An Overview of the Effects of Tenapanor on Visceral Hypersensitivity in the Treatment of Irritable Bowel Syndrome with Constipation

Background

Patients with irritable bowel syndrome with constipation (IBS-C) experience persistent abdominal pain, a common symptom leading to greater healthcare utilization and reports of treatment non-response. Clinically significant improvements in abdominal pain were observed in clinical trials of tenapanor, a first-in-class inhibitor of sodium/hydrogen exchanger isoform 3 (NHE3), for the treatment of IBS-C in adults.

Aim

This narrative review reports the current knowledge about visceral hypersensitivity as a mechanism for abdominal pain in patients with IBS-C and explores the published evidence for hypothesized mechanisms by which tenapanor may reduce visceral hypersensitivity leading to the observed clinical response of decreased abdominal pain.

Findings

Abdominal pain is experienced through activation and signaling of nociceptive dorsal root ganglia that innervate the gut. These sensory afferent neurons may become hypersensitized through signaling of transient receptor potential cation channel subfamily V member 1 (TRPV1), resulting in reduced action potential thresholds. TRPV1 signaling is also a key component of the proinflammatory cascade involving mast cell responses to macromolecule exposure following permeation through the intestinal epithelium. Indirect evidence of this pathway is supported by observations of higher pain in association with increased intestinal permeability in patients with IBS. Tenapanor reduces intestinal sodium absorption, leading to increased water retention in the intestinal lumen, thereby improving gastrointestinal motility. In animal models of visceral hypersensitivity, tenapanor normalized visceromotor responses and normalized TRPV1-mediated nociceptive signaling.

Conclusion

By improving gastrointestinal motility, decreasing intestinal permeability and inflammation, and normalizing nociception through decreased TRPV1 signaling, tenapanor may reduce visceral hypersensitivity, leading to less abdominal pain in patients with IBS-C. Therapies that have demonstrated effects on visceral hypersensitivity may be the future direction for meaningful abdominal pain relief for patients with IBS-C.

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.

Optimizing the Utility of Anorectal Manometry for Diagnosis and Therapy: A Roundtable Review and Recommendations

BACKGROUND & AIMS

Anorectal manometry (ARM) is a comprehensive diagnostic tool for evaluating patients with constipation, fecal incontinence, or anorectal pain; however, it is not widely utilized for reasons that remain unclear. The aim of this roundtable discussion was to critically examine the current clinical practices of ARM and biofeedback therapy by physicians and surgeons in both academic and community settings.

METHODS

Leaders in medical and surgical gastroenterology and physical therapy with interest in anorectal disorders were surveyed regarding practice patterns and utilization of these technologies. Subsequently, a roundtable was held to discuss survey results, explore current diagnostic and therapeutic challenges with these technologies, review the literature, and generate consensus-based recommendations.

RESULTS

ARM identifies key pathophysiological abnormalities such as dyssynergic defecation, anal sphincter weakness, or rectal sensory dysfunction, and is a critical component of biofeedback therapy, an evidence-based treatment for patients with dyssynergic defecation and fecal incontinence. Additionally, ARM has the potential to enhance health-related quality of life and reduce healthcare costs. However, it has significant barriers that include a lack of education and training of healthcare providers regarding the utility and availability of ARM and biofeedback procedures, as well as challenges with condition-specific testing protocols and interpretation. Additional barriers include understanding when to perform, where to refer, and how to use these technologies, and confusion over billing practices.

CONCLUSIONS

Overcoming these challenges with appropriate education, training, collaborative research, and evidence-based guidelines for ARM testing and biofeedback therapy could significantly enhance patient care of anorectal disorders.

Management of Constipation in Hospitalized Patients

Constipation is frequently encountered in hospital settings and can have potentially serious consequences yet is often underrecognized and undertreated. Opioid-induced constipation is a common cause of constipation in hospitalized patients. Opioids induce constipation through agonistic effects on enteric µ-opioid receptors. This review aims to provide insight on the identification and management of constipation in inpatient settings, with a particular focus on opioid-induced constipation. Constipation assessment should be routinely initiated at hospital admission and can be facilitated by thorough symptom assessments; relevant patient history, including recent medication use; physical examination; and patient assessment tools developed to evaluate the impact of constipation. Management of opioid-induced constipation should begin with ensuring adequate hydration and electrolyte balance and encouraging patient mobilization. Other treatments may include laxatives, enemas, intestinal secretagogues, peripherally acting µ-opioid receptor antagonists, and manual disimpaction. Surgical intervention may be required for some patients as a salvage therapy in severe, refractory cases.

Rifaximin Treatment for Individual and Multiple Symptoms of Irritable Bowel Syndrome With Diarrhea: An Analysis Using New End Points

PURPOSE

Rifaximin is indicated for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults. The current aim was to evaluate rifaximin efficacy on individual and composite IBS-D symptoms using definitions not previously examined.

METHODS

Phase III post hoc analyses of two randomized, double-blind, placebo-controlled trials and the open-label phase of a randomized, double-blind, placebo-controlled trial were conducted. Adults with IBS-D received a 2-week course of rifaximin 550 mg TID. Individual and composite responses for abdominal pain (mean weekly improvements from baseline of ≥30%, ≥40%, or ≥50%), bloating (mean weekly improvements from baseline of ≥1 or ≥2 points; or ≥30%, ≥40%, or ≥50%), stool consistency (mean weekly average stool consistency score <3 or <4), and urgency (improvement from baseline of ≥30% or ≥40% in percentage of days with urgency) for ≥2 of the first 4 weeks after treatment, and weekly for 12 weeks, were assessed.

FINDINGS

Overall, 1258 patients from the double-blind trials (rifaximin [n = 624]; placebo [n = 634]) and 2438 from an open-label trial were analyzed. The percentage of bloating or urgency responders was significantly greater with double-blind rifaximin versus placebo (P ≤ 0.03). A significantly greater percentage of the double-blind group were composite abdominal pain and bloating responders versus placebo for all thresholds analyzed (P < 0.05). A significantly greater percentage of the double-blind group were tri-symptom composite end point responders (abdominal pain, bloating, and fecal urgency) versus placebo (P = 0.001). A significantly greater percentage of patients achieved response (≥30% composite tri-symptom threshold) with double-blind rifaximin versus placebo as early as 1 week posttreatment, with significance maintained through ≥5 weeks after treatment. Open-label results were consistent with those of the double-blind study.

IMPLICATIONS

Rifaximin significantly improved multiple, concurrent IBS-D symptoms, using clinically relevant definitions of treatment response. Using a novel tri-symptom composite end point (ie, abdominal pain, bloating, fecal urgency), adults with IBS-D treated with a 2-week course of rifaximin were significantly more likely to be composite end point responders than those receiving placebo (≥30% or ≥40% threshold) for the three symptoms. Thus, rifaximin not only met current standard thresholds used for adjudication of responders in clinical trials but also achieved higher thresholds for many of these symptoms, suggesting potential for even more robust clinical improvements.

CLINICALTRIALS

gov identifiers: NCT00731679, NCT00724126, and NCT01543178. (Clin Ther. 2023;45:XXX-XXX) © 2023 Elsevier HS Journals, Inc.

Nutrient Drink Test to Assess Gastric Accommodation in Cyclic Vomiting Syndrome: Single-blinded Parallel Grouped Prospective Study

Background/Aims

Cyclic vomiting syndrome (CVS) is characterized by episodes of nausea and vomiting, separated by symptom-free intervals. The pathogenesis of CVS is poorly understood. Limited data exist on evaluating impaired gastric accommodation as a mechanistic means for symptoms. We aim to determine if CVS patients demonstrate impaired gastric accommodation applying a nutrient drink test (NDT) protocol.

Methods

Through this single-blinded pilot clinical trial, patients with CVS per Rome IV critera and healthy controls were assessed for presence of impaired gastric accommodation by administering an established NDT protocol. Statistical analysis was performed, with data presented as medians and interquartile range.

Results

Eleven CVS patients and 15 healthy controls participated in the study between January 2018 and October 2018. Median age was 42.0 years and 37.0 years; majority of subjects were female, 72.7% and 73.3%, respectively. Demographics were similar between CVS and healthy controls. Almost all healthy controls (93.3%) ingested the complete 500 mL protocol, whereas a smaller proportion (72.7%) were able to complete all 4 doses in the CVS group (P = 0.188). Post-prandial visual analogue scale scores of nausea and abdominal pain were found to be significantly higher in CVS patients compared to healthy controls.

Conclusions

To our knowledge, this is the first NDT protocol in CVS evaluating the role of impaired gastric accommodation and hypersensitivity as a possible pathophysiologic mechanism. Findings from this study suggest the presence of gastric hypersensitivity in a subset of CVS patients. These results provide the foundational data necessary for future larger testing of NDT and diagnostic accuracy in CVS.

Gallbladder Dyskinesia

Gallbladder dyskinesia is a functional disorder of the gastrointestinal tract, which can result in debilitating episodes of abdominal pain and associated symptoms. Key diagnostic criteria include a diminished gallbladder ejection fraction on scintigraphy and absence of other causes for the symptoms. Pathologic findings and follow-up suggest a distinct mechanistic basis for this condition. Unfortunately, the complexities of diagnosis and treatment combined with patient and provider preferences will likely continue to preclude randomized controlled studies to provide a clearer evidence-based management for this disorder. Patients meeting the clinical and diagnostic criteria for gallbladder dyskinesia should be referred for cholecystectomy, and most of these patients will have relief of their symptoms. A comprehensive preoperative discussion on expected outcomes needs to take place.

Episodic Memories Among Irritable Bowel Syndrome (IBS) Patients: An Important Aspect of the IBS Symptom Experience

Objective:

Some IBS patients possess detailed memories of the events surrounding their bowel symptom onset (“episodic memories”). In this exploratory study we sought to: (1) examine memory relationship with gastrointestinal (GI) symptom severity, extraintestinal symptoms, and mood; (2) qualitatively explore memory valence and content in IBS patients with or without episodic memories.

Methods

Referral IBS patients n = 29; age 47.0± 2.2 years, 79.3% female) enrolled in this cross-sectional, mixed methods research study. Participants completed validated specific memory instruments [Autobiographical Memory Test (AMT), Sentence Completion for Events from the Past Test (SCEPT)] and relevant questionnaires [IBS symptoms 10-cm visual analog scale); SF-36 Health-related quality of life (HRQOL); Perley-Guze and PHQ-15/12: somatization; Beck Depression/Anxiety Inventories). Qualitative analysis examined the content and valence of general memories.

Results

14/29 (48.3%) of IBS subjects endorsed episodic memories of IBS symptom onset, often GI infections/enteritis (35.7%). Recall of the exact year (69%) and month (60%) of symptom onset were common. Episodic memories were associated with greater IBS symptom severity/bother, higher anxiety/depression, and poorer HRQOL. Though AMT and SCEPT memory specificity were not different based on episodic memories, overgeneralization to negatively-valenced cues in the AMT was associated with more severe IBS in those without episodic memory. Qualitative analysis revealed no observable differences in topic focus of IBS patients with and without episodic memories.

Conclusions

IBS patients often endorse episodic memories associated with symptom onset, and this recall seems to associate with more severe symptoms. Overgeneralization responses to negative stimuli may lead to worse bowel symptoms in those without episodic memories. IBS memory specificity may associate with qualitative differences in processing psychosocial experiences and might be important to IBS pathophysiology.

Emerging therapies in the management of Irritable Bowel Syndrome (IBS)

INTRODUCTION

Irritable bowel syndrome (IBS) is a common, symptom-based disorder of chronic abdominal pain and altered bowel habits. The pathogenesis of IBS is multifactorial, leading to the potential for the development of multiple, diverse treatment strategies. This mechanistic heterogeneity also leads to the realization that available therapies are only effective in a subset of IBS suffers. Current US Food and Drug Administration (FDA) approved therapies for IBS with diarrhea (IBS-D) and IBS with constipation (IBS-C) are reviewed. Limited symptom responses and side effect experiences lead to considerable patient dissatisfaction with currently available IBS treatments. Only a small percentage of IBS patients are on prescription therapies underscoring the potential market and need for additional therapeutic options.

AREAS COVERED

: Expanding on currently available therapies, the serotonergic and endogenous opioid receptor systems continue to be a focus of future IBS treatment development. Additional novel emerging therapies include the endogenous cannabinoid system, bile acid secretion and sequestration, and exploit our enhanced understanding of visceral sensory signaling and intestinal secretomotor function.

EXPERT OPINION

While challenges remain for the future development of IBS therapies, the diverse etiologies underlying the disorder present an opportunity for novel therapies. Hence, great potential is anticipated for future IBS treatment options.

The Digital Rectal Examination: Appropriate Techniques for the Evaluation of Constipation and Fecal Incontinence

Disorders of defecation, including constipation and fecal incontinence, are very common. The digital rectal examination (DRE) is a key component in the early evaluation of patients with these complaints. Confident performance of a DRE requires dedicated training for the clinician and hands-on experience with the technique. DRE can yield a diagnostic accuracy comparable to specialized physiologic tests, including anorectal manometry. This review will describe in detail the steps required to perform a thorough DRE evaluation, as well as the proper interpretation of observations. Thereafter, the current evidence-based findings supporting the value of DRE in defecatory disorders will be summarized.

Improved work productivity and health-related quality of life in patients with irritable bowel syndrome with diarrhea receiving eluxadoline following inadequate response to loperamide

BACKGROUND: Irritable bowel syndrome with diarrhea (IBS-D) is a chronic disorder of gut-brain interaction that negatively affects work productivity and health-related quality of life (HRQOL). IBS-D therapeutic options are limited and include loperamide, an over-the-counter μ-opioid receptor agonist commonly used as an antidiarrheal agent, and eluxadoline, a mixed μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist approved in the United States for the treatment of IBS-D in adults. OBJECTIVE: To characterize the effect of eluxadoline on work productivity and HRQOL in patients with IBS-D with previous inadequate response to loperamide. METHODS: The Work Productivity and Activity Impairment Questionnaire for IBS-D (WPAI:IBS-D), Centers for Disease Control and Prevention Healthy Days Core Module (CDC HRQOL-4), and EuroQoL-5 Dimension (EQ-5D) instruments were administered at baseline and week 12 of a phase 4 clinical trial (RELIEF), assessing the efficacy and safety of eluxadoline treatment in adults with IBS-D reporting previous inadequate response to loperamide. Changes from baseline to week 12 for each assessment were evaluated using an analysis of covariance model. Indirect costs were calculated by converting overall work productivity losses into monetary values. RESULTS: A total of 346 patients were randomized to either eluxadoline (n = 172) or placebo (n = 174). From baseline to week 12, compared with placebo, twice-daily treatment with eluxadoline resulted in significantly greater reductions in absenteeism (2.6%; P = 0.046). Numerically greater decreases in presenteeism, overall work productivity loss, and daily activity impairment were also observed in patients receiving eluxadoline compared with those receiving placebo (P = not significant for each). Numerical reductions in overall work productivity loss from baseline to week 12 translate to approximately 2.4 hours per patient per week (123 hours annually) and correspond to an avoided overall work loss of $4,503 annually for an employee with IBS-D treated with eluxadoline. In addition, from baseline to week 12, treatment with eluxadoline led to a significantly greater reduction in the number of unhealthy days experienced (-1.7 days; P = 0.042), as well as numerical improvements in EQ-5D measures in comparison with placebo (P = not significant for each). CONCLUSIONS: In patients with IBS-D reporting inadequate response to loperamide, eluxadoline treatment was associated with significant reductions in absenteeism and the number of unhealthy days experienced. Eluxadoline treatment of IBS-D may lead to significant cost savings via mitigation of losses in work productivity. DISCLOSURES: This study was sponsored by Allergan plc (before acquisition by AbbVie, Inc.). Allergan plc and/or AbbVie, Inc., was involved in the study design, collection, analysis, interpretation of the data, writing of the report, and the decision to submit the report for publication. Abel and Burslem are employees of AbbVie, Inc., and own stock/stock options. Brenner has served as a consultant, speaker, and/or advisor for Allergan plc (before acquisition by AbbVie, Inc.), Alnylam, Alpha Sigma, Arena, Bayer, Ironwood Pharmaceuticals, Salix Pharmaceuticals, Shire, Synergy, and Takeda Pharmaceuticals. He is also supported in research by an unrestricted gift from the Irene D. Pritzker Foundation. Sayuk has served as a consultant and speaker for Allergan plc (before acquisition by AbbVie, Inc.), Gi Health Foundation, Ironwood Pharmaceuticals, Salix Pharmaceuticals, and Synergy. Portions of the current work were presented at AMCP Nexus; October 22-25, 2018; Orlando, FL.

A237 IMPROVEMENT IN ABDOMINAL SYMPTOMS WITH LINACLOTIDE IN PATIENTS WITH IRRITABLE BOWEL SYNDROME WITH CONSTIPATION: RESULTS FROM A PHASE 3B TRIAL

Background

Linaclotide (LIN) is a guanylate cyclase-C agonist approved to treat irritable bowel syndrome with constipation (IBS-C) in adults. Abdominal symptoms are important to patients with IBS-C. In a recent Phase 3b study, LIN significantly improved a composite score of abdominal bloating, pain, and discomfort (Abdominal Score), which was used as the primary endpoint in the study.

Aims

To evaluate the efficacy of LIN for improving additional efficacy abdominal symptom endpoints in a randomized, double-blind, placebo (PBO)-controlled Phase 3 study of LIN in patients with IBS-C.

Methods

Adults with IBS-C were randomized to PBO (N=308) or LIN 290 μg (N=306) once daily for 12 weeks. Patients recorded their daily abdominal symptoms, including the individual items of bloating, pain, and discomfort, using an 11-point scale (0–10; 0=none, 10=worst possible). The primary endpoint was the Abdominal Score. Additional efficacy endpoints included 6/12-week abdominal pain and constipation (APC)+1 responder, 6/12-week abdominal bloating responder, 6/12-week abdominal pain responder, and 6/12-week abdominal discomfort responder. For individual symptoms, a responder was a patient who had an improvement from baseline of ≥2 points in the respective endpoint for ≥6 of the 12 weeks. Changes from baseline (CFB) over 12 weeks in abdominal bloating, pain, and discomfort were evaluated using a mixed model with repeated measures framework. Proportions of responders were compared between groups for each responder endpoint using a Cochran-Mantel-Haenszel test.

Results

614 patients (mean age, 46.7 years; 81% female; similar baseline abdominal symptoms) were randomized. LIN-treated patients had greater least-squares mean (LSM) CFB in abdominal bloating (LSM difference [95% CI]: –0.889 [–1.249, –0.530], p&lt;0.001), pain (–0.881 [–1.238, –0.524], p&lt;0.001), and discomfort (–0.837 [–1.196, –0.478], p&lt;0.001) compared to PBO-treated patients. There was a greater proportion of LIN-treated vs. PBO-treated patients who were 6/12-week APC+1 (29% vs. 17%; p=0.0003), bloating (40% vs. 24%; p&lt;0.001), pain (42% vs. 25%; p&lt;0.001), and discomfort (42% vs. 26%; p&lt;0.001) responders (Figure). Diarrhea was the most common treatment-emergent adverse event (LIN: 4.6%; PBO: 1.6%).

Conclusions

LIN significantly improved multiple abdominal symptom and secondary responder endpoints in patients with IBS-C. These results support the effectiveness of LIN for improving a spectrum of abdominal symptoms in IBS-C.

Funding Agencies

This study was sponsored by Allergan plc, Dublin, Ireland (prior to acquisition by AbbVie Inc.). Writing and editorial assistance were provided to the authors by Brittany Y. Jarrett, PhD, Jane Beck, MA, and Rebecca Fletcher, BA(Hons) of Complete HealthVizion, Inc., Chicago, IL, USA and funded by Allergan plc (prior to acquisition by AbbVie Inc.).

The Brain-Gut-Microbiotal Axis: A framework for understanding functional GI illness and their therapeutic interventions

Functional gastrointestinal disorders (FGIDs), characterized by chronic abdominal complaints without a structural or biochemical cause, are common diseases that are frequently encountered by specialists in internal medicine. Collectively, irritable bowel syndrome (IBS) and functional dyspepsia are estimated to affect up to 22% of the population, and are often associated with additional somatic and pain complaints, all without an obvious structural source [1,2]. An appreciation of the current understanding of the mechanistic basis for these disorders is key to developing treatment goals and optimization of patient management strategies. In recent years, the brain-gut axis increasingly has been recognized as a central factor in the experience of functional abdominal pain disorders, including the most recent Rome IV guidelines which identify FGIDs as disorders of gut-brain interaction [3]. The brain-gut axis (BGA), simply defined, is a complex network of bidirectional communication between the central and enteric nervous systems. This axis broadly includes all the systems involved with communication between the GI tract and central nervous system (CNS), with principle inputs into this network occurring between the CNS, enteric nervous system (ENS), and autonomic nervous systems (ANS), but also includes interfaces with numerous other factors, including endocrine hormones and immune effector cells as well as interactions with the gut microbiota. Perturbances to this system have been found to play a critical role in the development of visceral hypersensitivity, bowel dysregulation, and mood. This review will summarize the principle processes involved in the neurologic and biologic function of the brain-gut axis, our current understanding of its role in functional GI disorders, and potential targets for therapeutic intervention.

Randomized Trial of 2 Delayed-Release Formulations of Linaclotide in Patients With Irritable Bowel Syndrome With Constipation

INTRODUCTION

Immediate-release (IR) formulation of linaclotide 290 μg improves abdominal pain and constipation (APC) in patients with irritable bowel syndrome (IBS) with constipation. Delayed-release (DR) formulations were developed on the premise that targeting the ileum (delayed-release formulation 1 [DR1]) or ileocecal junction and cecum (MD-7246, formerly DR2) would modulate linaclotide's secretory effects while preserving pain relief effects.

METHODS

This phase 2b study randomized patients with IBS with constipation to placebo or 1 of 7 once-daily linaclotide doses (DR1 30, 100, or 300 μg; MD-7246 30, 100, or 300 μg; or IR 290 μg) for 12 weeks. Key efficacy endpoints were change from baseline in abdominal pain and complete spontaneous bowel movement frequency, and 6/12-week combined APC+1 responder rate.

RESULTS

Overall, 532 patients were randomized; mean age was 45.1 years, and most were women (83.3%) and White (64.7%). All linaclotide DR1 and MD-7246 groups experienced greater improvements in abdominal pain from baseline and vs placebo throughout treatment. Linaclotide DR1 and IR led to numerically greater improvements from baseline in complete spontaneous bowel movement frequency and higher APC+1 responder rates compared with placebo; MD-7246 results were similar to placebo. Diarrhea was the most common adverse event with DR1 and IR; rates were similar between MD-7246 and placebo.

DISCUSSION

Altering the site of drug delivery in the intestine might uncouple linaclotide's pain relief from secretory effects. Persistent, modest abdominal pain improvement with limited impact on bowel symptom parameters, as seen across MD-7246 doses, warrants further study of MD-7246 as a novel treatment for abdominal pain, regardless of IBS subtype.

A Potential Role for Stress-Induced Microbial Alterations in IgA-Associated Irritable Bowel Syndrome with Diarrhea

Stress is a known trigger for flares of inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS); however, this process is not well understood. Here, we find that restraint stress in mice leads to signs of diarrhea, fecal dysbiosis, and a barrier defect via the opening of goblet-cell associated passages. Notably, stress increases host immunity to gut bacteria as assessed by immunoglobulin A (IgA)-bound gut bacteria. Stress-induced microbial changes are necessary and sufficient to elicit these effects. Moreover, similar to mice, many diarrhea-predominant IBS (IBS-D) patients from two cohorts display increased antibacterial immunity as assessed by IgA-bound fecal bacteria. This antibacterial IgA response in IBS-D correlates with somatic symptom severity and was distinct from healthy controls or IBD patients. These findings suggest that stress may play an important role in patients with IgA-associated IBS-D by disrupting the intestinal microbial community that alters gastrointestinal function and host immunity to commensal bacteria.

Stress in mice causes diarrhea, dysbiosis, barrier defect, increased antibacterial IgA

Stress-induced microbial changes are sufficient to elicit the above effects

IBS-D patients from two cohorts display increased and unique antibacterial IgA

Antibacterial IgA in IBS-D correlates with patient symptom severity

Patient Engagement with Interactive Text Message System Improves Successful Colonoscopy Rates in an Outpatient Endoscopy Center

INTRODUCTION

Text message-based interventions reduce colonoscopy no-show rates and improve bowel preparation scores. In this non-randomized study, we assessed whether an interactive text messaging system could improve colonoscopy outcomes.

METHODS

Colonoscopy pre-procedural instructions were programmed into a dedicated software platform created for this study. In the intervention arm, text messages were sent to veterans during a 4-week study period. Validated pre-procedural satisfaction questionnaires were completed by patients during standard protocol and intervention periods. Demographics and colonoscopy outcomes data were compared between the standard protocol and intervention arms, including procedure completion rate on scheduled date, Boston bowel preparation score (BPPS), adenoma detection rate, and satisfaction.

RESULTS

Of 241 patients, 128 were in the standard protocol arm and 113 in the intervention arm. Higher proportions of patients receiving text messages underwent colonoscopy on their scheduled date (69.9%) compared to the ones in the standard protocol (50.8%, p = 0.015). Patients with ≥3 interactions with the system had 80.6% likelihood of completing colonoscopy on the scheduled date compared to 56.9% with <3 interactions and 50.8% with standard protocol (p < 0.001). Frequency of interaction with the system was similar between older (>65 years) and younger patients (p = 1.0). Among older patients, colonoscopy was completed successfully in 84.2% when alert-based human interactions occurred compared to 65.6% in those without and 47.9% with standard protocol (p = 0.018). More than 90% indicated they would recommend the system to patients undergoing future colonoscopy.

CONCLUSION

An interactive text messaging system improves successful colonoscopy rates in a VA setting, with greatest impact in older patients.

Higher Esophageal Symptom Burden in Obese Subjects Results From Increased Esophageal Acid Exposure and Not From Dysmotility

BACKGROUND & AIMS

Esophageal motor disorders (EMD) and pathologic reflux are often identified in obese individuals, but it is not clear how obesity contributes to these symptoms. We examined the relationships among symptom burden, EMD, acid exposure time (AET), symptom association probability, and body mass index (BMI).

METHODS

We performed a retrospective study of 1089 consecutive patients who underwent high-resolution manometry, of which 426 patients also underwent reflux monitoring off acid suppression, over a 2-year period at a tertiary referral center. Symptom burden was assessed by questionnaires to determine dominant symptom intensity (DSI; product of symptom severity, and frequency, on 5-point Likert scales) and global symptom severity (GSS; global esophageal symptoms on 10-cm visual analog scales) at the time of esophageal testing; BMIs were recorded. We compared proportions of patients with EMD and abnormal reflux burden among BMI categories and correlated them with symptom burden.

RESULTS

Four-hundred thirty-three patients (39.8%) met the criteria for EMD. Esophageal outflow obstruction was observed in higher proportions of patients with low BMIs (underweight, 25.9%; normal, 14.1%; overweight, 13.9%; and obese, 9.8%; P = .037), but EMDs were less frequent in obese patients (P = .047), despite higher symptom burden compared with non-obese patients (DSI, 10.5 ± 0.3 vs 9.7 ± 0.2; P = .03 and GSS, 6.5 ± 1 vs 5.9 ± 1; P = .01). Among the 426 patients who underwent reflux monitoring, the proportions with total AET (P = .02), and upright AET (P < .001) increased among BMI categories, supine AET trended strongly (P = .06), in combination with increasing DSI and GSS (P ≤ .001 for each comparison). BMI correlated with symptom burden, higher AET, and positive symptom association probability (P < .01 for each analysis).

CONCLUSIONS

Increased symptom burden in obese individuals correlates with esophageal acid burden but not with motor disorders.

Survival benefit associated with early detection of spontaneous bacterial peritonitis in veteran inpatients with cirrhotic ascites

Background

Spontaneous bacterial peritonitis (SBP) is common in hospitalized cirrhotic patients with ascites and carries high mortality. This study aimed to determine whether early diagnostic paracentesis (EDP) <12 h of hospitalization conveys an intermediate‐term (6‐month) survival benefit in cirrhotic patients diagnosed with SBP.

Methods

Consecutive US veterans with cirrhosis diagnosed with SBP over 13 years at a single VA medical center were reviewed retrospectively. Kaplan‐Meyer analyses assessed the effects of EDP on survival.

Results

A total of 79 cirrhotic patients were diagnosed with SBP (61.8 ± 8.8 years, n = 77 male, n = 52 [66.8%] Caucasian, n = 23 [29.1%] African‐American). Underlying liver diseases included hepatitis c viral infection (HCV) (17.5%), alcohol (28.6%), alcohol and HCV (30.1%), and cryptogenic/metabolic (15.9%). Median baseline model for end‐stage liver disease (MELD) was 12 (range 6–34), and median MELD at presentation was 18. Seven subjects had a history of hepatocellular carcinoma (11.1%), and 26 (41.3%) presented with sepsis. Thirty‐three (52.4%) subjects died within 6 months after the SBP admission. Of the subjects, 41 (65.1%) underwent EDP, of which 23 (56.0%) survived at least 6 months, compared to only 7 of the 22 patients (31.8%) undergoing paracentesis >12 h from presentation (P = 0.057). The maximal benefit of EDP on survival was observed beyond days 14 and 30; at these time points, no statistical difference in mortality was discernable (P = 0.55 and 0.71). In a multivariate model including age, MELD at admission, hepatocellular cancer, and sepsis criteria, EDP (p 0.034) positively impacted patient survival at 6 months.

Conclusions

EDP is associated with improved 6‐month mortality in cirrhotic patients with ascites. In this veteran cohort, EDP was as important as MELD as a predictor of intermediate‐term survival.

Bile Acid Diarrhea and NAFLD: Shared Pathways for Distinct Phenotypes

Irritable bowel syndrome with diarrhea (IBS-D) and NAFLD are both common conditions that may be influenced by shared pathways of altered bile acid (BA) signaling and homeostatic regulation. Pathophysiological links between IBS-D and altered BA metabolism include altered signaling through the ileal enterokine and fibroblast growth factor 19 (FGF19) as well as increased circulating levels of 7α-hydroxy-4-cholesten-3-one, a metabolic intermediate that denotes increased hepatic BA production from cholesterol. Defective production or release of FGF19 is associated with increased BA production and BA diarrhea in some IBS-D patients. FGF19 functions as a negative regulator of hepatic cholesterol 7α-hydroxylase; therefore, reduced serum FGF19 effectively de-represses hepatic BA production in a subset of IBS-D patients, causing BA diarrhea. In addition, FGF19 modulates hepatic metabolic homeostatic response signaling by means of the fibroblast growth factor receptor 4/klotho beta receptor to activate cascades involved in hepatic lipogenesis, fatty acid oxidation, and insulin sensitivity. Emerging evidence of low circulating FGF19 levels in subsets of patients with pediatric and adult NAFLD demonstrates altered enterohepatic BA homeostasis in NAFLD. Conclusion: Here we outline how understanding of shared pathways of aberrant BA homeostatic signaling may guide targeted therapies in some patients with IBS-D and subsets of patients with NAFLD.

Perceived sleep quality mediates the relationship between posttraumatic stress and somatic symptoms

OBJECTIVE

Posttraumatic stress symptoms (PTSS) have been associated with increased somatic symptom expression. Sleep concerns have been associated with PTSS and somatic symptoms. Previous research suggests that sleep affects multiple domains of functioning including comorbid psychological and physical health concerns. The current study examines whether perceived sleep quality or sleep efficiency/duration may be mediating the relationship between PTSS and somatic symptoms in a trauma-exposed sample.

METHOD

The sample consisted of 864 students, recruited from a large Midwestern university and compensated with research participation credit. Data were collected online over approximately 39 months (October 2015 through January 2019), and the pertinent scales examined in this study included Pittsburgh Sleep Quality Index, Posttraumatic Stress Disorder Checklist for Diagnostic and Statistical Manual of Mental Disorders, fifth edition, and Screening for Somatoform Symptoms-7.

RESULTS

Of the 864 students, 668 participants identified as female (77.3%) and 540 identified as non-Hispanic White (62.5%), with an overall average age of 23.14 years (SD = 6.64). Mediation analyses indicated that the overall model examining global sleep quality complaints as a mechanism of the relationship between PTSS and somatic symptoms was significant, F(3, 860) = 193.97, R² = .40, p < .001, and that perceived sleep quality was found to be the only significant specific mediator (indirect effect = .21). Although females reported greater somatic severity, PTSS, and sleep concerns, models were significant, even after examining the influence of gender.

CONCLUSIONS

Global sleep complaints are associated with both PTSS and somatic symptoms. Perceived sleep quality specifically mediated the relationship between PTSS and somatic symptoms, highlighting a potential intervention for improving physical health consequences in trauma-exposed individuals. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Self-reported sleep disturbance in Crohn's disease is not confirmed by objective sleep measures

Sleep disturbance and fatigue are commonly reported among patients with Crohn’s disease (CD). In this prospective study, we aimed to define sleep quality in CD patients at various disease activity states and compare to healthy controls using objective and subjective measures. A prospective observational cohort study of CD patients seen at a tertiary academic inflammatory bowel diseases (IBD) clinic was compared to healthy volunteers. CD activity was assessed using the Harvey-Bradshaw Index (HBI). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) and objectively over 1-week using actigraphy (motion-based) and morning urinary melatonin metabolite. 121 subjects (CD patients N = 61; controls N = 60) completed the study. 34 had active CD (HBI > 4). Sleep disturbance was more frequently reported by CD subjects than controls (PSQI: 57% vs. 35%, p = 0.02) and in patients with active CD versus in remission state (PSQI 75.8% vs. 33.3%, p < 0.01; ESS: 45.5% vs. 19%, p = 0.03). Sleep parameters as measured by actigraphy and urine melatonin metabolite did not vary by group. Crohn’s patients report significantly more disturbed sleep than controls. However, poor sleep was not confirmed by objective measures of sleep quality. Excessive daytime sleepiness in CD patients may be driven by factors beyond objectively measured poor sleep.

Undifferentiated Abdominal Pain in Children Presenting to the Pediatric Emergency Department

Although common, little is known about the characteristics and management of undifferentiated abdominal pain (UAP) in the pediatric emergency department (ED). This study was a 12-month retrospective study for "abdominal pain" ED visits. Patients without an identifiable diagnosis were categorized as "UAP," while others with identified disease processes were categorized as "structural gastrointestinal diagnosis (SGID)." We included 2383 (72%) visits with 869 (36.5%) UAP visits and 1514 (63.5%) SGID visits. SGID patients had more laboratory tests (811 [53.6%] vs 422 [48.6%], P = .0186), and often had multiple tests performed (565 [69.7%] vs 264 [62.6%], P = .0116). Computed tomography and ultrasound scans were more common in SGID (computed tomography: 108 [7.1%] vs 27 [3.1%], P = .0004; ultrasound: 377 [24.9%] vs 172 [19.9%], P = .0044), and laboratory results (white blood cell count, hemoglobin, albumin, C-reactive protein) were abnormal at significantly higher rates. Analyses revealed the duration of pain as primary covariate in variance of pain etiology. Clinical features, such as duration of pain, may be augmented by laboratory tests to facilitate recognition of UAP in the ED.

Health-related quality of life and long-term outcomes after endoscopic therapy for walled-off pancreatic necrosis

BACKGROUND AND AIM

Walled-off pancreatic necrosis (WON) frequently develops after necrotizing pancreatitis. Endoscopic drainage has become the preferred modality for symptomatic or infected WON. The aim of the present study was to assess health-related quality of life (HR-QOL) and long-term outcomes in patients undergoing endoscopic drainage for WON.

METHODS

Patients undergoing endoscopic drainage of WON from January 2006 to May 2016 were identified. Data recorded included demographic information, and the incidence of long-term sequelae including pancreatic endocrine and exocrine insufficiency. Attempts were made to contact all patients. HR-QOL was assessed using the SF-36 questionnaire.

RESULTS

Eighty patients were analyzed, 41 (51.3%) of whom completed the SF-36. One-year all-cause mortality was 6.2%, and disease-related mortality was 3.7%. A notable proportion of patients developed exocrine insufficiency (32.5%), endocrine insufficiency (27.7%), and long-term opiate use (42.5%). Development of exocrine insufficiency was predictive of lower total SF-36 scores (P = 0.016). Patients with WON had better HR-QOL compared with cohorts of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). In patients developing exocrine insufficiency versus healthy controls, poorer scores in the physical role (P < 0.001), general health (P < 0.001), vitality (P = 0.001), and emotional role (P = 0.029) domains were observed. Exocrine insufficiency patients had better HR-QOL than the IBS and IBD cohorts, although these differences were less pronounced.

CONCLUSION

After undergoing endoscopic drainage for WON, patients have relatively preserved HR-QOL. The subset of patients that develop exocrine insufficiency have significantly poorer HR-QOL compared to healthy controls, although not to the degree of chronic gastrointestinal disorders such as IBS and IBD.

Chronic Cough Is Associated With Long Breaks in Esophageal Peristaltic Integrity on High-resolution Manometry

Background/Aims

Breaks in the peristaltic contour on esophageal high-resolution manometry (HRM) may be associated with bolus retention in the esophagus. We evaluated the relationship between peristaltic breaks and esophageal symptoms, reflux exposure, and symptom outcomes in a prospective patient cohort.

Methods

Two hundred and eighteen patients (53.2 ± 0.9 years, 68.3% female) undergoing both pH-impedance testing and HRM over a 5–year period were prospectively evaluated. Demographics, symptom presentation, acid exposure time, symptom association probability, and symptom burden scores were collected. Outcomes were assessed on follow-up using changes in symptom scores. Presence of long breaks (≥ 5 cm) on HRM was assessed by a blinded author. Relationships between breaks, reflux parameters, presenting symptoms, and outcomes were assessed.

Results

Patients with long breaks were more likely to have cough as a presenting symptom than those without (43.4% vs 28.6%, P = 0.024); statistical differences were not demonstrated with other symptoms (P ≥ 0.3). Numbers of swallows with long breaks were higher in patients with cough compared to those without (2.4 ± 0.3 vs 1.6 ± 0.2, P = 0.021); differences were not found with other symptoms (P ≥ 0.4). Long breaks were not associated with age, gender, race, reflux burden, symptom association, or changes in symptom metrics (P ≥ 0.1 for all comparisons). Among patients with cough, the presence of long breaks predicted suboptimal symptom improvement with antireflux therapy (P = 0.018); this difference did not hold true for other symptoms (P ≥ 0.2).

Conclusions

Long breaks in esophageal peristaltic integrity are associated with cough. The presence of long breaks is associated with suboptimal benefit from antireflux therapy.

Opioid medication use in patients with gastrointestinal diagnoses vs unexplained gastrointestinal symptoms in the US Veterans Health Administration

BACKGROUND

While opioid prescriptions have increased alarmingly in the United States (US), their use for unexplained chronic gastrointestinal (GI) pain (eg, irritable bowel syndrome) carries an especially high risk for adverse effects and questionable benefit.

AIM

To compare opioid use among US veterans with structural GI diagnoses (SGID) and those with unexplained GI symptoms or functional GI diagnoses (FGID), a group for whom opioids have no accepted role.

METHODS

Veterans Health Administration (VHA) administrative data from fiscal year 2012 were used to identify veterans with diagnostic codes recorded for SGID and FGID. This cohort study examined VHA pharmacy data to compare groups receiving ≥ 1 opioid prescription during the year and number of prescriptions filled. Bivariate and multiple logistic regression analyses adjusted for potential confounding factors (demographics, medical diagnoses, social factors) and identified potential mediators (service use, psychiatric comorbidity) of opioid use in these groups.

RESULTS

A greater proportion of veterans with FGID received an opioid prescription during fiscal year 2012 (36.0% of 272 431) compared to only 28.9% of 1 223 744 in the SGID group (Relative Risk [RR] = 1.25). In multivariate logistic regression, personality disorders and drug abuse (OR 1.23 for each group), recent homelessness (OR 1.22), psychotropic medication fills (OR 1.55) and emergency department encounters (OR 1.21) were independently associated with opioid prescription use.

CONCLUSIONS

Despite the potential for adverse consequences, opioids more often are prescribed for veterans with chronic, unexplained GI symptoms compared to those with structural diagnoses. Psychiatric comorbidities and frequent healthcare encounters mediate some of the opioid use risk.

Upper esophageal sphincter (UES) metrics on high-resolution manometry (HRM) differentiate achalasia subtypes

BACKGROUND

The upper esophageal sphincter (UES) reflexively responds to bolus presence within the esophageal lumen, therefore UES metrics can vary in achalasia.

METHODS

Within consecutive patients undergoing esophageal high-resolution manometry (HRM), 302 patients (58.2±1.0 year, 57% F) with esophageal outflow obstruction were identified, and compared to 16 asymptomatic controls (27.7±0.7 year, 56% F). Esophageal outflow obstruction was segregated into achalasia subtypes 1, 2, and 3, and esophagogastric junction outflow obstruction (EGJOO with intact peristalsis) using Chicago Classification v3.0. UES and lower esophageal sphincter (LES) metrics were compared between esophageal outflow obstruction and normal controls using univariate and multivariate analysis. Linear regression excluded multicollinearity of pressure metrics that demonstrated significant differences across individual subtype comparisons.

KEY RESULTS

LES integrated relaxation pressure (IRP) had utility in differentiating achalasia from controls (P<.0001), but no utility in segregating between subtypes (P=.27). In comparison to controls, patients collectively demonstrated univariate differences in UES mean basal pressure, relaxation time to nadir, recovery time, and residual pressure (UES-RP) (P≤.049). UES-RP was highest in type 2 achalasia (P<.0001 compared to other subtypes and controls). In multivariate analysis, only UES-RP retained significance in comparison between each of the subgroups (P≤.02 for each comparison). Intrabolus pressure was highest in type 3 achalasia; this demonstrated significant differences across some but not all subtype comparisons.

CONCLUSIONS AND INFERENCES

Nadir UES-RP can differentiate achalasia subtypes within the esophageal outflow obstruction spectrum, with highest values in type 2 achalasia. This metric likely represents a surrogate marker for esophageal pressurization.

Do Consultants Follow Up on Tests They Recommend? Insights from an Academic Inpatient Gastrointestinal Consult Service

BACKGROUND

Inpatient care is a fundamental part of gastroenterology training and involves the recommendation, performance, and interpretation of diagnostic tests. However, test results are not always communicated to patients or treating providers. We determined the process of communication of test results and recommendations in our inpatient gastroenterology (GI) consult service.

METHODS

Test recommendations on 304 consecutive new GI consults (age 60.2 ± 1.0 year) over a 2-month period were recorded. Demographic factors (age, race, gender, zip code, insurance status) were extracted from the electronic medical record (EMR). Charts were independently reviewed 6 months later to determine results of recommended tests, follow-up of actionable test results, 30-day readmission rates, and predictors of suboptimal communication.

RESULTS

Of 490 recommended tests, 437 (89.2%) were performed, and 199 (45.5%) had actionable findings. Of these, 48 (24.1%) did not have documented follow-up. Failure of follow-up was higher for upper endoscopy (31.9%) compared to colonoscopy (18.0%, p = 0.07). Women (p = 0.07), patients on Medicare (p = 0.05), and procedures supervised by advanced GI fellows (p = 0.06) were less likely to receive follow-up. Median income and identification of a primary provider did not influence follow-up rates; 30-day readmission rates were not impacted. Female gender, insurance (Medicare) status, and attending type remained independent predictors of failure of follow-up on multivariate regression (p ≤ 0.03).

CONCLUSIONS

Failure to follow up test results on inpatient services at a large academic center was unacceptably high. Maximizing personnel participation together with diligence and technology (EMR) will be required to improve communication.

Comparison of Symptoms, Healthcare Utilization, and Treatment in Diagnosed and Undiagnosed Individuals With Diarrhea-Predominant Irritable Bowel Syndrome

OBJECTIVES

Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by symptoms including abdominal pain and altered bowel function. Up to 75% of individuals with IBS may be undiagnosed. The aim of this study was to characterize symptoms, healthcare utilization, and treatments in populations with both diagnosed and undiagnosed IBS.

METHODS

An online survey was conducted to compare gastrointestinal (GI) symptoms, healthcare visits, well-being, symptom management, and treatment satisfaction in individuals with and without medically diagnosed IBS (Rome III criteria). Symptom severity, disruptiveness, and treatment satisfaction were rated using a 7-point scale. Adjustments to daily life were determined by predefined survey responses.

RESULTS

A total of 1,924 individuals with a history of GI symptoms were eligible and completed the survey. Of these, 1,094 individuals (56.9%) met the criteria for IBS; 830 individuals (43.1%) had no medical diagnosis of IBS despite meeting diagnostic criteria. Most participants received a diagnosis from either gastroenterologists (45%) or primary care physicians (42%). A greater percentage of diagnosed patients had severe GI symptoms (score ≥6) vs. undiagnosed individuals (16% vs. 8%, respectively; P<0.05); diagnosed patients were more likely to report that GI symptoms adversely affected their quality of life. Approximately 40% of participants received IBS-related treatment from primary care physicians; 26% and 43% of diagnosed and undiagnosed individuals, respectively, were not receiving treatment for GI symptoms.

CONCLUSIONS

Many individuals with IBS-related symptoms have not been medically diagnosed with IBS. IBS-related symptoms impact quality of life, yet more than one-third of individuals are not receiving treatment for IBS.

Erdheim-Chester Disease Presenting with Histiocytic Colitis and Cytokine Storm

Background: Non-Langerhans histiocytosis is a group of inflammatory lymphoproliferative disorders originating from non-clonal expansion of hematopoietic stem cells into cytokine-secreting dendritic cells or macrophages. Erdheim-Chester Disease (ECD) is a rare type of non-Langerhans cell histiocytosis characterized by tissue inflammation and injury caused by macrophage infiltration and histologic findings of foamy histiocytes. Often ECD involves the skeleton, retroperitoneum and the orbits. This is the first report documenting ECD manifesting as segmental colitis and causing cytokine-release syndrome.Case presentation: A 68-year old woman presented with persistent fever without infectious etiology and hematochezia. Endoscopy showed segmental colitis and pathology revealed infiltration of large foamy histiocytes CD3-/CD20-/CD68+/CD163+/S100- consistent with ECD. The patient was empirically treated with steroids but continued to have fever and developed progressive distributive shock.Conclusion: This case report describes the differential diagnosis of infectious and immune-mediated inflammatory and rheumatologic segmental colitis. Non-Langerhans histiocytosis and ECD are rare causes of gastrointestinal inflammation. Prompt diagnosis is imperative for the appropriate treatment to prevent hemodynamic compromise due to distributive shock or gastrointestinal bleeding. Importantly, gastrointestinal ECD might exhibit poor response to steroid treatment and other potential treatments including chemotherapy, and biologic treatments targeting IL-1 and TNF-alpha signaling should be considered.Abbreviations: AFB: acid-fast bacilli; ECD: Erdheim-Chester Disease; IBD: inflammatory bowel disease; PASD: periodic acid-Schiff with diastase; TB: tuberculosis

Distal mean nocturnal baseline impedance on pH-impedance monitoring predicts reflux burden and symptomatic outcome in gastro-oesophageal reflux disease

BACKGROUND

Mean nocturnal baseline impedance (MNBI), a novel pH-impedance metric, may be a surrogate marker of reflux burden.

AIM

To assess the predictive value of MNBI on symptomatic outcomes after anti-reflux therapy.

METHODS

In this prospective observational cohort study, pH-impedance studies performed over a 5-year period were reviewed. Baseline impedance was extracted from six channels at three stable nocturnal 10-min time periods, and averaged to yield MNBI. Distal and proximal oesophageal MNBI values were calculated by averaging MNBI values at 3, 5, 7 and 9 cm, and 15 and 17 cm respectively. Symptomatic outcomes were measured as changes in global symptom severity (GSS, rated on 100-mm visual analogue scales) on prospective follow-up after medical or surgical anti-reflux therapy. Univariate and multivariate analyses assessed the predictive value of MNBI on symptomatic outcomes.

RESULTS

Of 266 patients, 135 (50.8%) were tested off proton pump inhibitor (PPI) therapy and formed the study cohort (52.1 ± 1.1 years, 63.7% F). The 59 with elevated acid exposure time (AET) had lower composite and distal MNBI values than those with physiological AET (P < 0.0001), but similar proximal MNBI (P = 0.62). Linear AET negatively correlated with distal MNBI, both individually and collectively (Pearson's r = -0.5, P < 0.001), but not proximal MNBI (Pearson's r = 0, P = 0.72). After prospective follow-up (94 patients were followed up for 3.1 ± 0.2 years), univariate and multivariate regression models showed that distal MNBI, but not proximal MNBI, was independently predictive of linear GSS improvement.

CONCLUSIONS

Distal oesophageal MNBI negatively correlates with AET and, when assessed off PPI therapy, is independently predictive of symptomatic improvement following anti-reflux therapy.

The impact of abuse and mood on bowel symptoms and health-related quality of life in irritable bowel syndrome (IBS)

BACKGROUND

Irritable bowel syndrome (IBS) is a common abdominal pain disorder without an organic explanation. Abuse histories (physical, sexual, emotional) are prevalent in IBS. While abuse relates to mood disorders (depression and anxiety) also common in IBS, the influence of abuse on gastrointestinal (GI) symptoms and health-related quality of life (HRQOL) and its independence from psychological symptom comorbidity has not been studied.

METHODS

Consecutive GI outpatients completed the ROME III Research Diagnostic Questionnaire and questionnaires on trauma (Life-Stress Questionnaire), mood (Beck Depression/Anxiety Inventories), somatic symptoms (PHQ-12), and HRQOL (SF-36). Current GI symptom severity and bother were assessed using 10-cm Visual Analog Scales.

KEY RESULTS

272 ROME-defined IBS (47.6 ± 0.9 years, 81% female) and 246 non-FGID (51.6 ± 1.0 years, 65% female) subjects participated. IBS patients reported greater rates of physical, sexual, and emotional abuse (p < 0.006 each), and higher depression, anxiety, and somatic symptoms (p < 0.001). Greater bowel symptom bother (7.4 ± 0.2 vs 6.7 ± 0.2, p = 0.040), severity (7.7 ± 0.2 vs 6.5 ± 0.2, p < 0.001), recent symptomatic days (9.8 ± 0.4 vs 8.5 ± 0.3, p = 0.02), and poorer HRQOL (40.9 ± 2.3 vs 55.5 ± 1.7, p < 0.001) were noted in IBS with abuse. Abuse effects were additive, with greater IBS symptom severity and poorer HRQOL noted in cases with multiple forms of abuse. Mediation analyses suggested that abuse effects on GI symptoms and HRQOL were partially mediated by mood.

CONCLUSIONS & INFERENCES

Abuse experiences common among IBS sufferers are associated with reports of greater GI symptoms and poorer HRQOL, particularly in those with multiple forms of abuse; this relationship may be partially mediated by concomitant mood disturbances.

Effects of disturbed sleep on gastrointestinal and somatic pain symptoms in irritable bowel syndrome

BACKGROUND

Sleep disturbances are common, and perhaps are even more prevalent in irritable bowel syndrome (IBS).

AIMS

To determine the effect of measured sleep on IBS symptoms the following day, IBS-specific quality of life (IBS-QOL) and non-GI pain symptoms.

METHODS

IBS patients' sleep patterns were compared to healthy individuals via wrist-mounted actigraphy over 7 days. Daily bowel pain logs (severity, distress; 10-point Likert) stool pattern (Bristol scale) and supporting symptoms (e.g. bloating, urgency; 5-point Likert) were kept. Validated measures, including the GI Symptom Rating Scale-IBS, Visceral Sensitivity Index, Pittsburgh Sleep Quality Index and the IBS-Quality of Life were collected. Mediation analysis explored the relationship between sleep, mood and bowel symptoms.

RESULTS

Fifty subjects (38.6 ± 1.0 years old, 44 female; 24 IBS and 26 healthy controls) completed sleep monitoring. IBS patients slept more hours per day (7.7 ± 0.2 vs. 7.1 ± 0.1, P = 0.008), but felt less well-rested. IBS patients demonstrated more waking episodes during sleep (waking episodes; 12.1 vs. 9.3, P < 0.001). Waking episodes predicted worse abdominal pain (P ≤ 0.01) and GI distress (P < 0.001), but not bowel pattern or accessory IBS symptoms (P > 0.3 for each). Waking episodes negatively correlated with general- and IBS-specific QOL in IBS (r = -0.58 and -0.52, P < 0.001 for each). Disturbed sleep effects on abdominal pain were partially explained by mood as an intermediate.

CONCLUSIONS

Sleep disturbances are more common in irritable bowel syndrome, and correlate with IBS-related pain, distress and poorer irritable bowel syndrome-related quality of life. Disturbed sleep effects extend beyond the bowel, leading to worse mood and greater somatic pain in patients with the irritable bowel syndrome.

GERD phenotypes from pH-impedance monitoring predict symptomatic outcomes on prospective evaluation

BACKGROUND

Combinations of reflux parameters (acid exposure time, AET; symptom association probability, SAP) on pH-impedance monitoring describe varying confidence in reflux evidence. We compared outcomes between phenotypes with distinct pre-identified reflux parameters.

METHODS

In this observational cohort study, patients undergoing pH-impedance testing over a 5-year period were phenotyped by strength of reflux evidence as strong (abnormal AET, positive SAP), good (abnormal AET, negative SAP), reflux hypersensitivity (RH, normal AET, positive SAP), and equivocal evidence of reflux, and compared to two historical institutional pH monitoring cohorts. Symptom burden (dominant symptom intensity, DSI; global symptom severity, GSS) was assessed by questionnaire at baseline and on prospective follow-up and compared between phenotypes.

KEY RESULTS

Of 94 patients tested off proton pump inhibitor (PPI) therapy, baseline symptom burden was highest with strong reflux evidence and lowest when equivocal (DSI: p = 0.01; GSS: p = 0.03 across groups). After 3.1 ± 0.2 years follow-up, symptomatic improvement with surgical or medical therapy was highest with strong or good evidence, and lowest when equivocal (DSI: p = 0.008; GSS: p = 0.005 across groups). This was most pronounced for typical symptoms (DSI: p = 0.001; GSS: 0.016 across groups), but not atypical symptoms (DSI: p = 0.6; GSS: p = 0.2). For testing on PPI therapy, only GSS followed a similar trend (GSS: p = 0.057, DSI: p = 0.3). Compared to historical cohorts with pH monitoring alone, equivocal evidence for reflux was partly replaced by RH, especially off PPI (p < 0.0001).

CONCLUSIONS & INFERENCES

Phenotyping gastroesophageal reflux disease by the strength of reflux evidence on pH-impedance testing off PPI efficiently stratifies symptomatic outcome, especially for typical symptoms, and could be useful in planning management.

Achalasia symptom response after Heller myotomy segregated by high-resolution manometry subtypes

BACKGROUND

Achalasia is classified into three HRM subtypes that predict outcomes from diverse management strategies. We assessed if symptomatic response varied when a single management strategy-Heller myotomy (HM)-is employed.

METHODS

Treatment-naive subjects with achalasia referred for HM were followed in this observational cohort study. Chicago criteria designated achalasia subtypes (subtype I: no esophageal pressurization; subtype II: panesophageal pressurization in ≥20 % swallows; subtype III: premature contractions in ≥20 % swallows). Symptom questionnaires assessed symptom burden before and after HM on five-point Likert scales (0 = no symptoms, 4 = severe symptoms) and on 10-cm visual analog scales (global symptom severity, GSS); satisfaction with HM was recorded similarly. Data were analyzed to determine predictors of GSS change across subtypes.

RESULTS

Sixty achalasia subjects (56.1 ± 2.4 years, 55 % female) fulfilled inclusion criteria, 15 % with subtype I, 58 % with subtype II, and 27 % with subtype III achalasia. Baseline symptoms included dysphagia (solids: 85 %, liquids: 73 %), regurgitation (84 %), and chest pain (35 %); mean GSS was 7.1 ± 0.3. Upon follow-up 2.1 ± 0.2 years after HM, GSS declined to 1.9 ± 0.4 (p < 0.001), with surgical satisfaction score of 8.7 ± 0.3 out of 10; these were similar across achalasia subtypes. On univariate analysis, female gender, Eckardt score, severity of transit symptoms, and maximal IRP predicted linear GSS improvement; female gender (p = 0.003) and dysphagia for liquids (p = 0.043) remained predictive on multivariate analysis.

CONCLUSIONS

When a uniform surgical approach is utilized, symptomatic outcome and satisfaction with therapy are similar across achalasia subtypes. Female gender and severity of dysphagia for solids may predict better HM outcome.

No association between the common calcium-sensing receptor polymorphism rs1801725 and irritable bowel syndrome

BACKGROUND

The calcium-sensing receptor (CaSR) is a calcium (Ca(2+)) sensitive G protein-coupled receptor implicated in various biological processes. In particular, it regulates Ca(2+)/Mg(2+)- homeostasis and senses interstitial Ca(2+) levels and thereby controls downstream signalling cascades. Due to its expression in the gut epithelium, the enteric nervous system and smooth muscles and its key function in regulation and coordination of muscular contraction and secretion, it represents an excellent candidate gene to be investigated in the pathophysiology of irritable bowel syndrome (IBS). Disturbed CaSR structure and function may impact gastrointestinal regulation of muscular contraction, neuronal excitation and secretion and consequently contribute to symptoms seen in IBS, such as disordered defecation as well as disturbed gut motility and visceral sensitivity.

METHODS

We have therefore genotyped the functional CASR SNP rs1801725 in three case control samples from the UK, Belgium and the USA.

RESULTS

Genotype frequencies showed no association in the three genotyped case-control samples, neither with IBS nor with IBS subtypes.

CONCLUSIONS

Although we could not associate the SNP to any of the established bowel symptom based IBS subtypes we cannot rule out association to altered Ca(2+) levels and disturbed secretion and gut motility which were unfortunately not assessed in the patients genotyped. This underlines the necessity of a more detailed phenotyping of IBS patients and control individuals in future studies.

Irritable bowel syndrome: modern concepts and management options

Irritable bowel syndrome is the most common functional gastrointestinal disorder, manifesting as abdominal pain/discomfort and altered bowel function. Despite affecting as many as 20% of adults, a lack of understanding of etiopathogenesis and evaluation strategies results in diagnostic uncertainty, and in turn frustration of both the physician and the patient. This review summarizes the current literature on the diagnosis and management of irritable bowel syndrome, with attention to evidence-based approaches. A 4-step treatment strategy that has been used successfully in our tertiary referral practice is presented and should lead to successful therapeutic outcomes in the majority of patients with irritable bowel syndrome.