Systematic review and network meta-analysis: efficacy of licensed drugs for abdominal bloating in irritable bowel syndrome with constipation

Plecanatide Improves Abdominal Bloating and Bowel Symptoms of Irritable Bowel Syndrome with Constipation

BACKGROUND

Bloating is a bothersome symptom in irritable bowel syndrome with constipation (IBS-C).

AIM

To evaluate plecanatide efficacy in patients with IBS-C stratified by bloating intensity.

METHODS

Pooled phase 3 data (2 randomized, controlled IBS-C trials) from adults treated with plecanatide 3 mg or placebo for 12 weeks were analyzed. Patients were stratified post-hoc by baseline bloating severity (11-point scale: mild [≤ 5] and moderate-to-severe [> 5]). Assessments included change from baseline in bloating, abdominal pain, and complete spontaneous bowel movement (CSBM) frequency. Abdominal pain and bloating composite responders were defined as patients with ≥ 30% improvement from baseline in both bloating and abdominal pain at Week 12.

RESULTS

At baseline, 1104/1436 patients with IBS-C (76.9%) reported moderate-to-severe bloating. In the moderate-to-severe bloating subgroup, plecanatide significantly reduced bloating severity versus placebo (least-squares mean change [LSMC]: - 1.7 vs - 1.3; P = 0.002), reduced abdominal pain (- 1.7 vs - 1.3; P = 0.006), and increased CSBM frequency (1.4 vs 0.8; P < 0.0001). In the mild bloating subgroup, significant improvements were observed with plecanatide versus placebo for abdominal pain (LSMC: - 1.3 vs - 1.0; P = 0.046) and CSBM frequency (2.0 vs 1.2; P = 0.003) but not bloating (- 0.9 vs - 0.8; P = 0.28). A significantly greater percentage of patients were abdominal pain and bloating composite responders with plecanatide versus placebo (moderate-to-severe bloating: 33.6% vs 26.8% [P = 0.02]; mild bloating: 38.4% vs 27.2% [P = 0.03]).

CONCLUSION

Plecanatide treatment improved IBS-C abdominal and bowel symptoms, including in those who present with moderate-to-severe bloating.

The Disease Spectrum and Natural History of Patients With Abdominal Bloating or Distension: A Longitudinal Study

Background/Aims

Abdominal bloating or distension (AB/D) is a common complaint in the outpatient of gastroenterology department. Since the potential contributors are numerous and complex, a longitudinal study on the disease spectrum and natural history of patients was performed to better understand the key factors of AB/D.

Methods

Consecutive patients with the chief complaint of AB/D referred to the outpatient clinic were screened. Functional gastrointestinal disorders (FGIDs) were diagnosed according to Rome IV criteria. A 3-year follow-up was performed to seek for the changes in symptoms as well as disease spectrum.

Results

A total of 261 participants were enrolled and 139 completed the follow-up. Most patients suffered from moderate to severe symptoms more than 1 day per week. Common causes of AB/D were FGIDs (51.7%) and organic diseases (17.2%). The latter group was older with lower body mass index (BMI). Functional dyspepsia was the most common type of FGIDs in AB/D. The symptoms of 18.0% of participants failed to improve at the end of the 3-year follow-up, and those diagnosed with FGIDs were most likely to continue to suffer. Abdominal pain was a positive predictive factor for good prognosis in the FGIDs group. Besides, only 22.7% of participants had a consistent diagnosis of FGIDs during follow-up.

Conclusions

FGIDs are the most common diagnosis in patients with AB/D. Symptoms were especially hard to be improved. Classification diagnoses of FGIDs in AB/D patients fluctuated significantly over time.

Irritable bowel syndrome - less irritable, or better treatments?

PURPOSE OF REVIEW

Irritable bowel syndrome (IBS) is a chronic, often bothersome disorder of gut-brain interaction (DGBI) characterized by abdominal pain associated with a change in stool frequency and/or caliber. Recent advancements have improved our understanding of the underlying pathophysiology, thus opening new avenues for therapeutic intervention. The purpose of this review is to summarize the current literature regarding treatment modalities for IBS.

RECENT FINDINGS

Altering the gut microbiome via probiotic and antibiotic administration, avoiding dietary triggers, and modulating the gut-brain axis have all proven efficacious for the management of IBS symptoms. Several gut-specific pharmacotherapies are approved for the treatment of IBS, many of which primarily address either diarrhea or constipation, although many patients remain symptomatic despite appropriate use. Brain-gut behavioral therapies (BGBTs) are increasingly used to treat symptoms of IBS, particularly in those who do not respond to traditional therapies. Virtual reality represents an exciting new approach to treating DGBIs, like IBS, though data are limited.

SUMMARY

As our understanding of IBS continues to evolve, so should our therapeutic approach. Individualizing the therapeutic approach is of utmost importance.

AGA Clinical Practice Update on Evaluation and Management of Belching, Abdominal Bloating, and Distention: Expert Review

DESCRIPTION

Belching, bloating, and abdominal distention are all highly prevalent gastrointestinal symptoms and account for some of the most common reasons for patient visits to outpatient gastroenterology practices. These symptoms are often debilitating, affecting patients' quality of life, and contributing to work absenteeism. Belching and bloating differ in their pathophysiology, diagnosis, and management, and there is limited evidence available for their various treatments. Therefore, the purpose of this American Gastroenterological Association (AGA) Clinical Practice Update is to provide best practice advice based on both controlled trials and observational data for clinicians covering clinical features, diagnostics, and management considerations that include dietary, gut-directed behavioral, and drug therapies.

METHODS

This Expert Review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. These best practice advice statements were drawn from a review of the published literature based on clinical trials, the more robust observational studies, and from expert opinion. Because systematic reviews were not performed, these best practice advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: Clinical history and physical examination findings and impedance pH monitoring can help to differentiate between gastric and supragastric belching. BEST PRACTICE ADVICE 2: Treatment options for supragastric belching may include brain-gut behavioral therapies, either separately or in combination, such as cognitive behavioral therapy, diaphragmatic breathing, speech therapy, and central neuromodulators. BEST PRACTICE ADVICE 3: Rome IV criteria should be used to diagnose primary abdominal bloating and distention. BEST PRACTICE ADVICE 4: Carbohydrate enzyme deficiencies may be ruled out with dietary restriction and/or breath testing. In a small subset of at-risk patients, small bowel aspiration and glucose- or lactulose-based hydrogen breath testing may be used to evaluate for small intestinal bacterial overgrowth. BEST PRACTICE ADVICE 5: Serologic testing may rule out celiac disease in patients with bloating and, if serologies are positive, a small bowel biopsy should be done to confirm the diagnosis. A gastroenterology dietitian should be part of the multidisciplinary approach to care for patients with celiac disease and nonceliac gluten sensitivity. BEST PRACTICE ADVICE 6: Abdominal imaging and upper endoscopy should be ordered in patients with alarm features, recent worsening symptoms, or an abnormal physical examination only. BEST PRACTICE ADVICE 7: Gastric emptying studies should not be ordered routinely for bloating and distention, but may be considered if nausea and vomiting are present. Whole gut motility and radiopaque transit studies should not be ordered unless other additional and treatment-refractory lower gastrointestinal symptoms exist to warrant testing for neuromyopathic disorders. BEST PRACTICE ADVICE 8: In patients with abdominal bloating and distention thought to be related to constipation or difficult evacuation, anorectal physiology testing is suggested to rule out a pelvic floor disorder. BEST PRACTICE ADVICE 9: When dietary modifications are needed (eg, low-fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet), a gastroenterology dietitian should preferably monitor treatment. BEST PRACTICE ADVICE 10: Probiotics should not be used to treat abdominal bloating and distention. BEST PRACTICE ADVICE 11: Biofeedback therapy may be effective for bloating and distention when a pelvic floor disorder is identified. BEST PRACTICE ADVICE 12: Central neuromodulators (eg, antidepressants) are used to treat bloating and abdominal distention by reducing visceral hypersensitivity, raising sensation threshold, and improving psychological comorbidities. BEST PRACTICE ADVICE 13: Medications used to treat constipation should be considered for treating bloating if constipation symptoms are present. BEST PRACTICE ADVICE 14: Psychological therapies, such as hypnotherapy, cognitive behavioral therapy, and other brain-gut behavior therapies may be used to treat patients with bloating and distention. BEST PRACTICE 15: Diaphragmatic breathing and central neuromodulators are used to treat abdominophrenic dyssynergia.

Tenapanor in the Treatment of Irritable Bowel Syndrome with Constipation: Discovery, Efficacy, and Role in Management

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction (DGBI). IBS significantly impacts the quality of life of patients. Since its pathogenesis is unclear and can be multifactorial, it highlights the need for new and improved pharmaceutical drugs that not only improve bowel symptoms, but also address global IBS symptoms, such as abdominal pain. Tenapanor, a recently Food & Drug Administration (FDA)-approved medication for IBS with constipation (IBS-C), is a small molecule inhibitor of the sodium/hydrogen exchanger isoform 3 (NHE₃) that inhibits the absorption of sodium and phosphate in the gastrointestinal tract, resulting in fluid retention and softer stool. Furthermore, tenapanor reduces intestinal permeability to improve visceral hypersensitivity and abdominal pain. Due to its recent approval, tenapanor was not included in the recent IBS guidelines, however, it may be considered for IBS-C patients failing first-line treatment of soluble fiber. In this review article, we aim to provide in-depth information to the reader regarding the design of tenapanor, its development through Phase I, II and III randomized clinical trials, and its role in the treatment of IBS-C.

Immobilization of α-galactosidase in polyvinyl alcohol-chitosan-glycidyl methacrylate hydrogels based on directional freezing-assisted salting-out strategy for hydrolysis of RFOs

Raffinose family oligosaccharides (RFOs) in food are the main factors causing flatulence in Irritable Bowel Syndrome (IBS) patients and the development of effective approaches for reducing food-derived RFOs is of paramount importance. In this study, polyvinyl alcohol (PVA)-chitosan (CS)-glycidyl methacrylate (GMA) immobilized α-galactosidase was prepared by the directional freezing-assisted salting-out technique, aimed to hydrolyze RFOs. SEM, FTIR, XPS, fluorescence and UV characterization results demonstrated that α-galactosidase was successfully cross-linked in the PVA-CS-GMA hydrogels, forming a distinct porous stable network through the covalent bond between the enzyme and the carrier. Mechanical performance and swelling capacity analysis illustrated that α-gal @ PVA-CS-GMA not only had suitable strength and toughness for longer durability, but also exhibited high water content and swelling capacity for better retention of catalytic activity. The enzymatic properties of α-gal @ PVA-CS-GMA showed an improved Km value, pH and temperature tolerance range, anti-enzymatic inhibitor (melibiose) activity compared to the free α-galactosidase and its reusability was at least 12 times with prolonged storage stability. Finally, it was successfully applied in the hydrolysis of RFOs in soybeans. These findings provide a new strategy for the development of α-galactosidase immobilization system to biological transform the RFOs components in the food for diet intervention of IBS.

Assessment and management of disorders of gut-brain interaction in patients with eating disorders

Disorders of gut-brain interaction (DBGI), also known as functional gastrointestinal disorders, are common in individuals with eating disorders, and may precede or perpetuate disordered eating. Understanding the pathophysiology of common gastrointestinal symptoms in DGBI can be important for the care of many patients with eating disorders. In this review, we summarize the literature to date on the complex relationship between DBGI and eating disorders and provide guidance on the assessment and management of the most common symptoms of DBGI by anatomic region: esophageal symptoms (globus and functional dysphagia), gastroduodenal symptoms (functional dyspepsia and nausea), and bowel symptoms (abdominal pain, bloating and constipation).

Linaclotide Reduced Response Time for Irritable Bowel Syndrome With Constipation Symptoms: Analysis of 4 Randomized Controlled Trials

INTRODUCTION

These post hoc analyses provide clinically relevant data concerning time to response for individual irritable bowel syndrome with constipation (IBS-C) symptoms after linaclotide use.

METHODS

Time-to-response data were pooled from 4 randomized controlled trials. Response time for abdominal symptoms (pain, discomfort, and bloating) and complete spontaneous bowel movements (CSBMs) were analyzed using the Kaplan-Meier method; patients were categorized as early responders (≤4 weeks), late responders (>4-12 weeks), or nonresponders.

RESULTS

Among 2,350 patients (1,172 placebo and 1,178 linaclotide 290 μg), >50% of patients with IBS-C who initiated linaclotide treatment experienced a decrease of ≥30% in abdominal pain, discomfort, or bloating within 3-4 weeks (median). The median time to achieving ≥3 CSBMs was 4 weeks. Although not all linaclotide-treated patients responded within 12 weeks, a late response occurred between 4 and 12 weeks in 1 in 6 patients for abdominal pain and in approximately 1 in 10 patients for CSBM frequency. Comparisons of early responders, late responders, and nonresponders for both response definitions indicated that women, Whites, and patients with less severe baseline abdominal symptoms were more likely to respond early.

DISCUSSION

Although treatment responses with linaclotide occurred in >50% of patients with IBS-C within 4 weeks of treatment initiation, benefits for individual abdominal symptoms and/or CSBM frequency can still occur between 4 and 12 weeks. A lack of improvement in one symptom does not negate the possibility of response for others, highlighting the importance of discussing all symptoms with patients and not assuming treatment futility at 4 weeks.

Updates in functional dyspepsia and bloating

PURPOSE OF REVIEW

Functional dyspepsia and bloating are common gastrointestinal conditions that frequently lead to gastroenterology referral. Both disorders have a significant negative impact on patients' quality of life and the healthcare system. The purpose of this review is to highlight important new findings in the cause, pathophysiology and treatment of these two disorders.

RECENT FINDINGS

Confocal laser endomicroscopy identified changes in epithelial barrier structure and function, providing important insights into the development of functional dyspepsia symptoms when combined with new observations of localized duodenal inflammation. Changes in the gut microbiome may be responsible for functional dyspepsia symptoms in some patients and may respond to gut-selective antibiotics. New data from the NIH-sponsored Gastroparesis Consortium confirmed that functional dyspepsia and gastroparesis are not distinct disorders but rather exist on a spectrum. Virtual reality may be a new therapeutic option for the treatment of functional dyspepsia. A novel questionnaire was developed and validated to assess symptoms, prevalence and impact in patients with bloating and distension. A meta-analysis identified medications to treat symptoms of bloating in patients with irritable bowel syndrome and constipation.

SUMMARY

Advances in our understanding of the pathophysiology of functional dyspepsia and bloating are leading to important changes in medical therapies.

Latent class analysis does not support the existence of Rome IV functional bowel disorders as discrete entities

BACKGROUND

Previously, we used latent class analysis (LCA) to identify novel subgroups in people with irritable bowel syndrome (IBS). There are four other functional bowel disorders that, although characterized as discrete disorders, overlap considerably with, and fluctuate to, IBS. These might instead be conceptualized as a milder form of IBS. We explored this hypothesis using LCA in a cohort of people with non-IBS functional bowel disorders.

METHODS

We collected demographic, symptom, and psychological health data from 1375 adults in the community who self-identified as having IBS and identified individuals meeting Rome IV criteria for any non-IBS functional bowel disorder. We performed LCA to identify specific subgroups (clusters). We followed participants up at 12 months to reassess gastrointestinal and psychological heath and also gather data about healthcare utilization and impact of symptoms.

KEY RESULTS

811 people met Rome IV criteria for IBS and 558 Rome IV criteria for another functional bowel disorder (76 (5.5%) functional constipation; 198 (14.5%) functional diarrhea; 129 (9.5%) functional abdominal bloating or distension; and 155 (11.4%) unspecified functional bowel disorder). LCA in these 558 people identified five clusters defined by a combination of gastrointestinal symptoms and the extent of psychological co-morbidity. However, correlation between these clusters and the Rome IV functional bowel disorder diagnoses was poor and 75% of people were classified as having mild IBS using our previous IBS-derived model. By 12 months, one-third of people had fluctuated and met criteria for IBS. Clusters with high psychological burden had a poorer prognosis, with higher rates of medical consultation, medication use, and greater impact of symptoms on daily life.

CONCLUSIONS AND INFERENCES

The functional bowel disorders may be better characterized as a spectrum of IBS rather than separate disorders. Adopting this pragmatic stance may help to simply diagnosis, treatment, and recruitment of patients to research trials.

Management of bloating

Abdominal bloating is a subjective sensation of trapped abdominal gas, producing abdominal pressure, fullness sensation, and, in some patients, associated objective abdominal distension. In this month's edition of the journal, a new validated questionnaire to assess the prevalence and impact of gas-related symptoms is presented by Duracinsky et al., showing that gas-related abdominal symptoms are prevalent in patients with irritable bowel syndrome and have a measurable impact on patients daily life. A parallel study by Gardiner et al. assessing the severity of bloating in functional gastrointestinal disorders shows that severe bloating is associated with the severity of abdominal pain, constipation, and somatization, advancing our understanding of the clinical characteristics and relevance of gas-related symptoms in the broad spectrum of functional gastrointestinal disorders. Management of bloating includes non-pharmacological and pharmacological strategies. Dietary interventions to reduce intestinal fermentation and ingestion of food supplements like prebiotics or probiotics can reduce bloating by reducing gas production. The main targets of pharmacological treatments are to improve transit and evacuation with prokinetics, to improve intestinal gas tolerance with antispasmodics and/or neuromodulators, and to modify intestinal microbiota with antibiotics. Secretagogues act by increasing intestinal secretion and decreasing visceral sensitivity and have been reported to be an effective treatment alternative for patients with bloating associated with constipation. Biofeedback therapy addressed to correct abdomino-phrenic dysynergia may be useful for patients with objective abdominal distension, and patients with bloating associated with outlet obstructed defecation may benefit from anorectal biofeedback.

Antidiabetic Medications for Type 2 Diabetics with Nonalcoholic Fatty Liver Disease: Evidence From a Network Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD) are closely related, and antidiabetic medications have been shown to be potential therapeutics in NAFLD. Using a network meta-analysis, we sought to examine the effectiveness of antidiabetic agents for the treatment of NAFLD in patients with type 2 diabetes mellitus.

METHODS

Medline and Embase were searched for randomized controlled trials relating to the use of antidiabetic agents, including sodium-glucose transport protein 2 (SGLT2) inhibitors, glucagon-like peptide-1 receptor agonists, and peroxisome proliferator-activated receptor gamma (PPARγ) agonists, biguanides, sulfonylureas and insulin, on NAFLD in patients with diabetes. The p-score was used as a surrogate marker of effectiveness.

RESULTS

A total of 14 articles were included in the analysis. PPARγ agonists were ranked as the best treatment in steatosis reduction, resulting in the greatest reduction of steatosis. There was statistical significance between PPARγ agonists [mean difference (MD): -6.02%, confidence interval (CI): -10.37% to -1.67%] and SGLT2 inhibitors (MD: -2.60%, CI: -4.87% to -0.33%) compared with standard of care for steatosis reduction. Compared with PPARγ agonists, SGLT2 inhibitors resulted in a statistical significant reduction in fibrosis (MD: -0.06, CI: -0.10 to -0.02). Body mass index reduction was highest in SGLT2 inhibitors and glucagon-like peptide-1 receptor agonists. Additionally, SGLT2 inhibitors were ranked as the best treatment for increasing high-density lipoprotein and reducing low-density lipoprotein.

CONCLUSION

Glucagon-like peptide-1 receptor agonists and SGLT2 inhibitors were suitable alternatives for the treatment of NAFLD in those with type 2 diabetes mellitus with a reduction in body mass index, fibrosis, and steatosis. SGLT2 inhibitors also have the added benefit of lipid modulation.