United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

Disorders of gastric motility

Gastroparesis is a disorder of delayed gastric emptying with associated symptoms of postprandial fullness, early satiety, nausea, vomiting, bloating, and abdominal pain. Functional dyspepsia is an upper gastrointestinal disorder of gut-brain interaction that presents with similar symptoms but is defined according to symptom patterns rather than gastric motor dysfunction. Although delayed gastric emptying is a defining feature of gastroparesis, other aspects of gastric neuromuscular dysfunction, such as gastric accommodation and visceral hypersensitivity might contribute to symptoms. Similarly, although functional dyspepsia is not defined by impaired gastric emptying, disordered gastric motility might underlie pathogenesis in some patients with functional dyspepsia. In the last decade, it has been increasingly recognised that these two disorders might represent varying presentations along a common continuum of neuromuscular dysfunction, although with differentiating features with respect to outcomes, diagnosis, and treatments. In this Review, an overview of gastroparesis and functional dyspepsia from the perspective of gastric motility is provided, discussing what is distinct and what is shared between these disorders.

Nutritional Management of Pediatric Gastrointestinal Motility Disorders

Normal and optimal functioning of the gastrointestinal tract is paramount to ensure optimal nutrition through digestion, absorption and motility function. Disruptions in these functions can lead to adverse physiological symptoms, reduced quality of life and increased nutritional risk. When disruption or dysfunction of neuromuscular function occurs, motility disorders can be classified depending on whether coordination or strength/velocity of peristalsis are predominantly impacted. However, due to their nonspecific presenting symptoms and overlap with sensory disruption, they are frequently misdiagnosed as disorders of the gut-brain interaction. Motility disorders are a prevalent issue in the pediatric population, with management varying from medical therapy to psychological therapy, dietary manipulation, surgical intervention or a multimodal approach. This narrative review aims to discuss the dietary management of common pediatric motility disorders including gastroesophageal reflux, esophageal atresia, achalasia, gastroparesis, constipation, and the less common but most severe motility disorder, pediatric intestinal pseudo-obstruction.

Predicting Response to Neuromodulators or Prokinetics in Patients With Suspected Gastroparesis Using Machine Learning: The "BMI, Infectious Prodrome, Delayed GES, and No Diabetes" Model

INTRODUCTION

Pharmacologic therapies for symptoms of gastroparesis (GP) have limited efficacy, and it is difficult to predict which patients will respond. In this study, we implemented a machine learning model to predict the response to prokinetics and/or neuromodulators in patients with GP-like symptoms.

METHODS

Subjects with suspected GP underwent simultaneous gastric emptying scintigraphy (GES) and wireless motility capsule and were followed for 6 months. Subjects were included if they were started on neuromodulators and/or prokinetics. Subjects were considered responders if their GP Cardinal Symptom Index at 6 months decreased by ≥1 from baseline. A machine learning model was trained using lasso regression, ridge regression, or random forest. Five-fold cross-validation was used to train the models, and the area under the receiver operator characteristic curve (AUC-ROC) was calculated using the test set.

RESULTS

Of the 150 patients enrolled, 123 patients received either a prokinetic and/or a neuromodulator. Of the 123, 45 were considered responders and 78 were nonresponders. A ridge regression model with the variables, such as body mass index, infectious prodrome, delayed gastric emptying scintigraphy, no diabetes, had the highest AUC-ROC of 0.72. The model performed well for subjects on prokinetics without neuromodulators (AUC-ROC of 0.83) but poorly for those on neuromodulators without prokinetics. A separate model with gastric emptying time, duodenal motility index, no diabetes, and functional dyspepsia performed better (AUC-ROC of 0.75).

DISCUSSION

This machine learning model has an acceptable accuracy in predicting those who will respond to neuromodulators and/or prokinetics. If validated, our model provides valuable data in predicting treatment outcomes in patients with GP-like symptoms.

Meal effects on gastric bioelectrical activity utilizing body surface gastric mapping in healthy subjects

BACKGROUND

Gastric sensorimotor disorders are prevalent. While gastric emptying measurements are commonly used, they may not fully capture the underlying pathophysiology. Body surface gastric mapping (BSGM) recently emerged to assess gastric sensorimotor dysfunction. This study assessed varying meal size on BSGM responses to inform test use in a wider variety of contexts.

METHODS

Data from multiple healthy cohorts receiving BSGM were pooled, using four different test meals. A standard BSGM protocol was employed: 30-min fasting, 4-h post-prandial, using Gastric Alimetry® (Alimetry, New Zealand). Meals comprised: (i) nutrient drink + oatmeal bar (482 kcal; 'standard meal'); (ii) oatmeal bar alone; egg and toast meal, and pancake (all ~250 kcal). Gastric Alimetry metrics included BMI-adjusted Amplitude, Principal Gastric Frequency, Gastric Alimetry Rhythm Index (GA-RI) and Fed:Fasted Amplitude Ratio (ff-AR).

KEY RESULTS

238 participants (59.2% female) were included. All meals significantly increased amplitude and frequency during the first postprandial hour (p < 0.05). There were no differences in postprandial frequency across meals (p > 0.05). The amplitude and GA-RI of the standard meal (n = 110) were significantly higher than the energy bar alone (n = 45) and egg meal (n = 65) (all p < 0.05). All BSGM metrics were comparable across the three smaller meals (p > 0.05). A higher symptom burden was found in the oatmeal bar group versus the standard meal and pancake meal (p = 0.01, 0.003, respectively).

CONCLUSIONS & INFERENCES

The consumption of lower calorie meals elicited different postprandial responses, when compared to the standard Gastric Alimetry meal. These data will guide interpretations of BSGM when applied with lower calorie meals.

Efficacy of Tegoprazan in Patients With Functional Dyspepsia: A Prospective, Multicenter, Single-arm Study

Background/Aims

Acid-suppressive drugs, such as proton pump inhibitors (PPIs), are treatment options for functional dyspepsia (FD). However, the efficacy of potassium-competitive acid blockers (P-CABs) in treating FD has not yet been established. This prospective multicenter clinical trial-based study aimed to assess the efficacy and safety of tegoprazan as a P-CAB treatment in patients with FD.

Methods

FD was diagnosed using the Rome IV criteria. All patients received tegoprazan 50 mg once daily for 8 weeks. Dyspeptic symptoms were assessed using a dyspepsia symptom questionnaire (5-point Likert scale, Nepean Dyspepsia Index-Korean [NDI-K], and gastroesophageal reflux disease-health-related quality of life [GERD-HRQL]). The main outcome was satisfactory symptom relief rates at 8 weeks.

Results

In this study, from the initial screening of 209 patients, 173 were included in the per-protocol set analysis. Satisfactory symptom relief rates at 8 and 4 weeks were 86.7% and 74.6%, respectively. In addition, the NDI-K and GERD-HRQL scores significantly improved at 8 and 4 weeks compared with the baseline scores. The efficacy of tegoprazan was not influenced by the FD subtype or Helicobacter pylori status. In patients with overlapping FD and GERD, there was a greater improvement in the NDI-K and GERD-HRQL scores than in patients with FD symptoms only. No serious drug-related adverse events occurred during this study.

Conclusion

Tegoprazan (50 mg) administered once daily provided satisfactory symptom relief for FD.

The goals for successful development of treatment in gastroparesis

BACKGROUND

Gastroparesis is a motility disorder of the stomach characterized by cardinal symptoms and delayed gastric emptying of solid food in the absence of mechanical obstruction. There is significant unmet need in its management, and essentially there are no medications approved for its treatment over four decades.

PURPOSE

The objectives of this review are to develop an understanding of the goals of treatment, the evidence-based criteria for treatment success based on the current scientific understanding of gastroparesis as well as patient response outcomes, and to propose evidence-based principles for the successful development of treatments for gastroparesis. Specifically, we discuss the pathophysiologic targets in gastroparesis, eligibility criteria for clinical trial participation based on validated gastric emptying studies, and the patient response outcome measures that have been validated to appraise effects of treatment on clinically relevant outcomes. These considerations lead to recommendations regarding eligibility, design, and duration of proof-of-efficacy studies, and to endorsing the American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index Daily Diary as a validated patient response outcome and to justification of the shortening of proof-of-efficacy, placebo-controlled clinical trials to 4 weeks treatment duration after a baseline period. We believe that such approaches will increase the likelihood of successful assessment of efficacy of novel approaches to treating patients with gastroparesis.

Abnormal gastrointestinal motility is a major factor in explaining symptoms and a potential therapeutic target in patients with disorders of gut-brain interaction

The objective of this article is to review the evidence of abnormal gastrointestinal (GI) tract motor functions in the context of disorders of gut-brain interaction (DGBI). These include abnormalities of oesophageal motility, gastric emptying, gastric accommodation, colonic transit, colonic motility, colonic volume and rectal evacuation. For each section regarding GI motor dysfunction, the article describes the preferred methods and the documented motor dysfunctions in DGBI based on those methods. The predominantly non-invasive measurements of gut motility as well as therapeutic interventions directed to abnormalities of motility suggest that such measurements are to be considered in patients with DGBI not responding to first-line approaches to behavioural or empirical dietary or pharmacological treatment.

Epidemiology and Healthcare Utilization in Patients With Gastroparesis: A Systematic Review

BACKGROUND & AIMS

The authors performed a systematic review of epidemiologic data to understand the prevalence, incidence, etiologies, and hospitalizations related to gastroparesis (GP).

METHODS

Studies of the epidemiology of GP published in all languages, years, and countries from 5 databases in January 2022 were studied using prespecified search strategies.

RESULTS

Thirteen studies (data from 1994 to 2019) were included. All but one study (from the United Kingdom) were based in the United States. Prevalence of definite GP (symptoms plus delayed gastric emptying) ranged from 13.8 to 267.7 per 100,000 adults, and incidence was 1.9-6.3 per 100,000 person-years. The estimated 10-year cumulative incidence of GP in type 1 diabetes (DM) and type 2 DM was 5.2% and 1.0%, respectively. Across studies, GP was more common among female patients and those with DM. Rates of hospitalizations and emergency department visits for GP are increasing, ranging from 2- to 18-fold over approximately 2 decades. Mortality rates for patients with possible or definite GP were higher compared with the general population, with primary causes of death in GP being cardiovascular, respiratory failure, and malignancy. Multiple studies observed improved inpatient mortality over the mid-1990s to late 2000s. Limitations include the case identification in most studies (76.9%) used solely International Classification of Diseases codes or clinical record diagnoses; 2 studies (15.4%) used objective evaluation to diagnose GP. Only 4 studies (30.8%) used non-specialized community databases; the remaining 9 studies used inpatient, emergency department, or disease-specific databases.

CONCLUSIONS

There is a paucity of high-quality, demographically diverse, and population-based studies to accurately describe the epidemiology of GP. Future studies with valid gastric emptying measurement are needed to better characterize the epidemiology and natural history of GP.

Many pediatric patients with gastroparesis do not receive dietary education

BACKGROUND

Gastroparesis is delayed gastric emptying in the absence of obstruction; dietary modifications are first-line treatment. However, we do not know the factors related to provision of dietary recommendations.

METHODS

We sought to determine how often pediatric patients with gastroparesis receive dietary education (from a gastroenterology provider vs dietitian), the recommendations given, and factors related to these outcomes. We performed a retrospective chart review of children 2- to 18-years-old managed by pediatric gastroenterology providers at our institution. Patient demographics and clinical data, dietary advice given (if any), and dietitian consultation (if any), practice location, and prokinetic use were captured. An adjusted binomial regression model identified factors associated with dietary education provision, dietitian consultation, and diet(s) recommended.

RESULTS

Of 161 patients who met criteria, 98 (60.8%) received dietary education and 42 (26.1%) met with a dietitian. The most common recommendation by gastroenterology providers and dietitians was diet composition adjustment (26.5% and 47.6%, respectively). Patients with nausea/vomiting were less likely to receive dietary education or be recommended to adjust diet composition. Patients with weight loss/failure to thrive were more likely to receive dietitian support. Patients seen in the community vs medical center outpatient setting were more likely to be recommended a low-fat diet.

CONCLUSIONS

Only a little over half of children with gastroparesis receive dietary education and use of a dietitian's expertise is much less frequent. Symptoms and clinical setting appear related to what, where, and by whom guidance is provided.

Gastrointestinal Dysfunction in Parkinson's Disease: Neuro-Gastroenterology Perspectives on a Multifaceted Problem

Patients with Parkinson's disease (PD) face a multitude of gastrointestinal (GI) symptoms, including nausea, bloating, reduced bowel movements, and difficulties with defecation. These symptoms are common and may accumulate during the course of PD but are often under-recognized and challenging to manage. Objective testing can be burdensome to patients and does not correlate well with symptoms. Effective treatment options are limited. Evidence is often based on studies in the general population, and specific evidence in PD is scarce. Upper GI dysfunction may also interfere with the pharmacological treatment of PD motor symptoms, which poses significant management challenges. Several new less invasive assessment tools and novel treatment options have emerged in recent years. The current review provides an overview and a practical approach to recognizing and diagnosing common upper and lower GI problems in PD, e.g., dyspepsia, gastroparesis, small bowel dysfunction, chronic constipation, and defecatory dysfunction. Management aspects are discussed based on the latest evidence from the PD and general populations, with insights for future research pertaining to GI dysfunction in PD.

Do prokinetic agents provide symptom relief through acceleration of gastric emptying? An update and revision of the existing evidence

BACKGROUND

Gastroparesis and functional dyspepsia are disorders characterized by upper gastrointestinal symptoms and multifaceted etiologies. One of the main therapeutic approaches is accelerating gastric emptying (GE) by means of prokinetic agents. Their efficacy has been demonstrated, although the association between symptom improvement and acceleration of emptying is less clear. Meta-analyses have found contradictory results. Differences in applied methodology and included trials might drive these contradictions.

OBJECTIVE

To provide a transparent meta-analysis update to elucidate the association between symptom improvement and acceleration of GE due to gastroprokinetic agents available for long-term use in patients with gastroparesis.

DESIGN

Two approaches from earlier meta-analyses were executed and compared. One analyzed the relative changes on active treatment versus baseline, the other compared the change from baseline on active treatment versus the change from baseline on placebo. Papers that reported sufficient numerical data for both analyses were selected. Both analyses included the same trials.

RESULTS

Overall, both approaches yield the same positive direction of association between symptom improvement and acceleration of emptying (0.291 (-0.391, 0.972), p = 0.4 and 0.453 (0.123, 0.782), p = 0.007 for the active-only and placebo-controlled analysis respectively). The association between symptom improvement and GE acceleration for studies using optimal GE tests was either 0.028 (p > 0.9) or 0.463 (p = 0.007), and for sub-optimal GE tests was either 0.370 (p = 0.4) or 0.052 (p > 0.9) depending on the used meta-analysis methodology.

CONCLUSIONS

The applied methodology for GE testing, and the meta-analysis substantially impacts the conclusion. When considering the clinically relevant outcome of improvement from baseline, symptoms and emptying improve with prokinetics, but no correlation is found between both aspects. When the change over placebo is considered, limiting the analysis to scientifically more rigorous study approaches, changes in emptying rate and symptom improvement are positively associated.

Gastroparesis and Functional Dyspepsia: Spectrum of Gastroduodenal Neuromuscular Disorders or Unique Entities?

Gastroparesis is defined by delayed gastric emptying in the absence of mechanical obstruction of the stomach. Patients experience symptoms of nausea, vomiting, abdominal pain, fullness, and early satiety. The recognition of the disorder has progressed due to availability of gastric emptying scintigraphy and advancements made in understanding its pathophysiology and treatment options. The clinical presentation and treatment of gastroparesis overlap with a more commonly recognized disorder of gut-brain interaction, functional dyspepsia. Recent studies have reenergized the discussion whether these two are separate entities or perhaps reflect a spectrum of gastroduodenal neuromuscular disorders. The societal guidelines conflict on the utility of gastric emptying scintigraphy in assessment of patients with upper gastrointestinal symptoms. A better appraisal of similarities and differences between gastroparesis and functional dyspepsia will allow targeted treatment for these disorders. This is particularly important as specific pharmacological and endoscopic treatment options are being developed for gastroparesis which are unlikely to be helpful for functional dyspepsia. This review makes the case for considering these disorders in a spectrum where identification of both would most ideally position us toward providing the optimal clinical care.

Gastric sensorimotor function and its clinical measurement

BACKGROUND

Gastroduodenal symptoms are highly prevalent, with underlying sensorimotor dysfunction contributing in many patients. Common symptoms include early satiation, postprandial fullness, epigastric bloating, pain or burning, nausea and vomiting, which collectively affect over 7% of adults. However, the clinical evaluation of these symptoms remains challenging, with current tests of gastric function remaining limited in their ability or availability to separate specific patient subgroups or guide-targeted care.

PURPOSE

In the current edition of Neurogastroenterology & Motility, Silver et al. present new data showing correlations between patterns of intragastric meal distribution and symptom profiles in a large series of patients undergoing gastric emptying scintigraphy. Studies of this type are important, as they motivate understanding beyond existing disease labels, and orient focus toward deeper mechanistic profiling. This brief review provides an overview of gastric sensorimotor function and profiles several current and emerging methods of clinical evaluation. Perspectives are provided on accommodation testing, gastric emptying, measuring gastric myoelectrical activity including new approaches, and antroduodenal manometry. Although gastric physiology is complex, recent progress has been encouraging, with the heterogenous pathophysiology of gastric symptoms continuing to be unraveled, and new techniques for evaluating gastric function and symptoms emerging.

CONCLUSIONS AND INFERENCES

Ongoing progress will now depend on continuing to accurately profile the underlying mechanisms of gastroduodenal disorders to identify specific disease phenotypes that inform care.

Gastric dysfunction in patients with chronic nausea and vomiting syndromes defined by a noninvasive gastric mapping device

Chronic nausea and vomiting syndromes (NVSs) are prevalent and debilitating disorders. Putative mechanisms include gastric neuromuscular disease and dysregulation of brain-gut interaction, but clinical tests for objectively defining gastric motor function are lacking. A medical device enabling noninvasive body surface gastric mapping (BSGM) was developed and applied to evaluate NVS pathophysiology. BSGM was performed in 43 patients with NVS and 43 matched controls using Gastric Alimetry (Alimetry), a conformable high-resolution array (8 × 8 electrodes; 20-mm interelectrode spacing), wearable reader, and validated symptom-logging app. Continuous measurement encompassed a fasting baseline (30 minutes), 482-kilocalorie meal, and 4-hour postprandial recording, followed by spectral and spatial biomarker analyses. Meal responses were impaired in NVS, with reduced amplitudes compared to controls (median, 23.3 microvolts versus 38.0 microvolts, P < 0.001), impaired fed-fasting power ratios (1.1 versus 1.6, P = 0.02), and disorganized slow waves (spatial frequency stability, 13.6 versus 49.5; P < 0.001). Two distinct NVS subgroups were evident with indistinguishable symptoms (all P > 0.05). Most patients (62%) had normal BSGM studies with increased psychological comorbidities (43.5% versus 7.7%; P = 0.03) and anxiety scores (median, 16.5 versus 13.0; P = 0.035). A smaller subgroup (31%) had markedly abnormal BSGM, with biomarkers correlating with symptoms (nausea, pain, excessive fullness, early satiety, and bloating; all r > 0.35, P < 0.05). Patients with NVS share overlapping symptoms but comprise distinct underlying phenotypes as revealed by a BSGM device. These phenotypes correlate with symptoms, which should inform clinical management and therapeutic trial design.

Gastroparesis in pregnancy

Gastroparesis is a functional gastrointestinal disorder that more commonly affects women, with most cases being diagnosed during childbearing age. However, there is a paucity of data and guidelines to specifically highlight the epidemiology, disease course, maternal and fetal impact, and the management of existing gastroparesis during pregnancy. Apart from metoclopramide, there is no approved therapy specifically indicated for gastroparesis. More importantly, pregnant and breastfeeding women are excluded from clinical trials evaluating pharmacologic agents in the management of gastroparesis. This poses a real challenge to healthcare providers in counseling and managing patients with gastroparesis. In this systematic review, we summarize the current available literature and the knowledge gaps in the impact of pregnancy on gastroparesis and vice versa. We also highlight the efficacy and safety profiles of available pharmacologic and nonpharmacologic therapies in the management of patients with gastroparesis, with emphasis on judicious use of dietary approaches that are deemed relatively safe during pregnancy.

Poor Gastric Emptying in Patients with Paraesophageal Hernias: Pyloroplasty, Per-Oral Pyloromyotomy, BoTox, or Wait and See?

Gastric emptying delay may be caused with both functional and anatomic derangements. Gastroparesis is suspected in patients presenting with certain foregut symptoms without anatomic obstruction. Data are still emerging regarding the best treatment of this condition. In cases where large paraesophageal hernias alter the upper gastrointestinal anatomy, it is difficult to know if gastroparesis also exists. Management of hiatal hernias is also still evolving, with various strategies to reduce recurrence being actively investigated. In this article, we present a systematic review of the existing literature around the management of gastroparesis and the management of paraesophageal hernias when they occur separately. In addition, since there are limited data to guide diagnosis and management of these conditions when they are suspected to coexist, we provide a rational strategy based on our own experience in patients with paraesophageal hernias who have symptoms or studies that raise suspicion for a coexisting functional disorder.

Gastric Electrical Stimulation: Role and Clinical Impact on Chronic Nausea and Vomiting

Gastric electrical stimulation (GES) is currently used as an alternative treatment for medically refractory gastroparesis. GES has been initially developed to accelerate gastric motility, in order to relieve the symptoms of the patients. Subsequent studies, unfortunately, failed to demonstrate the acceleration of gastric emptying using high-frequency stimulation - low energy stimulation although the technique has shown a clinical impact with a reduction of nausea and vomiting for patients with gastroparesis. The present review details the clinical efficacy of GES in gastroparesis as well as its putative mechanisms of action.