Clinical response to tricyclic antidepressants in functional bowel disorders is not related to dosage

Anxiety and depression in Indian patients with irritable bowel syndrome: A meta-analysis

BACKGROUND

Functional gastrointestinal disorders (FGIDs), including irritable bowel syndrome (IBS), are associated with psychological abnormalities, such as anxiety and depression. Though the data on this are plenty in global literature, Indian data are sparse. We performed a systematic review and meta-analysis of Indian data on anxiety and depression among patients with IBS to estimate their pooled prevalence and to identify the shortcomings so that future areas of research can be identified.

METHOD

A comprehensive literature search was performed for studies applying tests for psychological issues in patients with IBS. After applying prospectively decided exclusion criteria, the eligible papers were examined using a meta-analysis approach for the prevalence of anxiety and depression in IBS patients using different tests. The odds ratios (OR) of anxiety and depression among subjects with IBS were calculated compared to controls.

RESULTS

Of seven studies (590 IBS patients and 1520 controls) included in the meta-analysis, the pooled OR of anxiety was 8.060 (95% confidence interval [CI] 4.007-16.213) as compared to controls (random-effect model). The pooled OR of depression was 7.049 (95% CI 3.281-15.147) compared to controls (random-effect model). There was significant heterogeneity in the included studies.

CONCLUSION

The current meta-analysis shows that the patients with IBS from India have eightfold greater risks of anxiety and sevenfold greater risks of depression than the controls. However, most of these data were from tertiary urban centers, and hence, there might be recruitment bias over-estimating the frequency.

Role of serum amitriptyline concentration and CYP2C19 polymorphism in predicting the response to low-dose amitriptyline in irritable bowel syndrome

BACKGROUND

Low-dose amitriptyline (AMT) is an effective treatment for diarrhea-dominant irritable bowel syndrome (IBS-D). Its efficacy depends upon its serum concentration and the patient's CYP2C19 genotype.

AIMS

To identify the association between serum AMT and nortriptyline (NT) concentration and CYP2C19 polymorphism and the clinical response in IBS-D patients.

METHODS

Ninety IBS-D patients were treated of AMT for 6 weeks. Efficacy was evaluated by the results of the Adequate Relief question each week and an IBS severity scoring system (IBS-SSS) at 0, 3, and 6 weeks. CYP2C19 genotyping was performed by direct sequencing. AMT and NT steady-state serum concentrations were detected by high-performance liquid chromatography.

RESULTS

The CYP2C19 polymorphism exhibited a significant influence on the NT serum concentration but did not predict the clinical efficacy of AMT for treating IBS-D. The NT steady-state and dose-corrected serum concentrations were significantly correlated with an improvement in the IBS-SSS score after 6 weeks, whereas the AMT serum concentration was not correlated with clinical improvement. The cut-off NT steady-state serum concentration of 2.91 ng/ml may help distinguish responders from non-responders.

CONCLUSIONS

NT serum concentration but not CYP2C19 polymorphism may be correlated with the clinical efficacy of AMT for treating IBS-D, and such a response may occur at the upper NT threshold of 2.91 ng/ml.

Medication use and polypharmacy in patients referred to a tertiary gastroenterology practice

Introduction. Commonly prescribed medications are associated with various gastrointestinal (GI) side effects but few data are available on prescription medication use and polypharmacy in a gastroenterology outpatient practice. We aimed to examine the prevalence of polypharmacy, defined as the simultaneous use of 5 or more medications.Methods. A descriptive correlational study of consecutive outpatient consultations in 988 patients referred to a tertiary gastroenterology practice. Main outcome measurements were frequency of prescription medication use and polypharmacy.Results. The most common GI symptoms were abdominal pain (72%), nausea (57%), and constipation (53%). The frequency of polypharmacy was 10%. Eighty percent of patients took at least one medication and 60% took two or more. The most frequently used medication classes were proton pump inhibitors (43%), followed by benzodiazepines (30%), selective serotonin-reuptake or norepinephrine-reuptake inhibitors (28%), non-steroidal anti-inflammatory drugs (27%), and opioids (21%).Conclusion. There was a higher use of prescription medicine including antidepressants, and a lower frequency of polypharmacy in our study cohort compared to the general population. The use of medications may have contributed to the symptoms leading to our study's population GI consultation.

Pharmacological and non-pharmacological treatments for irritable bowel syndrome: Protocol for a systematic review and network meta-analysis

BACKGROUND

The global prevalence of Irritable bowel syndrome (IBS) is estimated to be as high as 15% and a number of different non-pharmacological and pharmacological treatments have been used to manage IBS in clinical practice, which poses great challenges for clinicians to make appropriate decisions. Hence, a systematic review and network meta-analysis on all available pharmacological and non-pharmacological treatments for IBS is needed to provide reliable evidence.

METHODS

We will search the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane IBD Group Specialized Trials Register, MEDLINE, EMBASE, and Chinese Biomedical medicine (CBM) from inception to 31, May 2019. Randomized controlled trials of pharmacological and nonpharmacological interventions for IBS will be included. Study quality will be assessed on the basis of the methodology and categories described in the Cochrane Collaboration Handbook. Primary outcomes are global or clinical improvement and quality of life. A Bayesian network meta-analysis would be performed, and relative ranking of agents would be assessed. A node splitting method will be used to examine the inconsistency between direct and indirect comparisons when a loop connecting 3 arms exists.

RESULTS

Researchers will rank the effectiveness and safety of the potentials interventions for IBS according the characteristics of patients by conducting an advanced network meta-analysis based on Bayesian statistical model, and interpret the results by using GRADE approach.

CONCLUSION

The conclusion of our study will provide updated evidence to rank the effectiveness and safety of pharmacological and non-pharmacological interventions for IBS.

ETHICS AND DISSEMINATION

Ethical approval is not applicable since this study is a network meta-analysis based on published trials.

PROTOCOL REGISTRATION NUMBER

CRD42018083844.

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.

Clinical Practice Guidelines for Irritable Bowel Syndrome in Korea, 2017 Revised Edition

In 2011, the Korean Society of Neurogastroenterology and Motility (KSNM) published clinical practice guidelines on the management of irritable bowel syndrome (IBS) based on a systematic review of the literature. The KSNM planned to update the clinical practice guidelines to support primary physicians, reduce the socioeconomic burden of IBS, and reflect advances in the pathophysiology and management of IBS. The present revised version of the guidelines is in continuity with the previous version and targets adults diagnosed with, or suspected to have, IBS. A librarian created a literature search query, and a systematic review was conducted to identify candidate guidelines. Feasible documents were verified based on predetermined inclusion and exclusion criteria. The candidate seed guidelines were fully evaluated by the Guidelines Development Committee using the Appraisal of Guidelines for Research and Evaluation II quality assessment tool. After selecting 7 seed guidelines, the committee prepared evidence summaries to generate data exaction tables. These summaries comprised the 4 main themes of this version of the guidelines: colonoscopy; a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols; probiotics; and rifaximin. To adopt the core recommendations of the guidelines, the Delphi technique (ie, a panel of experts on IBS) was used. To enhance dissemination of the clinical practice guidelines, a Korean version will be made available, and a food calendar for patients with IBS is produced.

Efficacy and safety of nortriptyline in functional dyspepsia in Asians: A randomized double-blind placebo-controlled trial

BACKGROUND AND AIM

Current treatments of functional dyspepsia (FD) are unsatisfied. Tricyclic antidepressants alter visceral hypersensitivity and brain-gut interaction. We assessed the efficacy and safety of nortriptyline in patients with FD.

METHODS

Patients diagnosed with FD according to Rome III criteria who failed to respond to proton pump inhibitor and prokinetic treatment were randomly assigned to either once daily 10-mg nortriptyline or placebo. The primary endpoint was the rate of responders defined as > 50% reduction in dyspepsia symptom score after 8 weeks of treatment. The secondary endpoints were improvement in quality of life as assessed by 36-Item Short Form Health Survey score and safety.

RESULTS

Sixty-one patients (nortriptyline 28 and placebo 33) were enrolled. Dyspepsia symptom score and duration of symptoms were balanced at entry between both groups. Eight and seven patients in nortriptyline and placebo groups were lost to follow up. Seven patients withdrew due to mild adverse events (nortriptyline 1 and placebo 6). Overall, 19 with nortriptyline and 20 with placebo completed the study. Patients receiving nortriptyline did not achieve higher response rate than those in placebo in both intention-to-treat (53.6% vs 57.6%, P = 0.75) and per-protocol (76.5% vs 73.7%, P = 1.00) analyses. Nortriptyline did not provide improvement in quality of life. The mean difference was 3.8 (P = 0.36) and 0.88 (P = 0.86) by intention-to-treat and 2.9 (P = 0.57) and 3.5 (P = 0.57) by per-protocol analyses in physical and mental component, respectively. All adverse events were minor and similar in both groups.

CONCLUSION

Nortriptyline was not superior to placebo in management of patients with FD.

Centrally Mediated Disorders of Gastrointestinal Pain

Centrally Mediated Abdominal Pain Syndrome (CAPS), formerly known as Functional Abdominal Pain Syndrome, can be distinguished from other functional GI disorders by its strong central component and relative independence from motility disturbances. CAPS is a result of central sensitization with disinhibition of pain signals rather than increased peripheral afferent excitability. A newly described condition, Narcotic Bowel Syndrome (NBS)/Opioid-Induced GI Hyperalgesia, is characterized by the paradoxical development of or increases in abdominal pain associated with continuous or increasing dosages of opioids. Patients only have relief when opioids are withdrawn. We define both conditions in the context of epidemiology, pathophysiology, clinical evaluation and treatment, emphasizing the importance of a physician-patient relationship in all aspects of care.

Low-Dose Tricyclics for Esophageal Hypersensitivity: Is it all Placebo Effect?

Limsrivilai et al. report on a randomized control trial (RCT) testing the efficacy of imipramine for treating esophageal hypersensitivity and functional heartburn, the first RCT to test this therapy in this indication. Among 43 functional heartburn and esophageal hypersensitivity patients randomized to treatment with 25 mg qhs imipramine and 40 randomized to matched placebo, the response rates, judged by a 50% reduction in gastroesophageal reflux disease symptoms, were 37.2% and 37.5%, respectively, with no observed difference between patients with hypersensitivity and those with functional heartburn. On the positive side, imipramine treatment was associated with improvement in quality of life as assessed by total SF-36 score. Although negative at first glance, there are several important lessons from this study: (i) low-dose tricyclic is sufficient in these patients; (ii) proton pump inhibitors can (and should) be discontinued when they are ineffective; and (iii) distinguishing between functional heartburn and esophageal hypersensitivity is of unclear clinical relevance.

Effectiveness of osteopathic manipulative therapy for managing symptoms of irritable bowel syndrome: a systematic review

CONTEXT

Irritable bowel syndrome (IBS) is a common and often lifelong functional gastrointestinal disorder. There is a scarcity of effective management options for IBS.

OBJECTIVE

To assess the effectiveness of osteopathic manipulative therapy (OMTh) for managing the symptoms of IBS.

DATA SOURCES

Articles without language or publication-date restriction were searched in PubMed, Embase, Cochrane Library, PEDro, OSTMED.DR, and Osteopathic Research Web. Search terms included irritable bowel syndrome, IBS, functional colonic disease, colon irritable, osteopath*, osteopathic manipulation, osteopathic medicine, clinical trial, and randomized clinical trial. Experts in the field of visceral osteopathy were also contacted to identify additional studies.

STUDY SELECTION

The authors evaluated randomized controlled trials (RCTs) of OMTh for IBS in adults in whom IBS was diagnosed using Rome (I-III) criteria. If OMTh was not the sole intervention in the intervention group and if the same additional interventions were not applied to the control group, the study was excluded.

DATA EXTRACTION

Citation identification, study selection, and data extraction were independently undertaken by 2 reviewers with a data extraction form from the Cochrane Collaboration. A consensus method was used to resolve disagreements concerning the assessment of the methodologic quality of the RCTs that were reviewed.

RESULTS

The search identified 10 studies that examined OMTh for patients with IBS; 5 studies (204 patients) met the inclusion criteria. All studies were assessed as having low risk of bias according to the Cochrane Collaboration criteria, although there was heterogeneity in the outcome measures and control interventions. Three studies used visual analog scales for abdominal pain, whereas others used the IBS severity score and the Functional Bowel Disorder Severity Index. A variety of secondary outcomes were used. All studies reported more pronounced short-term improvements with OMTh compared with sham therapy or standard care only. These differences remained statistically significant after variable lengths of follow-up in 3 studies.

CONCLUSION

The present systematic review provides preliminary evidence that OMTh may be beneficial in the treatment of patients with IBS. However, caution is required in the interpretation of these findings because of the limited number of studies available and the small sample sizes.

Current and emerging drug options in the treatment of diarrhea predominant irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome diarrhea predominant (IBS-D) is a highly prevalent GI disease, affecting nearly a third of all patients diagnosed with irritable bowel syndrome. Current treatment options are limited.

AREAS COVERED

This review discusses the pharmacotherapeutic options for IBS-D including currently used medications, the two newly FDA approved medications, as well as emerging therapies with potential benefit in IBS-D. Particular emphasis is placed on rifaximin and eluxadoline and their possible use in IBS-D.

EXPERT OPINION

Current pharmacological treatment of IBS-D includes loperamide, bile acid sequestrants, antispasmodics, tricyclic antidepressants, alosetron, eluxadoline and rifaximin. The latter two treatments have significantly added to the pharmacotherapeutic options for patients suffering from IBS-D.

Prokinetic effects of mirtazapine on gastrointestinal transit

Mirtazapine is a noradrenergic and specific serotonergic antidepressant. The aim of this study was to investigate the effects of mirtazapine on gastrointestinal motility in dogs, including solid gastric emptying, antral and small intestinal contractions, and small intestinal and colonic transit. Six dogs were implanted with two cannulas located at the duodenum and the ascending colon; another six dogs were implanted with gastric cannula 6 cm proximal to the pylorus. Mirtazapine 45 mg was administered orally 90 min before the study. We found that 1) Mirtazapine accelerated gastric emptying during the entire 3 h in normal dogs (P < 0.04) and accelerated delayed gastric emptying induced by rectal distention (P < 0.04). 2) Mirtazapine restored impaired gastric tone and accommodation induced by rectal distention (P < 0.05). 3) No significant changes were noted in small intestinal contractions or transit with mirtazapine (P > 0.1). 4) Mirtazapine accelerated colonic transit at 2 and 4 h but not 6 h. The geometric center was increased from 1.9 ± 0.6 to 3.0 ± 0.5 and 3.9 ± 0.5 to 4.7 ± 0.1 at 2 and 4 h respectively (P = 0.04 vs. corresponding control). In conclusion, mirtazapine improves gastric emptying in healthy dogs and normalizes rectal distention-induced delay in gastric emptying and accelerates colon but not small intestinal transit in healthy dogs. Clinical studies are warranted to assess the effects of mirtazapine on gastrointestinal motility and sensory functions in patients with functional gastrointestinal diseases.

An open-label trial of duloxetine in patients with irritable bowel syndrome and comorbid generalized anxiety disorder

OBJECTIVE

Irritable bowel syndrome (IBS) is commonly comorbid with generalized anxiety disorder (GAD). We evaluated whether duloxetine would lead to improvement in symptoms and quality of life in patients with both conditions.

METHOD

A 12-week, open-label trial of duloxetine was conducted in 13 subjects with IBS and GAD. The primary outcome measure was the Clinical Global Impression (CGI) Scale. Secondary measures included the Hamilton Anxiety Rating Scale, IBS Quality of Life (IBS-QOL) Scale, and IBS Symptom Severity Scale (IBS-SSS).

RESULTS

Repeated measures ANOVA was used to examine the effect of treatment with duloxetine on ratings of anxiety and IBS. Significant improvement was observed on the CGI-Improvement (F = 14.19, df = 1,12, p < 0.001) and Severity scales (F = 16.16, df = 1,12, p < 0.001). Secondary measures revealed significant reduction in symptoms of anxiety (F = 11.66, df = 1,12, p < 0.01), ηp(2) = 0.56, and IBS-SSS (F = 6.05, df = 1,12, p < 0.001), ηp(2) = 0.34, in addition to IBS-QOL improvements (F = 11.66, df = 1,12, p < 0.01), ηp(2) = 0.56.

CONCLUSION

Results of this pilot study support the efficacious use of duloxetine in comorbid IBS and GAD. Participants reported significant reductions in IBS components, as well as improvement in GAD.

Associations between medication use and functional gastrointestinal disorders: a population-based study

BACKGROUND

Functional GI syndromes are known to be very prevalent, but this may be linked to unrecognized medications use. We aimed to estimate the prevalence of PPI, antidepressant, and narcotic use in the general population, and to evaluate the association between each medication and functional GI syndromes adjusting for potential confounders.

METHODS

In 2008 and 2009, newly revised versions of a validated bowel disease questionnaire were mailed to a community-based cohort (total mailed = 8006) of Olmsted County, MN residents; 3831 returned the questionnaire (response rate = 48.0%). Medication usage, specifically PPIs, narcotics, and antidepressants in the last year, was elicited via three separate questions on the questionnaire. The association between each medication and GI symptom complexes was assessed using multiple variable logistic regression models.

KEY RESULTS

A total of 3515 of the respondents (92%) had complete data (mean age: 61 ± 15; 54% female). The overall proportion reporting PPI use was 20% (95% CI: 19, 22), narcotic use 12% (95% CI: 11, 13), and antidepressant use 15% (95% CI: 14, 16). PPI use was significantly associated with IBS status (OR = 1.4, 95% CI 1.1, 1.7) as well as with GERD (OR = 3.5, 95% CI 2.7, 4.4) and dyspepsia (OR = 2.0, 95% CI 1.5, 2.7). The association of PPI use with IBS was not explained by coexistent GERD or dyspepsia. Antidepressant use was significantly associated only with bloating (OR = 1.6, 1.1, 2.2).

CONCLUSIONS & INFERENCES

Some medications that may alter intestinal transit or bowel flora are commonly utilized by the general population, and PPI use appears to be linked to IBS.

The use of psychotropic drugs in irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS), the most common functional gastrointestinal disorder, is manifested by chronic abdominal pain associated with irregular bowel movements. Although not life threatening, IBS is associated with impaired quality of life that ranges from mild to severe.

AREAS COVERED

The pathogenesis of IBS is not completely understood, but involves dysfunction of the "brain-gut axis" including peripheral visceral hypersensitivity and central maladaptive processing of visceral pain input. Stress and concomitant psychopathologies such as somatization, anxiety and depression are thought to play a major role in the development, clinical course and response to treatment. Psychopharmacological agents such as selective serotonin/serotonin-norepinephrine receptor antagonists, tricyclic antidepressants as well as other agents are commonly used in treating moderate to severe IBS. This review will provide the pathophysiological rationale for the use of psychopharmacological agents in IBS, review the main classes of drugs and evidence for their use in IBS and offer a practical approach to the use of these drugs.

EXPERT OPINION

Psychotropic drugs can play a pivotal role in the treatment of IBS patients, so doctors should be familiar with their use. Further research with these drugs is needed to solidify our current knowledge and increase our therapeutic options.

Diagnosis, comorbidities, and management of irritable bowel syndrome in patients in a large health maintenance organization

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) imposes significant clinical and economic burdens. We aimed to characterize practice patterns for patients with IBS in a large health maintenance organization, analyzing point of diagnosis, testing, comorbidities, and treatment.

METHODS

Members of Kaiser Permanente Northern California who were diagnosed with IBS were matched to controls by age, sex, and period of enrollment. We compared rates of testing, comorbidities, and interventions.

RESULTS

From 1995-2005, IBS was diagnosed in 141,295 patients (mean age, 46 years; standard deviation, 17 years; 74% female). Internists made 68% of diagnoses, gastroenterologists 13%, and others 19%. Lower endoscopy did not usually precede IBS diagnosis. Patients with IBS were more likely than controls to have blood, stool, endoscopic, and radiologic tests and to undergo abdominal or pelvic operations (odds ratios, 1.5-10.7; all P < .0001). Only 2.7% were tested for celiac disease, and only 1.8% were eventually diagnosed with inflammatory bowel disease. Chronic pain syndromes, anxiety, and depression were more common among IBS patients than among controls (odds ratios, 2.7-4.6; all P < .0001). Many patients with IBS were treated with anxiolytics (61%) and antidepressants (55%). Endoscopic and radiologic testing was most strongly associated with having IBS diagnosed by a gastroenterologist. Psychotropic medication use was most strongly associated with female sex.

CONCLUSIONS

In a large, managed care cohort, most diagnoses of IBS were made by generalists, often without endoscopic evaluation. Patients with IBS had consistently higher rates of testing, chronic pain syndromes, psychiatric comorbidity, and operations than controls. Most patients with IBS were treated with psychiatric medications.

Efficacy and safety of low-dose tricyclic antidepressants in patients with irritable bowel syndrome: a meta-analysis

AIM: To systematically assess the efficacy and safety of low-dose tricyclic antidepressants (TCAs) for irritable bowel syndrome (IBS).

METHODS: PubMed, The Cochrane Central Register of Controlled Trials and Chinese Biomedical Literature Database, and CNKI were searched for double-blind, placebo-controlled trials investigating the efficacy of TCAs in the management of IBS. The Revman4.2 software provided by the Cochrane Collaboration was used for assessment.

RESULTS: Eight placebo-controlled, double-blind, randomized trials including 334 patients were involved in this analysis. TCAs used in these studies included amitriptyline, imipramine, desipramine, doxepin and trimipramine. Compared to placebo (40.76%), TCAs (72.43%) were associated with a higher rate of global symptom relief [40.76% vs 72.43%; RR = 1.79, 95%CI = (1.48, 2.17), P < 0.05]. There was a greater improvement in abdominal pain score [SMD = -1.68, 95%CI = (-3.13, -0.23), P < 0.05)] with TCAs than placebo. There was no significant difference in the incidence of serious adverse events between the TCA and placebo groups [RR = 1.34, 95%CI = (0.91, 1.96), P > 0.05].

CONCLUSION: Low-dose TCAs may be effective and safe in relief of the symptoms of IBS patients, especially in the improvement of abdominal pain score.

Randomised clinical trial: the effects of amitriptyline on drinking capacity and symptoms in patients with functional dyspepsia, a double-blind placebo-controlled study

BACKGROUND

Functional dyspepsia is one of the most prevalent (15-40%) functional gastrointestinal disorders. Antidepressants such as amitriptyline are often used in these patients, but clinical studies are currently lacking.

AIM

To evaluate the effect of 8 weeks of treatment with amitriptyline on drinking capacity, symptoms evoked by a standardised drink test (primary endpoint) and clinical symptoms (secondary endpoint).

METHODS

Patients meeting the Rome III criteria for functional dyspepsia (FD) were invited to participate in a double blind, randomised, placebo-controlled trial and were treated with either amitriptyline (12.5-50 mg) or placebo during 8 weeks. All included patients underwent a nutrient drink test before and after treatment. Drinking capacity and evoked symptoms were recorded. In addition, dyspeptic symptoms were weekly assessed using PAGI SYM (patient assessment of upper gastrointestinal symptom severity index) questionnaire.

RESULTS

Thirty-eight patients (amitriptyline n=18, placebo n=20; age 41±2year, 61% F) completed the study. The drinking capacity of liquid meal was not affected by either amitriptyline or placebo treatment. Postprandial symptoms were not significantly different between amitriptyline and placebo. During the entire treatment, total symptom score (0.47 points, P=0.02) and nausea (0.86 points, P=0.004) on PAGI SYM were significantly reduced by amitriptyline compared with placebo.

CONCLUSIONS

Amitriptyline did not affect drinking capacity and postprandial symptoms evoked by the drink test in FD patients. However, total clinical symptom score and nausea were reduced during 8 weeks of treatment. Our data suggest that amitriptyline particularly improves nausea in functional dyspepsia, but larger clinical trials are needed to further confirm our findings.

Bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder. The role of pharmacotherapy for IBS is limited and focused mainly on symptom control.

OBJECTIVES

The objective of this systematic review was to evaluate the efficacy of bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome.

SEARCH STRATEGY

Computer assisted structured searches of MEDLINE, EMBASE, The Cochrane library, CINAHL and PsychInfo were conducted for the years 1966-2009. An updated search in April 2011 identified 10 studies which will be considered for inclusion in a future update of this review.

SELECTION CRITERIA

Randomized controlled trials comparing bulking agents, antispasmodics or antidepressants with a placebo treatment in patients with irritable bowel syndrome aged over 12 years were considered for inclusion. Only studies published as full papers were included. Studies were not excluded on the basis of language. The primary outcome had to include improvement of abdominal pain, global assessment or symptom score.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the selected studies. Risk Ratios (RR) and Standardized Mean Differences (SMD) with 95% confidence intervals (CI) were calculated. A proof of practice analysis was conducted including sub-group analyses for different types of  bulking agents, spasmolytic agents or antidepressant medication. This was followed by a proof of principle analysis where only the studies with adequate allocation concealment were included.

MAIN RESULTS

A total of 56 studies (3725 patients) were included in this review. These included 12 studies of bulking agents (621 patients), 29 of antispasmodics (2333 patients), and 15 of antidepressants (922 patients). The risk of bias was low for most items. However, selection bias is unclear for many of the included studies because the methods used for randomization and allocation concealment were not described. No beneficial effect for bulking agents over placebo was found for improvement of abdominal pain (4 studies; 186 patients; SMD 0.03; 95% CI -0.34 to 0.40; P = 0.87), global assessment (11 studies; 565 patients; RR 1.10; 95% CI 0.91 to 1.33; P = 0.32) or symptom score (3 studies; 126 patients SMD -0.00; 95% CI -0.43 to 0.43; P = 1.00). Subgroup analyses for insoluble and soluble fibres also showed no statistically significant benefit. Separate analysis of the studies with adequate concealment of allocation did not change these results. There was a beneficial effect for antispasmodics over placebo for improvement of abdominal pain (58% of antispasmodic patients improved compared to 46% of placebo; 13 studies; 1392 patients; RR 1.32; 95% CI 1.12 to 1.55; P < 0.001; NNT = 7), global assessment (57% of antispasmodic patients improved compared to 39% of placebo; 22 studies; 1983 patients; RR 1.49; 95% CI 1.25 to 1.77; P < 0.0001; NNT = 5) and symptom score (37% of antispasmodic patients improved compared to 22% of placebo; 4 studies; 586 patients; RR 1.86; 95% CI 1.26 to 2.76; P < 0.01; NNT = 3). Subgroup analyses for different types of antispasmodics found statistically significant benefits for cimteropium/ dicyclomine, peppermint oil, pinaverium and trimebutine. Separate analysis of the studies with adequate allocation concealment found a significant benefit for improvement of abdominal pain. There was a beneficial effect for antidepressants over placebo for improvement of abdominal pain (54% of antidepressants patients improved compared to 37% of placebo; 8 studies; 517 patients; RR 1.49; 95% CI 1.05 to 2.12; P = 0.03; NNT = 5), global assessment (59% of antidepressants patients improved compared to 39% of placebo; 11 studies; 750 patients; RR 1.57; 95% CI 1.23 to 2.00; P < 0.001; NNT = 4) and symptom score (53% of antidepressants patients improved compared to 26% of placebo; 3 studies; 159 patients; RR 1.99; 95% CI 1.32 to 2.99; P = 0.001; NNT = 4). Subgroup analyses showed a statistically significant benefit for selective serotonin releasing inhibitors (SSRIs) for improvement of  global assessment and for tricyclic antidepressants (TCAs) for improvement of abdominal pain and symptom score. Separate analysis of studies with adequate allocation concealment found a significant benefit for improvement of symptom score and global assessment. Adverse events were not assessed as an outcome in this review.

AUTHORS' CONCLUSIONS

There is no evidence that bulking agents are effective for treating IBS.  There is evidence that antispasmodics are effective for the treatment of IBS. The individual subgroups which are effective include: cimetropium/dicyclomine, peppermint oil, pinaverium and trimebutine. There is good evidence that antidepressants are effective for the treatment of IBS. The subgroup analyses for SSRIs and TCAs are unequivocal and their effectiveness may depend on the individual patient. Future research should use rigorous methodology and valid outcome measures.

[Guidelines for the treatment of irritable bowel syndrome]

Traditional symptom-based therapies of irritable bowel syndrome (IBS) are directed at the relief of individual IBS symptoms, but they are often of limited efficacy in addressing the entire symptom complex. Combinations of drugs to target bothersome symptoms are suggested as the first-line pharmacologic treatment. Increasing knowledge of the pathophysiology and molecular mechanisms of IBS has resulted in the development of several new therapeutic approaches. Thirteen consensus statements for the treatment of IBS were developed using the modified Delphi approach. Exclusion diets have modest efficacy in improving symptoms in some IBS patients. Symptom-based therapies with dietary fiber, bulking agents, laxatives, antispasmodics and laxatives are effective in the improvement of some individual symptoms, e.g. dietary fiber and bulking agents for constipation, laxatives for constipation, antispasmodics for abdominal pain and discomfort, antidiarrheals for diarrhea. 5HT3 receptor antagonists and 5HT((4)) receptor agonists are effective in the relief of global IBS symptoms and individual symptoms such as abdominal pain and abnormal bowel habits. A short term course of nonabsorbable antibiotics may improve global IBS symptoms, particularly in patients with diarrhea- predominant IBS. Some probiotics appear to have the potential benefit in improving global IBS symptoms. Selective C-2 chloride channel activator is more effective than placebo at relieving global IBS symptoms in patients with constipation-predominant IBS. Both tricyclic antidepressants and selective serotonin reuptake inhibitors are equally effective in relieving global IBS symptoms, and have some benefits in treating abdominal pain. Certain types of psychologic therapy may be effective in improving global symptoms in some IBS patients. Further studies are strongly needed to develop better treatment strategies for Korean patients with IBS.

Treatment of irritable bowel syndrome in women

Irritable bowel syndrome (IBS) is a complex clinical process with multiple pathophysiologic mechanisms. There has recently been a shift in the treatment of patients with severe IBS symptoms to disease-modifying therapies as opposed to symptomatic treatment. Because pathophysiologic differences exist between men and women, so does the efficacy of treatment options. These differences could further explain gender-related differences in disease prevalence and treatment response. A brief discussion of the definition, epidemiology, and diagnostic criteria of IBS is followed by a comprehensive review of the current treatment choices and potential future therapeutic options of IBS in women.

Centrally acting therapies for irritable bowel syndrome

Irritable bowel syndrome (IBS) and other functional gastrointestinal (GI) disorders typically defy traditional diagnostic methods based on structural abnormalities, and has led to the emergence of the discipline of neurogastroenterology or the study of the "brain-gut axis," which is based on dysregulation of neuroenteric pathways as a key pathophysiological feature of IBS. Centrally acting treatments can influence these pathways and improve the clinical manifestations of pain and bowel dysfunction associated with this disorder. To successfully implement these treatment strategies, it is important to recognize their dual effects on brain and gut, understanding the nature and severity of the GI symptoms and their psychosocial concomitants, and applying them within the context of the patient's understanding of their value.

Irritable bowel syndrome: epidemiology, diagnosis and treatment: an update for health-care practitioners

Irritable bowel syndrome (IBS), a chronic gastrointestinal disorder, affects from 3-20% of the US population, depending on sociocultural and comorbid factors. IBS is characterized by a symptom complex of abdominal pain and abnormal bowel habits that present as diarrhea or constipation, and general physical weakness in the absence of abnormal morphological, histological or inflammatory markers. The main diagnostic Rome III criteria as established by international professional organizations are based on exclusion criteria and the occurrence and rate of symptoms. Because the pathophysiology and causes of IBS are poorly understood, treatment approaches are mainly focused on symptom management to maintain everyday functioning and improve quality of life for persons with IBS. The mainstay of intervention is pharmacological treatment with antispasmodics and antidiarrheals for diarrhea, prokinetics and high-fiber diets for constipation, and supportive therapy with low-dose antidepressants to normalize gastrointestinal motility. Other interventions include lifestyle and dietary changes, psychotherapy, herbal therapies and acupuncture. The purpose of this review is to critically assess benefits and risks of current treatment approaches as well as promising complementary and alternative therapies.

Efficacy of tricyclic antidepressant therapy in adults with cyclic vomiting syndrome: a two-year follow-up study

AIM

To investigate the effects of prolonged tricyclic antidepressants (TCAs) therapy on the frequency and duration of episodes of cyclic vomiting syndrome (CVS) in adults, and the global assessment of clinical improvement and the number of emergency department (ED) visits and/or hospitalizations.

METHOD

An open labeled study was conducted in adult CVS patients treated with a TCA and followed for up to 2 years. Demographic data, TCA dosage, duration and frequency of CVS episodes, ED visits, and hospitalizations at baseline and during TCA therapy were recorded, and patients were monitored for any adverse events.

RESULTS

Forty-six patients initially met the inclusion criteria and 41 patients (22 male) with mean age of 35 years (range: 18 to 63 y) on TCA were able to be followed for 1 year and 23 were evaluated for 2 years. Mean age of onset of CVS symptoms was 26 years (range: 10 to 52 y) and mean age for making the diagnosis of CVS was 32 years (range: 15 to 63 y). The frequency and duration of an episode and ED visits related to CVS were all significantly reduced after both the first and second year of TCA therapy (P<0.05). Eighty-eight percent reported an improved clinical status by subjective global assessment. Mild side effects were reported in 34% not necessitating stoppage of the TCA.

CONCLUSIONS

Long-term TCA therapy significantly reduces the frequency and duration of CVS episodes, ED visits, and hospitalizations (P<0.05), and improves overall clinical well-being providing evidence that they are effective therapy for adult CVS.

Serotonin and the GI tract

Serotonin (5-hydroxytryptamine, 5-HT) participates in several functions of the gastrointestinal tract. Receptors in seven families (5-HT(1)-5-HT(7)) were identified, many of which are present on enterocytes, intrinsic and extrinsic neurons, interstitial cells, and gut myocytes. Most 5-HT is released from enterochromaffin cells in response to physiologic and pathologic stimuli. Roles of 5-HT in health include control of normal gut motor activity, secretion, and sensation, and regulation of food intake and cell growth. Abnormalities of serotonergic function contribute to symptom genesis in functional bowel disorders, inflammatory and infectious diseases of the gut, emetic responses to varied stimuli, obesity, and dysregulation of cell growth. Therapies acting as agonists or antagonists of 5-HT receptors or that modulate 5-HT reuptake play prominent roles in managing these conditions, although use of many agents is hampered by cardiopulmonary complications. Novel agents are in testing, which may exhibit efficacy without significant toxicity.

Serotoninergic and non-serotoninergic effects of two tricyclic antidepressants on visceral nociception in a rat model

OBJECTIVE

Tricyclic antidepressants (TCAs) are well established in the treatment of patients with irritable bowel syndrome (IBS). The effects are believed to be linked to serotoninergic antinociceptive properties, but data on the antinociceptive effects of various TCAs with variable serotoninergic and non-serotoninergic properties have not been investigated. The aim of this study was to compare the antinociceptive effects of different TCAs.

MATERIAL AND METHODS

Colorectal distension (CRD) using a barostat device was carried out in rats and the visceromotor response (VMR) to CRD was quantified by abdominal wall electromyography. Prior to CRD, saline (control), amitriptyline (AM), desipramine (DES), reserpine (RES) or a combination of TCAs and RES (AM + RES or DES + RES) was applied intraperitoneally. Serum 5-HT levels were determined using high-performance liquid chromatography (HPLC). RES was used to antagonize the serotoninergic actions of TCAs in order to discriminate between these effects and others.

RESULTS

Both TCAs decreased the VMR compared to placebo. After RES application without TCAs, the VMR was increased compared to controls (6403 microV+/-1772 microV). Co-administration of AM and RES resulted in a modest decrease in VMR (5774 microV+/-1953 microV), while in rats treated with RES and DES the VMR again was significantly lower (3446 microV (+/-1347 microV; p <0.05)). 5-HT levels were higher in TCA pretreated rats than those in controls and significantly lower 5-HT levels were found in all rats pretreated with RES.

CONCLUSIONS

AM and DES have antinociceptive properties while RES is pro-nociceptive. The antinociceptive effects of DES are not abolished by RES pretreatment, while AM only attenuates the pro-nociceptive effects of RES. The non-serotoninergic properties of TCAs substantially contribute to the differences in the antinococeptive effects of various TCAs.

Therapeutic advances in functional gastrointestinal disease: irritable bowel syndrome

Reported prevalence rates of irritable bowel syndrome (IBS) are between 8% to 20% in the US general population with an average medical expenditure of US$1.35 billion direct and US$205 million indirect costs. Current pathophysiologic theories are based on abnormalities of both the brain and gut, thus setting a new stage for current and future therapeutic approaches. There are numerous treatment options in IBS acting centrally and peripherally by influencing motility and visceral sensitivity. Clinical evidence is variable; however, newer emerging treatments are being evaluated using better-designed clinical trials. Accurate assessment of IBS drug efficacy is still hampered by heterogeneity of the IBS population. Novel methods such as pharmacogenomics or brain imaging may be helpful in the future to better understand and characterize IBS patient subtypes, and this in turn will lead to more specific and efficient therapeutic options. Patient subpopulation measurement of side effects is also a clinical challenge and further understanding could improve treatment efficacy enhancing the patient compliance.

Pain and inflammatory bowel disease

Abdominal pain is a common symptom of inflammatory bowel disease (IBD: Crohn's disease, ulcerative colitis). Pain may arise from different mechanisms, which can include partial blockage and gut distention as well as severe intestinal inflammation. A majority of patients suffering from acute flares of IBD will experience pain, which will typically improve as disease activity decreases. However, a significant percentage of IBD patients continue experiencing symptoms of pain despite resolving inflammation and achieving what appears to be clinical remission. Current evidence suggests that sensory pathways sensitize during inflammation, leading to persistent changes in afferent neurons and central nervous system pain processing. Such persistent pain is not only a simple result of sensory input. Pain processing and even the activation of sensory pathways is modulated by arousal, emotion, and cognitive factors. Considering the high prevalence of iatrogenic as well as essential neuropsychiatric comorbidities including anxiety and depression in IBD patients, these central modulating factors may significantly contribute to the clinical manifestation of chronic pain. The improved understanding of peripheral and central pain mechanisms is leading to new treatment strategies that view pain as a biopsychosocial problem. Thus, improving the underlying inflammation, decreasing the excitability of sensitized afferent pathways, and altering emotional and/or cognitive functions may be required to more effectively address the difficult and disabling disease manifestations.

Not all side effects associated with tricyclic antidepressant therapy are true side effects

BACKGROUND & AIMS

Patients with functional gastrointestinal disorders treated with tricyclic antidepressants sometimes report nongastrointestinal symptoms; it is unclear whether these are drug side effects or reflect a behavioral tendency to report symptoms. We evaluated whether symptoms reported before treatment with a tricyclic antidepressant (desipramine) increased in number or worsened in severity after 2 weeks of treatment and assessed the baseline factors that predispose patients to report symptoms.

METHODS

Female patients in a multicenter National Institutes of Health trial for functional bowel disorders completed a 15-item symptom questionnaire at baseline (before randomization), 2 weeks after they were given desipramine (n = 81) or placebo (n = 40), and at study completion (12 weeks). Patients were asked about the severity and frequency of 15 symptoms. Results were analyzed from 57 patients given desipramine who completed the questionnaires.

RESULTS

Symptoms reported as side effects to have occurred more frequently and also worsened at week 2 in the group given desipramine included dizziness, dry mouth/thirstiness, lightheadedness, jittery feelings/tremors, and flushing. Symptoms that did not change in severity or showed improvement at week 2 in the group given desipramine included morning tiredness, nausea, blurred vision, headaches, appetite reduction, and trouble sleeping. Psychologic distress but not desipramine blood level correlated with symptom reporting.

CONCLUSIONS

Most symptoms often attributed to side effects of desipramine were present before treatment; only a few, related to anticholinergic effects, worsened 2 weeks after treatment, suggesting that most so-called side effects were not associated specifically with desipramine use. Such symptoms might instead be associated with psychologic distress.

Psychopharmacologic and behavioral treatments for functional gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs) are commonly seen gastrointestinal (GI) conditions that are diagnosed using established symptom-based criteria. These disorders that typically defy traditional diagnostic methods based on structural abnormalities have intrigued researchers for several decades. This has led to the emergence of the current discipline of neurogastroenterology or the study of the "brain-gut axis," which is based on dysregulation of neuroenteric pathways as a key pathophysiologic feature of the FGIDs. Psychopharmacologic and behavioral treatments can influence the dysregulation of these pathways, especially at the severe end of the spectrum, and improve the clinical manifestations of these conditions, visceral discomfort or pain and bowel dysfunction. Their actions are mostly at spinal and supraspinal levels with some direct benefits at the level of the gut. Improvements in coping, global distress, and overall quality of life (QOL) have been shown more consistently with these treatments compared with improvement in GI symptoms. A successful approach to patients with these treatments requires a good physician-patient relationship. Strategizing treatments with these modalities is based on recognition of their dual effects on brain and gut, understanding the nature and severity of the GI symptoms and their psychosocial concomitants, and applying them within the context of the patient's understanding of their value.

Effects of amitriptyline on gastric sensorimotor function and postprandial symptoms in healthy individuals: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Low-dose tricyclic antidepressants have been used to treat chronic somatic and gastrointestinal pain disorders, including refractory functional dyspepsia. However, there are only limited data on the effects of these drugs on upper gastrointestinal function.

AIM

To compare the effects of two doses of amitriptyline (AMT) and placebo on gastric accommodation, emptying, satiation, and postprandial symptoms in healthy volunteers.

METHODS

Using a parallel-group, double-blind, placebo-controlled design, 41 healthy volunteers were randomized to AMT 25 mg, AMT 50 mg, or placebo for 2 wk. During the final 3 days of therapy, the following end points were assessed: fasting and postprandial gastric volumes, 2- and 4-h gastric emptying, time and volume to maximum satiation using a nutrient drink test, and postprandial symptoms 30 min later using 10-cm visual analog scales. AMT and metabolite levels were measured.

RESULTS

AMT slowed gastric emptying at 2 h (median 75% for placebo, 57% for AMT 25 mg, 67% for AMT 50 mg; P= 0.037) and 4 h (median 98% for placebo, 96% for AMT 25 mg, 92% for AMT 50 mg; P= 0.003). AMT did not affect gastric volumes or satiation volume, but it did reduce nausea scores at 30 min in a dose-dependent manner (median 2.1 for placebo, 0.9 for AMT 25 mg, and 0.0 for AMT 50 mg; P= 0.009).

CONCLUSION

In healthy volunteers, AMT slows gastric emptying of solids, but it does not significantly affect gastric volumes or satiation. AMT reduces nausea after challenge with a high calorie liquid load.

Clinical trial: the effect of amitriptyline in patients with diarrhoea-predominant irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome is the most common disorder diagnosed by gastroenterologists. Although several randomized-controlled trials have assessed the therapeutic role of antidepressant drugs, there is insufficient evidence to support their use.

AIM

To compare the effects of low-dose amitriptyline in the treatment of diarrhoea-predominant irritable bowel syndrome in a double-blind randomized-controlled trial.

METHODS

Fifty-four patients who fulfilled Rome II criteria for diarrhoea-predominant irritable bowel syndrome were included in this study. Organic causes were ruled out by standard laboratory and radiological tests, and rectosigmoidoscopy. Patients were randomly assigned to receive either 10 mg amitriptyline daily or placebo. Subjects were followed up for 2 months and symptoms were assessed using a questionnaire. Intention-to-treat and per-protocol analysis was performed.

RESULTS

Fifty patients completed the study. At 2 months, the amitriptyline group showed greater (P < 0.05) reduction in the incidence of loose stool and feeling of incomplete defecation. Patients receiving amitriptyline showed greater complete response, defined as loss of all symptoms, compared with those receiving placebo (68% vs. 28%, P = 0.01). Adverse effects were similar between the two groups.

CONCLUSION

Amitriptyline may be effective in the treatment of diarrhoea-predominant irritable bowel syndrome and at low dose is well tolerated.

The effect of short-term, low-dose tricyclic and tetracyclic antidepressant treatment on satiation, postnutrient load gastrointestinal symptoms and gastric emptying: a double-blind, randomized, placebo-controlled trial

Antidepressants are commonly prescribed for patients with functional dyspepsia. However, the effect of tricyclic antidepressants on satiation and gastric emptying remains unclear, and there are no data for tetracyclic compounds. To compare the effects of nortriptyline (maximum dose: 50 mg daily) and mirtazapine (30 mg daily) vs placebo on gastric emptying, gastric satiation and postprandial symptoms after a nutrient load in healthy volunteers. Randomized, double-blind, placebo-controlled study evaluated gastric function before and after 14 days of nortriptyline (n = 13), mirtazapine (n = 13), or placebo (n = 14) in healthy volunteers. Validated methods were used to study gastric emptying ((13)C-octanoate) and satiation postnutrient drink test. The three arms were comparable with regard to age, gender, body mass index and hospital anxiety/depression scale. There were no statistically significant effects of mirtazapine or nortriptyline on gastric emptying compared to placebo (P = 0.34). Maximum tolerated volume was similar on drug and placebo (P = 0.56). Aggregate symptom score 30 min postmaximum tolerated volume after nutrient drink challenge on placebo was 132 (+/-21), vs 165 (+/-21) on mirtazapine, and 126 (+/-21) on nortriptyline 50 mg respectively (P = 0.28). Tricyclic and tetracyclic antidepressant agents do not appear to have significant effects on gastric motor or satiation postnutrient challenge in healthy individuals at the doses tested.

Pharmacogenomics and serotonergic agents: research observations and potential clinical practice implications

Pharmacogenomics of serotonin are potentially relevant in research and clinical practice. There are few proven examples of the importance of pharmacogenetics of serotonin-modifying agents used in functional gastrointestinal or motility disorders. Drug metabolism is dependent on function of the cytochrome P450 enzymes, such as 2D6 and 3A4. Genetic variations in transporters and translation mechanisms have been associated with responses to treatment in irritable bowel syndrome and in obesity. Research on the impact of polymorphisms of key proteins on the pharmacokinetics and pharmacodynamics of drugs that alter serotonin-mediated signalling will assist in explaining diverse responses to those drugs and ultimately improve clinical practice, individualizing medicine.

Bacteria and irritable bowel syndrome: the evidence for small intestinal bacterial overgrowth

Irritable bowel syndrome (IBS) is a complex, yet common diagnosis in gastroenterology. Recent data suggest the increasing importance of bacteria in the pathophysiology of IBS. Some studies have shown that IBS can be precipitated by an acute case of gastroenteritis. These pathogenic organisms may contribute to long-term gut dysfunction. In another line of effort, a growing body of evidence links IBS to the presence of excessive bacteria in the small bowel, called bacterial overgrowth. Although the means by which this is determined have been indirect, studies demonstrating the benefit of unabsorbed antibiotics suggest that reduction in gut flora is important. Further work has also examined bacterial overgrowth in the context of the various symptoms of patients with IBS. These symptom complexes include constipation, diarrhea, and alternating forms of the condition. Although this idea seems initially counterintuitive, it has been demonstrated that the fermentation of methane in the gut is associated with and can result in the slowing of intestinal transit, resulting in constipation. In this review, these topics are discussed and outlined.

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.

Fundamentals of neurogastroenterology: basic science

The focus of neurogastroenterology in Rome II was the enteric nervous system (ENS). To avoid duplication with Rome II, only advances in ENS neurobiology after Rome II are reviewed together with stronger emphasis on interactions of the brain, spinal cord, and the gut in terms of relevance for abdominal pain and disordered gastrointestinal function. A committee with expertise in selective aspects of neurogastroenterology was invited to evaluate the literature and provide a consensus overview of the Fundamentals of Neurogastroenterology textbook as they relate to functional gastrointestinal disorders (FGIDs). This review is an abbreviated version of a fuller account that appears in the forthcoming book, Rome III. This report reviews current basic science understanding of visceral sensation and its modulation by inflammation and stress and advances in the neurophysiology of the ENS. Many of the concepts are derived from animal studies in which the physiologic mechanisms underlying visceral sensitivity and neural control of motility, secretion, and blood flow are examined. Impact of inflammation and stress in experimental models relative to FGIDs is reviewed as is human brain imaging, which provides a means for translating basic science to understanding FGID symptoms. Investigative evidence and emerging concepts implicate dysfunction in the nervous system as a significant factor underlying patient symptoms in FGIDs. Continued focus on neurogastroenterologic factors that underlie the development of symptoms will lead to mechanistic understanding that is expected to directly benefit the large contingent of patients and care-givers who deal with FGIDs.

Hypothesis driven research and molecular mechanisms in functional dyspepsia: the beginning of a beautiful friendship in research and practice?

There is accumulating evidence of a genetic predisposition in at least a subset of patients with functional GI symptoms. Hence, hunting for genes in irritable bowel syndrome and functional dyspepsia has become fashionable of late. Unfortunately, as in other fields, replication of gene association studies has most often been problematic. In this issue of the Journal, independent corroboration of an association of dyspepsia with GNbeta3 is reported. Other carefully selected putative genes including polymorphisms in the alpha2A adrenoreceptor, the serotonin reuptake transporter, and the 5-HT1A receptor were not associated. The study raises three key questions all considered in this editorial: (a) if GNbeta3 is truly associated with functional and uninvestigated dyspepsia, why might this be the case, (b) what molecular mechanisms may be of most relevance, and (c) perhaps most importantly, does or will this finding translate into clinical practice in terms of diagnosis or treatment? New knowledge of gene associations like GNbeta3 and their pathophysiological relevance may ultimately lead to better targeted therapy as well as new disease modifying treatments.