Controlled treatment trials in the irritable bowel syndrome: a critique

Placebo response variability on health-related quality of life outcomes in irritable bowel syndrome: an arm-based network meta-analysis

OBJECTIVES

The impact of placebo response on health outcomes in various diseases, including IBS, is significant. To better understand the effect of different placebo administration methods on the observed outcomes in IBS studies, this meta-analysis aims to explore research findings on the degree of improvement.

METHODS

The meta-analysis included 45 randomized, double-blind, placebo-controlled clinical trials involving 5174 patients with confirmed IBS (excluding those with significant comorbidities). The trials were designed to compare the efficacy of different placebo interventions. The primary outcome was the Irritable Bowel Syndrome Severity Scoring System (IBS-SSS), and secondary outcomes included the Irritable Bowel Syndrome Quality of Life Instrument (IBS-QoL) and the IBS Symptom Visual Analog Scale (VAS). An arm-based Bayesian network meta-analysis was performed to examine the relative effectiveness of the placebo interventions on the outcomes.

RESULTS

The analysis revealed that sham moxibustion exhibited the most significant efficacy in reducing IBS-SSS (MD -260.00, 95% CrIs: -288.00 to -232.00). Additionally, sham FMT resulted in significant improvements in IBS-QOL scores (MD 9.23, 95% CrIs - 3.69 to 22.30). Meanwhile, placebo tablet interventions were found to be the most effective in reducing VAS scores (MD 4.71, 95% CrIs, -1.14 to 11.10). Overall, this synthesis provides detailed insights into the effectiveness of placebos in addressing different outcome measures.

CONCLUSIONS

Sham moxibustion appears to provide subjective benefits for patients' IBS symptoms. However, the evidence for its efficacy is less robust compared to other interventions, as assessed by GRADE. Understanding the placebo effect in IBS management is crucial for clinical practice and drug development, particularly in placebo comparisons.

REGISTRATION ID

INPLASY2024110111. https://doi.org/10.37766/inplasy2024.11.0111 .

Chinese herbal formula Tongxie Yaofang granules for diarrhoea-predominant irritable bowel syndrome: a randomised, double-blind, placebo-controlled, phase II trial

OBJECTIVES

To assess the therapeutic effects and safety of Tongxie Yaofang (TXYF) granules vs placebo as an alternative treatment for diarrhoea-predominant irritable bowel syndrome (IBS-D). We hypothesised that TXYF would improve clinical responses among patients with IBS-D.

DESIGN

A randomised, double-blind, placebo-controlled, phase II, superiority trial.

SETTING

Outpatients attending the Fangshan Hospital, Beijing University of Chinese Medicine, Beijing, China.

PARTICIPANTS

96 eligible participants included men and women ranging from late adolescence to middle adulthood (18-65 years), diagnosed with IBS-D according to the Rome IV criteria. In addition, they were required to have an irritable bowel syndrome symptom severity score (IBS-SSS) of at least 75.

INTERVENTIONS

TXYF granules (3.7 g) twice daily (taken orally before meals) or placebo for 8 weeks.

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was the response rate measured by the change in IBS-SSS compared with baseline at week 8. Secondary outcomes included stool frequency; stool consistency at weeks 4, 8 and 20; and quality of life, anxiety and depression at week 8; and safety was monitored throughout the trial.

RESULTS

The TXYF and placebo groups each comprised 48 participants. The response rate was not significantly different at week 8 between the two groups (the unadjusted treatment effect estimate (intention-to-treat analysis) was 1.12 (95% CI (0.89, 1.41)), p=0.348). Both groups had a high and similar rate of symptom reduction (79.2% (38/48) vs 70.8% (34/48)). There were no statistically significant differences between the two groups on secondary outcomes, although both groups showed substantial improvements. Adverse events in the TXYF and placebo groups were one (sinus arrhythmia) and two (elevated transaminases, weakly positive faecal occult blood), respectively. No serious adverse events occurred.

CONCLUSIONS

Despite showing clinically meaningful improvements in IBS-D symptoms and a reasonable safety profile after 8 weeks, no significant differences were observed between the TXYF and placebo groups. This suggests that the severity of IBS-D symptoms in both treatment arms might have decreased over time, regardless of the treatment, and highlights the need to investigate the relationship between IBS-D and patient psychology. Future large-scale, rigorously designed trials with longer treatment and follow-up periods are essential to evaluate the therapeutic effects and safety of TXYF, and to explore the psychological factors.

TRIAL REGISTRATION NUMBER

ISRCTN12453166.

Patient-Reported Outcomes in Disorders of Gut-Brain Interaction

Disorders of gut-brain interaction are characterized by chronic gastrointestinal symptoms in the absence of abnormal endoscopic or radiologic findings or objective biomarkers that can be identified during routine clinical evaluation. The assessment of the symptom pattern and severity, therefore, is the key modality to evaluate the presence, impact, and evolution of these conditions, for both clinical and regulatory purposes. Patient-reported outcomes are structured symptom assessment questionnaires designed to evaluate symptom patterns, quantify severity of symptoms, and evaluate response to treatment at follow-up. This review provides an overview of currently available patient-reported outcomes for evaluating the main disorders of gut-brain interaction, specifically, functional dyspepsia; irritable bowel syndrome; and chronic constipation. It summarizes their content, level of validation for clinical practice and for research, and the regulatory approach to these conditions. Expected future developments and need for further research on patient-reported outcomes for these and other disorders of gut-brain interaction are highlighted.

Irritable bowel syndrome (IBS): could we decide what is behind?

Functional visceral problems are frequently present nowadays in the medical practice probably due to the significant mental and emotional load on people. Although physicians and psychophysiologists are active on the field, still we are far from a complete knowledge, despite the fact that scientists like the Hungarian Professor György Ádám already had initiated a new approach called visceral psychophysiology already a long time ago. In this article, we commemorate Professor Ádám by analyzing one of the most frequent functional disorders, irritable bowel syndrome (IBS), calling psychophysiology for help. First, we try to give a definition, then show the general descriptions and characteristics of IBS. Factors like stress, gender, and gastrointestinal pain are followed by the potential role of the immune system and the neuronal factors as well as the supposed brain mechanisms. We hope that this overview of the IBS-history would show how significant scientists can be decisive in certain fields of the science and practice.

Oral and parenteral anti-neuropathic agents for the management of pain and discomfort in irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a highly prevalent and economically burdensome condition; and pain is often the most unpleasant, disruptive, and difficult-to-treat symptom. Visceral hypersensitivity is a common feature driving pain in IBS, suggesting that neuropathic mechanisms may be implicated. We conducted a systematic review of available evidence to examine the role of anti-neuropathic medicines in the management of pain in IBS.

METHODS

We systematically searched scientific repositories for trials investigating conventional oral, and/or parenteral, pharmaceutical antineuropathic treatments in patients with IBS. We summarized key participant characteristics, outcomes related to pain (primary outcome), and selected secondary outcomes.

KEY RESULTS

We included 13 studies (n = 629 participants): six investigated amitriptyline, three duloxetine, three pregabalin, and one gabapentin. There was considerable methodological and statistical heterogeneity, so we performed a narrative synthesis and limited meta-analysis. Amitriptyline was most extensively studied, though only in diarrhea-predominant patients. In individual trials, amitriptyline, pregabalin and gabapentin generally appeared beneficial for pain outcomes. While duloxetine studies tended to report improvements in pain, all were un-controlled trials with high risk of bias. Meta-analysis of three studies (n = 278) yielded a pooled relative-risk of 0.50 (95%CI 0.38-0.66) for not improving with anti-neuropathic agent vs control. We did not identify any eligible studies investigating the role of parenteral anti-neuropathics.

CONCLUSIONS AND INFERENCES

Anti-neuropathic analgesics may improve pain in IBS, and deserve further, high-quality investigation, potentially considering parenteral administration and agents with minimal gastrointestinal motility effects. Investigation of amitriptyline's efficacy in non-diarrhea-predominant subtypes is currently lacking, and we recommend particular caution for its use in IBS-C.

Placebo Responses and Placebo Effects in Functional Gastrointestinal Disorders

Much has been written about the placebo effects in functional gastrointestinal disorders (FGD), especially in irritable bowel syndrome (IBS), driven by the early hypothesis that in randomized controlled trials (RCTs) of IBS, the placebo effect might be specifically high and thus, corrupts the efficacy of novel drugs developed for this condition. This narrative review is based on a specific search method, a database (www.jips.online) developed since 2004 containing more than 4,500 papers (data papers, meta-analyses, systematic reviews, reviews) pertinent to the topic placebo effects/placebo response. Three central questions-deducted from the body of current literature-are addressed to explore the evidence behind this hypothesis: What is the size placebo effect in FGD, especially in IBS, and is it different from the placebo effect seen in other gastrointestinal disorders? Is the placebo effect in FGD different from other functional, non-intestinal disorders, e.g. in other pain syndromes? Is the placebo effect in FGD related to placebo effects seen in psychiatry, e.g. in depression, anxiety disorders, and alike? Following this discussion, a fourth question is raised as the result of the three: What are the consequences of this for future drug trials in FGD? In summary it is concluded that, contrary to common belief and discussion, the placebo effect seen in RCT in FGD is not specifically high and extraordinary as compared to other comparable (i.e. functional) disorders. It shares less than expected commonalities with the placebo effect in psychiatry, and very few predictors have yet been identified that determine its effect size, especially some that are driven by design features of the studies. Current practice of RCT in IBS seems to limit and control the placebo effect quite well, and future trial practice, e.g. head-to-head trial, still offers options to maintain this control, even in the absence of placebos used.

Western herbal medicines in the treatment of irritable bowel syndrome: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of Western herbal medicines in the treatment of irritable bowel syndrome (IBS).

DESIGN

A computer-based search of MEDLINE, EMBASE, CINAHL, AMED, GreenFILE, Health Source: Nursing/Academic Edition, and the Cochrane Library was conducted. A hand-search of the bibliographies of relevant papers and previous meta-analyses and reviews was also undertaken. Trials were included in the review if they were double-blind and placebo-controlled investigating the effects of Western herbal medicines on IBS-related symptoms or quality of life. There were no language restrictions. Eligibility assessment and data extraction were performed by two independent researchers. For herbal medicines where there was more than 1 trial of similar design, data were synthesised using relative risk of symptoms improving using the random effects model.

RESULTS

Thirty-three trials were identified that met all eligibility criteria. Seventeen of these evaluated peppermint essential oil, fifteen other Western herbal medicines, and one trial evaluated peppermint oil in one arm and aniseed essential oil in the other arm. Eighteen different herbal preparations were evaluated in these trials. Data suggests that a number of Western herbal medicines may provide relief of IBS symptoms. Meta-analyses suggest that peppermint essential oil is both efficacious and well-tolerated in the short-term management of IBS. Aloe vera and asafoetida also demonstrated efficacy in reducing global IBS symptoms in meta-analyses. The herbal formulas STW 5, STW 5-II and Carmint, along with Ferula assa-foetida, Pimpenella anisum oil, the combination of Curcumin and Foeniculum vulgare oil, and the blend of Schinopsis lorentzii, Aesculus hippocastanum, and peppermint essential oil also demonstrated efficacy in rigorously-designed clinical trials.

CONCLUSION

A number of Western herbal medicines show promise in the treatment of IBS. With the exception of peppermint essential oil, Aloe vera, and asafoetida, however, none of the positive trials have been replicated. This lack of replication limits the capacity to make definitive statements of efficacy for these herbal medicines.

Increased Functional Foods' Consumption and Mediterranean Diet Adherence May Have a Protective Effect in the Appearance of Gastrointestinal Diseases: A Case⁻Control Study

Background: Epidemiological studies have suggested a possible correlation between nutritional factors and gastrointestinal diseases. Methods: A case–control study was designed in order to investigate if functional foods consumption and Mediterranean diet adherence have a positive effect in ulcerative colitis, Crohn’s disease, irritable bowel syndrome, and gastroesophageal reflux disease. In total, 142 patients (cases) and 147 gender-matched healthy people (controls) participated in the study. Functional food consumption was screened by using a Food Frequency Questionnaire based on the NHANES study, while Mediterranean diet adoption was evaluated by a 14-item Med Diet Assessment tool based on the PREDIMED study. The statistical analysis was performed with SPSS-22. Results: In the previous 2–3 years, the controls had more frequently consumed some categories (probiotics, prebiotics-enriched, and low-fat foods) and some kinds of functional foods (mountain tea, berries, pomegranate, oats, mastics, turmeric, soybeans, and raisins) compared to the cases (p < 0.05). Healthy people were more adherent to the Mediterranean diet than patients (p < 0.05). A multifactor analysis showed that the augmented score of the Mediterranean diet and the augmented consumption of categories and kinds of functional foods were protective factors in the appearance of gastrointestinal diseases. Conclusions: More studies should be conducted in order to further investigate the possible association between specific food components and gastrointestinal diseases’ pathophysiology.

Alosetron versus traditional pharmacotherapy in clinical practice: effects on resource use, health-related quality of life, safety and symptom improvement in women with severe diarrhea-predominant irritable bowel syndrome

OBJECTIVE

Severe diarrhea-predominant irritable bowel syndrome (IBS-D) is associated with decreased health-related quality of life (HRQOL) and increased health care costs. Treatment recommendations for IBS-D often start with traditional pharmacotherapy (TP), with escalation to alosetron, rifaximin or eluxadoline if there is no success. There has been no previous head-to-head clinical trial comparing IBS-D treatment outcome for alosetron versus TP. This study, GSK protocol S3B30020, evaluated resource use, work productivity, health-related quality of life and global symptom response in women with IBS-D who were treated with alosetron or TP.

METHODS

A total of 1956 patients who met criteria for severe IBS-D were randomized to treatment with alosetron 1 mg twice daily (BID) or only TP for up to 24 weeks. Work productivity and resource use were evaluated by standard questionnaires, HRQOL by the IBSQOL instrument and IBS symptoms by the Global Improvement Scale (GIS).

RESULTS

Compared to only TP, alosetron-treated patients reported: (1) fewer clinic/office visits for any health problem (p = .0181) or for IBS-D (p = .0004); (2) reduced use of over-the-counter medications for IBS-D (p < .0001); (3) fewer days of lost work productivity (p < .0001); (4) decreased restriction of social and outdoor activities (p < .0001); and (5) greater global improvement in IBS-D symptoms (p < .0001). Alosetron treatment improved HRQOL scores for all domains (p < .0001). Incidence of adverse events during alosetron use was not remarkable and was similar to that previously reported.

CONCLUSIONS

Alosetron 1 mg BID significantly reduced health care utilization and lost productivity, and significantly improved global IBS symptoms, HRQOL, and participation in outdoor and social activities compared with treatment response to TP.

Functional Gastrointestinal Disorders: History, Pathophysiology, Clinical Features and Rome IV

Functional gastrointestinal disorders (FGIDs), the most common diagnoses in gastroenterology are recognized by morphological and physiological abnormalities that often occur in combination including motility disturbance, visceral hypersensitivity, altered mucosal and immune function, altered gut microbiota and altered central nervous system processing. Research on these gut-brain interaction disorders is based on using specific diagnostic criteria. The Rome Foundation has played a pivotal role in creating diagnostic criteria thus operationalizing the dissemination of new knowledge in the field of FGIDs. Rome IV is a compendium of the knowledge accumulated since Rome III was published 10 years ago. It improves upon Rome III by: 1) updating the basic and clinical literature, 2) offering new information on gut microenvironment, gut-brain interactions, pharmacogenomics, biopsychosocial, gender and cross cultural understandings of FGIDs, 3) reduces the use of imprecise and occassionally stigmatizing terms when possible, 4) uses updated diagnostic algorithms, 5) incorporates information on the patient illness experience, and physiological subgroups or biomarkers that might lead to more targeted treatment. This introductory article sets the stage for the remaining 17 articles that follow and offers an historical overview of the FGIDs field, differentiates FGIDs from motility and structural disorders, discusses the changes from Rome III, reviews the Rome committee process, provides a biopsychosocial pathophysiological conceptualization of FGIDs, and offers an approach to patient care.

The role of fiber supplementation in the treatment of irritable bowel syndrome: a systematic review and meta-analysis

Irritable bowel syndrome (IBS) is a functional bowel disorder associated with a wide variety of clinical symptoms. The use of fiber in treatment of IBS is well established, but recent reviews have shown conflicting evidence. The aim of our review was to study the effects of fiber (soluble and insoluble) on the symptoms of IBS. Medline, EMBASE, Cochrane Central, CINAHL, LILACS, and ClinicalTrials.gov were searched for appropriate studies. Two reviewers screened the title/abstract and full text against the inclusion criterion - that is, randomized control trials/crossover studies that compare fiber with placebo for its effect on IBS in an outpatient setting. Independent double data extraction was performed across multiple fields. An assessment of the risk of bias and tests for heterogeneity were carried out, along with a meta-analysis of the outcomes of interest. The search yielded 4199 unique records: 121 were selected after title/abstract screening and 22 after full screening. There was moderate clinical, methodological, and statistical heterogeneity across studies, with a moderate risk of bias. Overall, there was a significant improvement in global assessment of symptoms among those randomized to fiber [risk ratio: 1.27; 95% confidence interval (CI): 1.05-1.54]. Soluble fiber improved assessment of symptoms (risk ratio 1.49; 95% CI: 1.09-2.03), as well as the abdominal pain score (mean difference: -1.84; 95% CI: -2.72 to -0.97), with insoluble fiber not showing improvement in any outcome. Soluble fiber appears to improve symptoms of IBS, whereas there is no evidence for recommending insoluble fiber for IBS.

Small Amounts of Gluten in Subjects With Suspected Nonceliac Gluten Sensitivity: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Trial

BACKGROUND & AIMS

There is debate over the existence of nonceliac gluten sensitivity (NCGS) intestinal and extraintestinal symptoms in response to ingestion of gluten-containing foods by people without celiac disease or wheat allergy. We performed a randomized, double-blind, placebo-controlled, cross-over trial to determine the effects of administration of low doses of gluten to subjects with suspected NCGS.

METHODS

We enrolled 61 adults without celiac disease or a wheat allergy who believed ingestion of gluten-containing food to be the cause of their intestinal and extraintestinal symptoms. Participants were assigned randomly to groups given either 4.375 g/day gluten or rice starch (placebo) for 1 week, each via gastrosoluble capsules. After a 1-week gluten-free diet, participants crossed over to the other group. The primary outcome was the change in overall (intestinal and extraintestinal) symptoms, determined by established scoring systems, between gluten and placebo intake. A secondary outcome was the change in individual symptom scores between gluten vs placebo.

RESULTS

According to the per-protocol analysis of data from the 59 patients who completed the trial, intake of gluten significantly increased overall symptoms compared with placebo (P = .034). Abdominal bloating (P = .040) and pain (P = .047), among the intestinal symptoms, and foggy mind (P = .019), depression (P = .020), and aphthous stomatitis (P = .025), among the extraintestinal symptoms, were significantly more severe when subjects received gluten than placebo.

CONCLUSIONS

In a cross-over trial of subjects with suspected NCGS, the severity of overall symptoms increased significantly during 1 week of intake of small amounts of gluten, compared with placebo. Clinical trial no: ISRCTN72857280.

Placebo effects and their determinants in gastrointestinal disorders

Placebo effects in clinical trials have sparked an interest in the placebo phenomenon, both in randomized controlled trials (RCTs) and in experimental gastroenterology. RCTs have demonstrated similar short-term and long-term placebo response rates in gastrointestinal compared to other medical diagnoses. Most mediators and moderators of placebo effects in gastrointestinal diseases are also of similar type and size to other medical diagnoses and not specific for gastrointestinal diagnoses. Other characteristics such as an increase in the placebo response over time and the placebo-enhancing effects of unbalanced randomization were not seen, at least in IBS. Experimental placebo and nocebo studies underscore the 'power' of expectancies and conditioning processes in shaping gastrointestinal symptoms not only at the level of self-reports, but also within the brain and along the brain-gut axis. Brain imaging studies have redressed earlier criticism that placebo effects might merely reflect a response bias. These findings raise hope that sophisticated trials and experiments designed to boost positive expectations and minimize negative expectations could pave the way for a practical and ethically sound use of placebo knowledge in daily practice. Rather than focusing on a 'personalized' choice of drugs based on biomarkers or genes, it might be the doctor-patient communication that needs to be tailored.

Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and meta-analysis

GOALS

The aim of this study was to assess the efficacy and safety of enteric-coated peppermint oil capsules compared with placebo for the treatment of active irritable bowel syndrome (IBS).

BACKGROUND

IBS is a common disorder that is often encountered in clinical practice. Medical interventions are limited and the focus is on symptom control.

STUDY

Randomized placebo-controlled trials with a minimum treatment duration of 2 weeks were considered for inclusion. Cross-over studies that provided outcome data before the first cross-over were included. A literature search upto February 2013 identified all applicable randomized-controlled trials. Study quality was evaluated using the Cochrane risk of bias tool. Outcomes included global improvement of IBS symptoms, improvement in abdominal pain, and adverse events. Outcomes were analyzed using an intention-to-treat approach.

RESULTS

Nine studies that evaluated 726 patients were identified. The risk of bias was low for most of the factors assessed. Peppermint oil was found to be significantly superior to placebo for global improvement of IBS symptoms (5 studies, 392 patients, relative risk 2.23; 95% confidence interval, 1.78-2.81) and improvement in abdominal pain (5 studies, 357 patients, relative risk 2.14; 95% confidence interval, 1.64-2.79). Although peppermint oil patients were significantly more likely to experience an adverse event, such events were mild and transient in nature. The most commonly reported adverse event was heartburn.

CONCLUSIONS

Peppermint oil is a safe and effective short-term treatment for IBS. Future studies should assess the long-term efficacy and safety of peppermint oil and its efficacy relative to other IBS treatments including antidepressants and antispasmodic drugs.

Randomised clinical trial: gluten may cause depression in subjects with non-coeliac gluten sensitivity - an exploratory clinical study

BACKGROUND

Current evidence suggests that many patients with self-reported non-coeliac gluten sensitivity (NCGS) retain gastrointestinal symptoms on a gluten-free diet (GFD) but continue to restrict gluten as they report 'feeling better'.

AIM

To investigate the notion that a major effect of gluten in those with NCGS is on mental state and not necessarily on gastrointestinal symptoms.

METHODS

Twenty-two subjects (24-62 years, five male) with irritable bowel syndrome who had coeliac disease excluded but were symptomatically controlled on a GFD, undertook a double-blind cross-over study. Participants randomly received one of three dietary challenges for 3 days, followed by a minimum 3-day washout before crossing over to the next diet. Challenge gluten-free food was supplemented with gluten (16 g/day), whey (16 g/day) or not supplemented (placebo). End-points included mental state as assessed by the Spielberger State Trait Personality Inventory (STPI), cortisol secretion and gastrointestinal symptoms.

RESULTS

Gluten ingestion was associated with higher overall STPI state depression scores compared to placebo [M = 2.03, 95% CI (0.55-3.51), P = 0.010] but not whey [M = 1.48, 95% CI (-0.14 to 3.10), P = 0.07]. No differences were found for other STPI state indices or for any STPI trait measures. No difference in cortisol secretion was identified between challenges. Gastrointestinal symptoms were induced similarly across all dietary challenges.

CONCLUSIONS

Short-term exposure to gluten specifically induced current feelings of depression with no effect on other indices or on emotional disposition. Gluten-specific induction of gastrointestinal symptoms was not identified. Such findings might explain why patients with non-coeliac gluten sensitivity feel better on a gluten-free diet despite the continuation of gastrointestinal symptoms.

Randomized clinical trial: effect of Lactobacillus plantarum 299 v on symptoms of irritable bowel syndrome

OBJECTIVES

Irritable bowel syndrome (IBS) is a common diagnosis in gastroenterology. Its etiology is unknown and therapeutic options limited. Trials suggest probiotics may be beneficial. The aim of this study was to assess the symptomatic efficacy of Lactobacillus plantarum 299 v (L. plantarum 299 v) for the relief of abdominal pain in patients with IBS fulfilling Rome II criteria.

METHODS

This study was conducted in a referral hospital. Trial participants were randomized to receive either two capsules of L. plantarum 299 v at a dosage of 5 × 10(9) cfu per capsule or placebo daily for 8 wk. Severity of abdominal pain was assessed using a visual analog scale at each visit and a quality-of-life IBS (QoL-IBS) questionnaire was also completed.

RESULTS

There was no significant difference in abdominal pain relief between the study and placebo groups (P = 0.800). There was also no difference in QoL- IBS scores between the groups (P = 0.687). Both groups had a significant improvement in abdominal pain scores over the study period, from an average of 251.55 to 197.90 (P < 0.0001) indicating a large placebo effect.

CONCLUSION

An 8-wk treatment with L. plantarum 299 v did not provide symptomatic relief, particularly of abdominal pain and bloating, in patients fulfilling the Rome II criteria.

Efficacy and safety of drotaverine hydrochloride in irritable bowel syndrome: a randomized double-blind placebo-controlled study

BACKGROUNDS/AIMS

To study the efficacy and safety of drotaverine hydrochloride (HCl) 80 mg tablet given thrice a day in the symptomatic relief of patients with irritable bowel syndrome (IBS).

PATIENTS AND METHODS

The study was a multicentric, randomized, double-blind, placebo-controlled parallel group study performed at three centers. The patients who fulfilled Rome II Criteria of IBS were included in the study. A total of 180 patients with IBS were randomized to drotaverine and placebo treatment groups. Abdominal pain and stool frequency were measured every week in both the groups for all the 4 weeks of treatment duration. Subject Global Assessment of Relief (SGA) of IBS symptoms was assessed at the end of the study. Appropriate statistical analysis was done using SPSS software.

STATISTICAL ANALYSIS USED

Mann-Whitney U-test (two-tailed), Wilcoxon signed ranks test, and McNemar tests.

RESULTS

Pain frequency decreased significantly (P < 0.01) in 22 (25.9%), 51 (60%), and 66 (77.7%) patients in the drotaverine group, at the end of 2nd, 3rd, and 4th weeks, respectively, as compared with 8 (9.4%), 18 (21.2%), and 26 (30.6%) in the placebo group. Pain severity scores also decreased significantly in the drotaverine group 66 (77.7%) as compared with placebo 26 (30.6%) after 4 weeks. Drotaverine HCl was shown to provide significant improvement (P < 0.01) in global relief in abdominal pain as perceived by the patient (85.9% vs 39.5%) and the clinician (82.4% vs 36.5%) in the drotaverine group as compared with placebo. There is significant (P < 0.01) improvement in stool frequency in drotaverine HCl treatment group as compared with placebo. The drug is well tolerated without any major side effects.

CONCLUSIONS

A 4-week treatment with drotaverine significantly improves abdominal symptoms in patients with IBS.

Efficacy and Safety of Tiropramide in the Treatment of Patients With Irritable Bowel Syndrome: A Multicenter, Randomized, Double-blind, Non-inferiority Trial, Compared With Octylonium

Background/Aims

Antispasmodics such as octylonium are widely used to manage irritable bowel syndrome (IBS) symptoms. However, the efficacy and safety of another antispasmodic, tiropramide, remain uncertain. We aimed to evaluate the efficacy and safety of tiropramide compared with octylonium in patients with IBS.

Methods

In this multicenter, randomized, non-inferiority trial, 287 patients with IBS (143 receiving tiropramide and 144 octylonium) were randomly allocated to either tiropramide 100 mg or octylonium 20 mg t.i.d (means 3 times a day) for 4 weeks. Primary endpoint was the mean change of abdominal pain from baseline assessed by visual analogue scales (VAS) score after 4 weeks of treatment. Secondary endpoints were the changes in abdominal pain from baseline at week 2 and in abdominal discomfort at weeks 2 and 4, using VAS scores, patient-reported symptom improvement including stool frequency and consistency, using symptom diaries, IBS-quality of life (IBS-QoL), and depression and anxiety, at week 4.

Results

The VAS scores of abdominal pain at week 4, were significantly decreased in both tiropramide and octylonium groups, but the change from baseline did not differ between the 2 groups (difference,-0.26 mm; 95% CI,-4.33-3.82; P = 0.901). Abdominal pain and discomfort assessed using VAS scores, diaries, and IBS-QoL were also improved by both treatments, and the changes from baseline did not differ. The incidence of adverse events was similar in the 2 groups, and no severe adverse events involving either drug were observed.

Conclusions

Tiropramide is as effective as octylonium in managing abdominal pain in IBS, with a similar safety profile.

Stress reactivity in traditional Chinese medicine-based subgroups of patients with irritable bowel syndrome

OBJECTIVES

This study aimed to examine differences in autonomic responses to stress, pain perception, and the role of negative affect in these responses in individuals with irritable bowel syndrome (IBS) according to Traditional Chinese Medicine (TCM) classifications.

DESIGN

Fifty-nine female patients with IBS age 18-65 years diagnosed by TCM practitioners as showing primarily an excess (n=32) or an overlap (n=27) pattern (mixed excess and deficiency) were assessed for symptom differences, heart rate, and skin conductance responses to a psychosocial stressor and pain perception. SETTINGS/LOCATIONS: University of California in Los Angeles, California.

RESULTS

Compared with the excess group, the overlap group showed significantly greater overall gastrointestinal symptom severity, abdominal pain, and negative affect. The excess group with higher levels of negative affect showed greater reactivity to stress, whereas the overlap group showed an opposite response pattern. The overlap group showed increased cold sensitivity.

CONCLUSIONS

IBS patients with the overlap pattern have greater disease severity and comorbidity than those with excess alone. Those with excess showed a pattern of increased stress response with greater negative affect, whereas the overlap group with greater deficiency showed lower physiologic arousal with greater negative affect, consistent with depletion resulting from allostatic load.

No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates

BACKGROUND & AIMS

Patients with non-celiac gluten sensitivity (NCGS) do not have celiac disease but their symptoms improve when they are placed on gluten-free diets. We investigated the specific effects of gluten after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates (fermentable, oligo-, di-, monosaccharides, and polyols [FODMAPs]) in subjects believed to have NCGS.

METHODS

We performed a double-blind cross-over trial of 37 subjects (aged 24-61 y, 6 men) with NCGS and irritable bowel syndrome (based on Rome III criteria), but not celiac disease. Participants were randomly assigned to groups given a 2-week diet of reduced FODMAPs, and were then placed on high-gluten (16 g gluten/d), low-gluten (2 g gluten/d and 14 g whey protein/d), or control (16 g whey protein/d) diets for 1 week, followed by a washout period of at least 2 weeks. We assessed serum and fecal markers of intestinal inflammation/injury and immune activation, and indices of fatigue. Twenty-two participants then crossed over to groups given gluten (16 g/d), whey (16 g/d), or control (no additional protein) diets for 3 days. Symptoms were evaluated by visual analogue scales.

RESULTS

In all participants, gastrointestinal symptoms consistently and significantly improved during reduced FODMAP intake, but significantly worsened to a similar degree when their diets included gluten or whey protein. Gluten-specific effects were observed in only 8% of participants. There were no diet-specific changes in any biomarker. During the 3-day rechallenge, participants' symptoms increased by similar levels among groups. Gluten-specific gastrointestinal effects were not reproduced. An order effect was observed.

CONCLUSIONS

In a placebo-controlled, cross-over rechallenge study, we found no evidence of specific or dose-dependent effects of gluten in patients with NCGS placed diets low in FODMAPs.

Treatment of diverticular disease of the colon and prevention of acute diverticulitis: a systematic review

BACKGROUND

Diverticular disease of the colon is a common disorder, characterized by recurrent symptoms and complications such as diverticulitis, requiring hospital admissions and surgery.

OBJECTIVE

This study aimed to systematically review the evidence for medical therapy of diverticular disease in reducing symptoms and preventing acute diverticulitis.

DATA SOURCES

MEDLINE and Embase databases (1966 to February 2010).

STUDY SELECTION

The studies selected were prospective clinical trials on uncomplicated diverticular disease of the colon.

INTERVENTIONS

Four investigators independently reviewed articles, extracted data, and assessed study quality according to standardized criteria.

MAIN OUTCOME MEASURES

The main outcomes measured were improvement in symptoms, complete remission of symptoms, and prevention of acute diverticulitis.

RESULTS

We identified 31 studies, including 6 placebo-controlled trials. The methodological quality of these studies was suboptimal. Only 10 trials provided a detailed description of the patient history, 8 assessed symptoms by the use of a validated questionnaire, and 14 appropriately defined inclusion and exclusion criteria. Only one long-term double-blind placebo-controlled study was identified. This reported a significant improvement in symptoms and greater prevalence of symptom-free patients at 1 year with fiber plus rifaximin in comparison with fiber alone. The efficacy of treatment in preventing acute diverticulitis was evaluated in 11 randomized trials. Four trials compared rifaximin plus fiber vs fiber alone and failed to show a significant difference between treatments. However, cumulative data from these trials revealed a significant benefit following rifaximin and fiber (1-year rate of acute diverticulitis: 11/970 (1.1%) vs 20/690 (2.9%); P = .012), but with a number needed to treat of 57, to prevent an attack of acute diverticulitis.

LIMITATIONS

: Heterogeneity of the study design, patients' characteristics, regimens and combination of studied treatment, and outcome reporting precluded the pooling of results and limited interpretation.

CONCLUSIONS

The treatment for diverticular disease relies mainly on data from uncontrolled studies. Treatment showed some evidence of improvement in symptoms, but its role in the prevention of acute diverticulitis remains to be defined.

Effects of two natural medicine formulations on irritable bowel syndrome symptoms: a pilot study

OBJECTIVE

The study objective was to assess the effects and tolerability of two novel natural medicine formulations in improving bowel habit and abdominal symptoms in patients with irritable bowel syndrome (IBS). The DA-IBS formula was designed to treat diarrhea-predominant and alternating bowel habit IBS, and the C-IBS formula was designed to treat constipation-predominant IBS.

DESIGN

This was a two arm, open-label, uncontrolled pilot study.

SETTINGS/LOCATION

Subjects were recruited from the greater Lismore area (NSW, Australia) in 2001.

SUBJECTS

The study included 31 patients who fulfilled the Rome II criteria for IBS. Twenty-one (21) patients were classified as suffering from diarrhea-predominant or alternating bowel habit IBS and 10 patients were classified with constipation-predominant IBS.

INTERVENTIONS

The DA-IBS formula consisted of a mixture of dried, powdered bilberry fruit, slippery elm bark, agrimony aerial parts, and cinnamon quills. The C-IBS formula consisted of a mixture of dried powdered slippery elm bark, lactulose, oat bran, and licorice root. The aim of each formula was to normalize stool frequency and stool consistency.

RESULTS

Ingestion of the DA-IBS formula was associated with a small, but significant increase in bowel movement frequency (p = 0.027). Subjects in the DA-IBS group also experienced reductions in straining (p = 0.004), abdominal pain (p = 0.006), bloating (p < 0.0001), flatulence (p = 0.0001), and global IBS symptoms (p = 0.002) during the treatment phase of the trial. Subjects in the C-IBS group experienced a 20% increase in bowel movement frequency (p = 0.016) and significant reductions in straining (p < 0.0001), abdominal pain (p = 0.032), bloating (p = 0.034), and global IBS symptom severity (p = 0.0005), as well as improvements in stool consistency (p < 0.0001). Both formulas were well-tolerated.

CONCLUSIONS

The DA-IBS formula was not effective in improving bowel habit in individuals with diarrhea-predominant or alternating bowel habit IBS, although it did significantly improve a number of IBS symptoms. The C-IBS formula significantly improved both bowel habit and IBS symptoms in patients with constipation-predominant IBS. Further research is warranted on C-IBS, as a potentially useful therapeutic formula.

Review article: endpoints used in functional dyspepsia drug therapy trials

BACKGROUND

The measurement of patient-reported outcomes (PRO) in treatment trials for functional gastrointestinal disorders is a matter of controversy.

AIM

To focus on instruments and endpoints that have been used to evaluate the efficacy of therapeutic agents in functional dyspepsia (FD) trials, also considering the newly defined Rome III FD criteria.

METHODS

A Medline search was conducted to identify relevant studies pertaining to FD treatment, with particular emphasis on the studies to date which have used validated outcome measures.

RESULTS

Currently available outcome measures are heterogeneous across studies. They include global binary endpoints, analogue or categorical scoring scales, uni- or multi-dimensional disease specific questionnaires, global outcome evaluations and quality of life questionnaires. Across the available outcome measures, substantial heterogeneity is found, not only in the type of endpoint measure, but also in the number and types of symptoms that are considered to be part of the FD symptom complex. Especially based on content validity, none of the existing questionnaires or endpoints can be considered sufficiently validated to be recommended unequivocally as the primary outcome measure for FD trials according to the Rome III criteria. On the other hand, existing well-validated multi-dimensional questionnaires that include many non-FD symptoms can be narrowed down to evaluate only the cardinal symptoms according to Rome III.

CONCLUSIONS

There is an urgent need to develop Rome III-based patient-reported outcomes for functional dyspepsia. Well-validated multi-dimensional questionnaires may serve as a guidance for this purpose, and could also be considered for use in ongoing clinical trials.

A Randomised, Cross-Over, Placebo-Controlled Study of Aloe vera in Patients with Irritable Bowel Syndrome: Effects on Patient Quality of Life

Background. Irritable bowel syndrome (IBS) is a chronic, difficult to treat condition. The efficacy of Aloe vera in treating IBS symptoms is not yet proven. The purpose of this study was to determine if Aloe vera is effective in improving quality of life. Methods. A multicentre, randomised, double-blind, cross-over placebo controlled study design. Patients were randomised to Aloe vera, wash-out, placebo or placebo, washout, Aloe vera. Each preparation (60 mL) was taken orally twice a day. Patient quality of life was measured using the Gastrointestinal Symptoms Rating Score, Irritable Bowel Syndrome Quality of Life, EuroQol and the Short-Form-12 at baseline and treatment periods 1 and 2. Results. A total of 110 patients were randomised, but only 47 completed all questionnaires and both study arms. Statistical analysis showed no difference between the placebo and Aloe vera treatment in quality of life. Discussion. This study was unable to show that Aloe vera was superior to placebo in improving quality of life. Drop outs and other confounding factors may have impacted on the power of the study to detect a clinically important difference. Conclusion. This study failed to find Aloe vera superior to placebo in improving quality of life proven Irritable Bowel Syndrome patients.

Treatment of irritable bowel syndrome using complementary and alternative medicine

The therapeutic objectives for irritable bowel syndrome (IBS) patients are to improve their functioning in society. Accordingly, recommended management is to develop a logical strategy including a positive diagnosis, consideration of the patient's agenda and emotional state, critical appraisal of the efficacies of various drugs and a graded therapeutic response. Unfortunately, none of the currently available drugs (e.g. antispasmodics, antidiarrheals, osmotics, cathartics, bulking agents, tranquilizers, sedatives) are globally effective in treating all IBS symptoms, and the advanced receptor-targeted drugs are not always successfully and safely marketed. Consequently, more than half of patients may seek complementary and alternative medicine (CAM) to treat the annoying bowel symptoms. Physicians have considered these CAM measures to have an "enhanced placebo effect". For example, many herbal medicine and plant products are globally used to treat IBS, whereas their efficacies are often inconclusive because of small sample sizes, inadequate data analyses and lack of standardized preparations. Meta-analyses do not establish their true efficacy. Acupuncture has long been employed by patients themselves to treat functional gastrointestinal disorders with satisfactory response, but its effect on IBS does not seem to be promising. Peppermint oil, melatonin and clay-like materials are effective in treating some IBS symptoms, while their true pharmacology remains enigmatic. In conclusion, IBS treatment is usually tailored to the individual's manifestations, ranging from reassurance to psychotherapy. Apart from conventional medications, CAM may be considered individually as a supplement or alternative to treat IBS patients that is at least equal in effect to placebo if patients do not exhibit any intolerable or serious side effects.

The response of Asian patients with functional dyspepsia to eradication of Helicobacter pylori infection

OBJECTIVES/BACKGROUND

The role of Helicobacter pylori infection in functional dyspepsia (FD) remains controversial. Several randomized controlled trials involving populations in the West, observed no statistically significant advantage over placebo. However, none of these studies involved Asian populations which have high infection rates.

METHODS

A double blind, randomized, placebo-controlled trial of H. pylori eradication for FD was conducted in our Singapore-based Asian population. Forty-one patients received active treatment consisting of a 1-week course of omeprazole 20 mg once daily, clarithromycin 250 mg twice daily and tinidazole 500 mg twice daily whereas another 41 patients received matching placebo tablets. A dyspepsia score was derived by grading 5 dyspeptic symptoms on a Likert scale. Symptom assessment and urea breath test were repeated at 6 weeks, 6 and 12 months from the start of treatment. The primary end point was symptom resolution, defined as a dyspepsia score of 0 or 1 at the end of 12 months follow-up.

RESULTS

On intention-to-treat analyses, symptom resolution was observed in 24% of patients on active treatment and 7% on placebo; the difference in proportion of patients with symptom resolution was statistically significant (P=0.02, 95% confidence interval: 1.1-17.7). H. pylori eradication rates perprotocol and intention-to-treat were 80.0 and 68.3%, on active treatment and 5.6 and 4.9% on placebo (both P values<0.0001). Among patients with H. pylori eradicated on active treatment the symptom resolution rate was 39% (10 of 26), whereas it was 3% (one of 35) among patients in the placebo group who had persistent H. pylori infection. In multivariate analysis, posttreatment H. pylori status was the only predictor of symptom resolution. The majority of patients, 91.5%, had ulcer-like dyspepsia; heartburn and acid regurgitation were uncommon, and no increase was observed after treatment.

CONCLUSION

In contrast to Western populations, our results suggest that patients with FD in Asia would benefit from treatment for H. pylori infection with as much as a 13-fold increased chance of symptom resolution following its eradication.

Psychological treatments for the management of irritable bowel syndrome

BACKGROUND

No consensus exists on the optimal treatment for irritable bowel syndrome (IBS). Psychological treatments are increasingly advocated but their effectiveness is unclear.

OBJECTIVES

To evaluate the efficacy of psychological interventions for the treatment of irritable bowel syndrome.

SEARCH STRATEGY

A computer assisted search of MEDLINE, EMBASE, PsychInfo, CINAHL, Web of Science, The Cochrane Library and Google Scholar was performed for the years 1966-2008. Local databases were searched in Europe.

SELECTION CRITERIA

Randomised trials comparing single psychological interventions with either usual care or mock interventions in patients over 16 years of age. No language criterion was applied.

DATA COLLECTION AND ANALYSIS

The search identified 25 studies that fulfilled the inclusion criteria. The relative risk (RR), risk difference (RD), number needed to treat (NNT) and standardized mean difference (SMD) along with 95% confidence intervals were calculated using a random effects model for each outcome.

MAIN RESULTS

Psychological interventions as a group The SMD for symptom score improvement at 2 and 3 months was 0.97 (95% CI 0.29 to 1.65) and 0.62 (95% CI 0.45 to 0.79) respectively compared to usual care. Against placebo, the SMDs were 0.71 (95% CI 0.08 to 1.33) and -0.17 (95% CI -0.45 to 0.11) respectively. For improvement of abdominal pain, the SMDs at 2 and 3 months were 0.54 (95%CI 0.10 to 0.98) and 0.26 (95% CI 0.07 to 0.45) compared to usual care. The SMD from placebo at 3 months was 0.31 (95% CI -0.16 to 0.79). For improvement in quality of life, the SMD from usual care at 2 and 3 months was 0.47 (95%CI 0.11 to 0.84) and 0.31 (95%CI -0.16 to 0.77) respectively. Cognitive behavioural therapy The SMD for symptom score improvement at 2 and 3 months was 0.75 (95% CI -0.20 to 1.70) and 0.58 (95% CI 0.36 to 0.79) respectively compared to usual care. Against placebo, the SMDs were 0.68 (95% CI -0.01 to 1.36) and -0.17 (95% CI -0.45 to 0.11) respectively. For improvement of abdominal pain, the SMDs at 2 and 3 months were 0.45 (95% CI 0.00 to 0.91) and 0.22 (95% CI -0.04 to -0.49) compared to usual care. Against placebo the SMD at 3 months was 0.33 (95% CI -0.16 to 0.82). For improvement in quality of life, the SMDs at 2 and 3 months compared to usual care were 0.44 (95% CI 0.04 to 0.85) and 0.92 (95% CI 0.07 to 1.77) respectively.Interpersonal psychotherapy The RR for adequate relief of symptoms was 2.02 (95% CI 1.13 to 3.62), RD 0.30 (95% CI 0.13 to 0.46), NNT 4 for comparison with care as usual. The SMD for improvement of symptom score was 0.35 (95% CI -0.75 to 0.05) compared with usual care. Relaxation/Stress management The SMD in symptom score improvement at 2 months was 0.50 (95%CI 0.02 to 0.98) compared with usual care. The SMD in improvement of abdominal pain at 3 months was 0.02 (95%CI -0.56 to 0.61) compared with usual care. Long term results Very few long term follow-up results were available. There was no convincing evidence that treatment effects were sustained following completion of treatment for any treatment modality.

AUTHORS' CONCLUSIONS

Psychological interventions may be slightly superior to usual care or waiting list control conditions at the end of treatment although the clinical significance of this is debatable. Except for a single study, these therapies are not superior to placebo and the sustainability of their effect is questionable. The meta-analysis was significantly limited by issues of validity, heterogeneity, small sample size and outcome definition. Future research should adhere to current recommendations for IBS treatment trials and should focus on the long-term effects of treatment.

Evaluation of the Birmingham IBS symptom questionnaire

BACKGROUND

Irritable Bowel Syndrome (IBS) is a chronic/common condition that causes a significant effect on the individual (reduced quality of life), society (time lost off work) and health services. Comparison of studies evaluating the management of IBS has been hindered by the lack of a widely adopted validated symptom score. The aim of this study was to develop and validate a disease specific score to measure the symptoms of patients with IBS.

METHODS

A self-administered 14-item symptom questionnaire (based on Rome II criteria) was mailed to 533 persons included in a prevalence study of IBS. The reliability of each underlying dimension identified was measured by Cronbach's alpha. Validity was assessed by comparing symptom scores with concurrent IBS specific quality of life (QoL) scores. Reproducibility was measured by the test-retest method and responsiveness measured by effect size.

RESULTS

379 (71%) questionnaires were returned. The underlying dimensions identified were pain, diarrhoea and constipation. Cronbach's alpha was 0.74 for pain, 0.90 for diarrhoea and 0.79 for constipation. Pain and diarrhoea dimensions had good external validity (r = -0.3 to -0.6), constipation dimension had moderate external validity (r = -0.2 to -0.3). All dimensions were reproducible (ICCs 0.75 to 0.81). Effect sizes of 0.27 to 0.53 were calculated for those with a reported improvement in symptoms.

CONCLUSION

The Birmingham IBS Symptom Questionnaire has been developed and tested. It has been shown to be suitable for self-completion and acceptable to patients. The questionnaire has 3 internal dimensions which have good reliability, external validity and are responsive to a change in health status.

Updates on treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder characterized by abdominal pain and discomfort in association with altered bowel habits. It is estimated to affect 10%-15% of the Western population, and has a large impact on quality of life and (in)direct healthcare costs. IBS is a multifactorial disorder involving dysregulation within the brain-gut axis, and it is frequently associated with gastrointestinal motor and sensory dysfunction, enteric and central nervous system irregularities, neuroimmune dysregulation, and post-infectious inflammation. As with other functional medical disorders, the treatment for IBS can be challenging. Conventional therapy for those with moderate to severe symptoms is largely unsatisfactory, and the development of new and effective drugs is made difficult by the complex pathogenesis, variety of symptoms, and lack of objective clinical findings that are the hallmark of this disorder. Fortunately, research advances over the past several decades have provided insight into potential mechanisms responsible for the pathogenesis of IBS, and have led to the development of several promising pharmaceutical agents. In recent years there has been much publicity over several of these new IBS medications (alosetron and tegaserod) because of their reported association with ischemic colitis and cardiovascular disease. While these agents remain available for use under restricted prescribing programs, this highlights the need for continued development of safe and effective medication for IBS. This article provides a physiologically-based overview of recently developed and frequently employed pharmaceutical agents used to treat IBS, and discusses some non-pharmaceutical options that may be beneficial in this disorder.

Effects of anti-secretory factor (ASF) on irritable bowel syndrome (IBS). A double-blind, randomized study

OBJECTIVE

To evaluate the role of the endogenous protein anti-secretory factor (ASF) on the symptoms, especially loose stools, in irritable bowel ayndrome (IBS).

DESIGN

A diet with specially processed cereals (SPC) known to induce ASF production was used in patients with IBS, in an eight-week randomized, placebo-controlled study.

SUBJECTS

Eighty-two patients with IBS were randomized to a diet with either SPC or placebo.

MAIN OUTCOME MEASURES

The overall clinical condition and the quality of life were measured by VAS and SF-36 questionnaire, respectively. The plasma levels of ASF were determined in 14 patients with dominating loose stools before and after diet.

RESULTS

All patients significantly (p<0.001) improved in IBS-related symptoms irrespective of active or placebo diet. In an active-diet sub-group with diarrhoea (n=11) there was a significant (p<0.05) correlation between the increase of plasma ASF level and the improvement on the VAS.

CONCLUSION

Both study groups improved significantly on the VAS but no additive effect was seen for the active treatment. In the sub-group with loose stools, the SPC diet induced ASF plasma levels in IBS patients and was correlated to significant symptom improvement in the individual patient.

Efficacy of dioctahedral smectite in treating patients of diarrhea-predominant irritable bowel syndrome

BACKGROUND AND AIM

Dioctahedral smectite (DS) is natural adsorbent clay useful in treating acute diarrhea. The aim of this study was to determine DS efficacy on patients with diarrhea-predominant irritable bowel syndrome (D-IBS in a phase III-, 8-week-randomized, double-blind, placebo-controlled trial.

METHODS

The 104 patients who met the D-IBS Rome II criteria were randomized to receive either DS (n = 52) or placebo (n = 52) treatment for 8 weeks (three sachets daily). The primary efficacy endpoint was the changes of the visual analog scale (VAS) score of IBS overall disorder and pain/discomfort-related symptoms after treatment on days 28 and 56, respectively. Other outcome measures included improvement of bowel movement disorders. The therapeutic global response was assessed by the patients and investigators at each visit, as was drug safety.

RESULTS

Both treatments diminished overall disorder at each visit (P < 0.01), with respect to primary efficacy. This effect was further observed in DS-treated patients on day 56 (P = 0.0167). Placebo had no effect on the VAS score of pain/discomfort at any visit, whereas DS improved this score on days 28 and 56, respectively (P < 0.05). DS and placebo similarly diminished bowel disorders at each visit; however, only DS improved abdominal bloating (P < 0.01). The global therapeutic responses evaluated by the patients and investigators were similarly distributed. The study drug was well tolerated during the 8-week period.

CONCLUSION

DS seems acceptable to treat D-IBS patients, particularly for pain-related symptoms.

Irritable bowel syndrome in psychiatric perspectives: a comprehensive review

We comprehensively reviewed the irritable bowel syndrome (IBS) in terms of pathogenesis, psychiatric implications, general management and appropriate role of antidepressants, in particular selective serotonin uptake inhibitors (SSRIs) in the treatment of IBS. English language papers cited in MEDLINE and PychInfo from January 2000 to July 2006 were searched with a combination of the following key words: irritable bowel syndrome, 5-HT, pathogenesis, comorbid, psychiatry, treatment, psychotropic drugs, antidepressant, selective serotonin reuptake inhibitors (fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram and sertraline), tricyclic antidepressants, review, meta-analysis and placebo. The papers on IBS describing the clinical features, pathophysiology, evaluation, management, and clinical trials [randomised placebo-controlled trial (RCT), open-label study or case report] were selected for this review. Further literatures were also detected from references of the identified papers. The epidemiology, diagnostic criteria, pathophysiology, general management, bidirectional comorbidity, summary of currently available RCTs and open-label studies investigating antidepressant efficacy (focusing on SSRIs), and suggestions for SSRI use in IBS were relevantly synthesised based on through review of identified data. This article summarised an up-to-date clinical overview of IBS in psychiatric perspectives as well as to position a current role of SSRIs in the treatment of IBS. From this review, the routine use of SSRIs for IBS treatment cannot be conclusive due to a paucity of RCTs, although a handful of RCTs suggested a potentially beneficial effect of SSRIs over placebo.

A meta-analysis of the placebo response in complementary and alternative medicine trials of irritable bowel syndrome

Among patients with irritable bowel syndrome (IBS) enrolled in clinical trials of conventional medical therapy, the placebo response rate is high. IBS patients also frequently use complementary and alternative medicine (CAM), which may act through an 'enhanced placebo effect'. The purpose of this study was to estimate the magnitude of the placebo response rate in CAM trials for IBS and to identify factors that influence this response. We performed a systematic review and meta-analysis of randomized, placebo-controlled clinical trials of CAM therapies for IBS identified from MEDLINE/EMBASE/PsychLIT databases from 1970 to 2006. Placebo and active treatment response rates for global symptom improvement were assessed. Nineteen studies met the inclusion criteria. The pooled estimate of the placebo response rate was 42.6% (95% confidence interval, 38.0-46.5%). Significant heterogeneity existed across trials (range 15.0-72.2%, P < 0.00001). Higher placebo response rates correlated with a longer duration of treatment (r = 0.455, P = 0.05) and a greater number of office visits (r = 0.633, P = 0.03). Among IBS patients in CAM trials, the placebo response rate is high. That this rate is similar in magnitude to that seen in conventional medicine trials suggests that the placebo response is independent of the type of therapy used and that it is not particularly 'enhanced' in CAM trials.

Placebo responses in patients with gastrointestinal disorders

Over the last several years there has been a growing interest in placebo, not only as an inert control in clinical trials, but also in the placebo effect as a group effect as well as a reaction in individual subjects. Methodological factors such as regression to the mean and natural history of the disease play a role in the evaluation of a possible placebo effect. In this report, we discuss several factors including Pavlovian conditioning, beliefs outcome, expectations, and other factors as potential mediators of the placebo response. Placebo effects are common in gastrointestinal diseases and there seems to be no clear difference between placebo effects in functional gastrointestinal diseases (functional dyspepsia and irritable bowel syndrome) and organic gastrointestinal disease (duodenal ulcer and inflammatory bowel disease).

Health technology assessment and ill-structured problems: a case study concerning the drug mebeverine

OBJECTIVES

The practical significance of health technology assessment (HTA) in policy decisions or clinical practice has been challenged. Possibly, problem definitions underlying HTA do not concur sufficiently with the problem definitions held by policy makers or clinicians. We performed an in-depth case study on mebeverine, a drug prescribed to patients with irritable bowel syndrome, to explore this hypothesis.

METHODS

The theoretical framework was provided by the theory of argumentative policy analysis. We analyzed documents and held semistructured interviews to collect data. We reconstructed interpretative frames to analyze actors' argumentation.

RESULTS

The funding and usage problems relating to mebeverine were ill-structured. Actors disagreed on the information needed and the norms at stake. As a result, the problem definition shifted, and the resulting problem definitions failed to correspond with the problems perceived by the target populations.

CONCLUSIONS

To ensure that future studies on healthcare problems are useful, it is imperative that policy makers take the problem definitions of potential users into account.

Irritable bowel syndrome in the 21st century: perspectives from Asia or South-east Asia

Asian irritable bowel syndrome (IBS) studies not only confirm the truth of this functional disorder but also describe the current disease situation of this continent, with its variable socioeconomic backgrounds. Most Asian community IBS prevalence is within 5-10%, regardless of gender or ethnic character. As well as meeting the main Rome II criteria, Asian IBS subjects also have many minor symptoms. Thus this recommendation remains useful to diagnose Asian IBS. Also, female patients commonly express constipation-predominant (C-) symptoms. Extra-colonic symptoms are common in Asia, for example dyspepsia, insomnia and irritable urinary bladder. Asian IBS subjects do experience psychological disturbances including anxiety, depression, agoraphobia and neuroticism. Accordingly, their quality of life is poor and there is absenteeism leading to excessive physician visits. Abnormal gut motor and sensory functions have been indicated among the Asian IBS subjects. Now, there is evidence of altered colonic neuroimmune function leading to gut hypersensitivity and dysmotility. An Asia-Pacific trial also confirmed tegaserod efficacy on female C-IBS subjects. More than 90% of nurses have very limited IBS knowledge, and are unable even to explain it clearly. In conclusion, Western recommended criteria clearly diagnose Asian IBS and many factors are mutual leading to IBS. Current IBS treatments remain useful but additional reeducation for medical professionals appears to be needed.

The placebo effect for gastroenterology: tool or torment

Placebo generally has a negative connotation both in clinical practice and in clinical trials. In this report the nature of placebo is explored in general and in relation to gastrointestinal diseases. The goodness of placebo is highlighted. PubMed was searched for articles and commentaries on placebo and for systematic reviews on placebo. Selected placebo-controlled trials in gastroenterology were reviewed. There are 5 key components impacting the placebo response: patient characteristics, practitioner characteristics, practitioner-patient interaction, the nature of the illness being treated, and the treatment being applied and the setting in which it is applied. There are also a number of factors that constitute the placebo response and likely all apply to some extent. These include the natural history of the condition, a regression to the mean (accounting for fluctuation in measurements over time), other time effects (ie, patient learning to cope, practitioner gaining expertise), unidentified parallel interventions (ie, change in habits or exogenous stress), the placebo effect of the administered agent being compared with placebo, and the physiologic effects of the placebo. In summary, there are positive aspects to placebo. Clinicians treating patients with gastrointestinal diseases can harness aspects of the placebo response to improve patient outcomes. Clinical trial planners can harness aspects of the placebo response to design disease-specific trials that can minimize the placebo response.

Bran and irritable bowel syndrome: the primary-care perspective

BACKGROUND

We have shown that bran exacerbates irritable bowel syndrome symptoms in a large proportion of secondary-care patients. However, it is unknown if this also happens in primary-care or whether a better response to bran occurs, leading to bran failures being selected for referral to the specialist.

AIMS

To assess the response to bran in primary-care irritable bowel syndrome comparing it to that obtained in secondary-care.

PATIENTS AND METHODS

One hundred consecutive primary-care irritable bowel syndrome patients were asked how bran or soluble fibre products affected their symptoms.

RESULTS

Bran improved symptoms in 27% of primary-care and 10% of secondary-care patients (p<0.01) and exacerbated symptoms in 22% of primary-care and 55% of secondary-care patients (p<0.001). Fifty-one percent of primary-care and 33% of secondary-care patients reported no change with bran. In primary-care, proprietary fibre led to improvement in 25%, deterioration in 19% and no change in 56% which was not significantly different to secondary-care.

CONCLUSION

Although not especially effective in primary-care irritable bowel syndrome patients, bran does not cause so many problems and is more helpful than in secondary-care. The effects of soluble fibre are similar in both primary-care and secondary-care. This study highlights the problem of extrapolating the response to treatment in irritable bowel syndrome from different care settings.

Functional bowel disorders

Employing a consensus approach, our working team critically considered the available evidence and multinational expert criticism, revised the Rome II diagnostic criteria for the functional bowel disorders, and updated diagnosis and treatment recommendations. Diagnosis of a functional bowel disorder (FBD) requires characteristic symptoms during the last 3 months and onset > or =6 months ago. Alarm symptoms suggest the possibility of structural disease, but do not necessarily negate a diagnosis of an FBD. Irritable bowel syndrome (IBS), functional bloating, functional constipation, and functional diarrhea are best identified by symptom-based approaches. Subtyping of IBS is controversial, and we suggest it be based on stool form, which can be aided by use of the Bristol Stool Form Scale. Diagnostic testing should be guided by the patient's age, primary symptom characteristics, and other clinical and laboratory features. Treatment of FBDs is based on an individualized evaluation, explanation, and reassurance. Alterations in diet, drug treatment aimed at predominant symptoms, and psychotherapy may be beneficial.