Review article: gender-related differences in functional gastrointestinal disorders

The underlying mechanism, efficiency, and safety of manual therapy for functional gastrointestinal disorders: A narrative review

INTRODUCTION

Functional gastrointestinal disorders encompass a range of conditions resulting from complicated gut-brain interactions, which can negatively impact sufferers' lives. They are prevalent in clinical practice and the community, with a lifetime prevalence of almost 40 % worldwide. The challenge in diagnosing these disorders lies in the non-specificity of symptoms and the absence of reliable biomarkers. The existing literature suggests a multidisciplinary approach, including cognitive-behavioral therapy, dietary changes, psychotropic drug therapy, and improving gastrointestinal motility. Manual therapy applied to the abdomen and adjacent areas can potentially enhance gastrointestinal motility.

OBJECTIVES

This review aims to examine the types of manual interventions, their mechanisms, efficiency, and safety in managing functional disorders of the digestive system.

METHODS

We searched PubMed and Google Scholar in English from May 2022 to February 2023 with no date restriction. We prioritized systematic reviews, meta-analyses, and clinical trials and did not exclude any data sources.

RESULTS AND CONCLUSION

s: Initial evidence suggests that manual interventions on the abdomen and adjacent areas are effective in managing functional gastrointestinal disorders, with no reported adverse events and relatively low costs. However, further studies with rigorous scientific methodology are needed to understand better the unknown dimensions influencing the outcomes observed with abdominal massage and its positive impact on patients. Manual abdominal techniques are a promising therapy option for functional gastrointestinal disorders, and their efficacy, safety, and cost-effectiveness should be further explored.

Functional gastrointestinal disorders among healthcare professionals at a tertiary Australian hospital

Background and Aim

The aim of this study was to determine the frequency, characteristics, and associations of functional gastrointestinal disorders (FGIDs) among healthcare professionals.

Methods

A qualitative survey was conducted among the staff at a tertiary Australian hospital between January 2017 and June 2018. Rome III criteria (excluding endoscopic) were used to define FGID. Multivariable logistic regression was used to explore associations.

Results

Of the 274 respondents (17% doctors, 66% nurses, 17% others; 77% female), 54% had experienced GI symptoms ≥3 times per week and 23% were diagnosed with FGIDs (2% IBS, 19% FD, 2% both). GI symptoms were more common in females (58% vs. 38%), Caucasians versus Asians (59% vs. 35%), respondents who were easily (67% vs. 40%) or often stressed (58% vs. 37%), and had irregular working hours (62% vs. 46%, each P < 0.05). Independent predictors of GI symptoms included being easily stressed (OR 2.7) and female sex (OR 2.4), while Asian ethnicity was protective (OR 0.42, each P < 0.05). FGIDs were more prevalent in respondents who often felt stressed (27% vs. 10%), felt easily stressed (29% vs. 17%), and in nurses compared to others (27% vs. 16%; each P < 0.05). The only independent predictor of FGID was being often stressed (OR 4.1, P = 0.011).

Conclusions

FGIDs and GI symptoms are prevalent among hospital workers. Stress, female sex, irregular working hours, and non-Asian ethnicity appeared to be associated with GI symptoms and FGIDs.

Sex-specific brain microstructural reorganization in irritable bowel syndrome

ABSTRACT

Preliminary evidence suggests that there are sex differences in microstructural brain organization among individuals with irritable bowel syndrome (IBS). The aim of this study was to further investigate sex-dependent differences in brain microstructure and organization in a large sample of well-phenotyped participants with IBS compared with healthy controls. We hypothesized that female patients with IBS would show evidence for increased axonal strength and myelination within and between brain regions concerned with pain and sensory processing, when compared with males with IBS. We also hypothesized that female compared with male IBS subjects show greater levels of somatic awareness and sensory sensitivity consistent with multisystem sensory sensitivity. Diffusion tensor images and clinical assessments were obtained in 100 healthy controls (61 females) and 152 IBS (107 females) on a 3T Siemens Trio. Whole brain voxel-wise differences in fractional anisotropy, mean, radial and axial diffusivity, and track density as differences in somatic awareness and sensory sensitivity were assessed using the general linear model. Female compared with male IBS participants showed extensive microstructural alterations in sensorimotor, corticothalamic, and basal ganglia circuits involved in pain processing and integration of sensorimotor information. Together with the observed increases in symptom severity, somatic awareness, and sensory sensitivity, the findings support the hypotheses that the etiology and maintenance of symptoms in females with IBS may be driven by greater central sensitivity for multiple sensory stimuli.

Greater interruption of visual processing and memory encoding by visceral than somatic pain in healthy volunteers - An fMRI study

Visceral pain is regarded as more salient than somatic pain. It has greater affective and emotional components, i.e., it elicits higher levels of pain-related fear and is perceived as more unpleasant than somatic pain. In this fMRI study, we examined the neural effects of painful visceral as compared to painful somatic stimulation on visual processing and memory encoding in a visual categorization and surprise recognition task in healthy volunteers. During the categorization task, participants received either rectal distensions or heat stimuli applied to the forearm, with stimuli being individually matched for unpleasantness. Behaviorally, visceral pain reduced memory encoding as compared to somatic pain (Kleine-Borgmann et al., 2021). Imaging analyses now revealed that visceral pain was associated with reduced activity (i.e., greater pain-related interruption) in neural areas typically involved in visual processing and memory encoding. These include the parahippocampal gyrus, fusiform gyrus, striatum, occipital cortex, insula, and the amygdala. Moreover, reduced engagement of the lateral occipital complex during visual categorization under visceral pain was associated with higher visceral pain-related fear. These findings obtained in healthy volunteers shed light on the neural circuitry underlying the interruptive effect of visceral pain and pave the way for future studies in patient samples.

Beyond depression and anxiety; a systematic review about the role of corticotropin-releasing hormone antagonists in diseases of the pelvic and abdominal organs

Evidence for beneficial effects of corticotropin releasing hormone (CRH) antagonists in abdominal and pelvic organs is emerging in preclinical studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement a compilation of preclinical studies using CRH receptor antagonists as a treatment for abdominal and pelvic disease was carried out. The Animal Research: Reporting of In Vivo Experiments (ARRIVE) essential 10 guidelines were used to determine quality of the included studies. A total of 40 studies from the last 15 years studying irritable bowel syndrome, inflammatory bowel disease, endometriosis, enteritis, stress impact on gastrointestinal processes and exogenous CRH administration effects were included. Blockage of the CRH receptor 1 was mainly associated with beneficial effects while that of CRH receptor 2 worsened studied effects. However, time of administration, route of administration and the animal model used, all had an impact on the beneficial outcomes. Frequency of drugs administered indicated that astressin-2B, astressin and antalarmin were among the most utilized antagonists. Of concern, studies included were predominantly carried out in male models only, representing a gender discrepancy in preclinical studies compared to the clinical scenario. The ARRIVE score average was 13 with ~60% of the studies failing to randomize or blind the experimental units. Despite the failure to date of the CRH antagonists in moving across the clinical trials pipeline, there is evidence for their beneficial effects beyond mood disorders. Future pre-clinical studies should be tailored towards effectively predicting the clinical scenario, including reduction of bias and randomization.

The dietary practices and beliefs of people living with older-onset inflammatory bowel disease

BACKGROUND AND OBJECTIVES

The role of diet in inflammatory bowel disease (IBD) remains incompletely understood. Studies have previously examined dietary practices in IBD, but none have specifically focused on older-onset disease. IBD may put vulnerable groups at risk of nutritional deficiency and associated complications, potentially heightened by comorbidities, frailty and polypharmacy. Our objective was to describe dietary practices and beliefs in older-onset IBD.

METHODS

A questionnaire exploring dietary practices and beliefs was prospectively administered to 137 people with older-onset IBD attending gastroenterology clinics.

RESULTS

Thirty-two percent believed diet was the initiating factor for their IBD. This was significantly more likely in people with Crohn's disease than ulcerative colitis (P = 0.05) and in those who felt limited in their dietary choices due to cost (P = 0.008). Forty-three percent believed diet could trigger IBD relapse and 68% avoided dietary components to avoid relapse. Most frequently avoided were spicy and fatty foods, carbonated drinks, red meat, alcohol and raw fruit and vegetables. Twenty-two percent of participants had tried a whole food exclusion diet, most frequently gluten- or lactose-free. Almost a third avoided eating out (29%) or eating the same meal as their family (32%) to prevent relapse. Respondents rarely relied upon healthcare professionals or patient support organisations for their dietary information.

CONCLUSION

Individuals with older-onset IBD report dietary practices with a high degree of consistency. Dietary avoidance may impact upon both nutritional and psychosocial wellbeing in this more vulnerable group and, as such, early dietetic assessment could help improve outcomes.

Nitric Oxide Regulates Estrus Cycle Dependent Colonic Motility in Mice

Women are more susceptible to functional bowel disorders than men and the severity of their symptoms such as diarrhea, constipation, abdominal pain and bloating changes over the menstrual cycle, suggesting a role for sex hormones in gastrointestinal function. Nitric oxide (NO) is a major inhibitory neurotransmitter in the gut and blockade of nitric oxide synthase (NOS; responsible for NO synthesis) increases colonic motility in male mice ex vivo. We assessed the effects of NOS inhibition on colonic motility in female mice using video imaging analysis of colonic motor complexes (CMCs). To understand interactions between NO and estrogen in the gut, we also quantified neuronal NOS and estrogen receptor alpha (ERα)-expressing myenteric neurons in estrus and proestrus female mice using immunofluorescence. Mice in estrus had fewer CMCs under control conditions (6 ± 1 per 15 min, n = 22) compared to proestrus (8 ± 1 per 15 min, n = 22, One-way ANOVA, p = 0.041). During proestrus, the NOS antagonist N-nitro-L-arginine (NOLA) increased CMC numbers compared to controls (189 ± 46%). In contrast, NOLA had no significant effect on CMC numbers during estrus. During estrus, we observed more NOS-expressing myenteric neurons (48 ± 2%) than during proestrus (39 ± 1%, n = 3, p = 0.035). Increased nuclear expression of ERα was observed in estrus which coincided with an altered motility response to NOLA in contrast with proestrus when ERα was largely cytoplasmic. In conclusion, we confirm a cyclic and sexually dimorphic effect of NOS activity in female mouse colon, which could be due to genomic effects of estrogens via ERα.

Gastrointestinal symptoms in HIV-positive kidney transplant candidates and recipients from an HIV-positive donor

Gastrointestinal symptoms (GIS) are common in kidney transplant candidates and recipients and may be worsened by HIV. Objective: To determine the frequency and severity of GIS in HIV-positive kidney transplant recipients from HIV-positive donors, and those waiting to receive one. A GIS rating scale (GSRS) was completed by 76 participants at baseline and at 6 months. GIS frequency was defined as having at least one symptom (GSRS > 1). Severity was indicated by the GSRS score. Transplant candidates: GIS frequency was 88.9% and 86.3% at baseline and 6 months respectively. Indigestion was the most frequent (79.6% and 66.7% at baseline and 6 months), and severe GIS (GSRS 2.3). Women reported global mean (p = 0.030) severity significantly more than men. Transplant recipients: GIS frequency was 95.2% and 76.2% at baseline and 6 months respectively. At both assessment points, indigestion occurred most frequently (85.7% and 61.9% respectively). Highest GSRS was reported for indigestion at baseline (2.33) and at 6 months (1.33). Waist circumference (WC) was positively associated with the severity of constipation GSRS. GIS are common in both groups, especially indigestions. WC in transplant recipients should be monitored.

The participation of basolateral amygdala in the efficacy of acupuncture with deqi treating for functional dyspepsia

Deqi is taken as an indispensable requirement to achieve acupuncture efficacy. This study aimed to explore the central influence of deqi on the efficacy of acupuncture for functional dyspepsia (FD). 70 FD patients were randomized to receive 20 sessions' acupuncture treatment with (n = 35) and without deqi (n = 35). In each group, 25 FD patients randomly selected underwent functional magnetic resonance imaging (fMRI) scans before and after treatment. After group re-division according to deqi response, changes of amygdala subregions-based resting-state functional connectivity (rsFC) were compared between the acupuncture with and without obvious deqi group. The clinical changes of the Nepean Dyspepsia Symptom Index (NDSI) measuring FD symptoms were also used to further assess the correlation with amygdala subregions rsFC in FD patients. The decrease in the NDSI scores (pre-pos) in the obvious deqi group was significantly greater than that in the acupuncture without obvious deqi group (p < 0.05). Compared to the without obvious deqi group, the obvious deqi group showed significantly decreased the left basolateral amygdala (BLA) rsFC with bilateral insular (INS), putamen and middle/posterior cingulate cortex (MCC/PCC), right pallidum and hippocampus (HIPP) after treatment. The changed NDSI scores(pre-post) of all 41 FD patients was significantly positively correlated with their Fisher's transformed z value of the left BLA rsFC with left INS (r = 0.376, FDR corrected p = 0.015), and rsFC with right HIPP (r = 0.394, FDR corrected p = 0.015). The changed NDSI scores(pre-post) of the obvious deqi group was significantly negatively correlated with their Fisher's transformed z value of the right centromedial amygdala (CMA) rsFC with left medial prefrontal cortex (mPFC) (r = -0.463, p = 0.035). The results tested the hypothesis that the advantage of deqi on efficacy is related to affecting the BLA and CMA rsFC. It suggested that deqi might influence the abnormal rsFC within the salience network (SN), and participate in the adaptive modulation of disrupted relationship between the SN and default mode network (DMN).

The dietary practices and beliefs of people living with inactive ulcerative colitis

OBJECTIVE

Diet is implicated in the aetiopathogenesis of inflammatory bowel disease (IBD) and in generating symptoms. Few studies have explored dietary practices in people with IBD, in which participants perceived strong links between diet in triggering flares and maintaining remission. Fewer studies have explored dietary habits in self-reported remission. Our aim was to describe dietary practices and beliefs in those with inactive ulcerative colitis.

METHODS

A questionnaire was developed and prospectively administered to 208 participants with inactive ulcerative colitis attending IBD clinics.

RESULTS

Thirty-one percent believed diet was the initiating factor for ulcerative colitis with 37% believing diet could trigger relapse. Fifty-nine percent avoided dietary items to prevent relapse. Most frequently avoided were spicy (43%) and fatty (38%) foods, alcohol (27%), carbonated drinks (26%), coffee (24%) and milk products (21%). Females were more likely to practice dietary avoidance (P = 0.007). Twenty-three percent had used exclusion diets, most commonly gluten- or lactose-free. Those reporting relapse in the previous year were more likely to avoid the same menu as their family (P = 0.01) and females were less likely to eat out in order to prevent relapse (P = 0.004). Information resources guiding food avoidance included participants' own experiences (90%), healthcare professionals' advice (19%) and the internet (11%).

CONCLUSION

People with inactive ulcerative colitis hold dietary beliefs and display practices with a high level of consistency around perceived triggers. Food avoidance whilst in remission raises the possibility of visceral hypersensitivity or altered physiology alongside psychosocial, neurocognitive or co-existing functional factors.

Effect of oat β-glucan of different molecular weights on fecal bile acids, urine metabolites and pressure in the digestive tract - A human cross over trial

While the development of oat products often requires altered molecular weight (MW) of β-glucan, the resulting health implications are currently unclear. This 3-leg crossover trial (n = 14) investigated the effects of the consumption of oat bran with High, Medium and Low MW β-glucan (average > 1000, 524 and 82 kDa respectively) with 3 consequent meals on oat-derived phenolic compounds in urine (UHPLC-MS/MS), bile acids in feces (UHPLC-QTOF), gastrointestinal conditions (ingestible capsule), and perceived gut well-being. Urine excretion of ferulic acid was higher (p < 0.001, p < 0.001), and the fecal excretion of deoxycholic (p < 0.03, p < 0.02) and chenodeoxycholic (p < 0.06, p < 0.02) acids lower after consumption of Low MW β-glucan compared with both Medium and High MW β-glucan. Duodenal pressure was higher after consumption of High MW β-glucan compared to Medium (p < 0.041) and Low (p < 0.022) MW β-glucan. The MW of β-glucan did not affect gut well-being, but the perceptions between females and males differed.

The impact of allergic rhinitis on gastrointestinal disorders among young adults

BACKGROUND

An association between allergic rhinitis (AR) and digestive diseases (DDs) has been reported; however, studies have only focused on the prevalence of DDs in populations of patients with AR. In individuals with specific DDs, the impact of AR on the frequency of clinical visits for each DD has not been studied. Moreover, the association between topical steroid usage for AR and DDs has not been investigated.

METHODS

Data from 16 526 men and 18 438 women, aged 21 to 30 years, were collected from a national database. Individuals were separated into the AR and non-AR groups. Eight common DDs were studied: (1) gastroesophageal reflux disease (GERD), (2) gastritis and duodenitis, (3) peptic ulcers, (4) irritable bowel syndrome, (5) gastric functional disease, (6) intestinal functional disease, (7) gastroenteritis and colitis, and (8) constipation. The rate of each DD was compared between groups. In individuals with specific DDs, the frequency of clinical visits for each DD was also compared between groups. Between users and nonusers of topical steroids in the AR group, the rate of DDs was compared.

RESULTS

Significant associations were observed between all eight DDs and AR in both sexes. In comparison to the non-AR group, women with AR visited clinics more frequently for gastritis/duodenitis, gastric and intestinal functional disease, gastroenteritis/colitis, and constipation, while men with AR visited clinics more frequently for gastritis/duodenitis, gastric functional disease, gastroenteritis/colitis, and constipation. Female topical-steroid users with AR had higher rates of GERD, irritable bowel syndrome, gastric or intestinal functional disease, and gastritis/colitis. Male topical-steroid users with AR had higher rates of GERD and peptic ulcers.

CONCLUSION

AR was associated with DDs in both sexes. However, the influence of AR on clinical visit frequency varied among specific DD groups. Topical steroid usage for AR was associated with some DDs, but the association requires future evaluation.

Altered Functional Connectivity of the Amygdala and Sex Differences in Functional Dyspepsia

INTRODUCTION

The influence of sex on the prevalence and clinical manifestations of functional dyspepsia (FD) has recently been a topic of increasing interest. However, brain MRI pathology based on sexual dimorphism in FD has not yet been investigated. The amygdala, which plays a vital role in processing gastrointestinal signals, may be associated with the sex-related pathophysiology of FD.

METHODS

We investigated the resting-state functional connectivity (rsFC) of amygdala subregions in patients with FD and healthy subjects as well as the sex differences between male and female FD patients.

RESULTS

The results showed that FD patients manifested altered rsFC in the basolateral amygdala (BLA) and centromedial amygdala subregions compared with HS and that female FD patients showed increased BLA rsFC with the insula (INS) and decreased BLA rsFC with the medial prefrontal cortex and dorsal lateral prefrontal cortex compared with male FD patients and female HS.

DISCUSSION

Our findings suggest that FD females tend to have more severe dysfunction of cognitive-affective processing among the brain regions associated with the salience network, central executive network, and default mode network.

Systematic review with meta-analysis: review of donor features, procedures and outcomes in 168 clinical studies of faecal microbiota transplantation

BACKGROUND

Faecal microbiota transplantation (FMT) is effective for Clostridium difficile infections (CDI) refractory to standard treatment and is being studied in other diseases.

AIM

To evaluate donor characteristics, procedures and clinical outcomes of FMT.

METHODS

We systematically reviewed FMT studies published up to 29 August 2018 using MEDLINE (R) and EMBASE and identified clinical studies with FMT donor information. We reported data on donor characteristics, screening criteria, administration, clinical outcomes and adverse events.

RESULTS

Among 5267 reports, 239 full-text articles were screened and 168 articles were included. FMT was performed commonly for CDI (n = 108) and inflammatory bowel disease (IBD) (n = 31). We reported characteristics of 1513 donors [58% male; mean age, 34.3 years; mean body mass index, 21.6]. Donors in Asia were younger than the West (mean age 30.7 vs 32.9, P = 0.00075). Less than 50% of studies screened donors for transmittable pathogens. Final cure rate for CDI was 95.6% (95% confidence interval [CI], 93.9%-97.1%) and final remission rates for ulcerative colitis (UC) and Crohn's disease (CD) were 39.6% (95% CI, 25.4%-54.6%) and 47.5% (95% CI, 29.4%-65.8%), respectively. Cure rates in CDI and final remission rates for CD and UC were comparable across all routes of FMT administration. Overall adverse event incidence was <1%, mostly GI-related. Adverse event rates did not differ significantly between routes of FMT administration or indication.

CONCLUSIONS

In a systematic review assessing donor characteristics and FMT efficacy, we observed heterogeneity in donor selection, application and outcomes of FMT. These data can facilitate standardisation of FMT protocols for various diseases.

Dietary Supplement and Complementary and Alternative Medicine Use Are Highly Prevalent in Patients with Gastrointestinal Disorders: Results from an Online Survey

The use of complementary and alternative medicine (CAM) is widespread among adults in the United States to self-treat a range of disorders, including gastrointestinal (GI) disorders. This study determined the self-reported use of CAM, including dietary supplements, in managing GI symptoms among Internet users and investigated perceived effects of supplement use on GI symptoms. We used a cross-sectional, descriptive, correlational design. A Qualtrics online survey was utilized to collect data through various websites. Focused areas include demographics, health evaluation, health issue(s), supplement and CAM use, and GI symptoms. Of the participants included in the study, a majority (88%) were women and half (50.1%) were between the ages of 26 and 45. Most participants (84.5%) reported use of herbal supplements, and 84.8% of the participants used herbal supplements for a specific health problem. The most common reported health condition was gastroesophageal reflux (44.4%). The attrition rate was low at 22%. The novelty of using an anonymous online survey to collect data on supplement use in GI disorders indicated a high prevalence of dietary and herbal supplement use among persons with GI disorders comparable to previous reports. Health-care providers should ask patients about supplement use in addition to prescribed medications and communicate effectively if conventional pharmacotherapy is not sufficient to manage symptoms or patients are inclined to use supplements.

Gastrointestinal and urinary complaints in adults with hereditary spastic paraparesis

BACKGROUND

Hereditary spastic paraparesis (HSP) is a group of rare genetic disorders affecting the central nervous system. Pure HSP is limited to lower limb spasticity and urinary voiding dysfunction. Complex HSP involves additional neurological features. Beyond the described core symptoms, knowledge about the burden of disease for adults with HSP is limited, particularly regarding gastrointestinal functions, fecal incontinence, and urinary symptoms.

METHODS

We conducted a cross-sectional self-report survey with 108 adult HSP patients (M_age = 57.7 years, SD = 11.5, range 30 to 81; 54.2% females) recruited from a national HSP user group association and a national (non-clinical) advisory unit for rare disorders. HSP data was compared to data from a Norwegian population study, HUNT-3 (N = 46,293).

RESULTS

The HSP group reported more gastrointestinal and urinary complaints compared to controls. Gastrointestinal complaints included at least "much" complaints with constipation (14.6%) and alternating constipation/diarrhea (8.0%), and at least daily uncontrollable flatulence (47.6%), fecal incontinence (11.6%), and inability to hold back stools (38.5%). Urinary complaints included frequent urination (27.4% > 8 times daily), sudden urge (51.9%) and urinary incontinence (30.5% at least daily/nightly).

CONCLUSION

This survey of adults with HSP recruited from non-clinical settings showed constipation, alternate constipation and diarrhea, fecal incontinence, and voiding dysfunction represent considerable problems for many persons with HSP. Health care providers should screen and manage often unrecognized gastrointestinal and fecal incontinence complaints among HSP patients.

Assessment and manifestation of central sensitisation across different chronic pain conditions

Different neuroplastic processes can occur along the nociceptive pathways and may be important in the transition from acute to chronic pain and for diagnosis and development of optimal management strategies. The neuroplastic processes may result in gain (sensitisation) or loss (desensitisation) of function in relation to the incoming nociceptive signals. Such processes play important roles in chronic pain, and although the clinical manifestations differ across condition processes, they share some common mechanistic features. The fundamental understanding and quantitative assessment of particularly some of the central sensitisation mechanisms can be translated from preclinical studies into the clinic. The clinical perspectives are implementation of such novel information into diagnostics, mechanistic phenotyping, prevention, personalised treatment, and drug development. The aims of this paper are to introduce and discuss (1) some common fundamental central pain mechanisms, (2) how they may translate into the clinical signs and symptoms across different chronic pain conditions, (3) how to evaluate gain and loss of function using quantitative pain assessment tools, and (4) the implications for optimising prevention and management of pain. The chronic pain conditions selected for the paper are neuropathic pain in general, musculoskeletal pain (chronic low back pain and osteoarthritic pain in particular), and visceral pain (irritable bowel syndrome in particular). The translational mechanisms addressed are local and widespread sensitisation, central summation, and descending pain modulation.

Significance

Central sensitisation is an important manifestation involved in many different chronic pain conditions. Central sensitisation can be different to assess and evaluate as the manifestations vary from pain condition to pain condition. Understanding central sensitisation may promote better profiling and diagnosis of pain patients and development of new regimes for mechanism based therapy. Some of the mechanisms underlying central sensitisation can be translated from animals to humans providing new options in development of therapies and profiling drugs under development.

Disrupted intrinsic connectivity of the periaqueductal gray in patients with functional dyspepsia: A resting-state fMRI study

BACKGROUND

Functional dyspepsia (FD) is a common functional gastrointestinal disorder. Accumulating evidence suggests the crucial role of central nervous system in the development and maintenance of FD. In particular, periaqueductal gray (PAG) has demonstrated an important role in modulation of pain and emotion, which may be related to FD. However, the study of the PAG in FD is still limited. This study aimed to assess intrinsic connectivity of the PAG in FD patients.

METHODS

Resting-state functional magnetic imaging (fMRI) data were collected from 66 FD patients and 42 healthy controls (HCs). Functional connectivity analysis was performed to investigate the PAG connectivity pattern differences between the patients and HCs. We then examined the relationships between functional connectivity within the PAG networks and FD symptoms.

KEY RESULTS

Compared to HCs, patients had increased PAG connectivity with the insula, and decreased PAG connectivity with the orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (dlPFC) and hippocampus/parahippocampus (HIPP/paraHIPP). There were positive correlations between disease duration and PAG connectivity with the putamen and supplementary motor area (SMA), and positive correlations between symptom severity and PAG connectivity with the insula. FD patients with high level of anxiety and depression had altered PAG connectivity with the anterior cingulate cortex (ACC), precuneus, dlPFC and caudate, compared to other patients.

CONCLUSIONS & INFERENCES

These findings indicate that abnormal intrinsic network of the PAG might be associated with abnormality of pain processing and disruption of emotion processing in FD patients. Our study further complements neuroimaging findings about FD.

Prevalence and Risk Factors of Chronic Constipation Among Women Aged 50 Years and Older in Shanghai, China

BACKGROUND Chronic constipation (CC) is a major public health problem worldwide, especially in elderly women. This study aimed to investigate the prevalence and risk factors of CC among women aged 50 years and older in Shanghai, China. MATERIAL AND METHODS A cross-sectional survey was conducted on 1950 women aged 50 years and older, randomly sampled in Yangpu District of Shanghai from April to October 2015. Information on demographic characteristics, lifestyle habits, medical history, and defecation situation was collected through in-person interviews. CC was defined according to Rome III criteria. The data were analyzed by chi-square test and multiple logistic regression analysis. RESULTS The response rate to the survey was 80.4%. Of the 1568 participants, 77 were diagnosed with CC, with a prevalence of 4.9%. Moreover, the prevalence increased with advancing age. Multiple logistic analyses showed that body mass index (BMI) ≥25.0 kg/m², non-manual occupation, premenopausal period, no delivery history, poor sleep quality, meat-based diet, and less physical exercise were significant risk factors for CC in the population of women aged 50 years and older. CONCLUSIONS CC was a common health problem among women aged 50 years and older in Shanghai, and the prevalence was positively associated with BMI ≥25.0 kg/m², non-manual occupation, premenopausal period, no delivery history, poor sleep quality, meat-based diet, and less physical exercise. Further studies are needed to identify the risk factors and potential interventions for CC.

Comparison of psychiatric morbidity in patients with irritable bowel syndrome and non-ulcer dyspepsia

BACKGROUND AND AIMS

The present study aimed to find psychiatric morbidity, stress, anxiety, and depression in patients with irritable bowel syndrome (IBS) and compare it with patients having non-ulcer dyspepsia (NUD).

METHODS

This case NUD study compared 50 patients each with IBS and NUD. The two groups were compared on demographic data, psychiatric diagnosis using the Structured Clinical Interview for DSM-IV Axis 1 disorders, anxiety levels using the Hamilton Anxiety Rating Scale (HAM-A), and depression using the Hamilton Depression Rating Scale (HAM-D). The Presumptive Stressful Life Events Scale (PSLES) was used to measure stress.

RESULTS

The cases of IBS were more likely to be of female gender (P = 0.012), married (P = 0.009), and employed (P < 0.001). Psychiatric diagnoses were more common in the cases of IBS than NUDs (88% vs. 30%, P < 0.001), the most common being major depression and somatization disorder. Symptoms of anxiety and depression were more common in patients with IBS (P < 0.001 for HAM-A and HAM-D). Logistic regression revealed that having IBS and increased age were independent predictors of having a psychiatric diagnosis.

CONCLUSIONS

IBS is associated with the considerable degree of psychiatric morbidity. Adequate attention should be paid toward comorbid psychiatric illnesses, and prompt treatment should be instituted.

Prevalence of gastroesophageal reflux disease in children, adults, and elderly in the same community

BACKGROUND AND AIM

The prevalence of gastroesophageal reflux disease (GERD) in adults is increasing in Japan as well as worldwide likely due to increasing obesity and the decreasing rate of Helicobacter pylori infection. However, data regarding the prevalence of GERD in children and adolescents in Japan are lacking. We investigated the prevalence of GERD in children, adults, and elderly living in the same community.

METHODS

We surveyed employees of Shimane University Hospital and a related facility and their families using the Gastroesophageal Reflux Disease Questionnaire (GerdQ) and Izumo Scale instruments with demographic information (age, sex, body height, and body weight) and information regarding concurrent medication being taken for GERD. The presence of GERD was defined as a GerdQ score of ≥ 8.

RESULTS

A total of 1859 subjects (771 males, 1088 females; 6-96 years old) were eligible for assessment. The prevalence of GERD in those under 20 years old was 4.4%, which was approximately one third of the rate in adults (11.6%). GERD prevalence was closely associated with obesity in adults, but not in subjects under 20 years old. GERD and other gastrointestinal symptoms frequently overlapped in both adults and younger subjects.

CONCLUSION

We found that the prevalence of GERD in subjects under 20 years of age was lower than that in adults and not associated with obesity. Nevertheless, it is important to be aware of symptoms such as heartburn and/or regurgitation when children and adolescents seek routine clinical care.

Irritable bowel syndrome: an integrated explanatory model for clinical practice

BACKGROUND

Although irritable bowel syndrome (IBS) is a symptom-based diagnosis, clinicians' management of and communication about the disorder is often hampered by an unclear conceptual understanding of the nature of the problem. We aimed to elucidate an integrated explanatory model (EM) for IBS from the existing literature for pragmatic use in the clinical setting.

METHODS

Systematic and exploratory literature searches were performed in PubMed to identify publications on IBS and EMs.

KEY RESULTS

The searches did not identify a single, integrated EM for IBS. However, three main hypotheses were elucidated that could provide components with which to develop an IBS EM: (i) altered peripheral regulation of gut function (including sensory and secretory mechanisms); (ii) altered brain-gut signaling (including visceral hypersensitivity); and (iii) psychological distress. Genetic polymorphisms and epigenetic changes may, to some degree, underlie the etiology and pathophysiology of IBS and could increase the susceptibility to developing the disorder. The three model components also fit into one integrated explanation for abdominal symptoms and changes in stool habit. Additionally, IBS may share a common pathophysiological mechanism with other associated functional syndromes.

CONCLUSIONS & INFERENCES

It was possible to elucidate an integrated, three-component EM as a basis for clinicians to conceptualize the nature of IBS, with the potential to contribute to better diagnosis and management, and dialog with sufferers.

Functional gastrointestinal disorders in 35,447 adults and their association with body mass index

BACKGROUND

Functional gastrointestinal disorders' (FGIDs) associations with body mass index (BMI) have not been thoroughly investigated in the general population.

AIM

To investigate the overlap between functional dyspepsia (FDy), irritable bowel syndrome (IBS), functional constipation (FC) and functional diarrhoea (FDh) and the relationship between BMI and those diagnoses in a large French adult population.

METHODS

Subjects participating in the Nutrinet-Santé cohort study completed a questionnaire based on Rome III criteria. Anthropometrics, socio-demographical and lifestyle data were collected via self-administered questionnaires. Associations between BMI and FGIDs were investigated with multivariate logistic regression.

RESULTS

A total of 35 447 subjects were included in the analysis. Among subjects with FGIDs, 10.4% presented more than one disorder. [FDy coexisted with IBS (23.6%) and FC (15.1%)]. Associations between BMI and FDy differed according to sex. In females, higher odds were observed for underweight and obesity subgroups (OR = 1.26 (95% CI: 0.99-1.59), OR = 1.35 (1.08-1.69), OR = 1.20 (0.81-1.77), OR = 1.47 (0.89-2.42) for underweight, class I, II and III obesity respectively compared with normal BMI), forming a U-shaped relationship confirmed with nonlinear model (P < 0.001). In females, FDh was associated with BMI [OR = 1.05 (1.03-1.07), P < 0.001]. In males, a negative association between BMI and IBS was observed [OR = 0.97 (0.94-0.99), P=0.04]. Other associations were not significant.

CONCLUSIONS

Our study showed an important overlap in FGIDs, supporting the contention of common pathophysiological mechanisms. Relationships between BMI and FGIDs appeared to be sex-dependent. Interaction by sex in the association between BMI and FGIDs should therefore be further explored.

Epidemiology of upper gastrointestinal symptoms in Brazil (EpiGastro): A population-based study according to sex and age group

AIM: To determine the prevalences of symptoms consistent with gastroesophageal reflux disease (GERD) and dyspepsia in South America.

METHODS: A telephone survey was conducted among adult owners of land-based telephones in São Paulo, Brazil, using previously validated computer-assisted sampling and survey protocols. The Portuguese-language survey included (1) sociodemographic characteristics (e.g., weight, height, smoking) and comorbidities; (2) dietary habits; (3) presence of symptoms consistent with GERD or dyspepsia within the prior 3 mo; and (4) use of medications and other therapies to manage symptoms. Data were stratified post-hoc into three homogeneous geographical regions of São Paulo according to the Social Exclusion Indices of the districts and postal codes. Survey response data from each respondent were weighted by the numbers of adults and landline telephones in each household. The analyses were weighted to account for sampling design and to be representative of the São Paulo population according to city census data.

RESULTS: Among 4570 households contacted, an adult from 3050 (66.7%) agreed to participate. The nonresponse rate was 33.3%. The mean (SE) respondent age was 42.6 (16.0) years. More than half of all respondents were women (53.1%), aged 18 through 49 years (66.7%), married or cohabitating (52.5%), and/or above normal-weight standards (i.e., 35.3% overweight and 16.3% obese). A total of 26.5% of women were perimenopausal. More than 20% of respondents reported highly frequent symptoms consistent with GERD (e.g., gastric burning sensation = 20.8%) or dyspepsia (e.g., abdominal swelling/distension = 20.9%) at least once per month. Prevalences of these symptoms were significantly (approximately 1.5- to 2.0-fold) higher among women than men but did not vary significantly as a function of advancing age. For instance, 14.1% of women reported that they experienced stomach burning (symptom of GERD) at least twice per week, compared to 8.4% of men (P = 0.012 by χ² test). A total of 15.7% of women reported that they experienced abdominal swelling (symptom of dyspepsia) at least twice per week, compared to 6.4% of men (P < 0.001 by χ² test). Despite frequent manifestations of GERD or dyspepsia, most (≥ 90%) respondents reported that they neither received prescription medications from physicians, nor took behavioral measures (e.g., dietary modifications), to manage symptoms.

CONCLUSION: Symptoms consistent with dyspepsia and GERD are prevalent in Brazil and represent major public-health and clinical challenges.

Altered structural covariance of the striatum in functional dyspepsia patients

BACKGROUND

Functional dyspepsia (FD) is thought to be involved in dysregulation within the brain-gut axis. Recently, altered striatum activation has been reported in patients with FD. However, the gray matter (GM) volumes in the striatum and structural covariance patterns of this area are rarely explored. The purpose of this study was to examine the GM volumes and structural covariance patterns of the striatum between FD patients and healthy controls (HCs).

METHODS

T1-weighted magnetic resonance images were obtained from 44 FD patients and 39 HCs. Voxel-based morphometry (VBM) analysis was adopted to examine the GM volumes in the two groups. The caudate- or putamen-related regions identified from VBM analysis were then used as seeds to map the whole brain voxel-wise structural covariance patterns. Finally, a correlation analysis was used to investigate the effects of FD symptoms on the striatum.

KEY RESULTS

The results showed increased GM volumes in the bilateral putamen and right caudate. Compared with the structural covariance patterns of the HCs, the FD-related differences were mainly located in the amygdala, hippocampus/parahippocampus (HIPP/paraHIPP), thalamus, lingual gyrus, and cerebellum. And significant positive correlations were found between the volumes in the striatum and the FD duration in the patients.

CONCLUSIONS & INFERENCES

These findings provided preliminary evidence for GM changes in the striatum and different structural covariance patterns in patients with FD. The current results might expand our understanding of the pathophysiology of FD.

Differential activation of the prefrontal cortex and amygdala following psychological stress and colorectal distension in the maternally separated rat

Visceral hypersensitivity is a hallmark of many clinical conditions and remains an ongoing medical challenge. Although the central neural mechanisms that regulate visceral hypersensitivity are incompletely understood, it has been suggested that stress and anxiety often act as initiating or exacerbating factors. Dysfunctional corticolimbic structures have been implicated in disorders of visceral hypersensitivity such as irritable bowel syndrome (IBS). Moreover, the pattern of altered physiological responses to psychological and visceral stressors reported in IBS patients is also observed in the maternally separated (MS) rat model of IBS. However, the relative contribution of various divisions within the cortex to the altered stress responsivity of MS rats remains unknown. The aim of this study was to analyze the cellular activation pattern of the prefrontal cortex and amygdala in response to an acute psychological stressor (open field) and colorectal distension (CRD) using c-fos immunohistochemistry. Several corticoamygdalar structures were analyzed for the presence of c-fos-positive immunoreactivity including the prelimbic cortex, infralimbic cortex, the anterior cingulate cortex (both rostral and caudal) and the amygdala. Our data demonstrate distinct activation patterns within these corticoamygdalar regions including differential activation in basolateral versus central amygdala following exposure to CRD but not the open field stress. The identification of this neuronal activation pattern may provide further insight into the neurochemical pathways through which therapeutic strategies for IBS could be derived.

Identifying neural patterns of functional dyspepsia using multivariate pattern analysis: a resting-state FMRI study

BACKGROUND

Previous imaging studies on functional dyspepsia (FD) have focused on abnormal brain functions during special tasks, while few studies concentrated on the resting-state abnormalities of FD patients, which might be potentially valuable to provide us with direct information about the neural basis of FD. The main purpose of the current study was thereby to characterize the distinct patterns of resting-state function between FD patients and healthy controls (HCs).

METHODOLOGY/PRINCIPAL FINDINGS

Thirty FD patients and thirty HCs were enrolled and experienced 5-mintue resting-state scanning. Based on the support vector machine (SVM), we applied multivariate pattern analysis (MVPA) to investigate the differences of resting-state function mapped by regional homogeneity (ReHo). A classifier was designed by using the principal component analysis and the linear SVM. Permutation test was then employed to identify the significant contribution to the final discrimination. The results displayed that the mean classifier accuracy was 86.67%, and highly discriminative brain regions mainly included the prefrontal cortex (PFC), orbitofrontal cortex (OFC), supplementary motor area (SMA), temporal pole (TP), insula, anterior/middle cingulate cortex (ACC/MCC), thalamus, hippocampus (HIPP)/parahippocamus (ParaHIPP) and cerebellum. Correlation analysis revealed significant correlations between ReHo values in certain regions of interest (ROI) and the FD symptom severity and/or duration, including the positive correlations between the dmPFC, pACC and the symptom severity; whereas, the positive correlations between the MCC, OFC, insula, TP and FD duration.

CONCLUSIONS

These findings indicated that significantly distinct patterns existed between FD patients and HCs during the resting-state, which could expand our understanding of the neural basis of FD. Meanwhile, our results possibly showed potential feasibility of functional magnetic resonance imaging diagnostic assay for FD.

Changes in the modulation of spinal pain processing are related to severity in irritable bowel syndrome

BACKGROUND

In irritable bowel syndrome (IBS) patients can be divided in two groups according to inhibition or facilitation of the RIII nociceptive spinal reflex induced by rectal distension. We further investigated the differences in pain processes in these two groups and their relationship to clinical symptoms.

METHODS

This study included 10 female IBS-C patients with facilitation (Group F) and 10 patients with inhibition (Group I) of the RIII reflex recorded on the left lower limb during slow-ramp rectal distension, and 11 healthy female volunteers. Diffuse noxious inhibitory control (DNIC)-induced inhibition was assessed by measuring the effects of noxious cold stimulation of the right hand on the RIII reflex and the concomitant sensation of pain. Functional magnetic resonance imaging (fMRI) was performed to compare the changes in brain activity induced by painful and non painful rectal distension. Irritable bowel syndrome symptom severity, mood, anxiety, and catastrophizing were also systematically assessed.

KEY RESULTS

Unlike the patients of Group I and healthy volunteers, Group F patients displayed no inhibition of the RIII reflex or of concomitant pain sensation during immersion of the hand in ice-cold water. The reduction of the inhibition induced by heterotopic noxious stimuli was directly correlated with the severity of IBS symptoms, but not with psychological symptoms. The fMRI study showed that non-painful and painful rectal distension induced similar changes in brain activity in the two groups of patients.

CONCLUSION & INFERENCES

Alterations of the modulation of spinal pain processing in IBS correlates with symptom severity but not with psychological factors or brain activity.

Appraisal of emerging symptoms of colorectal cancer: associations with dispositional, demographic, and tumor characteristics

The time it takes for individuals to realize that their emerging colorectal cancer (CRC) symptoms are serious is often an impediment to expeditious help-seeking. Tailored educational efforts to hasten symptom appraisal time would benefit from knowledge of the characteristics of individuals who tend to neglect their symptoms as well as the nature of symptoms that are most often neglected. In a sample of 112 CRC patients, we investigated associations between duration of symptom appraisal and: (1) trait anxiety, and (2) tumor location, which affects symptomatology. Symptom appraisal duration was associated with a sex-by-anxiety interaction (p = 0.007). The longest times (in weeks) were among high anxiety females (Mdn = 26.0) and low anxiety males (Mdn = 17.0), with shorter times among low anxiety females (Mdn = 9.0) and high anxiety males (Mdn = 2.0). Symptom appraisal times were also longer for patients with distal (vs. proximal) tumors (p = 0.036).

Gastric hypochlorhydria is associated with an exacerbation of dyspeptic symptoms in female patients

BACKGROUND

Gender and gastric acid have been suggested to be independently involved in the pathophysiology of functional dyspepsia, but the interrelationship among gender, dyspeptic symptoms, and gastric acid secretion remains to be evaluated. We sought to explore this issue in dyspeptic patients.

METHODS

A total of 89 outpatients (male, 36; mean age, 55.6 years) with dyspeptic symptoms were analyzed. The degree of dyspeptic symptoms was evaluated and scored using a symptom questionnaire consisting of 3 subcategories: dysmotility-related symptoms, reflux-related symptoms, and epigastric pain-related symptoms. Stimulated gastric acid secretion was directly measured using an endoscopic gastrin test.

RESULTS

The total symptom scores and the epigastric pain-related symptom scores were significantly higher in female patients than in male patients. The dysmotility-related and reflux-related symptom scores were also higher, but not significantly, in the female patients. Multiple regression analysis of age, gender, habitual drinking, smoking, Helicobacter pylori infection, and gastric acid secretion revealed that gender and gastric hypochlorhydria, defined as less than 2.1 mEq/10 min in the endoscopic gastrin test, were significantly associated with higher dyspeptic symptom scores. The total scores and the dysmotility-related scores were significantly higher in the patients with gastric hypochlorhydria than in those with gastric non-hypochlorhydria, and this difference was found to be present only in females.

CONCLUSIONS

Gastric hypochlorhydria in female dyspeptic patients may be involved in the exacerbation of dyspeptic symptoms. Differences in the responsiveness to gastric hypochlorhydria between males and females may be partly responsible for the gender differences in the prevalence and severity of dyspeptic symptoms.

Importance of sex to pain and its amelioration; relevance of spinal estrogens and its membrane receptors

Estrogens have a multitude of effects on opioid systems and are thought to play a key role in sexually dimorphic nociception and opioid antinociception. Heretofore, classical genomic actions of estrogens are largely thought to be responsible for the effects of these steroids on nociception and opioid antinociception. The recent discovery that estrogens can also activate estrogen receptors that are located in the plasma membrane, the effects of which are manifest in seconds to minutes instead of hours to days has revolutionized our thinking concerning the ways in which estrogens are likely to modulate pain responsiveness and the dynamic nature of that modulation. This review summarizes parameters of opioid functionality and nociception that are subject to modulation by estrogens, underscoring the added dimensions of such modulation that accrues from rapid membrane estrogen receptor signaling. Implications of this mode of signaling regarding putative sources of estrogens and its degradation are also discussed.

Brain-Gut Interactions in IBS

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with an estimated prevalence of 10–20%. Current understanding of the pathophysiology of IBS is incomplete due to the lack of a clearly identified pathological abnormality and due to the lack of reliable biomarkers. Possible mechanisms believed to contribute to IBS development and IBS like symptoms include physical stressors, such as infection or inflammation, psychological, and environmental factors, like anxiety, depression, and significant negative life events. Some of these mechanisms may involve the brain-gut axis (BGA). In this article we review the current knowledge on the possible involvement of the BGA in IBS and discuss new directions for potential future therapies of IBS.

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

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) is a widespread chronic health condition which is significantly more prevalent in women. We conducted a gender difference analysis by comparing findings of men and women to determine whether any significant differences exist or not.

METHODS

This single-center study was conducted in Tehran, Iran during 2009-2010. IBS was diagnosed on the basis of Rome III criteria. A simple "10 point" objective questionnaire was used.

RESULTS

A total number of 144 IBS patients including 44 (30.6%) males and 100 (69.4%) females with the mean age of 37.50 ± 11.50 years, were assessed. The only differently observed symptom was nausea which was significantly more prevalent in females (49% vs 18.2%, P < 0.001). The commonest subtype of IBS in male patients was diarrhea predominant IBS (38.6%); while, constipation predominant IBS was the most frequent type among females (38%). Moreover, the frequency of loose, mushy or watery stools within the last 3 months was significantly higher among males (2.11 ± 1.67 vs 1.37 ± 1.50, P = 0.009).

CONCLUSIONS

We report that gender is important in IBS. Although qualitative comparison of different subtypes of IBS between male and female failed to meet the statistically significant level, the answers to the corresponding questions of ROME III IBS module suggest the higher prevalence of bowel movements and looser stool in males. Moreover, nausea was reported more often by females.

Formation of mu-/kappa-opioid receptor heterodimer is sex-dependent and mediates female-specific opioid analgesia

Sexually dimorphic nociception and opioid antinociception is very pervasive but poorly understood. We had demonstrated that spinal morphine antinociception in females, but not males, requires the concomitant activation of spinal μ- and κ-opioid receptors (MOR and KOR, respectively). This finding suggests an interrelationship between MOR and KOR in females that is not manifest in males. Here, we show that expression of a MOR/KOR heterodimer is vastly more prevalent in the spinal cord of proestrous vs. diestrous females and vs. males. Cross-linking experiments in combination with in vivo pharmacological analyses indicate that heterodimeric MOR/KOR utilizes spinal dynorphin 1-17 as a substrate and is likely to be the molecular transducer for the female-specific KOR component of spinal morphine antinociception. The activation of KOR within the heterodimeric MOR/KOR provides a mechanism for recruiting spinal KOR-mediated antinociception without activating the concomitant pronociceptive functions that monomeric KOR also subserves. Spinal cord MOR/KOR heterodimers represent a unique pharmacological target for female-specific pain control.

Is there an overlap between irritable bowel syndrome and appendicopathy syndrome? A new theory

BACKGROUND AND AIMS

The costs of irritable bowel syndrome are huge - personally, socially and financially. Yet despite numerous articles on the subject, an effective treatment seems far away. The hypothesis to be offered in this paper is: that a (laparoscopic) appendicectomy could also be useful in treating at least some of the patients with IBS. Using data I have collected from my own surgery practice over a number of years, I will demonstrate the link between the effective treatment of appendicitis by laparoscopic appendectomy and propose that this could also be a useful treatment for some cases of IBS. The study of symptoms of IBS showed that it shared several of the symptoms found in appendicopathy. The aim of this study is: (1) to confirm the cure rate of the laparoscopic appendectomy in cases of appendicopathy, (2) to determine the overlap of symptoms and (3) examine a new theory - that some cases of IBS originate in the appendix.

SUPPORTING DATA

Two succeeding series of patients sent to me for possible appendicopathy were treated with laparoscopic appendectomy if their list of symptoms suggested this was appropriate. The first series comprised 114 patients. The results prompted a second series of 126 patients. This second group was primarily set up to confirm the results obtained from the first group. In our material we found statistical evidence that both groups were comparable indeed. Both groups suffered from not only pain, but also other side effects: indigestion, problems with exercise, feelings of stress, defecation disorders, disuria and loss of energy. The favourable results of the second series were roughly the same as those of the first one. Not only were about 80% of the patients pain free after 6 months or less, but the co-morbidity was gone in about 80% of the patients as well. In the literature, there are several reports describing a favourable outcome of appendicectomy for appendicopathy. Especially positive was one of only a few randomised, double-blinded, placebo controlled, parallel group trials in the history of surgery (Roumen, cs), which proved that "persistent or recurrent lower abdominal pain can be treated by elective appendicectomy with significant pain reduction in properly selected cases". An important part of the symptoms of both syndromes do overlap: (1) pain in the abdomen, varying in strength and more pain after a large meal, (2) changing bowel habits between constipation and diarrhoea, (3) indigestion and (4) stress.

CONCLUSION

Taking into account the overlap in several symptoms between IBS and Appendicopathy there is a possibility that both syndromes originate (partly) in the appendix and therefore laparoscopy and appendicectomy may play a part in the treatment of IBS as well. Pilot studies in this direction seem to be indicated.

Sex-related differences in prepulse inhibition of startle in irritable bowel syndrome (IBS)

Alterations in central networks involved in the regulation of arousal, attention, and cognition may be critical for irritable bowel syndrome (IBS) symptom maintenance and exacerbation. Differential sensitivities in these networks may underlie sex differences noted in IBS. The current study examined prepulse inhibition (PPI), a measure of sensorimotor gating, in male and female IBS patients. Relationships between PPI and symptom severity were examined, as well as potential menstrual status effects. Compared to healthy controls, male IBS patients had significantly reduced PPI; whereas female IBS patients (particularly naturally cycling women) had significantly enhanced PPI suggesting hypervigilance. Considering previously demonstrated sex-related differences in perceptual and brain imaging findings in IBS patients, the current findings suggest that different neurobiological mechanisms underlie symptom presentation in male and female IBS patients. Compromised filtering of information in male IBS patients may be due to compromised top down (prefrontal, midcingulate) control mechanisms while increased attention to threat due to increased limbic and paralimbic circuits may be characteristic of female IBS patients.

17Beta-estradiol restores excitability of a sexually dimorphic subset of myelinated vagal afferents in ovariectomized rats

We recently identified a myelinated vagal afferent subpopulation (Ah type) far more prevalent in female than male rats and showed that this difference extends to functionally specific visceral sensory afferents, baroreceptors of the aortic arch. Excitability of myelinated Ah-type afferents is markedly reduced after ovariectomy (OVX). Here we tested the hypothesis that 17beta-estradiol can selectively restore excitability of these sex-specific vagal afferents. Acutely isolated vagal afferent neurons (VGN) from intact and OVX adult female rats were used with patch-clamp technique and current-clamp protocols to assess the effect of acute application of 17beta-estradiol on neuronal excitability. At over physiologically relevant 17beta-estradiol concentrations for rat (1-10 nM) excitability of myelinated Ah-type vagal afferents is restored to discharge frequencies comparable to those in intact females, albeit with some interesting differences related to burst and sustained patterns of neuronal discharge. Restoration of excitability occurs within 3 min of hormone application and is stereo specific, because 1,000 nM 17alpha-estradiol fails to alter excitability. Furthermore, activation of G protein-coupled estrogen receptor GPR30 with highly selective agonist G-1 similarly restores excitability of Ah-type afferents. The effectiveness of 17beta-estradiol and G-1 is completely eliminated by application of high-affinity estrogen receptor ligand ICI-182,780. 17beta-Estradiol conjugated with BSA is approximately 70% as effective as 17beta-estradiol alone in restoring Ah-type VGN excitability. These data support our conclusions that the cellular mechanisms leading to rapid restoration of neuronal excitability of myelinated Ah-type VGN after OVX occur, at least in part, via membrane-bound estrogen receptors. We contend that recovery of high-frequency discharge at physiologically relevant 17beta-estradiol concentrations implies that this unique subtype of low-threshold myelinated vagal afferent may account for some of the sex-related differences in visceral organ system function. Sex differences in cardiovascular and gastrointestinal function and the potential role of GPR30 in modulation of sex-specific myelinated Ah-type vagal afferents are discussed.

A butyrate-induced model of non-inflammatory colonic hypersensitivity in rats

AIM: To investigate Butyrate-enema's efficacy on visceral hypersensitivity in rats and to explore a new method of establishing a model of non-inflammatory colonic hypersensitivity in rats.

METHODS: Rats of the model group received enemas of 1 mL of butyrate solution (300 mmol/L) twice a day for 6 d. After 3 d or 6 d when the model of visceral hypersensitivity was built, scores of abdominal withdrawal reflex (AWR) in colorectal distention (CRD) were recorded. Hypersensitivity parameters were determined. Meanwhile, the pressure thresholds of initial sensation and most endurance thresholds were recorded. Macroscopic and histologic activities of MPO and counting of mast leukocyte and eosinophile granulocyte were performed on colonic mucosa tissue at the end of the experiment.

RESULTS: Macroscopic and histologic activities of MPO analyses, counting of mast leukocyte and eosinophile granulocyte were not significantly different between control group and experimental group. At day 6, there was a significant increase in scores of CRD in experimental group against control group for the most pressure (t = 9.25, P < 0.01). There were a significant increase in average and highest pressure of colorectal motion in experimental group against control group (t = 36.71, 15.02, both P < 0.01).

CONCLUSION: Butyrate-enema may lead to colonic hypersensitivity while not bring damages to colonic mucosal structure. Colonic hypersensitivity has no correlation with mast cells.

Sex differences in the activation of the spinoparabrachial circuit by visceral pain

Women are more sensitive to most noxious visceral stimuli, both in terms of intensity and frequency. The spinoparabrachial (spino-PBn) pathway is an essential neural circuit for the central relay of viscerosensitive information, but studies characterizing the anatomical and physiological characteristics of this pathway have only been conducted in males. Sex differences in the anatomical and/or physiological organization of the spino-PBn may contribute to the sexually dimorphic incidence rate for visceral pain syndromes. Retrograde labeling and colorectal distention (CRD) induced Fos expression was used to delineate the spino-PBn circuit in male and cycling female Sprague-Dawley rats. The ability of morphine to suppress CRD evoked responses was also examined. Neurons retrogradely labeled from the PBn were localized primarily within the superficial dorsal horn and sacral parasympathetic nucleus of the L5-S1 spinal cord. While no sex differences were noted in either the distribution of spino-PBn neurons or in CRD-induced Fos expression, significantly greater Fos expression was noted specifically in spino-PBn neurons in males compared to females. Morphine selectively attenuated Fos expression in spino-PBn neurons in males, but not females. Subsequent anatomical studies showed significantly reduced mu opioid receptor protein levels and radioligand binding within the PBn of females in comparison to males. Together, these data indicate that there are profound sex differences in how a noxious visceral stimulus and opiates engage the spino-PBn pathway, which may account for the observed clinical differences in visceral pain sensitivity and morphine antinociception.

Design of treatment trials in irritable bowel syndrome: opioid agonists and atypical benzodiazepine antagonists

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by abdominal pain and altered bowel function. Few agents are available for the treatment of IBS. Historically, one impediment to the development of agents to treat IBS was lack of a uniform and robust clinical trial design. Studies occurred with different durations of treatment, endpoints and with different target populations. Great advances have been made over the past decade in trial design including: optimal duration of study, mode of data collection, populations to evaluate and identification of endpoints. Using these refinements, it was possible to demonstrate the efficacy of some new agents. These advances are illustrated by a review of trials with kappa opioid agonists and atypical benzodiazepine antagonists, which appear to be promising new classes of treatments for symptoms in IBS.

Susceptibility to nausea and motion sickness as a function of the menstrual cycle

PURPOSE

The present study examined whether susceptibility to nausea and other symptoms of vection-induced motion sickness vary as a function of phase of the menstrual cycle, as research findings in this area are sparse and contradictory.

DESIGN

Ninety young women (42 current users of oral contraceptives) were exposed to a rotating optokinetic drum during the peri-menses or peri-ovulatory phase of the menstrual cycle in an independent-groups, quasi-experimental design. Nausea and motion sickness symptoms were assessed using the Nausea Profile (NP) and the Subjective Symptoms of Motion Sickness (SSMS) questionnaire.

RESULTS

Among women not on oral contraceptives, reports of nausea and motion sickness by women in the peri-menses phase were more severe than reports by women in the peri-ovulatory phase. By contrast, among women taking oral contraceptives, reports of nausea and motion sickness did not differ by the same categorical phase of the menstrual cycle.

CONCLUSIONS

We speculate that fluctuating estrogen levels over the course of the menstrual cycle may influence the experience of or susceptibility to nausea and motion sickness during illusory self-motion and other nauseogenic contexts.

Irritable bowel syndrome is more common in women regardless of the menstrual phase: a Rome II-based survey

Functional gastrointestinal disorders are more common in women in relation to the fluctuations of female sex hormones. We tried to know the gender-related differences in the prevalence of irritable bowel syndrome and gastrointestinal symptoms according to the menstrual phase. A total of 253 women before menopause and 252 men below age 50 were examined by a gastroenterologist after completing the questionnaire. Blood tests, endoscopic procedures, and imaging studies were done, if needed. Women were subclassified into three groups according to their menstruation period; menstrual phase, proliferative phase, and secretory phase. Finally, 179 men and 193 women were analyzed. Irritable bowel syndrome was more frequently noticed in women than in men (p=0.01). The diarrhea-dominant type was more common in men, while constipation-dominant or alternating types were more common in women (p<0.001). Of 193 women, there was no significant difference in their gastrointestinal symptoms according to their menstrual phase. Regardless of the menstrual phase, gastrointestinal symptoms are more frequent in women. Physicians should consider different symptomatic manifestations between men and women should be considered when evaluating functional gastrointestinal disorders.

Neural mechanisms of pelvic organ cross-sensitization

Clinical observations of viscerovisceral referred pain in patients with gastrointestinal and genitourinary disorders suggest an overlap of neurohumoral mechanisms underlying both bowel and urinary bladder dysfunctions. Close proximity of visceral organs within the abdominal cavity complicates identification of the exact source of chronic pelvic pain, where it originates, and how it relocates with time. Cross-sensitization among pelvic structures may contribute to chronic pelvic pain of unknown etiology and involves convergent neural pathways of noxious stimulus transmission from two or more organs. Convergence of sensory information from discrete pelvic structures occurs at different levels of nervous system hierarchy including dorsal root ganglia, the spinal cord and the brain. The cell bodies of sensory neurons projecting to the colon, urinary bladder and male/female reproductive organs express a wide range of membrane receptors and synthesize many neurotransmitters and regulatory peptides. These substances are released from nerve terminals following enhanced neuronal excitability and may lead to the occurrence of neurogenic inflammation in the pelvis. Multiple factors including inflammation, nerve injury, ischemia, peripheral hyperalgesia, metabolic disorders and other pathological conditions dramatically alter the function of directly affected pelvic structures as well as organs located next to a damaged domain. Defining precise mechanisms of viscerovisceral cross-sensitization would have implications for the development of effective pharmacological therapies for the treatment of functional disorders with chronic pelvic pain such as irritable bowel syndrome and painful bladder syndrome. The complexity of overlapping neural pathways and possible mechanisms underlying pelvic organ crosstalk are analyzed in this review at both systemic and cellular levels.

Relationship of abuse history to functional gastrointestinal disorders and symptoms: some possible mediating mechanisms

The primary goals of this article are to review the evidence that links sexual and physical abuse and intimate partner violence (IPV) with functional gastrointestinal (GI) symptoms and disorders and to explore physiological mechanisms that might mediate these health effects. The literature cited in this review has shown strong and consistent relationships of sexual and physical abuse history and IPV with functional GI symptoms and disorders. Among patients with these disorders, abuse history is associated with worse health-related quality of life, more health care utilization, and more pain. Although research has not determined what mechanisms might account for these associations, alterations in psychophysiological and cortico-limbic pain modulatory systems have been suggested. Given the high prevalence of abuse and long-lasting health consequences, referral for psychiatric and psychological treatment makes sense for many patients with abuse history seen within medical settings.

The emerging presence of interstitial cystitis in gynecologic patients with chronic pelvic pain

Emerging data are changing the pelvic pain paradigm for gynecologic patients. Historically, interstitial cystitis (IC) was rarely considered as a cause of chronic pelvic pain (CPP), but recent data suggest that IC is a common cause of CPP in gynecologic patients and perhaps is even the most common cause. It is important to consider the bladder as a generator of symptoms early in the evaluation of the gynecologic patient with CPP. New tools have been developed to aid the gynecologist in ruling out IC in patients with CPP, including a new IC symptom questionnaire and the Potassium Sensitivity Test (PST). By determining whether the pain is of bladder origin, the physician can more successfully treat the patient with CPP.

Distinct clinical characteristics between patients with nonerosive reflux disease and those with reflux esophagitis

BACKGROUND & AIMS

It has been postulated that nonerosive reflux disease (NERD) and erosive reflux disease (ERD) are 2 distinct entities of gastroesophageal reflux disease. The aim of this study was to compare the clinical characteristics between patients with NERD and those with ERD.

METHODS

We prospectively recruited consecutive patients presenting with weekly attacks of heartburn or acid regurgitation. Exclusion criteria included gastric surgery, recent use of nonsteroidal anti-inflammatory drug or proton pump inhibitor, and peptic ulcer disease. Concomitant functional dyspepsia, irritable bowel syndrome, and psychological disorders were documented. Endoscopy, esophageal manometry, acid perfusion test, and 24-hour ambulatory pH monitoring were performed. Risk factors of NERD were determined by multivariate analysis.

RESULTS

Two hundred fourteen patients (NERD, 113; ERD, 111) were studied. NERD patients were characterized by higher prevalence of Helicobacter pylori (36.3% vs 18%, P = .005), functional dyspepsia (64.6% vs 42.3%, P = .003), irritable bowel syndrome (44.2% vs 15.3%, P < .001), psychological disorders (9% vs 0.9%, P = .04), and positive acid perfusion test (40.7% vs 19.8%, P = .004). ERD patients had more hiatal hernias (35.1% vs 17.1%, P = .009), higher esophageal acid exposure (total time esophageal pH <4, 4.2% +/- 2.1% vs 5.9% +/- 2.3%; P = .01), and esophageal dysmotility (P < .05). With multivariate analysis, H pylori (odds ratio, 1.8; 95% confidence interval [CI], 1.1-3.2), irritable bowel syndrome (odds ratio, 2.8; 95% CI, 1.6-5.3), and positive acid perfusion test (odds ratio, 1.9; 95% CI, 1.4-2.8) were independent risk factors for NERD.

CONCLUSIONS

Patients with NERD and ERD have distinct differences in clinical characteristics. NERD is characterized by higher prevalence of functional gastrointestinal disorders and esophageal acid hypersensitivity.

Tales from the crypts: regulatory peptides and cytokines in gastrointestinal homeostasis and disease

The gastrointestinal (GI) tract is composed of a diverse set of organs that together receive extracorporeal nutrition and convert it to energy substrates and cellular building blocks. In the process, it must sort through all that we ingest and discriminate what is useable from what is not, and having done that, it discards what is "junk." To accomplish these many and varied tasks, the GI tract relies on endogenous enteric hormones produced by enteroendocrine cells and the enteric nervous system. In many instances, the mediators of these tasks are small peptides that home to the CNS and accessory gut organs to coordinate oral intake with digestive secretions. As the contents of ingested material can contain harmful agents, the gut is armed with an extensive immune system. A breach of the epithelial barrier of the GI tract can result in local and eventually systemic disease if the gut does not mount an aggressive immune response.

Cross-organ interactions between reproductive, gastrointestinal, and urinary tracts: modulation by estrous stage and involvement of the hypogastric nerve

Central nervous system neurons process information converging from the uterus, colon, and bladder, partly via the hypogastric nerve. This processing is influenced by the estrous cycle, suggesting the existence of an estrous-modifiable central nervous system substrate by which input from one pelvic organ can influence functioning of other pelvic organs. Here, we tested predictions from this hypothesis that acute inflammation of colon, uterine horn, or bladder would produce signs of inflammation in the other uninflamed organs (increase vascular permeability) and that cross-organ effects would vary with estrous and be eliminated by hypogastric neurectomy (HYPX). Under urethane anesthesia, the colon, uterine horn, or bladder of rats in proestrus or metestrus, with or without prior HYPX, was treated with mustard oil or saline. Two hours later, Evans Blue dye extravasation was measured to assess vascular permeability. Extravasation was increased in all inflamed organs, regardless of estrous stage. For rats in proestrus, but not metestrus, either colon or uterine horn inflammation significantly increased extravasation in the uninflamed bladder. Much smaller cross-organ effects were seen in colon and uterine horn. HYPX reduced extravasation in the inflamed colon and inflamed uterine horn, but not the inflamed bladder. HYPX eliminated the colon-to-bladder and uterine horn-to-bladder effects. These results demonstrate that inflaming one pelvic organ can produce estrous-modifiable signs of inflammation in other pelvic organs, particularly bladder, and suggest that the cross-organ effects involve the hypogastric nerve and are at least partly centrally mediated. Such effects could contribute to cooccurrence and cyclicity of distressing pelvic disorders in women.