Patient-Reported Outcomes in Disorders of Gut-Brain Interaction.

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

Opioids and the Gastrointestinal Tract: The Role of Peripherally Active µ-Opioid Receptor Antagonists in Modulating Intestinal Permeability.

Opioid receptors are found throughout the gastrointestinal tract, including the large intestine. Many patients treated with opioids experience opioid-induced constipation (OIC). Laxatives are not effective in most patients, and in those who do initially respond, the efficacy of laxatives generally diminishes over time. In addition, OIC does not spontaneously resolve for most patients. However, complications of opioids extend far beyond simply slowing gastrointestinal transit. Opioid use can affect intestinal permeability through a variety of mechanisms. Toll-like receptors are a crucial component of innate immunity and are tightly regulated within the gut epithelium. Pathologic µ-opioid receptor (MOR) and toll-like receptor signaling, resulting from chronic opioid exposure, disrupts intestinal permeability leading to potentially harmful bacterial translocation, elevated levels of bacterial toxins, immune activation, and increased cytokine production. Peripherally active MOR antagonists, including methylnaltrexone, are effective at treating OIC. Benefits extend beyond simply blocking the MOR; these agents also act to ameliorate opioid-induced disrupted intestinal permeability. In this review, we briefly describe the physiology of the gastrointestinal epithelial border and discuss the impact of opioids on gastrointestinal function. Finally, we consider the use of peripherally active MOR antagonists to treat disrupted intestinal permeability resulting from opioid use and discuss the potential for improved morbidity and mortality in patients treated with methylnaltrexone for opioid-induced bowel disorders.

Abdominal Symptom Improvement During Clinical Trials of Tenapanor in Patients With Irritable Bowel Syndrome With Constipation: A Post Hoc Analysis.

INTRODUCTION: This post hoc analysis evaluated the efficacy of tenapanor on abdominal symptoms in patients with irritable bowel syndrome with constipation. Abdominal symptoms assessed included pain, discomfort, bloating, cramping, and fullness. METHODS: The abdominal symptom data were pooled from 3 randomized controlled trials (NCT01923428, T3MPO-1 [NCT02621892], and T3MPO-2 [NCT02686138]). Weekly scores were calculated for each abdominal symptom, and the Abdominal Score (AS) was derived as the average of weekly scores for abdominal pain, discomfort, and bloating. The overall change from baseline during the 12 weeks was assessed for each symptom weekly score and the AS. The AS 6/12-week and 9/12-week response rates (AS improvement of ≥2 points for ≥6/12- or ≥9/12-week) were also evaluated. The association of weekly AS response status (reduction of ≥30%) with weekly complete spontaneous bowel movement (CSBM) status (=0 and >0) was assessed. RESULTS: Among 1,372 patients (684 tenapanor [50 mg twice a day] and 688 placebo), the least squares mean change from baseline in AS was -2.66 for tenapanor vs -2.09 for placebo ( P < 0.0001). The 6/12-week AS response rate was 44.4% for tenapanor vs 32.4% for placebo ( P < 0.0001), and for 9/12-week AS, 30.6% for tenapanor vs 20.5% for placebo ( P < 0.0001). A significant association between weekly CSBM status and weekly AS response status was observed each week ( P < 0.0001), with a greater proportion achieving an AS reduction in patients with >0 CSBMs in a week. DISCUSSION: Tenapanor significantly reduced abdominal symptoms in patients with irritable bowel syndrome with constipation, particularly pain, discomfort, and bloating measured by AS, compared with placebo.

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.

Prevalence and patterns of laxative use in subjects with self-reported constipation: results from a multinational digestive health survey.

Background: Constipation is characterized by symptoms of straining, hard stool, difficult evacuation, and infrequent bowel movements. Online surveys provide valuable information about patients' perspectives, symptoms, management, treatment satisfaction, and risk factors. Methods: This survey explored subject experiences involving 20 gastrointestinal (GI) conditions. In total, 20,099 respondents in seven countries with varied cultural and socioeconomic backgrounds participated. Post hoc analysis of 'self-reported constipation' and related symptoms experienced within the past 6 months and the last episode of constipation provided data on prevalence, demographics, frequency and duration of episodes and related symptoms, impact on quality of life (QoL), management with or without laxatives, and resulting treatment satisfaction. Results: In total, 10,425 subjects reported constipation within 6 months and 2637 at the last episode. Prevalence was highest in females and younger adults. Most subjects reported various coexisting GI symptoms. Almost 80% of 6865 episodes reported by 5337 subjects occurred every 2-3 months to every 2-3 weeks. A higher frequency of constipation correlated with a greater impact on QoL. On a 10-point scale, the mean impact was 6.4. More than 90% of respondents had episodes ranging from 1 day to 1 week. More than 90% took action; 16% used laxatives, of whom 80.3% were satisfied. Conclusion: Constipation, a highly prevalent disorder, spans cultures and socioeconomic classes. Its chronic recurrence has a significant impact on QoL, resulting in symptom self-management in >90% of subjects. Significantly higher satisfaction rates in subjects treated with than without laxatives reflect subjects' reports that self-reported constipation can be treated effectively with laxatives.

Intestinal Permeability, Irritable Bowel Syndrome with Constipation, and the Role of Sodium-Hydrogen Exchanger Isoform 3 (NHE3).

Increased intestinal permeability has been identified as one of the many pathophysiological factors associated with the development of irritable bowel syndrome (IBS), a common disorder of gut-brain interaction. The layer of epithelial cells that lines the intestine is permeable to a limited degree, and the amount of paracellular permeability is tightly controlled to enable the absorption of ions, nutrients, and water from the lumen. Increased intestinal permeability to macromolecules can be triggered by a variety of insults, including infections, toxins from food poisoning, or allergens, which in turn cause an inflammatory response and are associated with abdominal pain in patients with IBS. This review article discusses increased intestinal permeability in IBS, focusing on IBS with constipation (IBS-C) through the lens of a patient case with a reported prior diagnosis of "leaky gut syndrome" upon initial contact with a gastrointestinal specialist. We review advantages and disadvantages of several methods of measuring intestinal permeability in patients and discuss when measuring intestinal permeability is appropriate in the therapeutic journey of patients with IBS-C. Furthermore, we discuss a possible mechanism of restoring the intestinal barrier to its healthy state through altering intracellular pH by inhibiting sodium-hydrogen exchanger isoform 3 (NHE3). Tenapanor is a minimally absorbed, small-molecule inhibitor of NHE3 that has been approved by the US Food and Drug Administration for the treatment of IBS-C in adults. Preclinical studies showed that tenapanor may restore the intestinal barrier in IBS-C by affecting the conformation of tight junction proteins via NHE3 inhibition to block the paracellular transport of macromolecules from the intestinal lumen. Testing for increased permeability in patients with IBS-C who experience abdominal pain may help inform the choice of therapeutics and alter patients' misconceptions about "leaky gut syndrome".

A novel pilot study to evaluate the efficacy and safety of a wireless patch system in patients with chronic nausea and vomiting.

BACKGROUND: Gastric sensorimotor disorders (functional dyspepsia [FD] and gastroparesis [GP]) are prevalent and burdensome. Prolonged ambulatory recording using a wireless patch may provide novel information in these patients. METHODS: Consecutive adult patients (age ≥ 18 years) referred for gastric emptying scintigraphy (GES) were eligible for study inclusion. Patients were excluded if they had prior foregut surgery; were taking opioids or other medications known to affect gastric emptying; had a HgbA1C > 10; or were recently hospitalized. Three wireless motility patches were applied to the skin prior to GES. Patients wore the patches for 6 days while recording meals, symptoms, and bowel movements using an iPhone app. KEY RESULTS: Twenty-three consecutive adults (87% women; mean age = 43.9 years; mean BMI = 26.7 kg/m2) were enrolled. A gastric histogram revealed three levels of gastric myoelectric activity: weak, moderate, and strong. Patients with delayed gastric emptying at 4 h had weak gastric myoelectrical activity. Patients with nausea and vomiting had strong intestinal activity. Those with FD had weak gastric and intestinal myoelectric activity, and a weak meal response in the stomach, intestine, and colon compared to those with nausea alone or vomiting alone. CONCLUSIONS AND INFERENCES: Patients with FD, and those with delayed gastric emptying, had unique gastrointestinal myoelectrical activity patterns. Reduced postprandial pan-intestinal myoelectric activity may explain the symptoms of FD in some patients. Recording gastrointestinal activity over a prolonged period in the outpatient setting has the potential to identify unique pathophysiologic patterns and meal-related activity that distinguishes patients with distinct gastric sensorimotor disease states.

Treatment-Free Interval: A Novel Approach to Assessing Real-World Treatment Effectiveness and Economic Impact Among Patients with Irritable Bowel Syndrome with Diarrhea.

INTRODUCTION: Objective assessment of treatment effectiveness using real-world claims data is challenging. This study assessed treatment-free intervals (TFI) as a proxy for treatment effectiveness, and all-cause healthcare costs among adult patients with irritable bowel syndrome with diarrhea (IBS-D) treated with rifaximin or eluxadoline in the USA. METHODS: Adult patients (18-64 years) with IBS-D and ≥ 1 rifaximin or eluxadoline prescription were identified in the IQVIA PharMetrics® Plus database (10/01/2015-12/31/2021) and classified into two mutually exclusive cohorts (i.e., rifaximin and eluxadoline). Index date was the date of rifaximin or eluxadoline initiation. Entropy-balanced baseline characteristics, TFI (periods of ≥ 30 consecutive days without IBS-D treatment), and healthcare costs were reported. Healthcare costs were compared between cohorts using mean cost differences. RESULTS: There were 7094 and 2161 patients in the rifaximin and eluxadoline cohorts, respectively. After balancing, baseline characteristics (mean age 44.1 years; female 72.4%) were similar between cohorts. A higher proportion of patients treated with rifaximin achieved a TFI of ≥ 30 days (76.2% vs. 66.7%), ≥ 60 days (67.0% vs. 47.0%), ≥ 90 days (61.0% vs. 38.7%), ≥ 180 days (51.7% vs. 31.0%), and ≥ 240 days (47.7% vs. 27.9%) compared to eluxadoline. Among patients with a TFI ≥ 30 days, mean TFI durations were 8.3 and 6.0 months for the rifaximin and eluxadoline cohorts. Mean all-cause healthcare costs were lower for rifaximin vs. eluxadoline ($18,316 vs. $23,437; p = 0.008), primarily driven by pharmacy costs ($7348 vs. $10,250; p < 0.001). In a simulated health plan of one million commercially insured lives, initiating 50% of patients on rifaximin instead of eluxadoline resulted in total cost savings of $2.1 million per year or $0.18 per-member-per-month. CONCLUSIONS: This real-world study suggests that TFI is a meaningful surrogate measure of treatment effectiveness in IBS-D. Patients treated with rifaximin had longer treatment-free periods and lower healthcare costs than patients treated with eluxadoline.

The effect of virtual reality on perioperative pain management in patients undergoing gastrointestinal procedures and surgeries: a systematic review of clinical trials.

BACKGROUND: Virtual reality (VR) is an advanced technology that transports users into a virtual world. It has been proven to be effective in pain management via distraction and alteration of pain perception. However, the impact of VR on treating perioperative pain is inconclusive. This systematic review aimed to evaluate the effect of VR on perioperative pain after a gastrointestinal (GI) procedure or surgery. METHODS: A systematic review of randomized controlled trials was conducted from inception to January 31, 2024, following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The updated Cochrane risk of bias (RoB 2) assessment tool was used to evaluate the risk of bias. RESULTS: Of 724 articles screened, 8 studies with 678 participants were included in the systematic review. Four studies evaluated the effect of VR on perioperative pain during GI procedure (eg, colonoscopy) focused on its use after GI surgeries (eg, abdominal surgeries). Some studies reported a reduction in pain scores after the procedure; however, the findings of pain difference in before or during vs after the procedure in the VR vs control groups were mixed. CONCLUSION: VR is a promising tool to control perioperative pain after a GI procedure or surgery. Differences in study protocols, pain assessment scales, and pain therapy used were limitations in performing a comprehensive meta-analysis. Further studies are needed to better evaluate the effects of VR on perioperative pain compared with standard of care.

Treatment for chronic idiopathic constipation: Use and satisfaction from a nationwide survey of US participants.

BACKGROUND: Chronic idiopathic constipation (CIC) is a disorder of gut-brain interaction characterized by a variety of bowel movement-related and abdominal symptoms. A greater understanding of medication use and satisfaction with symptom control may provide insights to optimize patient care. Therefore, we explored these aspects of the disorder in adults with CIC. METHODS: This study assessed data collected from a large nationwide survey of adult participants in the United States, querying demographics, clinical characteristics, and comorbid conditions, as well as medication use, care-seeking behaviors, and satisfaction with symptom control. Participants were grouped into the CIC cohort if they met Rome IV criteria, with controls matched 1:1 according to age, sex, race, region, and Charlson Comorbidity Index score. All data were self-reported. KEY RESULTS: Two thousand five hundred and thirty-three participants with CIC were matched 1:1 to controls. In the CIC cohort, abdominal pain was the most reported symptom leading to medication use: 15.9% of respondents were receiving a prescription medication in addition to an over-the-counter medication, while 26.3% were taking neither. In addition, only one-third were satisfied with the control of their symptoms; however, satisfaction was significantly higher in respondents taking a prescription medication (p < 0.001). The proportion of reported comorbidities was significantly higher in the CIC cohort versus the control cohort, with chronic pain, anxiety, and depression among the highest (p < 0.001 for all). CONCLUSIONS AND INFERENCES: This study emphasizes the need for better communication regarding prescription medications and their benefits, with the goal of further improving CIC patients' overall symptoms.