorithm and a three-step treatment was provided for patients with chronic abdominal pain or abdominal discomfort and/or abnormal bowel movement. If more than one alarm symptom/sign, risk factor and/or routine examination is positive, colonoscopy is indicated. If all of them, or the subsequent colonoscopy, are/is negative, Rome III or compatible criteria is applied. After IBS diagnosis, step 1 therapy consisting of diet therapy, behavioral modification and gut-targeted pharmacotherapy is indicated for four weeks. Non-responders to step 1 therapy proceed to the second step that includes psychopharmacological agents and simple psychotherapy for four weeks. In the third step, for patients non-responsive to step 2 therapy, a combination of gut-targeted pharmacotherapy, psychopharmacological treatments and/or specific psychotherapy is/are indicated. Clinical guidelines and consensus for IBS treatment in Japan are well suited for Japanese IBS patients; as such, they may provide useful insight for IBS treatment in other countries around the world.

Irritable bowel syndrome and the incidence of colorectal neoplasia: a prospective cohort study with community-based screened population in Taiwan

Background:

We aim to report the prevalence of irritable bowel syndrome (IBS) and elucidate the influence of IBS on the incidence of colorectal neoplasm through a community-screening-based, longitudinal follow-up study.

Methods:

We enroled 39 384 community residents aged 40 years or older who had participated in a community-based colorectal cancer-screening programme with an immunochemical faecal occult test since 1999. We followed a cohort that was free of colorectal neoplasm (excluding colorectal neoplasm at baseline) to ascertain the incident colorectal neoplasm through each round of screening and used a nationwide cancer registry. Information on IBS was obtained by linking this screened cohort with population-based health insurance claim data. Other confounding factors were also collected via questionnaire or biochemical tests.

Results:

The overall period prevalence of IBS was 23%, increasing from 14.7% for subjects aged 40–49 years to 43.7% for those aged 70 years and more. After controlling for age, gender and family history of colorectal cancer, screenees who had been diagnosed as having IBS exhibited a significantly elevated level (21% adjusted hazard ratio (HR)=1.21 (95% CI: 1.02–1.42)) of incident colorectal adenoma compared with those who had not been diagnosed with IBS. A similar finding was noted for invasive carcinoma; however, the size of the effect was of borderline statistical significance (adjusted HR=1.20 (95% CI: 0.94–1.53)).

Conclusions:

IBS led to an increased risk for incident colorectal neoplasm.

Are IBD patients more likely to have a prior diagnosis of irritable bowel syndrome? Report of a case-control study in the General Practice Research Database

BACKGROUND

Inflammatory bowel disease (IBD) patients are sometimes first diagnosed with irritable bowel syndrome (IBS), which may be construed as a misdiagnosis.

OBJECTIVE

The objective of this article is to determine if this occurs more than expected by chance.

METHODS

We conducted a case-control study nested in the General Practice Research Database. We selected incident cases of IBD and up to 10 matched controls for each. We assessed the proportions with IBS recorded prior to the IBD diagnosis and variation by age, sex, and calendar time. We compared proportions affected in fixed time periods and conducted conditional logistic regression to derive odds ratios.

RESULTS

The 20, 193 cases were three times as likely as controls to have a prior record of IBS. Fifteen per cent of IBD cases and 5% of controls had IBS coded before diagnosis with 11% having a code for IBS over one year before IBD (cf. 5% of controls) and 6% over five years earlier (cf. 3%). These figures roughly doubled if typical antispasmodic therapies were assumed to represent IBS diagnoses.

CONCLUSION

If excess IBS diagnoses represent misdiagnoses of IBD, our results suggest that about 10% of IBD patients are misdiagnosed and in 3% of cases this may persist for five or more years.

The incidence of other gastroenterological disease following diagnosis of irritable bowel syndrome in the UK: a cohort study

Background

Guidelines recommend Irritable Bowel Syndrome (IBS) diagnosis and management in primary care with minimal investigations; however little evidence exists regarding risk of organic gastrointestinal conditions following diagnosis of IBS and how such risks vary over the long term. This study assesses excess incidence of coeliac disease, inflammatory bowel disease (IBD) and colorectal cancer (CRC) and variation with age and time after IBS diagnosis.

Methods

IBS patients and controls were identified within the UK Clinical Practice Research Dataset. Incidence rates were calculated and stratified by age and time since IBS diagnosis with incident rate ratios generated.

Results

Fifteen years after IBS diagnosis there is a significant cumulative excess incidence of coeliac disease, IBD and CRC in IBS of 3.7% compared to 1.7% in controls. For every 10000 patient years, IBS patients experienced an additional 4 diagnoses of coeliac disease, 13 of IBD and 4 CRCs. In each condition peak excess incidence was in the 6 months following diagnosis. After one year, increased incidence of coeliac disease remained consistent without variation by age. IBD incidence fell slowly, with higher rates in those under 30. CRC incidence was increased only in patients aged 30 to 74 during the first 5 years.

Conclusion

Some IBS patients later receive organic gastrointestinal diagnoses, with the early excess incidence likely detected during diagnostic investigation at the time of IBS diagnosis. More than 5 years after IBS diagnosis there is no increased risk of CRC compared to the general population, but a small excess risk of coeliac disease and IBD persists. Overall, though our findings provide reassurance that non-specialists, especially those in primary care, are unlikely to be missing an organic condition in the majority of their patients. This suggests that current guidelines suggesting avoidance of universal referral for these patients are appropriate.

Prevalence of irritable bowel syndrome-like symptoms in ulcerative colitis patients with clinical and endoscopic evidence of remission: prospective multicenter study

OBJECTIVE

Irritable bowel syndrome (IBS)-like symptoms are often found in ulcerative colitis (UC) patients in remission. However, the prevalence of those symptoms in UC patients with endoscopic evidence of remission shown by mucosal healing remains unknown.

MATERIAL AND METHODS

IBS diagnosis was evaluated by questionnaire results according to the Rome III criteria. Clinical remission was assessed by clinical activity index (CAI), whereas endoscopic remission was evaluated by endoscopic index (Matts grade).

RESULTS

We enrolled 172 patients in clinical remission (CAI ≤ 4), after excluding 36 for incomplete questionnaire results or nonremission findings, as well as 330 control subjects. Of the 172 UC patients, 46 (26.7%) met the Rome III criteria, which was a significantly higher rate as compared with the controls (4.8%). The prevalence rate of IBS-like symptoms in UC patients with endoscopic remission findings (Matts grade ≤2) was 25.6%, which was similar to that of those with clinical remission. When endoscopic remission was defined as Matts grade 1, the prevalence rate of IBS-like symptoms was decreased to 15.4%, although the prevalence rate remained higher than that of the control subjects.

CONCLUSIONS

The prevalence of IBS-like symptoms in UC patients with clinical and endoscopic remission findings was significantly higher than that of control subjects. Furthermore, the prevalence rate in patients with complete endoscopic remission was decreased. These findings suggest that residual low-grade inflammation may influence the presence of IBS-like symptoms in UC patients in remission.