Gender Role in Irritable Bowel Syndrome: A Comparison of Irritable Bowel Syndrome Module (ROME III) Between Male and Female Patients

Prevalence of chronic diarrhea and its association with obesity in a Chinese community-based population

BACKGROUND

Epidemiological data on chronic diarrhea in the Chinese population are lacking, and the association between obesity and chronic diarrhea in East Asian populations remains inconclusive. This study aimed to investigate the prevalence of chronic diarrhea and its association with obesity in a representative community-dwelling Chinese population.

METHODS

This cross-sectional study was based on a multistage, randomized cluster sampling involving 3503 residents aged 20-69 years from representative urban and rural communities in Beijing. Chronic diarrhea was assessed using the Bristol Stool Form Scale (BSFS), and obesity was determined based on body mass index (BMI). Logistic regression analysis and restricted cubic splines were used to evaluate the relationship between obesity and chronic diarrhea.

RESULTS

The standardized prevalence of chronic diarrhea in the study population was 12.88%. The average BMI was 24.67 kg/m 2 . Of all the participants, 35.17% (1232/3503) of participants were classified as overweight and 16.13% (565/3503) as obese. After adjustment for potential confounders, individuals with obesity had an increased risk of chronic diarrhea as compared to normal weight individuals (odds ratio = 1.58, 95% confidence interval: 1.20-2.06). A nonlinear association between BMI and the risk of chronic diarrhea was observed in community residents of males and the overall participant group ( P  = 0.026 and 0.017, respectively).

CONCLUSIONS

This study presents initial findings on the prevalence of chronic diarrhea among residents of Chinese communities while offering substantiated evidence regarding the significant association between obesity and chronic diarrhea. These findings offer a novel perspective on gastrointestinal health management.

Glutamatergic and GABAergic anteroventral BNST projections to PVN CRH neurons regulate maternal separation-induced visceral pain

Early-life stress (ELS) is thought to cause the development of visceral pain disorders. While some individuals are vulnerable to visceral pain, others are resilient, but the intrinsic circuit and molecular mechanisms involved remain largely unclear. Herein, we demonstrate that inbred mice subjected to maternal separation (MS) could be separated into susceptible and resilient subpopulations by visceral hypersensitivity evaluation. Through a combination of chemogenetics, optogenetics, fiber photometry, molecular and electrophysiological approaches, we discovered that susceptible mice presented activation of glutamatergic projections or inhibition of GABAergic projections from the anteroventral bed nucleus of the stria terminalis (avBNST) to paraventricular nucleus (PVN) corticotropin-releasing hormone (CRH) neurons. However, resilience develops as a behavioral adaptation partially due to restoration of PVN SK2 channel expression and function. Our findings suggest that PVN CRH neurons are dually regulated by functionally opposing avBNST neurons and that this circuit may be the basis for neurobiological vulnerability to visceral pain.

Epigenetic mechanisms underlying stress-induced visceral pain: Resilience versus vulnerability in a two-hit model of early life stress and chronic adult stress

BACKGROUND

Women with a history of early life stress (ELS) have a higher risk of developing irritable bowel syndrome (IBS). In addition, chronic stress in adulthood can exacerbate IBS symptoms such as abdominal pain due to visceral hypersensitivity. We previously showed that sex and the predictability of ELS determine whether rats develop visceral hypersensitivity in adulthood. In female rats, unpredictable ELS confers vulnerability and results in visceral hypersensitivity, whereas predictable ELS induces resilience and does not induce visceral hypersensitivity in adulthood. However, this resilience is lost after exposure to chronic stress in adulthood leading to an exacerbation of visceral hypersensitivity. Evidence suggests that changes in histone acetylation at the promoter regions of glucocorticoid receptor (GR) and corticotrophin-releasing factor (CRF) in the central nucleus of the amygdala (CeA) underlie stress-induced visceral hypersensitivity. Here, we aimed to investigate the role of histone acetylation in the CeA on visceral hypersensitivity in a two-hit model of ELS followed by chronic stress in adulthood.

METHODS

Male and female neonatal rats were exposed to unpredictable, predictable ELS, or odor only (no stress control) from postnatal days 8 to 12. In adulthood, rats underwent stereotaxic implantation of indwelling cannulas. Rats were exposed to chronic water avoidance stress (WAS, 1 h/day for 7 days) or SHAM stress and received infusions of vehicle, the histone deacetylase inhibitor trichostatin A (TSA) or the histone acetyltransferase inhibitor garcinol (GAR) after each WAS session. 24 h after the final infusion, visceral sensitivity was assessed and the CeA was removed for molecular experiments.

RESULTS

In the two-hit model (ELS + WAS), female rats previously exposed to predictable ELS, showed a significant reduction in histone 3 lysine 9 (H3K9) acetylation at the GR promoter and a significant increase in H3K9 acetylation at the CRF promoter. These epigenetic changes were associated with changes in GR and CRF mRNA expression in the CeA and an exacerbation of stress-induced visceral hypersensitivity in female animals. TSA infusions in the CeA attenuated the exacerbated stress-induced visceral hypersensitivity, whereas GAR infusions only partially ameliorated ELS+WAS induced visceral hypersensitivity.

CONCLUSION

The two-hit model of ELS followed by WAS in adulthood revealed that epigenetic dysregulation occurs after exposure to stress in two important periods of life and contributes to the development of visceral hypersensitivity. These aberrant underlying epigenetic changes may explain the exacerbation of stress-induced abdominal pain in IBS patients.

Peripheral CRF-R1/CRF-R2 antagonist, astressin C, induces a long-lasting blockade of acute stress-related visceral pain in male and female rats

Peptide CRF antagonists injected peripherally alleviate stress-induced visceral hypersensitivity (SIVH) to colorectal distension (CRD) in rodents. Here we further evaluated the dose and time-dependent inhibitory activity of several long-acting peptide CRF receptor antagonists related to astressin on SIVH, focusing on astressin C (AstC), which previously showed high efficacy on stress-related alterations of HPA axis and gut secretomotor functions. Male and female Sprague-Dawley rats pretreated subcutaneously (SC) with AstC were injected intraperitoneally (IP) with CRF 15 min later. The visceromotor responses (VMR) to graded phasic CRD (10, 20, 40 and 60 mmHg) were monitored at basal, 15 min and up to 1-8 days after pretreatment. Two other astressin analogs, hexanoyl-astressin D (Hex-AstD) and [CαMeVal^19,32]-AstC, were also tested. The response to IP CRF was sex-dependent with female rats requiring a higher dose to exhibit visceral hyperalgesia. Pretreatment with AstC (30-1000 µg/kg) resulted in a dose-related inhibition of IP CRF-induced SIVH and diarrhea in both sexes. The highest dose prevented SIVH and diarrhea up to 5-7 days after a single SC injection and was lost on day 7 (females) and day 8 (males) but reinstated after a second injection of AstC on day 8 or 9 respectively. [CαMeVal^19,32]-AstC and Hex-AstD (1000 µg/kg in males) also prevented SIVH. These data show the potent long-lasting anti-hyperalgesic effect of AstC in an acute model of SIVH in both male and female rats. This highlights the potential of long-acting peripheral CRF antagonists to treat stress-sensitive irritable bowel syndrome.

A Resting-state Functional Magnetic Resonance Imaging Study of Whole-brain Functional Connectivity of Voxel Levels in Patients With Irritable Bowel Syndrome With Depressive Symptoms

Background/Aims

Depressive symptom is one of the most common symptoms in patients with irritable bowel syndrome (IBS), but its pathogenetic mechanisms remain unclear. As a voxel-level graph theory analysis method, degree centrality (DC) can provide a new perspective for exploring the abnormalities of whole-brain functional network of IBS with depressive symptoms (DEP-IBS).

Methods

DC, voxel-wise image and clinical symptoms correlation and seed-based functional connectivity (FC) analyses were performed in 28 DEP-IBS patients, 21 IBS without depressive symptoms (nDEP-IBS) patients and 36 matched healthy controls (HC) to reveal the abnormalities of whole brain FC in DEP-IBS.

Results

Compared to nDEP-IBS patients and HC, DEP-IBS patients showed significant decrease of DC in the left insula and increase of DC in the left precentral gyrus. The DC's z-scores of the left insula negatively correlated with depression severity in DEP-IBS patients. Compared to nDEP-IBS patients, DEP-IBS patients showed increased left insula-related FC in the left inferior parietal lobule and right inferior occipital gyrus, and decreased left insula-related FC in the left precentral gyrus, right supplementary motor area (SMA), and postcentral gyrus. In DEP-IBS patients, abstracted clusters' mean FC in the right SMA negatively correlated with depressive symptoms.

Conclusions

DEP-IBS patients have abnormal FC in brain regions associated with the fronto-limbic and sensorimotor networks, especially insula and SMA, which explains the vicious circle between negative emotion and gastrointestinal symptoms in IBS. Identification of such alterations may facilitate earlier and more accurate diagnosis of depression in IBS, and development of effective treatment strategies.

Effects of stress-related peptides on chloride secretion in the mouse proximal colon

BACKGROUND

Stress increases intestinal secretion and exacerbates symptoms of irritable bowel syndrome (IBS). Peripherally derived corticotropin-releasing factor (CRF) is known to mediate stress-induced intestinal secretion, presumably by activation of CRF₁ receptors in the gut. The present study aimed to ascertain the role of CRF₂ activation in intestinal secretion by three other members of CRF peptide family, urocortin (UCN) 1-3, in wild type (WT) and CRF₂ knockout (Crhr2^-/- ) mice.

METHODS

Mucosal/submucosal preparations from proximal colon of WT and Crhr2^-/- mice of both sexes were mounted in Ussing chambers for measurement of short-circuit current (I_sc ) as an indicator of ion secretion.

KEY RESULTS

Male mice demonstrated a significantly higher baseline I_sc than female in both WT and Crhr2^-/- genotypes. CRF and UCN1-3 (1 μM) caused greater increases in colonic I_sc (ΔI_sc ) in male than female. Colonic I_sc response to the selective CRF₁ agonist, stressin1, was similar in both sexes. In male mice, the selective CRF₂ agonists (UCN2 and UCN3) caused significantly greater ΔI_sc than CRF and stressin1. UCN2- and UCN3-evoked ΔI_SC was significantly reduced in preparations pretreated with the selective CRF₂ antagonist antisauvagine-30 and in Crhr2^-/- mice. The prosecretory effects of urocortins were due to increases in Cl^- secretion and involved enteric neurons and mast cells.

CONCLUSIONS AND INFERENCE

The findings revealed sex differences in baseline colonic secretion and responses to stress-related peptides. CRF₂ receptors play a more prominent role in colonic secretion in male mice. The greater baseline secretion and responses to UCNs may contribute to the higher prevalence of diarrhea-predominant IBS in males.

Irritable Bowel Syndrome in a Population of a Developing Country: Prevalence and Association

Introduction: Irritable bowel syndrome (IBS) is included as one of the functional gastrointestinal (GI) related disorders presenting with pain in abdomen of chronic duration in the absence of any identifiable organic cause. Bloating, distension of abdomen, and defecation in disordered manner are other features commonly associated with IBS. It is a complex disorder with mixed physiological, psychological, and social interactions. The present study was carried out with the aim to determine the frequency of IBS in patients presenting with abdominal pain in a population of a developing country.

Materials and methods: A descriptive cross-sectional study was undertaken at the outpatient department of a large tertiary care hospital. Patients of either gender aged between 20 and 50 years presenting with abdominal pain were included. The diagnosis of IBS was established using Rome III criteria. Prevalence of IBS was calculated and confounding factors such as age, gender, marital status, duration of abdominal pain, and economic status were stratified to see their effect on outcome variable by applying chi-square test and taking p-value of <0.05 as significant.

Results: A total of 186 patients were included in this study. Some 100 (53.76%) were male and 86 (46.24%) were female. Mean age of the patients was 33.67 ± 7.08 years. Some 58.6% were married and 41.4% were single. Some 61.83% had mild abdominal pain and 38.17% had moderate pain. Out of the total 186 patients, the frequency of IBS was found to be 35.48%. There was no significant effect of confounding variables such as age, gender, duration of abdominal pain, marital status, and economic status on IBS.

Conclusion: In our study the frequency of IBS in patients with abdominal pain is high with no significant effect of gender, marital status, economic status, and duration of abdominal pain on IBS.

Irritable Bowel Syndrome and Neurological Deficiencies: Is There A Relationship? The Possible Relevance of the Oxidative Stress Status

Background: Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, exhibiting complex and controversial pathological features. Both oxidative stress and inflammation-related reactive oxygen species production may be involved in IBS pathological development. Thus, we focused on several aspects regarding the causes of oxidative stress occurrence in IBS. Additionally, in the molecular context of oxidative changes, we tried to discuss these possible neurological implications in IBS. Methods: The literature search included the main available databases (e.g., ScienceDirect, Pubmed/Medline, Embase, and Google Scholar). Articles in the English language were taken into consideration. Our screening was conducted based on several words such as “irritable bowel syndrome”, “gut brain axis”, “oxidative stress”, “neuroendocrine”, and combinations. Results: While no consistent evidence suggests clear pathway mechanisms, it seems that the inflammatory response may also be relevant in IBS. The mild implication of oxidative stress in IBS has been described through clinical studies and some animal models, revealing changes in the main markers such as antioxidant status and peroxidation markers. Moreover, it seems that the neurological structures involved in the brain-gut axis may be affected in IBS rather than the local gut tissue and functionality. Due to a gut-brain axis bidirectional communication error, a correlation between neurological impairment, emotional over-responsiveness, mild inflammatory patterns, and oxidative stress can be suggested. Conclusions: Therefore, there is a possible correlation between neurological impairment, emotional over-responsiveness, mild inflammatory patterns, and oxidative stress that are not followed by tissue destruction in IBS patients. Moreover, it is not yet clear whether oxidative stress, inflammation, or neurological impairments are key determinants or in which way these three interact in IBS pathology. However, the conditions in which oxidative imbalances occur may be an interesting research lead in order to find possible explanations for IBS development.

Sex differences in the epigenetic regulation of chronic visceral pain following unpredictable early life stress

BACKGROUND

We previously reported that early life stress (ELS) dysregulated glucocorticoid receptor (GR) and corticotrophin-releasing hormone (CRH) expression in the central nucleus of the amygdala (CeA). Epigenetic modifications serve as memories of adverse events that occurred during early life. Therefore, we hypothesized that epigenetic mechanisms alter GR and CRH expression in the CeA and underlie chronic visceral pain after ELS.

METHODS

Neonatal rats were exposed to unpredictable, predictable ELS, or odor only (no stress control) from postnatal days 8 to 12. In adulthood, visceral sensitivity was assessed or the CeA was isolated for Western blot or ChiP-qPCR to study histone modifications at the GR and CRH promoters. Female adult rats underwent stereotaxic implantation of indwelling cannulas for microinjections of garcinol (HAT inhibitor) into the CeA. After 7 days of microinjections, visceral sensitivity was assessed or the CeA was isolated for ChIP-qPCR assays.

RESULTS

Unpredictable ELS increased visceral sensitivity in adult female rats, but not in male counterparts. ELS increased histone 3 lysine 9 (H3K9) acetylation in the CeA and H3K9 acetylation levels at the GR promoter in the CeA of adult female rats. After unpredictable ELS, H3K9 acetylation was increased and GR binding was decreased at the CRH promoter. Administration of garcinol in the CeA of adult females, that underwent unpredictable ELS, normalized H3K9 acetylation and restored GR binding at the CRH promoter.

CONCLUSION

Dysregulated histone acetylation and GR binding at the CRH promoter in the CeA are an important mechanism for "memorizing" ELS events mediating visceral pain in adulthood.

Nanomaterial-based gas sensors used for breath diagnosis

Gas-sensing applications commonly use nanomaterials (NMs) because of their unique physicochemical properties, including a high surface-to-volume ratio, enormous number of active sites, controllable morphology, and potential for miniaturisation.

Effect of Samryungbaekchul-san Combined with Otilonium Bromide on Diarrhea-Predominant Irritable Bowel Syndrome: A Pilot Randomized Controlled Trial

Conventional and herbal drugs are frequently used together to treat many disorders. Samryungbaekchul-san (SRS, a herbal formula) and otilonium bromide (OB, an antispasmodic agent) are widely used to treat diarrhea-predominant irritable bowel syndrome (D-IBS) in Eastern Asian countries. However, there have been no studies on the co-administration of SRS and OB. Therefore, we aimed to preliminarily assess the feasibility of SRS combined with OB for D-IBS treatment in a pilot double-blind, four-arm, parallel-group, randomized controlled trial (RCT), including 80 patients diagnosed with D-IBS according to the Rome III criteria. The patients were randomly assigned to four treatment groups and were administered drugs for eight weeks after a two-week preparatory period. Follow-up was conducted four weeks after the administration period. The primary outcome was evaluated by using a global D-IBS symptom improvement score; no statistically significant difference was observed between the groups. However, multiple logistic regression analysis of primary outcome scores shows that SRS significantly improved D-IBS symptoms (p < 0.05). For secondary outcomes, better results were observed in the SRS + OB group, in terms of symptoms, including abdominal pain, discomfort, frequency of abdominal pain, and stool form than in OB alone or placebo groups (p < 0.05). In conclusion, the co-administration of SRS and OB might be an effective and safe strategy for the treatment of D-IBS. Large-scale RCTs are warranted to further confirm and clarify these findings.

Blastocystis ST-1 is associated with Irritable Bowel Syndrome-diarrhoea (IBS-D) in Indonesian adolescences

Objective

IBS is a functional gastrointestinal disorder and commonly presents in children and adolescences, presented as diarrhoea, constipation or mixed type. Blastocystis is a common intestinal protozoa found worldwide, which pathogenicity is still controversial. This study aimed to identify the risk factors of IBS, the association between IBS types with Blastocystis subtypes and analyse Blastocystis pathogenicity.

Design

A comparative cross-sectional study was conducted among senior high school students. Rome III Criteria for IBS diagnosis, questionnaires on the risk factors of IBS and types of IBS were recorded. Students were further selected and classified into IBS and non-IBS groups to analyse the association between IBS, IBS types with Blastocystis infection and its subtypes. Direct microscopic stool examination to identify single Blastocystis infection was performed, followed by culture in Jones' medium, PCR, sequencing of 18S rRNA and phylogenetic analysis to determine Blastocystis subtype. Data was analysed using SPSS v22.0 and P value <0.05 was considered statistically significant (95% confidence intervals).

Results

IBS was found in 30.2% of 454 students, consisted of 33.3% IBS Diarrhoea, 27.7% IBS Mixed, 27.7% IBS Unclassified and 11.1% IBS Constipation. Major risk factors to IBS consisted of family history of recurrent abdominal pain, abuse, bullying and female gender in respective order (OR 3.6–2.1). Blastocystis ST-1 was significantly associated to IBS-D with 2.9 times risk factor.

Conclusions

Blastocystis infection is a risk factor to develop IBS-D type in adolescence; Blastocystis ST-1 can be regarded as a pathogenic subtype.

Serum zonulin is elevated in IBS and correlates with stool frequency in IBS-D

Background

Studies have shown increased intestinal permeability in irritable bowel syndrome. Validating serum biomarkers for altered intestinal permeability in irritable bowel syndrome will facilitate research and pathophysiology-based therapy.

Objective

To measure serum zonulin and intestinal fatty acid binding protein levels in diarrhea-predominant irritable bowel syndrome and constipation-predominant irritable bowel syndrome and compare with healthy controls and celiac disease.

Methods

Serum zonulin and intestinal fatty acid binding protein levels were measured using enzyme-linked immunosorbent assays in constipation-predominant irritable bowel syndrome (n = 50), diarrhea-predominant irritable bowel syndrome (n = 50), celiac disease (n = 53) and healthy controls (n = 42). Irritable bowel syndrome symptom severity was measured using the irritable bowel syndrome-symptom severity scale.

Results

Patients with constipation-predominant irritable bowel syndrome and diarrhea-predominant irritable bowel syndrome had higher zonulin levels compared with healthy controls (p = 0.006 and 0.009 respectively), which was comparable to those with active celiac disease. Although zonulin levels did not correlate with the overall irritable bowel syndrome symptom severity scale, it positively correlated with stool frequency per week (p = 0.03) and dissatisfaction with bowel habits (p = 0.007) in diarrhea-predominant irritable bowel syndrome. Patients with diarrhea-predominant irritable bowel syndrome and constipation-predominant irritable bowel syndrome had lower intestinal fatty acid binding protein levels compared with celiac patients (p = 0.005 and p = 0.047 respectively).

Conclusion

Serum zonulin is upregulated in irritable bowel syndrome and the levels are comparable to those in celiac disease. Zonulin levels correlated with severity of bowel habits in diarrhea-predominant irritable bowel syndrome. Intestinal fatty acid binding protein levels in irritable bowel syndrome patients were not increased suggesting no significant increase in enterocyte death.

Symptom Severity Following Rifaximin and the Probiotic VSL#3 in Patients with Chronic Pelvic Pain Syndrome (Due to Inflammatory Prostatitis) Plus Irritable Bowel Syndrome

This study investigated the effects of long-term treatment with rifaximin and the probiotic VSL#3 on uro-genital and gastrointestinal symptoms in patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) plus diarrhoea-predominant irritable bowel syndrome (D-IBS) compared with patients with D-IBS alone. Eighty-five patients with CP/CPPS (45 with subtype IIIa and 40 with IIIb) plus D-IBS according to the Rome III criteria and an aged-matched control-group of patients with D-IBS alone (n = 75) received rifaximin and VSL#3. The primary endpoints were the response rates of IBS and CP/CPPS symptoms, assessed respectively through Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) and The National Institute of Health Chronic Prostatitis Symptom Index (NIH-CPSI), and performed at the start of therapy (V0) and three months after (V3). In IIIa prostatitis patients, the total NIH-CPSI scores significantly (p < 0.05) decreased from a baseline mean value of 21.2 to 14.5 at V3 , as did all subscales, and in the IIIb the total NIH-CPSI score also significantly decreased (from 17.4 to 15.1). Patients with IBS alone showed no significant differences in NIH-CPSI score. At V3, significantly greater improvement in the IBS-SSS and responder rate were found in IIIa patients. Our results were explained through a better individual response at V3 in IIIa prostatitis of urinary and gastrointestinal symptoms, while mean leukocyte counts on expressed prostate secretion (EPS) after prostate massage significantly lowered only in IIIa cases.

Mapping of Brain Activations to Rectal Balloon Distension Stimuli in Male Patients with Irritable Bowel Syndrome Using Functional Magnetic Resonance Imaging

Background/Aims

Irritable bowel syndrome (IBS) is associated with exaggerated cerebral response including emotional processing following visceral stimulation; though data on this issue is available in female IBS patients, it is scanty among males. Hence, we aimed to study brain response of male IBS patients following rectal balloon distension as compared to healthy controls using functional magnetic resonance imaging (fMRI). Data between diarrhea and constipation predominant IBS (IBS-D and IBS-C) were also compared.

Methods

Rectal balloon distension threshold was assessed in 20 male IBS patients (10 IBS-C and 10 IBS-D) and 10 age-matched male healthy controls. Subsequently, fMRI on all the participants was performed at their respective rectal pain threshold. The fMRI data were analysed using the Statistical Parametric Mapping software.

Results

IBS patients showed greater cerebral activations in insula, middle temporal gyrus, and cerebellum in the left hemisphere compared to healthy controls. Neural activation was found in bilateral precuneus/superior parietal lobules in controls but not in patients with IBS. The brain activation differed among IBS-C and IBS-D patients; while the right mid-cingulate cortex was activated in IBS-C, the left inferior orbito-frontal cortex, left calcarine, and bilateral fusiform gyri were activated among patients with IBS-D following rectal balloon distension.

Conclusions

Brain response to rectal balloon distension differed among male patients with IBS and controls and among patients with IBS-C and IBS-D. Differential activation among patients with IBS-C and IBS-D was seen in the brain regions controlling affective motivation, homeostatic emotions, and autonomic responses to pain.

Smoking in Irritable Bowel Syndrome: A Systematic Review

OBJECTIVE

The aim of this review was to examine (1) the prevalence of smoking in subjects with irritable bowel syndrome (IBS), (2) whether smoking prevalence significantly differs between subjects with and without IBS, and (3) whether smoking significantly predicts the presence or the development of IBS.

METHODS

Articles were retrieved by systematically searching the Scopus, Web of Science, and PubMed electronic databases from inception to July 2016, using the keywords "smoking" and "tobacco" combined with "irritable bowel syndrome." Reference lists of included articles were also searched. Articles were included if they (1) reported data on smoking prevalence in subjects with IBS and/or on the association (assessed by means of multivariate analyses) between smoking and IBS, (2) identified IBS according to Manning criteria or Rome I-III criteria, (3) were English-language articles, and (4) involved only adult subjects.

RESULTS

The electronic searches yielded a total of 1,637 records, and 42 articles met inclusion criteria. Another 13 articles were retrieved through manual search, leading to a total of 55 included articles. Smoking prevalence in subjects with IBS was assessed by 48 articles and ranged from 0% in university students to 47.1% in patients with microscopic colitis. Thirty-three articles compared smoking prevalence between subjects with and without IBS. In 25 articles no significant difference was found. In seven articles smoking was significantly more frequent in subjects with IBS compared to those without IBS, while one study found a significantly higher smoking prevalence in controls. Eighteen multivariate analyses assessing the association between smoking and IBS were presented in 16 articles. Only one study employed a prospective design. In 11 analyses, smoking was not significantly associated with IBS after adjusting for covariates. In seven studies smoking independently predicted the presence of IBS.

CONCLUSIONS

According to the selected articles, a significant association between smoking and IBS cannot be confirmed. However, different shortcomings may hinder generalizability and comparability of many studies. A dimensional assessment of smoking, a prospective design, the differentiation between IBS subgroups, and the recruitment of patients in clinical settings, especially in primary care, are necessary to clarify the role of smoking in IBS.

The self-evaluation of upper-gastrointestinal symptoms in Chinese patients with digestive disease: A multicenter questionnaire survey

AIM

To investigate the self-evaluation of upper gastrointestinal symptoms in Chinese patients. To observe the role of patients' characters, such as sex, age, education background, and clinic visits, which might affect the self-understanding of patients.

METHODS

The nationwide cross-sectional questionnaire was administered to 3000 patients with upper gastrointestinal symptoms at 50 hospitals across 9 provinces in China. Questionnaire items covered four basic patients' characters and five major upper gastrointestinal symptoms.

RESULTS

A total of 2799 questionnaires (response rate: 93.3%) were analyzed. Only 35.29% patients could precisely understand the definition of dyspepsia. The misunderstanding of lower-gastroenterology discomforts is the major reason leading to low accuracy rate of dyspepsia. The accuracy rate of early satiety and postprandial fullness is 37.7% and 52.27% separately; they are most interrelated and easily confused concepts to each other. The accuracy rate of heartburn is 30.02%, while the location of burning sensation is the key aspect for misunderstanding of heartburn. The self-understanding of symptoms in patients was decreased with increasing age, and enhanced with higher education background and time of clinic visits. Gender is not the independent factor.

CONCLUSION

Based on the low accuracy rate of self-understanding of patients, this survey suggests that the gastroenterologists should re-evaluate the symptoms of patients during the clinical inquiry.

Anxiety and Depression Increase in a Stepwise Manner in Parallel With Multiple FGIDs and Symptom Severity and Frequency

OBJECTIVES

Anxiety and depression occur frequently in patients with functional gastrointestinal disorders (FGIDs), but their precise prevalence is unknown. We addressed this issue in a large cohort of adult patients and determined the underlying factors.

METHODS

In total, 4,217 new outpatients attending 2 hospitals in Hamilton, Ontario, Canada completed questionnaires evaluating FGIDs and anxiety and depression (Hospital Anxiety and Depression scale). Chart review was performed in a random sample of 2,400 patients.

RESULTS

Seventy-six percent of patients fulfilled Rome III criteria for FGIDs, but only 57% were diagnosed with FGIDs after excluding organic diseases, and the latter group was considered for the analysis. Compared with patients not meeting the criteria, prevalence of anxiety (odds ratio (OR) 2.66, 95% confidence interval (CI): 1.62-4.37) or depression (OR 2.04, 95% CI: 1.03-4.02) was increased in patients with FGIDs. The risk was comparable to patients with organic disease (anxiety: OR 2.12, 95% CI: 1.24-3.61; depression: OR 2.48, 95% CI: 1.21-5.09). The lowest prevalence was observed in asymptomatic patients (OR 1.37; 95% CI 0.58-3.23 and 0.51; 95% CI 0.10-2.48; for both conditions, respectively). The prevalence of anxiety and depression increased in a stepwise manner with the number of co-existing FGIDs and frequency and/or severity of gastrointestinal (GI) symptoms. Psychiatric comorbidity was more common in females with FGIDs compared with males (anxiety OR 1.73; 95% CI 1.35-2.28; depression OR 1.52; 95% CI 1.04-2.21). Anxiety and depression were formally diagnosed by the consulting physician in only 22% and 9% of patients, respectively.

CONCLUSIONS

Psychiatric comorbidity is common in patients referred to a secondary care center but is often unrecognized. The prevalence of both anxiety and depression is influenced by gender, presence of organic diseases, and FGIDs, and it increases with the number of coexistent FGIDs and frequency and severity of GI symptoms.

Potential Causes and Present Pharmacotherapy of Irritable Bowel Syndrome: An Overview

BACKGROUND

Irritable bowel syndrome (IBS) is currently one of the most common disorders of the digestive system in the Western society. Almost 2 out of 10 people suffer from IBS with women being more affected than men. IBS is associated with abdominal pain, bloating and altered stool consistency and imposes a heavy burden for the affected patients.

SUMMARY

The pathophysiology of IBS remains elusive although potential causes have been suggested, such as a deranged brain-gut signaling, hypersensitivity of visceral sensory afferent fibers, bacterial gastroenteritis, small intestinal bacterial overgrowth (SIBO), genetic alterations and food sensitivity. Targets for the pharmacotherapy of IBS include the serotonergic and opioidergic system, and the microbial population of the gut. Alternative therapies like traditional Chinese medicine have shown some success in the combat against IBS. Key Messages: Many therapeutics for the treatment of IBS have emerged in the past; however, only a few have met up with the expectations in larger clinical trials. Additionally, the multifactorial etiology of IBS and its variety of cardinal symptoms requires an individual set of therapeutics. This review provides a short overview of potential causes and current pharmacological therapeutics and of additional and alternative therapies for IBS.

Chronic bacterial prostatitis and irritable bowel syndrome: effectiveness of treatment with rifaximin followed by the probiotic VSL#3

This study was undertaken to evaluate the influence of treatment with rifaximin followed by the probiotic VSL#3 versus no treatment on the progression of chronic prostatitis toward chronic microbial prostate-vesiculitis (PV) or prostate-vesiculo-epididymitis (PVE). A total of 106 selected infertile male patients with bacteriologically cured chronic bacterial prostatitis (CBP) and irritable bowel syndrome (IBS) were randomly prescribed rifaximin (200 mg, 2 tablets bid, for 7 days monthly for 12 months) and probiotic containing multiple strains VSL#3 (450 × 10⁹ CFU per day) or no treatment. Ninety-five of them (89.6%) complied with the therapeutic plan and were included in this study. Group A = “6Tx/6-”: treatment for the initial 6 and no treatment for the following 6 months (n = 26); Group B = “12Tx”: 12 months of treatment (n = 22); Group C = “6-/6Tx”: no treatment for the initial 6 months and treatment in the last 6 months (n = 23); Group D = “12-”: no treatment (n = 24). The patients of Groups A = “6Tx/6-” and B = “12Tx” had the highest frequency of chronic prostatitis (88.5% and 86.4%, respectively). In contrast, group “12-”: patients had the lowest frequency of prostatitis (33.4%). The progression of prostatitis into PV in groups “6Tx/6-” (15.5%) and “6-/6Tx” (13.6%) was lower than that found in the patients of group “12-” (45.8%). Finally, no patient of groups “6Tx/6-” and “6-/6Tx” had PVE, whereas it was diagnosed in 20.8% of group “12-” patients. Long-term treatment with rifaximin and the probiotic VSL#3 is effective in lowering the progression of prostatitis into more complicated forms of male accessory gland infections in infertile patients with bacteriologically cured CBP plus IBS.

More similarities than differences between men and women with irritable bowel syndrome

BACKGROUND

Differences regarding symptoms, coping abilities, and quality of life (QOL) between men and women with irritable bowel syndrome (IBS) have been reported but data are sparse and sometimes conflicting. The aim of present study was to investigate gender differences in gastrointestinal, extra-intestinal, and psychological symptoms, and sense of coherence (SOC) and QOL in a large group of patients diagnosed with IBS.

METHODS

We analyzed questionnaire data from 557 patients (152 men) diagnosed with IBS consecutively included in studies at an outpatient clinic for functional bowel disorders between 2002 and 2010. Following questionnaires were included: IBS severity scoring system (IBS-SSS), Hospital Anxiety and Depression Scale (HAD), IBSQOL Scale, Visceral Sensitivity Index (VSI), SOC Scale, Bristol Stool Form Scale (BSFS), and Patient Health Questionnaire (PHQ-15).

KEY RESULTS

Women had harder stools (FDR-adjusted p-value: q = 0.033), more severe bloating (q = 0.020), higher symptom severity (q = 0.042), higher total somatic symptom burden (q = 0.035), lower SOC (q = 0.042), and lower QOL. Women rated more general anxiety (q = 0.017) and gastrointestinal-specific anxiety (q = 0.042), but there were no group differences in depression, pain, stool frequency, impact on daily life, dissatisfaction with bowel habit, or extra-colonic symptoms. The differences found were small (effect sizes: r < 0.3).

CONCLUSIONS & INFERENCES

In this study, we demonstrated more similarities than differences between men and women with IBS. The largest difference were seen for QOL which might reflect certain structural stressors to which women in general are more exposed than men.

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

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

A school-based study of irritable bowel syndrome in medical students in beijing, china: prevalence and some related factors

Purpose. To investigate the prevalence and some related factors about irritable bowel syndrome (IBS) in medical students. Methods. A cross-sectional study was carried out from February 2014 to Jun 2014 in Beijing University of Chinese Medicine, Beijing, China. All participants were asked to completed self-administered questionnaires. Results. Seven hundred and sixty-seven medical students (23.26 ± 2.88 years, 25.6% males) completed the survey. The prevalence of IBS was 33.3%, with a high prevalence in women (36.1%). Among the IBS patients, 112 cases were IBS-M (43.9%) and 77.6% had moderately severe IBS. There were no statistical differences between control group and IBS patients in anxiety and depression scores (P > 0.05). The total score of Pittsburgh sleep quality index (PSQI) was significantly higher for medical students with IBS and 35.5% of IBS patients had severe sleep disorder; the scores of child trauma questionnaire (CTQ) and student-life stress inventory (SLSI) were also higher in IBS patients. Sex and sleep disorder were independently associated with IBS (OR, 1.914, 95%CI, 1.281-2.860; OR, 1.143, 95%CI, 1.074-1.216). Conclusion. Our study has many valuable findings and they may provide valuable suggestions for the necessary intervention and treatment measures towards medical students.

Subtypes of irritable bowel syndrome in children and adolescents

BACKGROUND & AIMS

Pharmacologic treatments for irritable bowel syndrome (IBS) and medical management of symptoms are increasingly based on IBS subtype, so it is important to accurately differentiate patients. Few studies have classified subtypes of pediatric IBS, and conclusions have been challenged by methodologic limitations. We performed a prospective study to investigate the distribution of IBS subtypes among children and adolescents based on stool diary information, and compared subtypes according to demographic and pain characteristics.

METHODS

We studied 129 subjects, ages 7 to 18 years (mean age, 11.4 ± 2.8 y; 60.5% female; 69.0% white) who met Pediatric Rome III IBS criteria and were part of larger studies of children with functional gastrointestinal disorders, recruited from primary and tertiary care centers. Children completed daily pain and stool diaries for 2 weeks. Participants were assigned IBS subtypes based on their reported stool information per adult Rome III criteria. IBS subtypes were compared for demographic variables and pain characteristics.

RESULTS

IBS with constipation was the most common subtype of the disorder (58.1% of subjects), whereas mixed IBS was the least common (2.3% of subjects); 34.1% of subjects were unsubtyped IBS and 5.4% had IBS with diarrhea. The groups of different IBS subtypes did not differ significantly by sex, age, ethnicity, or pain characteristics.

CONCLUSIONS

In contrast to adults, in children, IBS with constipation and unsubtyped IBS are the most common subtypes, whereas IBS with diarrhea and mixed IBS are less common. Demographic and pain characteristics cannot distinguish subtypes.

Expression of G protein-coupled estrogen receptor in irritable bowel syndrome and its clinical significance

OBJECTIVES

Estrogen is suggested to participate in pathogenesis of irritable bowel syndrome (IBS), but expression of G protein-coupled estrogen receptor (GPER) in the colon of IBS patients has never been investigated. The aim of this study was to investigate the expression of GPER and classical estrogen receptors in the colon of IBS patients and healthy controls.

METHODS

Colonic biopsies were obtained by endoscopy from patients with IBS (n=46) and healthy subjects (n=13). Expression of GPER, estrogen receptor α (ERα) and estrogen receptor β (ERβ) in mast cells were measured by double-labelling immunofluorescence. Quantification of mRNA expression was performed for GPER, ERα and ERβ by real-time polymerase chain reaction.

RESULTS

Differential distribution of GPER, ERα and ERβ were detected in human colonic mucosa. The expression of GPER in the cytoplasm of mast cells and GPER-positive cells was significantly higher in diarrhea-predominant IBS (D-IBS) patients than that in constipation-predominant IBS (C-IBS, P<0.001) patients and healthy subjects (P=0.005). ERα and ERβ were not detected in majority of mast cells in colonic mucosa and no difference of immunostaining results for ERα and ERβ was found among these three groups. A positive correlation (r=0.451, P=0.011) between GPER-positive cell counts and abdominal pain severity was observed in D-IBS group. Relative mRNA expression of GPER in D-IBS was also higher than that in C-IBS (P=0.018) and healthy subjects (P=0.011).

CONCLUSIONS

The present study, for the first time, demonstrated the expression of GPER in human colonic mucosa and its correlation with abdominal pain severity.

A review of the clinical manifestations, pathophysiology and management of opioid bowel dysfunction and narcotic bowel syndrome

Opioids are widely used for the treatment of malignant and non-malignant pains. These medications are accompanied by adverse effects, in particular gastrointestinal symptoms known as opioid bowel dysfunction (OBD). The most common symptom of OBD is refractory constipation that is usually stable regardless of the use of laxatives. Narcotic bowel syndrome (NBS) is a subset of OBD described as ambiguous chronic pain aggravated by continual or increased opioid use for pain relief. Pathophysiology of these disorders are not definitely disentangled. Some challenging hypothesis have been posed leading to specific management in order to mitigate the adverse effects. This article is a review of the literature on the prevalence, pathophysiology and management of OBD and NBS.

Comparison of long-term effects of cognitive-behavioral therapy versus mindfulness-based therapy on reduction of symptoms among patients suffering from irritable bowel syndrome

AIM

The aim of this study was to compare the long-term effects of cognitive-behavioral treatment and mindfulness-based treatment on decreasing symptoms of patients suffering from irritable bowel syndrome (IBS).

BACKGROUND

One of the most modern therapies put forward in therapy of IBS is mindfulness-based metacognitive therapy.

PATIENTS AND METHODS

In this quasi-experimental study, 36 people with mean age of 32 years old, including 24 patients with IBS and 12 healthy normal subjects as control group, were studied. Patients with IBS were randomly divided into two experimental groups of cognitive-behavioral treatment (n=12) and mindfulness-based treatment (n=12). Data were analysed by one-way covariance analysis.

RESULTS

There was significant decrease of the symptoms of IBS among two treatment groups versus control group in long-term (p<0.05). Mindfulness-based therapy was the most effective technique in decreasing symptoms.

CONCLUSION

This study showed mindfulness-based therapy, as a modern psychotherapy technique, is an effective method to decrease symptoms of patients with irritable bowel syndrome, compared with old methods. Therefore, this technique is advised among these patients, especially those who have refractory symptoms.

Abdominal bloating: pathophysiology and treatment

Abdominal bloating is a very common and troublesome symptom of all ages, but it has not been fully understood to date. Bloating is usually associated with functional gastrointestinal disorders or organic diseases, but it may also appear alone. The pathophysiology of bloating remains ambiguous, although some evidences support the potential mechanisms, including gut hypersensitivity, impaired gas handling, altered gut microbiota, and abnormal abdominal-phrenic reflexes. Owing to the insufficient understanding of these mechanisms, the available therapeutic options are limited. However, medical treatment with some prokinetics, rifaximin, lubiprostone and linaclotide could be considered in the treatment of bloating. In addition, dietary intervention is important in relieving symptom in patients with bloating.

The Crohn's disease activity index (CDAI) is similarly elevated in patients with Crohn's disease and in patients with irritable bowel syndrome

BACKGROUND

While the Crohn's disease activity index (CDAI) is the gold standard for defining clinical endpoints in Crohn's disease (Crohn's) clinical trials, its ability to distinguish symptoms due to inflammation from those that are non-inflammatory has been questioned.

AIM

To compare CDAI scores in patients with Crohn's and those with Irritable Bowel Syndrome (IBS).

METHODS

This was a prospective, cross-sectional cohort study of 91 patients with either Crohn's (n = 44) or IBS (n = 47). Total CDAI and individual component scores were recorded and comparisons were made between Crohn's and IBS patients.

RESULTS

Mean CDAI scores were higher in the IBS patients (183 vs. 157, P = 0.1). Sixty-two per cent (n = 29) of IBS patients had CDAI scores greater than 150. Mean CDAI haematocrit score (35.9 vs. 23.0, P = 0.02) and CRP level (6.8 vs. 2.0, P = 0.002) were higher in the Crohn's group. Analysis of CDAI sub-scores demonstrated that IBS patients had significantly higher pain (mean 1.7 vs. 0.8, P = 0.0007) and well-being scores (mean 1.2 vs. 0.8, P = 0.04) relative to patients with Crohn's. Specifically evaluating patients with CDAI greater than 150 (n = 51), IBS patients had higher pain sub-scores (mean 2.4 vs. 1.4, P = 0.002), whereas patients with Crohn's had higher CRP (mean 8.4 vs. 1.8, P = 0.001).

CONCLUSIONS

Our study demonstrates that the CDAI does not discriminate patients with symptoms due to active Crohn's from patients with IBS. Patients with IBS can have CDAI scores in the clinically meaningful range. Objective measures, such as CDAI haematocrit score and CRP, are more specific markers of inflammation.

Association between irritable bowel syndrome and restless legs syndrome: a comparative study with control group

BACKGROUND/AIMS

As a common gastrointestinal (GI) disorder, irritable bowel syndrome (IBS) has been reported to be associated with some psychological and neurological factors. This study aimed to evaluate the prevalence rate of restless legs syndrome (RLS) in a sample of IBS patients and to compare this prevalence with that of matched healthy controls.

METHODS

This prospective comparative study was conducted in Tehran, Iran during 2010-2011. Based on the Rome III criteria, a total number of 225 definite IBS patients and 262 age- and sex-matched healthy controls were recruited in the final assessment to compare the prevalence rate of RLS between the 2 groups.

RESULTS

RLS was significantly more frequent in IBS group (25.3% vs 6.5%, P < 0.001) which led to an odds ratio (OR) of 4.89 (95% CI, 2.75-8.70). IBS patients with co-morbid RLS significantly suffered more from stomach pain (96.5% vs 86.3%, OR = 4.36 [95% CI, 1.00-19.12]), nausea (40.4% vs 21.4%, OR = 2.48 [95% CI, 1.30-4.73]) and vomiting (10.5% vs 2.4%, OR = 4.82 [95% CI, 1.31-17.76]).

CONCLUSIONS

By enrolling a considerable number of IBS patients and healthy controls, our study showed a significantly higher prevalence of RLS in IBS patients. Surprisingly, a higher prevalence rate of RLS was also accompanied with a more severe discomfort and stomach pain in IBS patients. It seems that screening patients with IBS for RLS may lead to greater identification of RLS and improved treatment for both conditions.