Irritable bowel syndrome with constipation: a European-focused systematic literature review of disease burden

Efficacy and tolerability of chitin-glucan combined with simethicone (GASTRAP® DIRECT) in irritable bowel syndrome: A prospective, open-label, multicenter study

BACKGROUND

Irritable bowel syndrome (IBS), defined according to the Rome IV diagnostic criteria, is a chronic functional gastrointestinal disorder characterized by recurrent abdominal pain related to altered bowel habits. First-line recommended treatments are limited to combining drugs targeting predominant symptoms, particularly pain (antispasmodics), constipation (laxatives), and diarrhea (loperamide), yielding only a limited therapeutic gain. GASTRAP^® DIRECT is a class IIa medical formulation composed of a combination of chitin-glucan and simethicone indicated for the symptomatic treatment of gas-related gastrointestinal disorders by combining different mechanisms of action.

AIM

To evaluate the efficacy, tolerability, and safety of 4-week GASTRAP^® DIRECT treatment in patients with IBS.

METHODS

In this prospective, multicenter, open-label trial, 120 patients with IBS received three sticks of GASTRAP^® DIRECT (1.5 g/d of chitin-glucan and 0.75 mg/d of simethicone) per day for 4 weeks. The primary endpoint was the responder rate, defined as the number of patients whose abdominal pain score decreased by ≥ 30% from baseline to week (W) 4. The analysis was performed using the per-protocol set. Cardinal symptoms, impact of global symptoms on daily life, change in stool consistency, and improvement in defecatory disorders were evaluated.

RESULTS

Overall, 100 patients were evaluated. At W4, 67% (95%CI: 57-75) showed improvement in abdominal pain (score: 5.8 ± 2.4 vs 2.9 ± 2.0, P < 0.0001). Similar improvements were observed for bloating [8.0 ± 1.7 vs 4.7 ± 2.9, P < 0.0001; 60% (95%CI: 50-70) responders], abdominal distension [7.2 ± 2.1 vs 4.4 ± 3.1, P < 0.0001; 53% (95%CI: 43-63) responders], and impact of global symptoms on daily life [7.1 ± 2.0 vs 4.6 ± 2.9, P < 0.0001; 54% (95%CI: 44-64) responders]. Stool consistency improved in most patients (90% and 57% for patients with liquid and hard stools, respectively). Overall, 42% of patients with defecatory disorders reported very much/considerable improvements by W2. No severe adverse event occurred, and tolerability was rated “good” or “very good” by 93% of patients.

CONCLUSION

GASTRAP^® DIRECT is safe and well tolerated, alleviating IBS symptoms rapidly in 2 weeks. This open-label study suggests that the combination of chitin-glucan and simethicone could be beneficial in patients with IBS.

Chitin-glucan improves important pathophysiological features of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most frequent and debilitating conditions leading to gastroenterological referrals. However, recommended treatments remain limited, yielding only limited therapeutic gains. Chitin-glucan (CG) is a novel dietary prebiotic classically used in humans at a dosage of 1.5-3.0 g/d and is considered a safe food ingredient by the European Food Safety Authority. To provide an alternative approach to managing patients with IBS, we performed preclinical molecular, cellular, and animal studies to evaluate the role of chitin-glucan in the main pathophysiological mechanisms involved in IBS.

AIM

To evaluate the roles of CG in visceral analgesia, intestinal inflammation, barrier function, and to develop computational molecular models.

METHODS

Visceral pain was recorded through colorectal distension (CRD) in a model of long-lasting colon hypersensitivity induced by an intra-rectal administration of TNBS [15 milligrams (mg)/kilogram (kg)] in 33 Sprague-Dawley rats. Intracolonic pressure was regularly assessed during the 9 wk-experiment (weeks 0, 3, 5, and 7) in animals receiving CG (n = 14) at a human equivalent dose (HED) of 1.5 g/d or 3.0 g/d and compared to negative control (tap water, n = 11) and positive control (phloroglucinol at 1.5 g/d HED, n = 8) groups. The anti-inflammatory effect of CG was evaluated using clinical and histological scores in 30 C57bl6 male mice with colitis induced by dextran sodium sulfate (DSS) administered in their drinking water during 14 d. HT-29 cells under basal conditions and after stimulation with lipopolysaccharide (LPS) were treated with CG to evaluate changes in pathways related to analgesia (µ-opioid receptor (MOR), cannabinoid receptor 2 (CB2), peroxisome proliferator-activated receptor alpha, inflammation [interleukin (IL)-10, IL-1b, and IL-8] and barrier function [mucin 2-5AC, claudin-2, zonula occludens (ZO)-1, ZO-2] using the real-time PCR method. Molecular modelling of CG, LPS, lipoteichoic acid (LTA), and phospholipomannan (PLM) was developed, and the ability of CG to chelate microbial pathogenic lipids was evaluated by docking and molecular dynamics simulations. Data were expressed as the mean ± SEM.

RESULTS

Daily CG orally-administered to rats or mice was well tolerated without including diarrhea, visceral hypersensitivity, or inflammation, as evaluated at histological and molecular levels. In a model of CRD, CG at a dosage of 3 g/d HED significantly decreased visceral pain perception by 14% after 2 wk of administration (P < 0.01) and reduced inflammation intensity by 50%, resulting in complete regeneration of the colonic mucosa in mice with DSS-induced colitis. To better reproduce the characteristics of visceral pain in patients with IBS, we then measured the therapeutic impact of CG in rats with TNBS-induced inflammation to long-lasting visceral hypersensitivity. CG at a dosage of 1.5 g/d HED decreased visceral pain perception by 20% five weeks after colitis induction (P < 0.01). When the CG dosage was increased to 3.0 g/d HED, this analgesic effect surpassed that of the spasmolytic agent phloroglucinol, manifesting more rapidly within 3 wk and leading to a 50% inhibition of pain perception (P < 0.0001). The underlying molecular mechanisms contributing to these analgesic and anti-inflammatory effects of CG involved, at least in part, a significant induction of MOR, CB2 receptor, and IL-10, as well as a significant decrease in pro-inflammatory cytokines IL-1b and IL-8. CG also significantly upregulated barrier-related genes including muc5AC, claudin-2, and ZO-2. Molecular modelling of CG revealed a new property of the molecule as a chelator of microbial pathogenic lipids, sequestering gram-negative LPS and gram-positive LTA bacterial toxins, as well as PLM in fungi at the lowesr energy conformations.

CONCLUSION

CG decreased visceral perception and intestinal inflammation through master gene regulation and direct binding of microbial products, suggesting that CG may constitute a new therapeutic strategy for patients with IBS or IBS-like symptoms.

Tenapanor for the treatment of irritable bowel syndrome with constipation

INTRODUCTION

Irritable bowel syndrome with constipation is associated with higher rates of functional impairment, as compared to other subtypes of the syndrome. Conventional laxative-based pharmacologic therapy of IBS-C, which is mostly symptom-based, is often unsatisfactory. Tenapanor represents a first-in-class orally available inhibitor of NHE3, which is minimally absorbed in the GI tract, what constitutes a significant therapeutic benefit, as it may act on the drug target.

AREAS COVERED

Aim of this article is to sum up the evidences about pharmacodynamics and pharmacokinetics of tenapanor, focusing on animal models and in vitro studies, but also discuss clinical trials on tenapanor's safety and efficacy in view of its important potential role in IBS-C treatment.

EXPERT OPINION

In the challenging setting of irritable bowel syndrome with constipation, tenapanor represents a novel strategy in the pipeline of the therapies of IBS-C. Its pharmacokinetic and pharmacodynamic profile provides that it is minimally absorbed from the intestinal lumen and that its action is local, but not systemic action, therefore guaranteeing the reduction of drug-drug interactions, toxicity and severe adverse effects. Phase 2b and 3 trials showed an optimal satisfaction of primary and secondary endpoints.

Depression but Not Symptom Severity is Associated With Work and School Absenteeism in Refractory Chronic Constipation

GOALS

We sought to determine the patient characteristics associated with increased absenteeism and Emergency Department (ED) utilization among patients with constipation.

BACKGROUND

Chronic constipation is associated with significant direct and indirect economic costs. There has been limited study of the predictors of direct and indirect costs in a population with refractory constipation.

STUDY

We conducted a cross-sectional cohort study of patients with chronic constipation who presented to a tertiary care center for anorectal manometry. We used standardized instruments to assess disease severity, quality of life, somatization, and psychiatric comorbidities. We used multivariable logistic regression to determine the predictors of work and school absenteeism as well as ED visits for constipation.

RESULTS

There were 148 consecutive patients enrolled (87% female, mean age 43) of whom 32 (21.6%) had high absenteeism and 36 (24.3%) visited the ED for constipation in the past year. Patients with high absenteeism and ED visits were more likely to be depressed (56.3% vs. 18.5%, P<0.0001 for high absenteeism; 47.2% vs. 19.6%, P<0.01 for ED visits). After multivariable adjustment and sensitivity analyses, only depression (OR, 4.41; P<0.01) was associated with increased absenteeism while there was a trend toward an association between depression and ED visits (OR, 2.57; P=0.067). Symptom severity was not associated with high absenteeism or ED utilization.

CONCLUSIONS

Among patients with chronic constipation, depression is a stronger predictor of absenteeism than symptom severity. Depression may drive a portion of the indirect costs of chronic constipation.

Referrals to a tertiary hospital: A window into clinical management issues in functional gastrointestinal disorders

BACKGROUND AND AIM

To investigate the quality of and reasons for referrals of patients with likely functional gastrointestinal disorders (FGID) and explore patients' experience of clinical management.

METHODS

A cross sectional, mixed-methods study was undertaken. Referrals (July 2013-2015) to one gastroenterology outpatient department triaged as "likely FGID", the referred patients and their referring primary healthcare providers were examined.

RESULTS

A total of 69% of patients reported not yet receiving an initial diagnosis, 52% reported persistent/distressing symptoms or reduced quality of life, 24% feared missed or worsening pathology, and 35% were seeking repeat specialist consultation. Most patients were dissatisfied (40%) or only partially satisfied (36%) with current management. Dissatisfaction was significantly related to the lack of provision of a diagnosis and effective treatment options (P < 0.001). Referral quality was poor and with the reason for referral clearly communicated in only 25%. Common referral reasons included repeat presentations (n = 32), diagnostic uncertainty (n = 19), to ensure nothing is missed (n = 19), patient request (n = 17), no response to treatment (n = 16), and to allay patient fears (n = 14). A total of 28/60 primary healthcare providers were confident that their patient had a FGID, yet sought confirmation (n = 16), second opinion (n = 8), or advice (n = 4).

CONCLUSION

Current management of FGID in usual care is suboptimal, as evidenced by the tertiary referral load, patient dissatisfaction, and the lack of provision of diagnoses and effective treatment options. Some clinicians lack confidence in effectively identifying and managing these conditions. Resources and supports to equip and assist clinicians to identify and manage FGID successfully may enhance patient care.

Smoking in Irritable Bowel Syndrome: A Systematic Review

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Functional urological disorders: a sensitized defence response in the bladder-gut-brain axis

Functional urological and gastrointestinal disorders are interrelated and characterized by a chronic course and considerable treatment resistance. Urological disorders associated with a sizeable functional effect include overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). Poor treatment outcomes might be attributable to untreated underlying psychological and psychiatric disorders, as the co-occurrence of functional urological and gastrointestinal disorders with mood and anxiety disorders is common. The hypothetical bladder-gut-brain axis (BGBA) is a useful framework under which this interaction can be studied, suggesting that functional disorders represent a sensitized response to earlier threats such as childhood adversity or previous traumatic events, resulting in perceived emotional and bodily distress - the symptoms of functional disorders. Psychological and physical stress pathways might contribute to such alarm falsification, and neuroticism could be a risk factor for the co-occurrence of functional disorders and affective conditions. Additionally, physical threat - either from external sources or internal sources such as infection - might contribute to alarm falsification by influencing body-brain crosstalk on homeostasis and, therefore, affecting mood, cognition, and behaviour. Multidisciplinary research and an integrated care approach is, therefore, required to further elucidate and remediate functional urological and gastrointestinal polymorphic phenotypes.

Comparison of Electroacupuncture and Moxibustion for Relieving Visceral Hypersensitivity in Rats with Constipation-Predominant Irritable Bowel Syndrome

Aim. To compare whether there is different effect between electroacupuncture (EA) and moxibustion (Mox) on visceral hypersensitivity (their analgesic effects) in constipation-predominant irritable bowel syndrome (C-IBS). Methods. EA at 1 mA and 3 mA and Mox at 43°C and 46°C were applied to the Shangjuxu (ST37, bilateral) acupoint in rats with C-IBS and normal rats. An abdominal withdrawal reflex (AWR) score was used to assess visceral hypersensitivity. Toluidine blue staining was used to assess mast cell (MC) activity in colon of rats. Immunochemistry was used to measure 5-HT and 5-HT4 receptor expression in the colon. Results. AWR scores in all EA (1 mA and 3 mA) and Mox (43°C and 46°C) treatment groups after colorectal distention (CRD) stimulation pressure of 20, 40, 60, and 80 mmHg were significantly lower than those of the model (MC) group (P all < 0.01). The MC counts and degranulation rates in the colon of all EA and Mox treatment groups and the MC group were significantly higher than those of the NC group (P all < 0.01). MC degranulation rates in the colon of all EA and Mox treatment groups were lower than those of the MC group (P all < 0.05). 5-HT expression in colon of all EA and Mox treatment groups was significantly lower than that of the MC group (P all < 0.01), and 5-HT4R expression in colon of both EA groups was significantly higher than that of the MC group (P both < 0.01). Conclusion. EA and Mox treatments may both ameliorate visceral hypersensitivity at different degree in rats with C-IBS, and EA treatment was better than Mox.

Integrated medical-psychiatric outpatient care in functional gastrointestinal disorders improves outcome: a pilot study

BACKGROUND AND OBJECTIVES

Functional gastrointestinal disorders have a multifactorial etiology, including somatic and psychosocial factors. We provide multidisciplinary outpatient consultations by a gastroenterologist and a psychiatrist using an integrated approach toward somatic and psychosocial factors in complex functional gastrointestinal disorders. The aim of this study was to determine the efficacy of this approach assessing gastrointestinal and psychiatric symptoms and quality of life.

METHODS

All patients with complex functional gastrointestinal disorders visiting for consultation were included and treated with antidepressants, psychotherapy, or both, or given advice for treatment in their own region. Questionnaires testing gastrointestinal and psychiatric symptoms, and quality of life at first visit and after 6 and 12 months were completed.

RESULTS

A total of 124 patients were included (70% women, mean age 48 years): 57% were diagnosed with irritable bowel syndrome and about 80% had a psychiatric diagnosis (50% anxiety disorder, 20% mood disorder). Of the patients, 57% were treated with antidepressants and psychotherapy, 6% with psychotherapy alone, and 38% received advice for treatment in their own region. After 1 year, patients showed significant improvement in all questionnaires, with the exception of those testing gastrointestinal symptoms, although there were significant improvements in these at 6 months.

CONCLUSION

This is the first prospective study on the efficacy of an integrated medical-psychiatric outpatient care model in patients with complex functional gastrointestinal disorders, showing significant improvement in gastrointestinal and psychiatric symptoms as well as quality of life after 6 months. With the exception of improvement in gastrointestinal symptoms, improvement persisted at the 1-year follow-up. This indicates that longer follow-up focusing on gastrointestinal symptoms may be needed.

A randomized clinical trial of Saccharomyces cerevisiae versus placebo in the irritable bowel syndrome

BACKGROUND

We aimed to evaluate clinical symptoms in subjects with irritable bowel syndrome receiving Saccharomyces cerevisiae in a randomized double-blind placebo-controlled clinical trial.

METHODS

Overall, 179 adults with irritable bowel syndrome (Rome III criteria) were randomized to receive once daily 500 mg of Saccharomyces cerevisiae, delivered by one capsule (n = 86, F: 84%, age: 42.5 ± 12.5), or placebo (n = 93, F: 88%, age: 45.4 ± 14) for 8 weeks followed by a 3-week washout period. After a 2-week run-in period, cardinal symptoms (abdominal pain/discomfort, bloating/distension, bowel movement difficulty) and changes in stool frequency and consistency were recorded daily and assessed each week. A safety assessment was carried out throughout the study.

RESULTS

The proportion of responders, defined by an improvement of abdominal pain/discomfort, was significantly higher (p = 0.04) in the treated group than the placebo group (63% vs 47%, OR = 1.88, 95%, CI: 0.99-3.57) in the last 4 weeks of treatment. A non-significant trend of improvement was observed with Saccharomyces cerevisiae for the other symptoms. Saccharomyces cerevisiae was well tolerated and did not affect stool frequency and consistency.

CONCLUSION

Saccharomyces cerevisiae is well tolerated and reduces abdominal pain/discomfort scores without stool modification. Thus, Saccharomyces cerevisiae may be a new promising candidate for improving abdominal pain in subjects with irritable bowel syndrome.

Comparison of psychological characteristics between patients with irritable bowel syndrome with constipation and those with functional constipation

AIM: To explore the difference in psychological characteristics between patients with irritable bowel syndrome with constipation (IBS-C) and those with functional constipation (FC), to seek the role of psychological factors in the pathogenesis of the two diseases, and to provide a theoretical basis for the development of individualized treatments for them.

METHODS: We retrospectively compared the psychological characteristics (depression, anxiety profiles and score for life quality) between patients with IBS-C vs those with FC using validated questionnaires. Subjects rated the intensity of digestive symptoms experienced using visual analogue scales and questionnaires. Colonic transit time measurements and anorectal manometry were performed.

RESULTS: Of the 208 consecutive constipated patients included, 102 suffered from IBS-C and 106 from FC. Demographic and physiological traits were similar between the two groups. Levels of the common symptoms such as constipation, bloating, abdominal pain and diarrhea in patients with IBS-C were higher than those in patients with FC (P < 0.05), although there was no significant difference in Bristol stool form scale or constipation symptom score (P > 0.05). Patients with FC had higher transit time in the recto-sigmoid area than IBS-C patients, although transit time in other regions was similar between the two groups. There was no significant difference in anorectal manometry measures between the two groups. Patients suffering from IBS-C reported significantly higher depression score (18.156 ± 1.476 vs 11.902 ± 1.351, P < 0.01), and high depression scores were found more frequently in the IBS-C group as compared to the FC group, although trait anxiety and state anxiety were similar between the two groups (P > 0.05). Multiple linear regression showed a positive correlation between symptom intensity and depression and anxiety scores only for FC patients.

CONCLUSION: IBS-C and FC have some differences in the psychological aspects. IBS-C patients are more depressed than patients with FC. There is a correlation between depression, anxiety and levels of symptoms in FC patients.

[Correlation of the microbiota and intestinal mucosa in the pathophysiology and treatment of irritable bowel, irritable eye, and irritable mind syndrome]

Accumulating clinical evidence supports co-morbidity of irritable bowel, irritable eye and irritable mind symptoms. Furthermore, perturbation of the microbiota-host symbiosis (dysbiosis) is considered a common pathogenic mechanism connecting gastrointestinal, ocular and neuropsychiatric symptoms. Consequently, maintaining or restoring microbiota-host symbiosis represents a new approach to treat these symptoms or to prevent their relapses. Current treatment approach assigned a primary role to live probiotics alone or in combination with prebiotics to enhance colonization of beneficial bacteria and to strengthen the symbiosis. However, several papers showed major benefits of heat-killed probiotics as compared to their live counterparts on both intestinal and systemic symptoms. Recently, in addition to killing probiotics, in a proof of concept study lysates (fragments) of probiotics in combination with vitamins A, B, D and omega 3 fatty acids were successfully tested. These findings suggested a conceptual change in the approach addressed to both the microbiota and host as targets for intervention.

A four-country comparison of healthcare systems, implementation of diagnostic criteria, and treatment availability for functional gastrointestinal disorders: a report of the Rome Foundation Working Team on cross-cultural, multinational research

BACKGROUND

Variations in healthcare provision around the world may impact how patients with functional gastrointestinal disorder (FGIDs) are investigated, diagnosed, and treated. However, these differences have not been reviewed.

PURPOSES

The Multinational Working Team of the Rome Foundation, established to make recommendations on the conduct of multinational, cross-cultural research in FGIDs, identified seven key issues that are analyzed herein: (i) coverage afforded by different healthcare systems/providers; (ii) level of the healthcare system where patients with FGIDs are treated; (iii) extent/types of diagnostic procedures typically undertaken to diagnose FGIDs; (iv) physicians' familiarity with and implementation of the Rome diagnostic criteria in clinical practice; (v) range of medications approved for FGIDs and approval process for new agents; (vi) costs involved in treating FGIDs; and (vii) prevalence and role of complementary/alternative medicine (CAM) for FGIDs. Because it was not feasible to survey all countries around the world, we compared a selected number of countries based on their geographical and ethno-cultural diversity. Thus, we included Italy and South Korea as representative of nations with broad-based coverage of healthcare in the population and India and Mexico as newly industrialized countries where there may be limited provision of healthcare for substantial segments of the population. In light of the paucity of formal publications on these issues, we included additional sources from the medical literature as well as perspectives provided by local experts and the media. Finally, we provide future directions on healthcare issues that should be taken into account and implemented when conducting cross-cultural and multinational research in FGIDs.

A preliminary evaluation of comparative effectiveness of riluzole in therapeutic regimen for irritable bowel syndrome

OBJECTIVE

To develop agents that are specifically effective in controlling the key disturbance of visceral hyperalgesia besides abating of associated multiple symptoms, and evaluate comparative effectiveness for IBS symptom relief for standard regimen (antispasmodic and probiotic) and add-on amitriptyine or riluzole regimens following two weeks administration.

METHODS

108 patients with visceral hypersensitivity accompanying IBS, divided into three groups were studied. First group received standard treatment (mebeverine 200 mg twice daily and probiotic 200 mg twice daily). Second group received add-on amitriptyline 25 mg before bedtime, while the third group got add-on riluzole 50 mg twice daily. Overall gastrointestinal symptom rating scale improving symptoms and hospital anxiety depression scale improving associated psychological morbidity were employed as measures at induction and at two-week follow-up period. Individual symptom scores were also examined to define the outcome profiles.

RESULTS

Riluzole regimen resulted in significant reduction of overall gastrointestinal symptom rating scale score, not the other two regimens. Pain relief was seen with both riluzole and amitriptyline regimens significantly superior to standard treatment regimen, but riluzole effect appeared specific and independent anxiolytic effect. Amitriptyline caused relief in diarrhea and did not benefit in constipation point to non-specific remedial role in IBS.

CONCLUSIONS

Riluzole specifically relieves visceral hypersensitivity and is proved to be superior to current treatments in IBS patients. It appears a lead remedy based on glutamate transporter mechanisms in visceral hypersensititvity.

Constipation-predominant irritable bowel syndrome: A review of current and emerging drug therapies

Irritable bowel syndrome (IBS) is a highly prevalent medical condition that adversely affects patient quality of life and constitutes a significant economic burden on healthcare resources. A large proportion of patients suffer from the constipation subtype of IBS (IBS-C), most commonly afflicting older individuals and those with a lower socioeconomic status. Conventional pharmacologic and nonpharmacologic treatment options have limited efficacies and/or significant adverse events, which lead to increased long-term health care expenditures. Failure to effectively treat IBS-C patients over the past decades has largely been due to a poor understanding of disease pathophysiology, lack of a global view of the patient, and an inappropriate selection of patients and treatment endpoints in clinical trials. In recent years, however, more effective and safer drugs have been developed for the treatment of IBS-C. The advancement in the area of pharmacologic treatment is based on new knowledge of the pathophysiologic basis of IBS-C and the development of drugs with increased selectivity within pharmacologic classes with recognized efficacies. This narrative review covers the spectrum of available drugs and their mechanisms of action, as well as the efficacy and safety profiles of each as determined in relevant clinical trials that have investigated treatment options for IBS-C and chronic constipation. A brief summary of laxative-based treatment options is presented, followed by up-to-date assessments for three classes of drugs: prokinetics, prosecretory agents, and bile acid modulators.

Impact of parental-rearing styles on irritable bowel syndrome in adolescents: a school-based study

BACKGROUND AND AIM

A strong association between family function and irritable bowel syndrome (IBS) has been observed. Parental rearing styles, as a comprehensive mark for family function, may provide new clues to the etiology of IBS. This study aimed to explore which dimensions of parental rearing styles were risk factors or protective factors for IBS in adolescents.

METHODS

Two thousand three hundred twenty adolescents were recruited from one middle school and one high school randomly selected from Jiangan District (an urban district in Wuhan City). Data were collected using two Chinese versions of validated self-report questionnaires including the Rome III diagnostic criteria for pediatric IBS and the Egna Minnen Beträffande Uppfostran: One's Memories of Upbringing for perceived parental rearing styles.

RESULTS

Ninety-six subjects diagnosed as pediatric IBS were compared with 1618 controls. The IBS patients reported less both paternal and maternal emotional warmth (all P < 0.01) and more both paternal and maternal punishment, overinterference, rejection, and overprotection (only for father) (all P < 0.01) than the controls. Furthermore, the IBS patients had higher total scores of parental rearing styles (all P < 0.001) than the controls. With univariate logistic regression, standardized regression coefficients and odds ratios of parental rearing variables were calculated. Multivariate logistic regression revealed that paternal rejection (P = 0.001) and maternal overinterference (P = 0.002) were independent risk factors for IBS in adolescents.

CONCLUSIONS

Parental emotional warmth is a protective factor for IBS in adolescents and parental punishment, overinterference, rejection, and overprotection are risk factors for IBS in adolescents.

Review article: Linaclotide for the management of irritable bowel syndrome with constipation

BACKGROUND

Irritable bowel syndrome with constipation (IBS-C) represents a significant burden to patients and healthcare systems due to its prevalence and lack of successful symptomatic resolution with established treatment options. Linaclotide 290 μg has recently been approved by the European Medicines Agency (EMA) for moderate-to-severe IBS-C and by the US Food and Drug Administration for IBS-C (290 μg dose) and for chronic constipation (145 μg dose).

AIM

To summarise data leading to the approval of linaclotide for IBS-C, with focus on EMA-pre-specified outcome measures.

METHODS

Literature search of a peer-review database (PubMed) and review of congress abstracts on linaclotide preclinical and clinical trial data in IBS-C.

RESULTS

Preclinical studies suggest that the guanylate cyclase C agonist (GCCA) linaclotide acts through elevation of cyclic guanosine monophosphate (cGMP) levels, leading to accelerated gastrointestinal (GI) transit through increased fluid secretion and reduced visceral hypersensitivity. Clinical trial data demonstrate that linaclotide improves abdominal symptoms (pain, bloating) and bowel symptoms (constipation) compared with placebo in patients with IBS-C. The most frequent side effect, diarrhoea, results from the therapeutic action of linaclotide. Linaclotide acts locally in the GI tract with minimal systemic exposure, resulting in low oral bioavailability and thus a low risk of relevant systemic adverse effects.

CONCLUSION

Linaclotide, a first-in-class GCCA, is a promising new drug with a novel, dual mechanism of action that, unlike more well-established agents, can relieve the abdominal pain, bloating and constipation associated with IBS-C and has a low propensity for systemic side effects.

An international Delphi study to assess the need for multiaxial criteria in diagnosis and management of functional gastrointestinal disorders

PURPOSE

To assess agreement, consensus, and disagreement between experts in different domains in the evaluation of functional gastrointestinal disorders (FGIDs).

METHODS

We conducted a modified Delphi study using 90 purposively sampled experts using an online survey tool to develop, distribute and analyse the Delphi rounds. Experts were sent 132 items generated from a literature review examining present and proposed future FGID evaluation. The survey items examined contributory factors and were divided into four sections examining risk and contributing factors, the therapeutic relationship, domains of measurement and the pros and cons of multiaxial assessment. The consensus level was set at 75%.

KEY RESULTS

36 of 68 eligible participants (52%) replied to round one and 96 items gained consensus. Using expert feedback, we used thematic analysis to generate 33 additional items for round two. 31 of 36 participants (86%) replied to rounds two and three. In round two, 19 items gained consensus, and in round three, nine items gained consensus. Agreement was high concerning systematic approaches for both physiological and psychosocial components of FGIDs (91%) using laboratory and self-reporting findings (83%). Opinion was divided regarding physical risk factors such as previous surgery (53%) and genetic association (71%). Overall, 124 of the 167 items gained consensus.

CONCLUSION AND INFERENCES

We have identified expert consensus and disagreement on domains of information relevant to the evaluation of FGIDs. Experts agreed there is an immediate need for multi-axial assessment. Physiological and genetic risk factors are not fully accepted and require further study.