Systematic review: the efficacy of treatments for irritable bowel syndrome--a European perspective

Exploring Gut Microbiota Imbalance in Irritable Bowel Syndrome: Potential Therapeutic Effects of Probiotics and Their Metabolites

Irritable bowel syndrome is a common functional gastrointestinal disorder characterized by recurrent abdominal discomfort, bloating, cramping, flatulence, and changes in bowel movements. The pathophysiology of IBS involves a complex interaction between motor, sensory, microbiological, immunological, and psychological factors. Diversity, stability, and metabolic activity of the gut microbiota are frequently altered in IBS, thus leading to a situation of gut dysbiosis. Therefore, the use of probiotics and probiotic-derived metabolites may be helpful in balancing the gut microbiota and alleviating irritable bowel syndrome symptoms. This review aimed to report and consolidate recent progress in understanding the role of gut dysbiosis in the pathophysiology of IBS, as well as the current studies that have focused on the use of probiotics and their metabolites, providing a foundation for their potential beneficial effects as a complementary and alternative therapeutic strategy for this condition due to the current absence of effective and safe treatments.

Asociación Española de Neurogastroenterología y Motilidad (ASENEM) updated review on the management of functional abdominal pain

Functional abdominal pain is a disorder in which central and peripheral sensitization processes converge, leading to hypersensitivity and allodynia. Differential diagnosis is made with organic digestive, renal, gynecological, endocrine, or neurological diseases. Treatment should be individualized for each patient. In cases of debilitating pain, therapy combining drugs with different mechanisms of action can be initiated, while in less severe cases, therapy with a progressive introduction of drugs based on clinical response is advised. The first line includes general lifestyle advice and antispasmodic substances, like peppermint oil, anticholinergic/antimuscarinic, and calcium channels antagonists. In the second line of treatment, neuromodulating agents are added. Finally, when these measures fail, third-line treatments such as gabapentine and atypical antipsychotics are considered. Psychological interventions should be considered if specialized therapists are available to manage these disorders.

Effect of alverine citrate plus simethicone in colonoscopy: a randomized controlled trial

Colonoscopy is the standard procedure for screening, and surveillance of colorectal cancer, including the treatment for colonic lesions. Colonic spasm is an important problem from colonoscopy that affects both surgeons and patients. The spasm also might be the cause of longer cecal intubation time, difficulty of the procedure, and increased pain. Previous reports indicated that antispasmodic agents can decrease such symptoms. Therefore, we conducted this study to investigate the cecal intubation time of antispasmodic agents. A single blinded randomized controlled trial was conducted from 01/11/2020 to 31/08/2021. One hundred four patients were allocated to antispasmodic agent group and control group, in 1:1 ratio. The efficacy of median (range) cecal intubation time showed similar results of 5 (2, 14) and 5 (2, 15) minutes with no statistically significant difference. The mean scores of all domains i.e., pain, spasm, cleanliness, and difficulty were better in the antispasmodic agent group about 2.6 (1.4), 1.8 (0.8), 2.4 (0.9), and 2.0 (0.9), respectively, than control group but there were spasm and cleanliness showed statistically significant difference. Moreover, the satisfaction scores showed better efficacy in decreased spasm, decreased difficulty, and increased cleanliness than control group. Prescribing of antispasmodic drugs before colonoscopy might be the choice of treatment for the patients. The antispasmodic drugs will be beneficial to both of the patient and the doctor.

Prokinetics-safety and efficacy: The European Society of Neurogastroenterology and Motility/The American Neurogastroenterology and Motility Society expert review

BACKGROUND

Prokinetics are a class of pharmacological drugs designed to improve gastrointestinal (GI) motility, either regionally or across the whole gut. Each drug has its merits and drawbacks, and based on current evidence as high-quality studies are limited, we have no clear recommendation on one class or other. However, there remains a large unmet need for both regionally selective and/or globally acting prokinetic drugs that work primarily intraluminally and are safe and without systemic side effects.

PURPOSE

Here, we describe the strengths and weaknesses of six classes of prokinetic drugs, including their pharmacokinetic properties, efficacy, safety and tolerability and potential indications.

Effectiveness of Osteopathic Manipulative Treatment in Adults with Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the effectiveness of the osteopathic manipulative treatment (OMT) in adults with irritable bowel syndrome (IBS). A literature resview was carried out on the following databases: PubMed, Embase, Cochrane, Cinahl, Scopus, PEDro and ClinicalTrials.gov. 350 articles were recovered. Eligibility criteria were evaluated by two independent reviewers, including randomized controlled trials (RCTs), quasi-RCTs, or ongoing RCTs with OMT compared to any kind of control in patients diagnosed with IBS. Six studies (five RCTs and one ongoing RCT) were considered eligible. Four RCTs were classified as some concerns and one as high risk of bias. In the meta-analysis, OMT compared to sham/no intervention showed statistically significant results for abdominal pain (effect size ES = -1.14 [-1.66, -0.62]; p < 0.0001) and constipation (ES = -0.66 [-1.12, -0.20]; p = 0.005). Instead, OMT was not superior to the control for the IBS symptoms measured with the IBS Severity Score and the Likert scale (ES = -0.34 [-0.83, 0.16]; p = 0.19), and diarrhea (ES = -1.20 [-2.84, 0.43]; p = 0.15). The quality of evidence was "low" for IBS symptoms in general for abdominal pain and constipation, while it was judged as "very low" for diarrhea. OMT turns out to be safe in the treatment of IBS without major adverse effects. OMT may be effective in IBS patients, however the results must be interpreted carefully due to the low methodological quality of the studies.

The Potential of Honey as a Prebiotic Food to Re-engineer the Gut Microbiome Toward a Healthy State

Honey has a long history of use for the treatment of digestive ailments. Certain honey types have well-established bioactive properties including antibacterial and anti-inflammatory activities. In addition, honey contains non-digestible carbohydrates in the form of oligosaccharides, and there is increasing evidence from in vitro, animal, and pilot human studies that some kinds of honey have prebiotic activity. Prebiotics are foods or compounds, such as non-digestible carbohydrates, that are used to promote specific, favorable changes in the composition and function of the gut microbiota. The gut microbiota plays a critical role in human health and well-being, with disturbances to the balance of these organisms linked to gut inflammation and the development and progression of numerous conditions, such as colon cancer, irritable bowel syndrome, obesity, and mental health issues. Consequently, there is increasing interest in manipulating the gut microbiota to a more favorable balance as a way of improving health by dietary means. Current research suggests that certain kinds of honey can reduce the presence of infection-causing bacteria in the gut including Salmonella, Escherichia coli, and Clostridiodes difficile, while simultaneously stimulating the growth of potentially beneficial species, such as Lactobacillus and Bifidobacteria. In this paper, we review the current and growing evidence that shows the prebiotic potential of honey to promote healthy gut function, regulate the microbial communities in the gut, and reduce infection and inflammation. We outline gaps in knowledge and explore the potential of honey as a viable option to promote or re-engineer a healthy gut microbiome.

Gut Microbiota-Derived Metabolites in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is the most common functional bowel disorder worldwide and is associated with visceral hypersensitivity, gut motility, immunomodulation, gut microbiota alterations, and dysfunction of the brain-gut axis; however, its pathophysiology remains poorly understood. Gut microbiota and its metabolites are proposed as possible etiological factors of IBS. The aim of our study was to investigate specific types of microbiota-derived metabolites, especially bile acids, short-chain fatty acids, vitamins, amino acids, serotonin and hypoxanthine, which are all implicated in the pathogenesis of IBS. Metabolites-focused research has identified multiple microbial targets relevant to IBS patients, important roles of microbiota-derived metabolites in the development of IBS symptoms have been established. Thus, we provide an overview of gut microbiota and their metabolites on the different subtypes of IBS (constipation-predominant IBS-C, diarrhea-predominant IBS-D) and present controversial views regarding the role of microbiota in IBS.

Efficacy of pinaverium bromide in the treatment of irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Spasmolytic agents are an attractive first line treatment option for irritable bowel syndrome (IBS). Pinaverium bromide (pinaverium) has antispasmodic effects on gastrointestinal smooth muscle and can relieve major IBS symptoms, but an up-to-date meta-analysis comparing the efficacy of pinaverium with placebo is lacking. The aim is to perform a systematic review and meta-analysis to assess the efficacy of pinaverium compared with placebo for IBS treatment.

METHODS

All placebo-controlled trials evaluating pinaverium for IBS treatment were included, up to October 2019. Treatment efficacy was evaluated by overall patient IBS symptoms. Individual symptoms were also evaluated. The effect of pinaverium versus placebo was expressed as standardized mean difference (SMD) and risk ratio (RR). Odds ratio (OR) and number needed to treat (NNT) were also calculated.

RESULTS

Eight studies were included for analysis. Pinaverium treatment had a beneficial effect on overall IBS symptom relief with a positive SMD of 0.64 [95% confidence interval (CI) 0.45-0.82, p < 0.0001] and a positive RR of 1.75 (1.26-2.43, p < 0.0008). No significant difference was found by publication year, gender, age, methodological quality score (MQS), or sample size. No publication bias was detected. OR was 3.43 (2.00-5.88, p < 0.0001), and NNT was 4. Pinaverium also demonstrated a beneficial treatment effect for abdominal pain, stool change, and bloating improvement or resolution.

CONCLUSION

Pinaverium is superior to placebo for the treatment of IBS symptoms, irrespective of patient age or gender, study publication year, sample size, or MQS. The NNT in this meta-analysis is amongst the lowest for studies and meta-analyses of antispasmodics versus placebo in IBS.

A Mini Review on Characteristics and Analytical Methods of Otilonium Bromide

Irritable bowel syndrome (IBS) is a world-wide disease prevalently in Western nations. It influences about 15% of the western populace, with a negative effect on the quality of life and furthermore on medical services costs. Anticholinergic antispasmodics are first line of treatment for discomfort or abdominal pain, particularly if unrelieved after alleviation of stoppage or antidiarrheal treatment. Otilonium bromide (OTB) is quaternary ammonium compound with action on distal GI tract as antispasmodic. It is utilized in the treatment of patients influenced by Irritable inside disorder (IBS) because of its particular pharmacokinetic and pharmacodynamic properties. OTB is poorly absorbed systematically was viable in contrast with different medications used for same purpose, for example, pinaverium bromide and mebeverine, with a good tolerability profile. The effects are long lasting, even after stopping the dosage regime for reduction of abdominal pain. In this review, an overview of mechanism of action, pharmacologic action, synthesis and particularly various analytical and bioanalytical methods are discussed. The analytical methods discussed are spectrophotometry including Near Infrared Spectroscopy (NIRS), chromatography and capillary electrophoresis methods are described with the range, limit of detection and quantification. The paper also provides details of scope of further extension of analytical methods. It was found that most of the analytical methods involves usage of toxic solvents e.g., methanol, acetonitrile, chloroform etc. posing risk to the analyst as well as environment.

Irritable Bowel Syndrome and Me: A Sworn Rivalry

“Three more hours”, I tell myself as I find my way to the exam hall. I see a bunch of my classmates cramming for the last minute, and here I am, in a corner, reminding myself that it's just three more hours till I get away from this horror. Irritable Bowel Syndrome is a gastrointestinal disorder in which there is dull achy lower abdominal pain associated with either diarrhea or constipation. Though it has high prevalence, it is still an underrated disease which can be easily missed in clinical settings.

Evidence-based clinical practice guidelines for irritable bowel syndrome 2020

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

Pharmacological Therapies and Their Clinical Targets in Irritable Bowel Syndrome With Diarrhea

Irritable bowel syndrome (IBS) is one of the most common disorders of the gut-brain axis, which affects approximately 4% of the global population. The Rome IV criteria define IBS as chronic or recurrent abdominal pain associated with altered bowel habits. Patients can be categorized in four subtypes: IBS with predominant constipation (IBS-C), predominant diarrhea (IBS-D), mixed bowel habits (IBS-M), and unclassified (IBS-U). IBS is associated with a lower quality of life, reduced work productivity, and high healthcare costs. When comparing subtypes, patients with IBS-D report lower disease related quality of life. Due to the scope of this review, we have solely focused on patients with IBS-D. Choosing the right pharmacological treatment in these patients remains challenging due to the heterogeneous patient population, patients' expectation of the treatment outcome, unavailability of efficacious drugs, and the multifactorial and incompletely understood underlying pathophysiology. Currently, pharmacological treatment options target individual symptoms, such as abdominal pain, altered bowel habits, and bloating. In this review, we aimed to summarize the current and recent pharmacological treatment options in IBS-D, targeting the predominant gastrointestinal symptoms. Additionally, we proposed a pharmacological treatment algorithm which healthcare professionals could use when treating individual patients with IBS-D.

Molecular Mechanisms of Microbiota-Mediated Pathology in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders, and accumulating evidence gained in both preclinical and clinical studies indicate the involvement of enteric microbiota in its pathogenesis. Gut resident microbiota appear to influence brain activity through the enteric nervous system, while their composition and function are affected by the central nervous system. Based on these results, the term “brain–gut–microbiome axis” has been proposed and enteric microbiota have become a potential therapeutic target in IBS cases. However, details regarding the microbe-related pathophysiology of IBS remain elusive. This review summarizes the existing knowledge of molecular mechanisms in the pathogenesis of IBS as well as recent progress related to microbiome-derived neurotransmitters, compounds, metabolites, neuroendocrine factors, and enzymes.

Shortcomings of Trials Assessing Antidepressants in the Management of Irritable Bowel Syndrome: A Critical Review

Irritable bowel syndrome (IBS) is a common disorder requiring complex, multidisciplinary management. Antidepressants are commonly used and recommended in guidelines for the treatment of patients with IBS. We assessed randomized controlled trials (RCTs) on antidepressants in patients with IBS, with specific attention to study design and data quality/reporting characteristics. Following a comprehensive search, data and RCT characteristics were systematically summarized. Fragility index, representing the number of positive “events” that the study relies on for its significance, was calculated. Eighteen RCTs were included. Overall, tricyclic antidepressants (TCAs), but not selective serotonin reuptake inhibitors (SSRIs), appeared to be efficacious in IBS. Eight studies reported on adverse events (AEs), which were significantly greater in patients receiving antidepressants versus placebo. The median (mean) fragility index of TCA trials was 0 (1.5). RCTs with positive results had significantly lower placebo rates (20.8%) versus negative studies (45.7%; p < 0.0001). RCTs exhibited limitations related to study design (sample size and blinding), data analysis (outcomes and placebo response), and data reporting (selective reporting of AEs and publication bias). Careful consideration of limitations of RCTs on antidepressants in IBS is warranted to formulate a safe and beneficial treatment regimen for patients with IBS.

The Effect of Phloroglucinol in Patients With Diarrhea-predominant Irritable Bowel Syndrome: A Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND/AIMS

We aim to evaluate the efficacy and safety of phloroglucinol in patients with diarrhea-predominant irritable bowel syndrome (IBS-D).

METHODS

Seventy-two patients with IBS-D who met Rome III criteria were 1:1 randomized in a parallel, double-blind design to receive phloroglucinol or placebo for 2 weeks. Patients were followed for 1 week after the end of treatment. The primary outcome was the proportion of responders, defined as those who answered "moderate or more of improvement" to the subject global assessment for at least 1 week of the 2-week treatment period. Secondary outcomes included the proportion of these patients during the 3-week period including 1 week of follow-up, IBS symptoms (abdominal pain/discomfort, diarrhea, urgency, mucus in stool, bloating, and passage of gas), stool frequency and consistency, and IBS quality of life (IBS-QOL).

RESULTS

The proportion of responders during 2-week treatment period tended to be higher in the phloroglucinol group than in the placebo group, although the difference did not reach statistical significance (55.6% vs 30.6%, P = 0.056). The proportion of responders during the 3-week period was significantly higher in the phloroglucinol group than in the placebo group (61.6% vs 30.6%, P = 0.013). Individual symptom scores, IBS-QOL, stool frequency and consistency tended to improve in the phloroglucinol group, but there were no statistical significances compared to those of the placebo group. No serious adverse events were reported in both groups.

CONCLUSIONS

Phloroglucinol could be a safe and beneficial option for the management of overall IBS symptoms in patients with IBS-D. Further large scaled studies are warranted.

Does Irritable Bowel Syndrome Exist? Identifiable and Treatable Causes of Associated Symptoms Suggest It May Not

Significant shortcomings in irritable bowel syndrome (IBS) diagnosis and treatment may arise from IBS being an “umbrella” diagnosis that clusters several underlying identifiable and treatable causes for the same symptom presentation into one classification. This view is compatible with the emerging understanding that the pathophysiology of IBS is heterogeneous with varied disease mechanisms responsible for the central pathological features. Collectively, these converging views of the pathophysiology, assessment and management of IBS render the traditional diagnosis and treatment of IBS less relevant; in fact, they suggest that IBS is not a disease entity per se and posit the question “does IBS exist?” The aim of this narrative review is to explore identifiable and treatable causes of digestive symptoms, including lifestyle, environmental and nutritional factors, as well as underlying functional imbalances, that may be misinterpreted as being IBS.

Economic burden of moderate to severe irritable bowel syndrome with constipation in six European countries

Background

Irritable bowel syndrome with predominant constipation (IBS-C) is a complex disorder with gastrointestinal and nervous system components. The study aim was to assess the economic burden of moderate to severe IBS-C in six European countries (France, Germany, Italy, Spain, Sweden and the UK).

Methods

An observational, one year retrospective-prospective (6 months each) study of patients diagnosed in the last five years with IBS-C (Rome III criteria) and moderate to severe disease at inclusion (IBS Symptom Severity Scale score ≥ 175). The primary objective was to assess the direct cost to European healthcare systems.

Results

Five hundred twenty-five patients were included, 60% (range: 43.1–78.8%) suffered from severe IBS-C. During follow-up 11.1–24.0% of patients had a hospitalisation/emergency room (ER) visit, median stay range: 1.5–12.0 days and 41.1–90.4% took prescription drugs for IBS-C. 21.4–50.8% of employed patients took sick leave (mean: 11.6–64.1 days). The mean annual direct cost to the healthcare systems was €937.1- €2108.0. The total direct cost (combined costs to healthcare systems and patient) for IBS-C was €1421.7–€2487.1.

Conclusions

IBS-C is not a life-threatening condition; however, it has large impact on healthcare systems and society. Direct and indirect costs for moderate to severe IBS-C were high with the largest direct cost driver being hospitalisations/ER visits.

Key mechanisms of cognitive behavioural therapy in irritable bowel syndrome: The importance of gastrointestinal related cognitions, behaviours and general anxiety

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterised by abdominal pain and altered bowel movements. Cognitive behavioural therapy (CBT) has been shown to be effective in reducing symptom severity in IBS and enhancing quality of life/functioning. The present study sought to identify how CBT achieves change in these outcomes.

METHOD

Secondary analysis was conducted on 149 patients with irritable bowel syndrome who had been randomised to cognitive behavioural therapy plus an antispasmodic medication or antispasmodic alone. Single and sequential mediation was modelled using structural equation modelling. Gastrointestinal (GI) related avoidance behaviour, safety behaviour, cognitions and general anxiety were included as mediators.

RESULTS

GI safety behaviours, cognitions and general anxiety mediated treatment effect on the outcomes of symptom severity and work and social adjustment. Avoidance behaviour was not a significant mediator for either outcome. Sequential mediation models indicated that unhelpful GI related cognitions reduced before anxiety did, and this sequential path (R➔GI related cognitions➔anxiety➔outcome) was significant for both symptom severity (b = -0.22, CI [-0.40 to -0.90], p = .005) and work and social adjustment (b = -0.26, CI [-0.44 to -0.11], p = .003) where 'R' is randomisation. Reduction in GI safety behaviours also preceded reduction in anxiety. This sequence (R ➔GI safety behaviours➔anxiety➔outcome) was significant for both symptom severity (b = -0.11, CI [-0.24 to -0.01], p = .049) and work and social adjustment (b = -0.12, CI [-0.23 to -0.03], p = .03).

CONCLUSION

Results suggest that it is important for psychological treatments to target IBS specific factors for change.

A retrospective and prospective 12-month observational study of the socioeconomic burden of moderate to severe irritable bowel syndrome with constipation in Spain

INTRODUCTION

The socioeconomic burden of irritable bowel syndrome with constipation (IBS-C) has never been formally assessed in Spain.

PATIENTS AND METHODS

This 12-month (6-month retrospective and prospective periods) observational, multicentre study assessed the burden of moderate-to-severe IBS-C in Spain. Patients were included if they had been diagnosed with IBS-C (Rome III criteria) within the last 5 years and had moderate-to-severe IBS-C (IBS Symptom Severity Scale score [IBS-SSS] ≥175) at inclusion. The primary objective was to assess the direct cost to the Spanish healthcare system (HS).

RESULTS

A total of 112 patients were included, 64 (57%) of which had severe IBS-C at inclusion. At baseline, 89 (80%) patients reported abdominal pain and distention. Patient quality of life (QoL), measured by the IBS-C QoL and EQ-5D instruments, was found to be impaired with a mean score of 59 and 57 (0-100, worst-best), respectively. Over the 6-month prospective period the mean IBS-C severity, measured using the IBS-SSS showed some improvement (315-234 [0-500, best-worst]). During the year, 89 (80%) patients used prescription drugs for IBS-C, with laxatives being the most frequently prescribed (n=70; 63%). The direct cost to the HS was €1067, and to the patient was €568 per year. The total direct cost for moderate-to-severe IBS-C was €1635.

DISCUSSION

The majority of patients reported continuous IBS-C symptoms despite that 80% were taking medication to treat their IBS-C. Overall healthcare resource use and direct costs were asymmetric, with a small group of patients consuming the majority of resources.

Antidepressants vs. Placebo for the Treatment of Functional Gastrointestinal Disorders in Adults: A Systematic Review and Meta-Analysis

Objective: To integrate high-quality evidence of the efficacy of antidepressants across different subtypes of functional gastrointestinal disorders (FGIDs). Methods: The Medline, PsycINFO, EMBASE, the Cochrane Library, and Chinese local database were searched up to October 1, 2017. Keywords included all subtypes of FGIDs, antidepressants, and randomized controlled trials (RCTs). We included RCTs with low to moderate risks of bias in comparing antidepressants with placebos as the only intervention in treating adult patients with FGIDs (PROSPERO ID: CRD42015030123). Language was restricted to English or Chinese. Data extraction was independently carried out by two authors, following the Cochrane Handbook for systematic reviews. Results: Of 2,460 records identified, 31 studies reporting on 2,340 participants were included in the meta-analysis. Antidepressants were more effective than placebos in terms of the rate of responder [RR = 1.35 (95% CI 1.12 to 1.63)], and the reduction of target gastrointestinal symptoms [SMD = -0.94 (95% CI -1.33 to -0.54)], and disability severity (moderate effect sizes). Those effects partly remained both at the presence and absence of comorbid depression, and among different subtypes of FGIDs. Subgroup analyses confirmed the benefit of tricyclic and tetracyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), and trazodone. Efficacy of serotonin and norepinephrine reuptake inhibitors (SNRIs), low doses of antidepressants, and antidepressants in intermediate to long term treatment was inconclusive due to the scarcity of eligible evidence. Compared to placebo, patients on antidepressants reported more adverse events [RR = 1.91 (95% CI 1.23 to 2.96)] and more frequent withdrawal. On average one in 7.4 (95% CI 5.4 to 11.9) patients treated with antidepressants responded, while one in 4.8 (95% CI 3.7 to 6.8) experienced certain adverse effects. Conclusions: Antidepressants were inferior to placebo in terms of tolerability and partly superior regarding efficacy. Before prescribing antidepressants, the benefits and side effects should be carefully evaluated.

Management Options for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is associated with diverse pathophysiologic mechanisms. These mechanisms include increased abnormal colonic motility or transit, intestinal or colorectal sensation, increased colonic bile acid concentration, and superficial colonic mucosal inflammation, as well as epithelial barrier dysfunction, neurohormonal up-regulation, and activation of secretory processes in the epithelial layer. Novel approaches to treatment include lifestyle modification, changes in diet, probiotics, and pharmacotherapy directed to the motility, sensation, and intraluminal milieu of patients with IBS. Despite recent advances, there is a need for development of new treatments to relieve pain in IBS without deleterious central or other adverse effects.

New treatments and therapeutic targets for IBS and other functional bowel disorders

Functional bowel disorders (FBDs) are a spectrum of disorders characterized by combinations of symptoms attributable to the lower gastrointestinal tract. Most current first-line therapies for IBS and other FBDs target the predominant symptom and mainly affect one symptom in the symptom complex. Additional broadly effective treatment alternatives targeting the entire symptom complex are needed. New drugs for FBDs (such as lubiprostone, linaclotide, plecanatide, prucalopride, eluxadoline and rifaximin) target key mechanisms in the pathophysiology of these disorders and improve both the abnormal bowel habit and other key symptoms, such as abdominal pain and bloating. The current development of new treatment alternatives is focusing on different aspects of the complex pathophysiology of IBS and other FBDs: gut microenvironment (via diet and modulation of gut microbiota), enterohepatic circulation of bile acids, gastrointestinal secretion, motility and sensation, gut-brain interactions, gut barrier function and the immune system within the gastrointestinal tract. Studies also suggest that personalized treatment of IBS and other FBDs is possible using various diagnostic markers.

Treatment of irritable bowel syndrome

Irritable bowel syndrome is a chronic functional gastrointestinal disorder that presents with abdominal pain related to defecation accompanied by a change in stool frequency or form Despite its impact on a patient’s quality of life it has no effect on mortality

A positive clinical diagnosis should be made if the characteristic symptoms are present and red flags are absent Red flags should prompt specialist referral

Consultations should be provided in an empathetic manner addressing the concerns of the patient while providing reassurance

Manipulating diet with the assistance of a dietitian is an appropriate initial treatment for irritable bowel syndrome A low-FODMAP diet is an effective therapy

Linaclotide in irritable bowel syndrome with constipation: A Phase 3 randomized trial in China and other regions

BACKGROUND AND AIM

Linaclotide is a guanylate cyclase-C agonist approved in multiple countries to treat irritable bowel syndrome with constipation (IBS-C). China has unmet need for well-tolerated therapy that is effective in treating both bowel and abdominal symptoms of IBS-C. This trial evaluated linaclotide's efficacy and safety in IBS-C patients in China and other regions.

METHODS

This Phase 3, double-blind trial randomized IBS-C patients to once-daily oral 290-μg linaclotide or placebo at centers in China, North America, and Oceania. Patients reported bowel and abdominal symptoms daily; adverse events were monitored. Co-primary and secondary endpoints were tested using a predefined three-step serial gatekeeping multiple comparisons procedure.

RESULTS

The intent-to-treat population included 839 patients (mean age = 41 years; 82% female; 81% Asian). The trial met all co-primary and secondary endpoints. Co-primary responder criteria were met by 60.0% of linaclotide patients versus 48.8% of placebo patients for abdominal pain/discomfort (≥ 30% decrease for ≥ 6/12 weeks; P < 0.05), and 31.7% of linaclotide versus 15.4% of placebo patients for IBS degree of relief (score ≤ 2 for ≥ 6/12 weeks; P < 0.0001). Secondary 12-week change-from-baseline endpoints (spontaneous bowel movement/complete spontaneous bowel movement frequency, stool consistency, straining, abdominal pain, abdominal discomfort, and abdominal bloating) were significantly improved with linaclotide versus placebo (all P < 0.0001). Diarrhea was the most common adverse event (9.4% linaclotide, 1.2% placebo). Discontinuation rates due to diarrhea were low (0.7% linaclotide, 0.2% placebo).

CONCLUSIONS

Once-daily 290-μg linaclotide improved bowel habits, abdominal symptoms, and global measures in a predominantly Chinese IBS-C population.

Dysbiosis in Functional Bowel Disorders

Functional bowel disorders (FBD) resemble a group of diseases of the gastrointestinal (GI) tract that are without a clear pathogenesis; the best known is probably the "irritable bowel syndrome" (IBS). Only recently we have been able to explore the role of the gut microbiota in FBD due to progress in microbiological analytic techniques. There are different ways to explore the role of the gut microbiota and its dysbiosis in FBD. Comparison of the microbial composition in a group of patients with FBD, for example, with IBS to a group of healthy volunteers is one way. Studies have shown that the microbiota in FBD is different from that of healthy controls, but the recorded differences are not necessarily specific for FBD, they may also occur in other diseases. Another approach to explore the role of the gut microbiota in FBD is to challenge the existing "flora" with novel bacteria (probiotics) or with nutritional substrates that stimulate bacterial growth (prebiotics). More than 60 such trials including several thousand patients have been performed in IBS. These studies have produced mixed outcome: some probiotics appear to be better than others, and some appear to work only for a part of the IBS symptoms and not for all. An extreme form of this approach is the transfer of an entire microbiota from 1 healthy person to another, called fecal microbiota transplantation. This has rarely been tested in FBD but is not without risk in benign disorders.

Mind-Body Interventions for Irritable Bowel Syndrome Patients in the Chinese Population: a Systematic Review and Meta-Analysis

PURPOSE

The aim of this study is to identify and assess evidence related to the efficacy of mind-body interventions on irritable bowel syndrome (IBS) in the Chinese population.

METHOD

Drawn from Chinese databases, nine RCTs and three Q-E studies were included in the systematic review. The methodological quality of RCTs was evaluated based on the following criteria: adequate sequence generation, allocation concealment, blinding, completeness of outcome data, selective reporting, and other potential biases. For continuous variables, the effect size (ES) was determined by calculating the standardized mean difference between groups. For dichotomous variables, the ES was determined by calculating the risk ratio (RR) between groups. Given the heterogeneity between the trials and the small number of studies included, both random effects and fixed effects models were used. The inverse variance method was used for pooling. Statistical analyses were performed using Review Manager version 5.0.

RESULTS

The total number of papers identified was 710: 462 from English language databases and 248 from Chinese language databases. Twelve studies met our eligibility criteria. Among the studies selected, three were Q-E studies the rest RCTs. Two studies described the randomization process. None of the studies reported allocation concealment nor blinding. Seven studies reported no dropouts. One of the studies mentioned the total amount of dropouts; though the reason for dropping out was not referenced. The other four studies did not clearly report dropouts. With the exception of three studies, there was inadequate information to determine biased reporting for the majority; the level of risk for bias in these studies is unclear. Finally, six meta-analyses were performed. One was conducted with four randomized controlled trials (RCTs) that used cure rate as outcome measures to evaluate gastrointestinal (GI) symptoms, which suggested that mind-body interventions were effective in improving GI symptoms (random effects model: RR = 1.08; 95 % CI 1.01 to 1.17; fixed effects model: RR = 1.07; 95 % CI 1.01 to 1.12). The remaining five were conducted in three RCTs, which suggested that mind-body interventions were effective in improving several aspects of quality of life, including interference with activity (random effects and fixed effects models: SMD = 0.64; 95 % CI 0.41 to 0.86), body image (random effects model: SMD = 0.36; 95 % CI 0.06 to 0.67; fixed effects model: SMD = 0.33; 95 % CI 0.11 to 0.55), health worry (random effects and fixed effects models: SMD = 0.67; 95 % CI 0.44 to 0.90), food avoidance (random effects and fixed effects models: SMD = 0.45; 95 % CI 0.23 to 0.68), and social reaction (random effects model: SMD = 0.79; 95 % CI 0.47 to 1.12; fixed effects model: SMD = 0.78; 95 % CI 0.55 to 1.01), as measured by Irritable Bowel Syndrome Quality of Life Questionnaire ( IBS-QOL).

CONCLUSION

Mind-body interventions may have the potential to improve GI symptoms in Chinese patients with IBS. The improvement of GI symptoms was also accompanied with the improvement of various outcomes, including depression, anxiety, and quality of life, just to mention a few. However, the published studies generally had significant methodological limitations. Future clinical trials with rigorous research design are needed in this field. More studies focusing on the mind-body interventions originated in China, such as tai chi and qi gong should be encouraged.

Pharmacotherapy for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a disorder of the brain-gut axis; the pathophysiological mechanisms include altered colonic motility, bile acid metabolism, neurohormonal regulation, immune dysfunction, alterations in the epithelial barrier and secretory properties of the gut. This article reviews the mechanisms, efficacy, and safety of current pharmacotherapy, and medications that are in phase III trials for the treatment of IBS. There remains a significant unmet need for effective treatments-particularly for the pain component of IBS-although the introduction of drugs directed at secretion, motility and a non-absorbable antibiotic provide options for the bowel dysfunction in IBS.

Review of Rifaximin: Latest Treatment Frontier for Irritable Bowel Syndrome Mechanism of Action and Clinical Profile

Background:

Irritable bowel syndrome is classified as a functional gastrointestinal disorder with the primary symptom of abdominal pain in conjunction with bloating and bowel movement disorder. It affects up to 15% of the world’s population. Among its subtypes, the most common is diarrhoea predominant. However, the current treatment options for diarrhoea-predominant irritable bowel syndrome have had not very promising results; most, such as antispasmodics, only provide partial symptomatic relief. Treatment with antidepressants and alosetron (a 5HT3 antagonist) has shown the most promise to date. The latest drug to be approved for the treatment of irritable bowel syndrome-diarrhoea is rifaximin, which was approved in May 2015. It is a minimally absorbed antibiotic that is used to change the gut microbiota. Small intestinal bacterial overgrowth is one of the causes suggested for irritable bowel syndrome, particularly for the diarrhoea-predominant type. There are various methods for detecting bacterial overgrowth, the simplest of which is breath tests. Rifaximin has been shown to be of benefit to these patients.

Purpose:

The purpose of the study is to discuss the potential mechanism of action of rifaximin, a minimally absorbed antibiotic. In addition, we evaluate the various clinical trials undertaken to study the efficacy and safety profile of rifaximin.

The neurokinin-2 receptor antagonist ibodutant improves overall symptoms, abdominal pain and stool pattern in female patients in a phase II study of diarrhoea-predominant IBS

BACKGROUND

Tachykinins have been implicated in the pathophysiology of IBS with diarrhoea (IBS-D). Our aim was to study the efficacy and safety of ibodutant, a selective neurokinin-2 (NK2) receptor antagonist, in patients with IBS-D.

METHODS

This multinational double-blind, placebo-controlled study recruited 559 patients with IBS-D according to Rome III criteria. After a 2-week treatment-free run-in, patients were randomised to ibodutant 1 mg, 3 mg, 10 mg or placebo once daily for eight consecutive weeks. Responders were those with a combined response of satisfactory relief (weekly binary question yes/no) of overall IBS symptoms and abdominal pain/discomfort on ≥75% weeks (primary end point). Secondary end points included abdominal pain and stool pattern. Data were also analysed according to US Food and Drug Administration (FDA)-approved interim end points (improvement of pain and stool consistency). Safety was assessed by monitoring adverse events and laboratory tests. Prespecified statistical analysis involved the whole group as well as gender subgroups.

RESULTS

Demographics and baseline characteristics were comparable for all treatment arms. In the overall population, responsiveness tended to increase with escalating ibodutant doses. In the prespecified analysis by gender, ibodutant 10 mg demonstrated significant superiority over placebo in females (p=0.003), while no significant effect occurred in males. This was confirmed for secondary end points and for the responder analysis according to FDA-approved end points. The tolerability and safety of ibodutant was excellent at all doses.

CONCLUSIONS

Ibodutant showed dose-dependent efficacy response in IBS-D, reaching statistical significance at the 10 mg dose in female patients. The safety and tolerability profile of ibodutant was similar to placebo.

TRIAL REGISTRATION NUMBER

NCT01303224.

Dietary and pharmacological treatment of abdominal pain in IBS

This review introduces the principles of visceral sensation and appraises the current approaches to management of visceral pain in functional GI diseases, principally IBS. These approaches include dietary measures including fibre supplementation, low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet, and pharmacological approaches such as antispasmodics, peppermint oil, antidepressants (tricyclic agents, selective serotonin reuptake inhibitors), 5-HT₃ receptor antagonists (alosetron, ondansetron, ramosetron), non-absorbed antibiotic (rifaximin), secretagogues (lubiprostone, linaclotide), μ-opioid receptor (OR) and κ-OR agonist, δ-OR antagonist (eluxadoline), histamine H1 receptor antagonist (ebastine), neurokinin-2 receptor antagonist (ibodutant) and GABAergic agents (gabapentin and pregabalin). Efficacy and safety are discussed based on pivotal trials or published systematic reviews and meta-analysis, expressing ORs or relative risks and their 95% CIs. Potential new approaches may be based on recent insights on mucosal expression of genes, and microRNA and epigenetic markers in human biopsies and in animal models of visceral hypersensitivity.The objectives of this review are to appraise the physiology and anatomy of gut sensation and the efficacy in the relief of visceral pain (typically in IBS) of several classes of therapies. These include fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and different classes of medications (box 1). Box 1Classes of pharmacological agents for visceral painAntidepressants (tricyclic agents, selective serotonin reuptake inhibitors)Peppermint oil5-HT₃ receptor antagonists (alosetron, ondansetron, ramosetron)Non-absorbed antibiotic (rifaximin)Secretagogues (lubiprostone, linaclotide)μ-Opioid receptor (OR) and κ-OR agonist and δ-OR antagonist (eluxadoline)Histamine H1 receptor antagonist (ebastine)Neurokinin-2 receptor antagonist (ibodutant)GABAergic agents (gabapentin and pregabalin).

Managing irritable bowel syndrome: The impact of micro-physiotherapy

Background Irritable bowel syndrome (IBS) has a complex pathology, high prevalence and large impact on patients' quality of life. As conventional therapy may yield unsatisfactory results, a more holistic approach may be desirable. The current study assessed the effect of micro-physiotherapy on the severity of IBS symptoms. Methods In a double-blind study, 61 recurrent IBS patients were randomised to two sessions of micro-physiotherapy or sham micro-physiotherapy. Inclusion criteria were the presence of ≥1 IBS symptom from abdominal pain, constipation, diarrhoea or bloating. Exclusion criteria were previous major intestinal surgery and the presence of chronic diseases. The mean patient age was 53.5±15.3 years. Micro-physiotherapy consisted of micro-palpatory examination to identify osteopathic lesions, followed by micro-massage to stimulate self-healing. The control group underwent a sham procedure. The presence and severity of symptoms was assessed at baseline and at 1-month follow-up by the same gastroenterologist. Results Two patients did not complete the study. There was a significant difference in percentage of patients that improved after the first session, at 74 % for the micro-physiotherapy group and 38 % for the sham group, respectively (p=0.005). After the second session, the initial improvement was maintained in both groups, although with no further gains, and the differences between the study groups remained significant (p=0.007). Conclusions Micro-physiotherapy significantly improves IBS symptoms and should be explored further for use in mainstream healthcare.

Modern Management of Irritable Bowel Syndrome: More Than Motility

In the treatment of irritable bowel syndrome (IBS), loperamide seems efficacious for diarrhea and ispaghula for constipation, while musculotropic spasmolytics may relieve abdominal pain. Antidepressants were found to be efficacious for abdominal pain, but their tolerance may be problematic and the therapeutic effect varied largely between trials. While meta-analyses suggest efficacy of probiotics as a group, the quality of the trials is often suboptimal and there is large variability. Lubiprostone, a chloride channel activator, and linaclotide, a guanylyl cyclase-C agonist, showed favorable effects on multiple symptoms in IBS with constipation. For IBS with diarrhea (IBS-D), the 5-HT3 receptor antagonist ramosetron showed efficacy in men and women, but is currently only approved in Japan. A multicenter study with the anti-emetic 5-HT3 receptor antagonist ondansetron showed efficacy on stool pattern in IBS-D. The poorly absorbable antibiotic rifaximin and eluxadoline, a mu opioid receptor agonist and delta antagonist, both showed efficacy in phase III trials in IBS-D and were approved by the FDA. Eluxadoline was associated with increased occurrence of sphincter of Oddi spasm and biliary pancreatitis. The non-pharmacological treatment of IBS, with dietary interventions (mainly gluten elimination and low FODMAP (fructose, oligo-, di-, monosaccharides and polyols)) has received a lot of attention lately. While responder rates vary across studies, perhaps based on regional variations in dietary intake of FODMAPs, the dietary approach seems to have acquired recognition as a valid therapeutic alternative. Long-term studies and comparative studies with pharmacotherapy, as well as elucidation of the underlying mechanisms of action, are needed.

Alterations in serotonin metabolism in the irritable bowel syndrome

BACKGROUND

Alterations in serotonin (5-HT) metabolism have been postulated to play a role in the pathogenesis of irritable bowel syndrome (IBS). However, previous reports regarding 5-HT metabolism in IBS are contradicting.

AIM

To compare platelet poor plasma (PPP) 5-HT and 5-hydroxyindole acetic acid (5-HIAA) levels and their ratio in a large cohort of IBS patients and healthy controls (HC), including IBS-subgroup analysis.

METHODS

Irritable bowel syndrome patients and HC were evaluated for fasting PPP 5-HT and 5-HIAA levels. Furthermore, GI-symptom diary, GSRS, quality of life, anxiety and depression scores were assessed in the 2 weeks before blood sampling.

RESULTS

One hundred and fifty four IBS patients and 137 HC were included. No differences were detected in plasma 5-HT between groups. The 5-HIAA concentrations and 5-HIAA/5-HT ratio were significantly lower in IBS compared to HC: 24.6 ± 21.9 vs. 39.0 ± 29.5 μg/L (P < 0.001) and 8.4 ± 12.2 vs. 13.5 ± 16.6 (P < 0.01), respectively. Subtype analysis for 5-HIAA showed all IBS subtypes to be significantly different from HC. The 5-HIAA/5-HT ratio was significantly lower in the IBS-M subtype vs. HC. Linear regression analysis points to an influence of gender but not of GI-symptoms, psychological scores or medication use.

CONCLUSIONS

We demonstrated that fasting 5-HT plasma levels are not significantly different in IBS patients compared to controls. However, decreased 5-HIAA levels and 5-HIAA/5-HT ratio in IBS patients may reflect altered serotonin metabolism in IBS. Gender affects 5-HIAA levels in IBS patients, but no effects of drugs, such as SSRIs, or higher GI-symptom or psychological scores were found.

Efficacy of a Chinese Herbal Medicine in Providing Adequate Relief of Constipation-predominant Irritable Bowel Syndrome: A Randomized Controlled Trial

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is the most common chronic functional bowel disorder, with few treatment options. IBS affects 10%-20% of the population; as many as 58% of patients have constipation-predominant IBS (IBS-C). We evaluated efficacy and safety of a standardized, specifically formulated Chinese herbal medicine (CHM) preparation in treatment of patients with IBS-C.

METHODS

We performed a double-blind trial of 125 patients with IBS-C (according to Rome III criteria), who were recruited from 13 medical centers or clinics in Australia from July 2009 through February 2012. Patients were randomly assigned to groups given a standardized extract of 7 selected CHM ingredients (n = 61) or placebo (controls, n = 64) for 8 weeks (5 capsules, twice daily). Subjects were then followed for 16 weeks. Chemical definition, standardization, and stability testing of the formulation were completed. Subjects completed a self-administered, validated binary questionnaire of global symptom improvement at weeks 2, 4, 8, and 16 (primary outcome). Secondary outcomes included results from the self-administered IBS Symptom Severity Scale and the Bristol Stool Form Scale (BSFS), which were completed at weeks 4, 8, and 16.

RESULTS

There was statistically and clinically significant (per protocol analyses) improvement among subjects who received CHM (n = 50) vs controls (n = 58) for 8 weeks. A greater proportion of subjects receiving CHM reported adequate relief (P = .010). Compared with controls, the CHM group had improved bowel habits vs controls at week 8, including lower IBS Symptom Severity Scale scores (P < .001), reduced straining during defecation (P = .002), and a significant decrease in hard lumpy stools (P = .031). The CHM group also had increased stool consistency, which was based on the Bristol Stool Form Scale (week 8, P < .001). There was no statistically significant difference between groups in abdominal pain at week 8 (P = .692). The CHM was well-tolerated.

CONCLUSIONS

In a prospective, controlled study, CHM reduced symptoms of IBS-C, increased bowel satisfaction and stool consistency, and reduced straining and hard lumpy stools, compared with placebo. Clinical trial registration no: ACTRN12609000558224.

Change in Quality of Life for Patients with Irritable Bowel Syndrome following Referral to a Gastroenterologist: A Cohort Study

BACKGROUND

Irritable bowel syndrome (IBS), a chronic functional condition, considerably reduces quality of life (QoL) and referral to gastroenterology is common. Until now, however, the impact of seeing a gastroenterologist for IBS on patients' QoL and utility has not been assessed.

METHODS

Patients referred with "probable IBS" to the Nottingham Treatment Centre between October 2012 and March 2014 were invited to complete a QoL questionnaire (EuroQol-5 Dimension) before their first appointment. Patients with confirmed IBS who completed this baseline assessment were sent follow-up questionnaires three and twelve months later. Global QoL and utility were measured at each time point and change from baseline calculated. Paired t-tests analysed the significance of any change.

RESULTS

Of 205 invited patients, 69 were eligible and recruited. Response at three and twelve months was 45% and 17% respectively. Median global QoL at baseline was 67.5 (Interquartile range [IQR] 50.0 to 80.0), with a mean increase of 3.25 (95% confidence interval [CI] -5.38 to 11.88) three months later and a mean decrease of -1.82 (95% CI -16.01 to 12.38) after one year. The median utility at baseline was 0.76 (IQR 0.69 to 0.80), with a mean increase of 0.06 (95%CI -0.01 to 0.14) at three months and no change, 0.00 (-0.16 to 0.16), after one year.

CONCLUSION

Patients experienced a small but not statistically significant increase in QoL and utility three months after seeing a gastroenterologist for IBS, which was not maintained. Gastroenterology referral does not appear to appreciably improve Qol for most people with IBS.

Pharmacologic Agents for Chronic Diarrhea

Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reduction of fluid and electrolyte loss and an increase in stool consistency. Cholestyramine is a bile acid sequestrant that is generally considered as the first-line treatment for bile acid diarrhea. 5-HT3 receptor antagonists have significant benefits in patients with irritable bowel syndrome (IBS) with diarrhea. Ramosetron improves stool consistency as well as global IBS symptoms. Probiotics may have a role in the prevention of antibiotic-associated diarrhea. However, data on the role of probiotics in the treatment of chronic diarrhea are lacking. Diosmectite, an absorbent, can be used for the treatment of chronic functional diarrhea, radiation-induced diarrhea, and chemotherapy-induced diarrhea. Antispasmodics including alverine citrate, mebeverine, otilonium bromide, and pinaverium bromide are used for relieving diarrheal symptoms and abdominal pain. Rifaximin can be effective for chronic diarrhea associated with IBS and small intestinal bacterial overgrowth. Budesonide is effective in both lymphocytic colitis and collagenous colitis. The efficacy of mesalazine in microscopic colitis is weak or remains uncertain. Considering their mechanisms of action, these agents should be prescribed properly.

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.

Health related quality of life in irritable bowel syndrome patients, Kashan, Iran: A case control study

BACKGROUND

Irritable bowel syndrome has significant impacts on the quality of life (QOL) but IBS subtypes may be different in QOL. This study aimed to assess QOL in IBS subtypes and also two prevalent questionnaires applied to evaluate the QOL in IBS.

MATERIALS AND METHODS

In this case-control study conducted in Kashan in 2010-2013. One hundred and eighty- eight patients with IBS with 215 of non-IBS patients were included in the baseline. Subjects divided into three subtypes based on symptoms of diarrhea-predominant (IBS-D), constipation-predominant (IBS-C) and IBS with mixed bowel habits (IBS-M) and in each subtype were 42, 62 and 84 patients, respectively. All IBS subjects completed questionnaires containing the disease-specific QOL for IBS (IBSQOL), World Health Organization QOL Assessment-BREF (WHOQOL-BREF) and IBS severity scores (IBSSS). The non-IBS subjects completed the WHOQOL-BREF only.

RESULTS

Mean scores of IBSQOL in person with subtypes of IBS-D, IBS-C and IBS-M were 74.34 ± 19.01, 76.77 ± 22.91 and 73.15 ± 26.51, respectively which was not significantly different (P value = 0.507). As well as mean scores of WHOQOL-BREF in person with subtypes of IBS-D, IBS-C and IBS-M were 81.01 ± 16.23, 88.32 ± 15.66, and 82.65 ± 16.67, respectively, which were not significantly different (P value = 0.412) but mean scores of WHOQOL-BREF in non-IBS subjects was 89.53 ± 11.71 which was significantly different from IBS subjects (P value = 0.022). Strong positive relationship between two instruments was shown (r = 0.826 when P < 0.05).

CONCLUSIONS

The WHOQOL-BREF instrument showed poorer QOL in IBS patients. The QOL was not different significantly among IBS-M, IBS-C, and IBS-D subtypes. We found that WHOQOL-BREF instrument strongly correlate with QOLIBS instrument.

Emerging drug for diarrhea predominant irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders with a 9 - 23% prevalence estimated in the general population. Patients can be subdivided into those who tend to have predominant diarrhea (IBS-D) or predominant constipation (IBS-C). Total annual productivity loss related to IBS in US is estimated at $205 million, with a significant impairment of health-related quality of life. A gold standard for the treatment of IBS is not established. Symptoms might improve with the use of few drugs and behavioral therapy, however, data concerning efficacy, safety and tolerability are limited. Therefore, development and validation of new therapies targeting at the molecular level are widely awaited.

AREAS COVERED

We will specifically describe in this review Phase II and Phase III trials, with specific focus on treatment of IBS-D patients. Unfortunately, it is difficult to draw definite conclusions from Phase II and Phase III trials, because of the known high placebo effect.

EXPERT OPINION

Drugs active on opioid receptor subtypes and neurokinin (NK) receptors seem to be the most promising, but substantial progress of information in this field is still needed. The achievement of more insights on the pathogenesis of IBS could surely better drive and target the therapy, but still strong efforts are awaited.

Survey of clinical practice for irritable bowel syndrome in East asian countries

AIM

Sociocultural factors are important because their different effects on the features of irritable bowel syndrome (IBS) between countries will provide clues towards solving this problem. The aims of this study were to depict the clinical realities of IBS in East Asian countries and test the hypothesis that the diagnosis and treatment of IBS differ between countries.

SUBJECTS AND METHODS

Study participants were 251 physicians involved in the clinical practice of IBS at major institutions in Japan, South Korea, China, the Philippines, Indonesia and Singapore. The questionnaire contained 45 questions focused on the clinical practice of IBS.

RESULTS

Subjects in Japan, South Korea, China, Indonesia, the Philippines and Singapore accounted for 55.4, 17.9, 8.8, 8.0, 6.4 and 3.6% of the study cohort, respectively. Amongst East Asian physicians, the most important symptom was considered to be abdominal pain by 33.4%, whilst 24.3% regarded alternating diarrhea and constipation to be the most important symptoms. Total colonoscopy and histopathology use showed no difference among countries. Prescriptions given for mild (p < 0.0001), moderate (p < 0.0001), severe (p < 0.0001), intractable (p = 0.002), diarrheal (p < 0.0001) and constipating (p < 0.0001) patients with IBS significantly differed between the countries. Except for several minor points, IBS specialists showed no significant difference in their diagnosis and treatment of IBS when compared to nonspecialists.

CONCLUSION

This survey provided data on the clinical treatment of IBS among East Asian countries. The results supported the hypothesis that the diagnosis and treatment of IBS differs between countries.

Evidence-based clinical practice guidelines for irritable bowel syndrome

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

Current and emerging pharmacotherapeutic options for irritable bowel syndrome

Treatment of irritable bowel syndrome (IBS) is challenging for both primary care physicians and gastroenterologists because of the heterogeneity of the patient population and the multifactorial pathophysiologies responsible for the symptoms in IBS. This review focuses on the current and emerging pharmacological treatments for IBS. Many of the current medications used to treat this disorder have distinct properties such as efficacy for different symptoms, safety profiles, contraindications, costs, dosing regimens, treatment duration and long-term data. All of these factors, in addition to patient preference and cognitive, food and environmental triggers, must be considered prior to any medication selection. This review will focus on randomized controlled trials with a general uniformity in study design, a rigorous patient selection and appropriate treatment durations. We will also discuss other exciting emerging treatments for IBS such as the µ-opioid receptor (agonists and antagonists), selective κ-opioid receptor agonists, anti-inflammatory drugs, serotonergic agents, bile acid modulators and intestinal bile acid transporters, which may prove promising in treating our patients.

Otilonium bromide in irritable bowel syndrome: A dose-ranging randomized double-blind placebo-controlled trial

AIM: To examine the efficacy and safety of otilonium bromide (OB) in treatment-sensitive functional irritable bowel syndrome (IBS) clinical parameters.

METHODS: Ninety-three patients (44.8 ± 12.6 years, 69% female) with IBS symptoms complying with Rome II criteria participated in this double-blind, placebo-controlled, randomised, dose-ranging phase I/II study. Patients were administered OB 20 mg (n = 24), 40mg (n = 23) and 80 mg (n = 23) tid or placebo (n = 23) in 4 parallel groups for 4 wk. Primary efficacy variables included abdominal discomfort, intestinal habits, number of daily evacuations and stool consistency. Secondary efficacy measures included return to regular intestinal habits and global discomfort. Safety was also assessed.

RESULTS: Baseline clinical characteristics were similar among the 4 groups. Although individual parameters such as intensity and frequency of abdominal discomfort, bloating or pain were reduced by OB over the 4 wk, no significant differences were observed between groups. Similarly, no difference was observed between OB treatment or placebo for mucus in stool and incomplete or difficulty of evacuation. However, evacuation frequency was significantly reduced after 4 wk by 80 mg OB compared to placebo (-8.36% for placebo vs -41.9% for 80 mg OB, P < 0.01). While 21.7% of patients in the placebo group experienced regular intestinal habits after 4 wk, this improvement was greater for patients treated with 40 mg OB (P < 0.01 vs placebo). Furthermore, a dose-dependent reduction in frequency of diarrhoea (χ²-test for trend = 11.5, P < 0.001) and an increase in normal stool frequency was observed. Combining individual variables into a global discomfort index revealed significant improvement among increasing OB doses, favouring 40 mg (P = 0.013) and 80mg OB (P = 0.001) over placebo. No difference was observed between frequency of adverse events for placebo vs OB.

CONCLUSION: This dose-ranging study demonstrates that OB at 40 and 80 mg can improve individual and global clinical symptoms of IBS compared to placebo over a 4-wk period.