Effect of Brain-Gut Behavioral Treatments on Abdominal Pain in Irritable Bowel Syndrome: Systematic Review and Network Meta-Analysis.

BACKGROUND & AIMS: Some brain-gut behavioral treatments (BGBTs) are beneficial for global symptoms in irritable bowel syndrome (IBS). United States management guidelines suggest their use in patients with persistent abdominal pain, but their specific effect on this symptom has not been assessed systematically. METHODS: We searched the literature through December 16, 2023, for randomized controlled trials (RCTs) assessing efficacy of BGBTs for adults with IBS, compared with each other or a control intervention. Trials provided an assessment of abdominal pain resolution or improvement at treatment completion. We extracted data as intention-to-treat analyses, assuming dropouts to be treatment failures and reporting pooled relative risks (RRs) of abdominal pain not improving with 95% confidence intervals (CIs), ranking therapies according to the P score. RESULTS: We identified 42 eligible randomized controlled trials comprising 5220 participants. After treatment completion, the BGBTs with the largest numbers of trials and patients recruited demonstrating efficacy for abdominal pain, specifically, included self-guided/minimal contact cognitive behavioral therapy (CBT) (RR, 0.71; 95% CI, 0.54-0.95; P score, 0.58), face-to-face multicomponent behavioral therapy (RR, 0.72; 95% CI, 0.54-0.97; P score, 0.56), and face-to-face gut-directed hypnotherapy (RR, 0.77; 95% CI, 0.61-0.96; P score, 0.49). Among trials recruiting only patients with refractory global IBS symptoms, group CBT was more efficacious than routine care for abdominal pain, but no other significant differences were detected. No trials were low risk of bias across all domains, and there was evidence of funnel plot asymmetry. CONCLUSIONS: Several BGBTs, including self-guided/minimal contact CBT, face-to-face multicomponent behavioral therapy, and face-to-face gut-directed hypnotherapy may be efficacious for abdominal pain in IBS, although none was superior to another.

Novel Symptom Subgroups in Individuals With Irritable Bowel Syndrome Predict Disease Impact and Burden.

BACKGROUND & AIMS: Current classification systems based on bowel habit fail to capture the multidimensional nature of irritable bowel syndrome (IBS). We previously derived and validated a classification system, using latent class analysis, incorporating factors beyond bowel habit. We applied this in another cohort of people with IBS to assess its ability to capture the impact of IBS on the individual, the health care system, and society. METHODS: We collected demographic, symptom, and psychological health data from adults in the community self-identifying as having IBS, and meeting Rome IV criteria. We applied our latent class analysis model to identify the 7 subgroups (clusters) described previously, based on overall gastrointestinal symptom severity and psychological burden. We assessed quality of life, health care costs (£1 = $1.20), employment status, annual income, work productivity, and ability to perform work duties in each cluster. RESULTS: Of 1278 responders, 752 (58.8%) met Rome IV criteria. The 7-cluster model fit the data well. The patients in the 4 clusters with the highest psychological burden, and particularly those in cluster 6 with high overall gastrointestinal symptom severity and high psychological burden, showed lower educational levels, higher gastrointestinal symptom-specific anxiety, were more likely to have consulted a gastroenterologist, and used more drugs for IBS. IBS-related and generic quality of life were impaired significantly in these 4 clusters and significantly fewer individuals reported earning ≥£30,000 per year. Productivity and the ability to work, manage at home, engage in social and private leisure activities, and maintain close relationships all were impacted significantly, and IBS-related health care costs over the previous 12 months were highest in these 4 clusters. In those in cluster 6, costs were more than £1000 per person per year. CONCLUSIONS: Our clusters identify groups of individuals with significant impairments in quality of life, earning potential, and ability to work and function socially, who are high utilizers of health care.

Systematic Review and Meta-analysis: Efficacy of Mesalamine in Irritable Bowel Syndrome.

BACKGROUND & AIMS: Some patients with irritable bowel syndrome (IBS) demonstrate low-grade inflammation in the intestine. Mesalamine, which has anti-inflammatory effects, may be an efficacious treatment for IBS, but studies are conflicting. We conducted a systematic review and meta-analysis to assess efficacy and safety of mesalamine in IBS. METHODS: We searched the medical literature up to September 14, 2022, to identify randomized controlled trials (RCTs) of mesalamine in IBS. We judged efficacy and safety using dichotomous assessments of effect on global IBS symptoms, abdominal pain, bowel habit or stool frequency, and occurrence of any adverse event. We pooled data using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: We identified 8 eligible RCTs (820 patients). Mesalamine was more efficacious than placebo for global IBS symptoms (RR of global symptoms not improving, 0.86; 95% CI, 0.79-0.95; number needed to treat = 10; 95% CI, 6-27), but not for abdominal pain or bowel habit or stool frequency. Subgroup analyses demonstrated efficacy of mesalamine in IBS with diarrhea for global IBS symptoms (RR, 0.88; 95% CI, 0.79-0.99), but not patients with other predominant bowel habits or those with post-infection IBS. Adverse event rates were no higher with mesalamine (RR, 1.20; 95% CI, 0.89-1.63) but were reported in only 5 trials. CONCLUSIONS: Mesalamine may be modestly efficacious for global symptoms in IBS, particularly IBS with diarrhea, but quality of evidence was low. Adequately powered high quality RCTs of mesalamine in IBS are needed.

Assessing Diagnostic Performance of Modifications to the Rome IV Criteria for Irritable Bowel Syndrome.

The gold standard symptom-based criteria for diagnosis of irritable bowel syndrome (IBS) are the Rome IV criteria.1 These are more restrictive than their predecessor, Rome III, because the cardinal feature required to meet criteria for IBS was changed to presence of abdominal pain alone, rather than abdominal pain or discomfort.2 This change was made because discomfort was believed to be an ambiguous term, with no equivalent in some languages. In addition, symptom frequency required for the presence of abdominal pain was increased to 1 day per week from 2 to 3 days per month. This has led to reduced sensitivity for detecting IBS and a 50% decrease in the prevalence of the disorder in the community.3,4 In a cross-sectional survey applying both Rome IV and III criteria to people living with IBS, 89% of those with Rome III-defined IBS not meeting Rome IV criteria did not meet Rome IV criteria because of this change in pain frequency.5 Previous iterations of the Rome criteria have performed only modestly in predicting a diagnosis of IBS.6-8 However, in a validation study, the Rome IV criteria outperformed Rome III,9 largely because their more restrictive nature made them more specific than Rome III. We assessed whether modifications to the Rome IV criteria led to a better trade-off between sensitivity and specificity.

Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Some probiotics may be beneficial in irritable bowel syndrome (IBS), but differences in species and strains used, as well as endpoints reported, have hampered attempts to make specific recommendations as to which should be preferred. We updated our previous meta-analysis examining this issue. METHODS: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to March 2023). Randomized controlled trials (RCTs) recruiting adults with IBS, comparing probiotics with placebo were eligible. Dichotomous symptom data were pooled to obtain a relative risk of global symptoms, abdominal pain, or abdominal bloating or distension persisting after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardized mean difference with a 95% CI. Adverse events data were also pooled. RESULTS: We identified 82 eligible trials, containing 10,332 patients. Only 24 RCTs were at low risk of bias across all domains. For global symptoms, there was moderate certainty in the evidence for a benefit of Escherichia strains, low certainty for Lactobacillus strains and Lactobacillus plantarum 299V, and very low certainty for combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains. For abdominal pain, there was low certainty in the evidence for a benefit of Saccharomyces cerevisae I-3856 and Bifidobacterium strains, and very low certainty for combination probiotics, Lactobacillus, Saccharomyces, and Bacillus strains. For abdominal bloating or distension there was very low certainty in the evidence for a benefit of combination probiotics and Bacillus strains. The relative risk of experiencing any adverse event, in 55 trials, including more than 7000 patients, was not significantly higher with probiotics. CONCLUSIONS: Some combinations of probiotics or strains may be beneficial in IBS. However, certainty in the evidence for efficacy by GRADE criteria was low to very low across almost all of our analyses.

Efficacy and Safety of Drugs for Gastroparesis: Systematic Review and Network Meta-analysis.

BACKGROUND & AIMS: Although there have been multiple drugs tested in gastroparesis, their relative efficacy and safety are unknown. We evaluated this in a network meta-analysis of randomized controlled trials (RCTs). METHODS: We searched the literature to September 7, 2022. We judged the efficacy of drugs based on global symptoms of gastroparesis; individual symptoms, including nausea, vomiting, abdominal pain, bloating, or fullness; and safety according to total adverse events and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses, assuming dropouts to be treatment failures and reporting pooled relative risks (RRs) of not improving with 95% confidence intervals (CIs), ranking drugs according to P-score. RESULTS: We identified 29 RCTs (3772 patients). Based on global symptoms, clebopride ranked first for efficacy (RR, 0.30; 95% CI, 0.16-0.57; P-score = .99) followed by domperidone (RR, 0.68; 95% CI, 0.48-0.98; P-score = .76). No other drug was superior to placebo. Only 2 drug classes were efficacious: in rank order, oral dopamine antagonists (RR, 0.58; 95% CI, 0.44-0.77; P-score = .96) and tachykinin-1 antagonists (RR, 0.69; 95% CI, 0.52-0.93; P-score = .83). For individual symptoms, oral metoclopramide ranked first for nausea (RR 0.46; 95% CI, 0.21-1.00; P-score = .95), fullness (RR 0.67; 95% CI, 0.35-1.28; P-score = .86), and bloating (RR 0.53; 95% CI, 0.30-0.93; P-score = .97), based on only 1 small trial. Only prucalopride was more likely to be associated with adverse events than placebo. CONCLUSIONS: In a network meta-analysis, oral dopamine antagonists and tachykinin-1 antagonists were more efficacious than placebo for gastroparesis, but confidence in the evidence was low to moderate for most comparisons. There is an unmet need for efficacious therapies for gastroparesis.

Novel Irritable Bowel Syndrome Subgroups are Reproducible in the Global Adult Population.

BACKGROUND & AIMS: Current classification systems for irritable bowel syndrome (IBS) based on bowel habit do not consider psychological impact. We validated a classification model in a UK population with confirmed IBS, using latent class analysis, incorporating psychological factors. We applied this model in the Rome Foundation Global Epidemiological Survey (RFGES), assessing impact of IBS on the individual and the health care system, and examining reproducibility. METHODS: We applied our model to 2195 individuals in the RFGES with Rome IV-defined IBS. As described previously, we identified 7 clusters, based on gastrointestinal symptom severity and psychological burden. We assessed demographics, health care-seeking, symptom severity, and quality of life in each. We also used the RFGES to derive a new model, examining whether the broader concepts of our original model were replicated, in terms of breakdown and characteristics of identified clusters. RESULTS: All 7 clusters were identified. Those in clusters with highest psychological burden, and particularly cluster 6 with high overall gastrointestinal symptom severity, were more often female, exhibited higher levels of health care-seeking, were more likely to have undergone previous abdominal surgeries, and had higher symptom severity and lower quality of life (P < .001 for trend for all). When deriving a new model, the best solution consisted of 10 clusters, although at least 2 seemed to be duplicates, and almost all mapped on to the previous clusters. CONCLUSIONS: Even in the community, our original clusters derived from patients with physician-confirmed IBS identified groups of individuals with significantly higher rates of health care-seeking and abdominal surgery, more severe symptoms, and impairments in quality of life.

Efficacy of biological therapies and small molecules in induction and maintenance of remission in luminal Crohn's disease: systematic review and network meta-analysis.

OBJECTIVE: There are numerous biological therapies and small molecules licensed for luminal Crohn's disease (CD), but these are often studied in placebo-controlled trials, meaning relative efficacy is uncertain. We examined this in a network meta-analysis. DESIGN: We searched the literature to 1 July 2022, judging efficacy according to induction of clinical remission, clinical response and maintenance of clinical remission, and according to previous exposure or non-exposure to biologics. We used a random effects model and reported data as pooled relative risks (RRs) with 95% CIs, ranking drugs according to p-score. RESULTS: We identified 25 induction of remission trials (8720 patients). Based on failure to achieve clinical remission, infliximab 5 mg/kg ranked first versus placebo (RR=0.67, 95% CI 0.56 to 0.79, p-score 0.95), with risankizumab 600 mg second and upadacitinib 45 mg once daily third. However, risankizumab 600 mg ranked first for clinical remission in biologic-naïve (RR=0.66, 95% CI 0.52 to 0.85, p-score 0.78) and in biologic-exposed patients (RR=0.74, 95% CI 0.67 to 0.82, p-score 0.92). In 15 maintenance of remission trials (4016 patients), based on relapse of disease activity, upadacitinib 30 mg once daily ranked first (RR=0.61, 95% CI 0.52 to 0.72, p-score 0.93) with adalimumab 40 mg weekly second, and infliximab 10 mg/kg 8-weekly third. Adalimumab 40 mg weekly ranked first in biologic-naïve patients (RR=0.59, 95% CI 0.48 to 0.73, p-score 0.86), and vedolizumab 108 mg 2-weekly first in biologic-exposed (RR=0.70, 95% CI 0.57 to 0.86, p-score 0.82). CONCLUSION: In a network meta-analysis, infliximab 5 mg/kg ranked first for induction of clinical remission in all patients with luminal CD, but risankizumab 600 mg was first in biologic-naïve and biologic-exposed patients. Upadacitinib 30 mg once daily ranked first for maintenance of remission.

Comparison of drugs for active eosinophilic oesophagitis: systematic review and network meta-analysis.

BACKGROUND: There is currently no recommendation regarding preferred drugs for active eosinophilic oesophagitis (EoE) because their relative efficacy is unclear. We conducted an up-to-date network meta-analysis to compare proton pump inhibitors, off-label and EoE-specific topical steroids, and biologics in EoE. METHODS: We searched MEDLINE, Embase, Embase Classic and the Cochrane Central Register of Controlled Trials from inception to June 2023. We included randomised controlled trials (RCTs) comparing efficacy of all drugs versus each other, or placebo, in adults and adolescents with active EoE. Results were reported as pooled relative risks with 95% CIs to summarise effect of each comparison tested, with drugs ranked according to P score RESULTS: Seventeen RCTs were eligible for systematic review. Of these, 15 studies containing 1813 subjects with EoE reported extractable data for the network meta-analysis. For histological remission defined as ≤6 eosinophils/high-power field (HPF), lirentelimab 1 mg/kg monthly ranked first. For histological remission defined as ≤15 eosinophils/HPF, budesonide orally disintegrating tablet (BOT) 1 mg two times per day ranked first. For failure to achieve symptom improvement, BOT 1 mg two times per day and budesonide oral suspension (BOS) 2 mg two times per day were significantly more efficacious than placebo. For failure to achieve endoscopic improvement based on the EoE Endoscopic Reference Score, BOT 1 mg two times per day and BOS 1 mg two times per day or 2 mg two times per day were significantly more efficacious than placebo. CONCLUSIONS: Although this network meta-analysis supports the efficacy of most available drugs over placebo for EoE treatment, significant heterogeneity in eligibility criteria and outcome measures among available trials hampers the establishment of a solid therapeutic hierarchy.

Response and Adverse Event Rates With Placebo in Gastroparesis: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Multiple drugs have been used to treat gastroparesis symptoms, yet their therapeutic benefits are poorly understood partly due to lack of insight into response and adverse event rates with placebo in randomized controlled trials (RCTs). We evaluated these issues systematically in drug trials for gastroparesis. METHODS: We searched the medical literature through August 2, 2022 to identify RCTs comparing active drug with placebo in patients with gastroparesis. We assessed placebo response rates according to at least one of the following endpoints: improvement according to a composite outcome, nausea, vomiting, abdominal pain, bloating, or fullness, as well as total adverse events, and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses with dropouts assumed to be treatment failures. We pooled placebo response and adverse event rates using a random effects model and expressed as proportions with 95% confidence intervals (CIs). RESULTS: Thirty-five studies were eligible. Among 23 trials reporting a composite endpoint of improvement, the pooled placebo response rate was 29.3% (95% CI, 23.7%-35.2%). Pooled placebo response rates were higher in idiopathic compared with diabetic gastroparesis (34.2% vs 28.1%), among trials that did not use validated symptom questionnaires (31.2% vs 27.4%), and in RCTs of shorter duration (<4 weeks, 32.6% vs ≥9 weeks, 23.2%). Adverse events occurred in 33.8% (95% CI, 26.4%-41.8%) of patients with placebo, in 27 trials, and were less common in idiopathic compared with diabetic gastroparesis (17.9% vs 43.4%), trials of shorter duration (<4 weeks, 33.7% vs ≥9 weeks, 40.7%), and trials with lower randomization ratios of active drug to placebo (1:1, 26.7% vs 3:1, 50.5%). CONCLUSIONS: This meta-analysis assessed placebo response and adverse event rates in gastroparesis. To accurately assess therapeutic gain, future trials should be a minimum of 8 weeks duration, use validated questionnaires, and distinguish gastroparesis subtypes.