Ineffective esophageal motility and bolus clearance. A study with combined high-resolution manometry and impedance in asymptomatic controls and patients

Esophageal motor abnormalities in gastroesophageal reflux disorders

Gastroesophageal reflux disease (GERD), a prevalent condition with multifactorial pathogenesis, involves esophageal motor dysmotility as a key contributing factor to its development. When suspected GERD patients have an inadequate response to proton-pump inhibitor (PPI) therapy and normal upper endoscopy results, high-resolution manometry (HRM) is utilized to rule out alternative diagnosis such as achalasia spectrum disorders, rumination, or supragastric belching. At present, HRM continues to provide supportive evidence for diagnosing GERD and determining the appropriate treatment. This review focuses on the existing understanding of the connection between esophageal motor findings and the pathogenesis of GERD, along with the significance of esophageal HRM in managing GERD patients. The International GERD Consensus Working Group introduced a three-step method, assessing the esophagogastric junction (EGJ), esophageal body motility, and contraction reserve with multiple rapid swallow (MRS) maneuvers. Crucial HRM abnormalities in GERD include frequent transient lower esophageal sphincter relaxations, disrupted EGJ, and esophageal body hypomotility. Emerging HRM metrics like EGJ-contractile integral and innovative provocative maneuver like straight leg raise have the potential to enhance our understanding of factors contributing to GERD, thereby increasing the value of HRM performed in patients who experience symptoms suspected of GERD.

Interpretation of Impedance Data on High-resolution Impedance Manometry Studies-A Worldwide Survey

Background/Aims

Esophageal manometry is the gold standard for esophageal motility evaluation. High-resolution esophageal manometry with impedance (HRIM) allows concurrent assessment of bolus transit and manometry. Inconsistencies between concomitant impedance and manometry data pose a clinical dilemma and has not yet been addressed. We aim to assess interpretation trends of HRIM data among gastroenterologists worldwide.

Methods

A cross-sectional study using an anonymous survey was conducted among gastroenterologists worldwide. Statistical analysis was performed to compare responses between providers.

Results

We received responses from 107 gastroenterologists (26 countries). Most were adult providers (69, 64.5%), and most (77, 72.0%) had > 5 years of experience. Impedance was found to be helpful by 83 (77.6%) participants, but over 30% reported inconsistencies between impedance and manometry data. With incomplete bolus clearance and normal manometry 41 (38.7%) recommended observation, 41 (38.7%) recommended 24-hours pH-impedance, and 16 (15.1%) recommended prokinetics. With abnormal manometry and complete bolus clearance, 60 (57.1%) recommended observation while 18 (17.1%) recommended 24-hours pH impedance and 15 (14.3%) recommended prokinetics. A significant difference was found between providers from different continents in treating cases with discrepancy between impedance and manometry findings (P < 0.001). No significant differences were seen in responses between adult versus pediatric providers and between providers with different years of experience.

Conclusions

There is no consensus on interpreting HRIM data. Providers' approaches to studies with inconsistencies between manometry and impedance data vary. There is an unmet need for guidelines on interpreting impedance data in HRIM studies.

Ineffective esophageal motility: The impact of change of criteria in Chicago Classification version 4.0 on predicting outcome after magnetic sphincter augmentation

BACKGROUND

The most recent update of the Chicago Classification (CCv4.0) attempts to provide a more clinically relevant definition for ineffective esophageal motility (IEM). The impact of this new definition on predicting outcome after antireflux surgery is unknown. The aim of this study was to compare utility of IEM diagnosis based on CCv4.0 to CCv3.0 in predicting surgical outcome after magnetic sphincter augmentation (MSA) and to assess any additional parameters that hold value in future definitions.

METHODS

Records of 336 patients who underwent MSA at our institution between 2013 and 2020 were reviewed. Preoperative manometry files were re-analyzed using both Chicago Classification version 3.0 (CCv3.0) and CCv4.0 definitions of IEM. The utility of each IEM definition in predicting surgical outcome was then compared. Individual manometric components and impedance data were also assessed.

KEY RESULTS

Immediate dysphagia was reported by 186 (55.4%) and persistent dysphagia by 42 (12.5%) patients. CCv3.0 IEM criteria were met by 37 (11%) and CCv4.0 IEM by 18 (5.4%) patients (p = 0.011). CCv3.0 and CCv4.0 IEM were equally poor predictors of immediate (AUC = 0.503 vs. 0.512, p = 0.7482) and persistent (AUC = 0.519 vs. 0.510, p = 0.7544) dysphagia. The predicted dysphagia probability of less than 70% bolus clearance (BC) was 17.4%, higher than CCv4.0 IEM at 16.7%. When BC was incorporated into CCv4.0 IEM criteria, the probability increased significantly to 30.0% (p = 0.0042).

CONCLUSIONS & INFERENCES

The CCv3.0 and CCv4.0 of IEM are poor predictors of dysphagia after MSA. Adding BC to the new definition improves its predictive utility and should be considered in future definitions.

Non-acid reflux and esophageal dysmotility is associated with early esophageal squamous cell carcinoma

BACKGROUND

Studies have demonstrated that non-acid reflux (NAR) is associated with esophageal squamous cell carcinoma (ESCC). Esophageal dysmotility is associated with NAR but few studies have focused on the esophageal motility of ESCC patients. We explored the relationship between ESCC, NAR and esophageal dysmotility with the aid of multichannel intraluminal impedance and pH (MII-pH) and high-resolution manometry (HRM).

METHODS

From Jan 2021 to Oct 2022, 20 patients with superficial ESCC were enrolled as the ESCC group, while 20 age and gender matched individuals without gastroesophageal reflux disease (GERD) symptoms and 20 age and gender matched patients with GERD symptoms were recruited as the control groups. Patients received 24 h MII-pH and HRM procedure before endoscopic submucosal dissection (ESD), and the data were then collected to identify the type of reflux and esophageal dysmotility.

RESULTS

Prevalence of esophageal dysmotility was significantly different among the three groups, 75.0% in the ESCC group, 35.0% in the non-GERD group and 70.0% in the GERD group (P = 0.029). NAR episodes at 15 cm above the lower esophageal sphincter (LES) in the ESCC group were significantly higher than that in the non-GERD group (6.5 (3.5-9.3) vs 1.0 (0.8-4.0), P = 0.001) and were similar with that in the GERD group (6.5 (3.5-9.3) vs 5.5 (3.0-10.5), P > 0.05). NAR episodes at 5 cm above LES was significantly higher in the ESCC group than that in the non-GERD group (38.0 (27.0-60.0) vs 18.0 (11.8-25.8), P = 0.001) and was significantly higher than that in the GERD group (38.0 (27.0-60.0) vs 20.0 (9.8-30.5)), P = 0.010). Prevalence of pathologic non-acid reflux was significantly different among the three groups, 30.0% in the ESCC group, 0.0% in the non-GERD group and 10.0% in the GERD group (P < 0.001).

CONCLUSION

Our study found NAR and esophageal dysfunction frequently occur in ESCC patients. NAR and esophageal dysmotility may be associated with ESCC.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR2200061456.

Comparing Patients Diagnosed With Ineffective Esophageal Motility by the Chicago Classification Version 3.0 and Version 4.0 Criteria

Background

The Chicago Classification version 4.0 (CCv4.0) of ineffective esophageal motility (IEM) is more stringent than the Chicago Classification version 3.0 (CCv3.0) definition. We aimed to compare the clinical and manometric features of patients meeting CCv4.0 IEM criteria (group 1) versus patients meeting CCv3.0 IEM but not CCv4.0 criteria (group 2).

Methods

We collected retrospective clinical, manometric, endoscopic, and radiographic data on 174 adults diagnosed with IEM from 2011 to 2019. Complete bolus clearance was defined as evidence of exit of the bolus by impedance measurement at all distal recording sites. Barium studies included barium swallow, modified barium swallow, and barium upper gastrointestinal series studies, and collected data from these reports include abnormal motility and delay in the passage of liquid barium or barium tablet. These data along with other clinical and manometric data were analyzed using comparison and correlation tests. All records were reviewed for repeated studies and the stability of the manometric diagnoses.

Results

Most demographic and clinical variables were not different between the groups. A lower mean lower esophageal sphincter pressure was correlated with greater percent of ineffective swallows in group 1 (n = 128) (r = -0.2495, P = 0.0050) and not in group 2. In group 1, increased percent of failed contractions on manometry was associated with increased incomplete bolus clearance (r = 0.3689, P = 0.0001). No such association was observed in group 2. A lower median integrated relaxation pressure was correlated with greater percent of ineffective contractions in group 1 (r = -0.1825, P = 0.0407) and not group 2. Symptom of dysphagia was more prevalent (51.6% versus 69.6%, P = 0.0347) in group 2. Dysphagia was not associated with intrabolus pressure, bolus clearance, barium delay, or weak or failed contractions in either group. In the small number of subjects with repeated studies, a CCv4.0 diagnosis appeared more stable over time.

Conclusions

CCv4.0 IEM was associated with worse esophageal function indicated by reduced bolus clearance. Most other features studied did not differ. Symptom presentation cannot predict if patients are likely to have IEM by CCv4.0. Dysphagia was not associated with worse motility, suggesting it may not be primarily dependent on bolus transit.

Clinical Characteristics of Patients With Ineffective Esophageal Motility by Chicago Classification Version 4.0 Compared to Chicago Classification Version 3.0

Background/Aims

Chicago classification version 4.0 (CCv4.0) of esophageal motility disorders developed a more stringent diagnostic criteria for ineffective esophageal motility (IEM) than version 3.0. We studied the implications of the new diagnostic criteria on the prevalence of IEM, and clinically characterized and compared the population of patients who no longer meet diagnostic criteria for IEM to those who retain the diagnosis.

Methods

We included all consecutively performed high-resolution esophageal impedance manometries from 2014 to 2021. Three cohorts of patients with IEM were created: Patients with IEM by Chicago classification version 3.0 (CCv3.0; CC3 group), by CCv4.0 only (CC4 group), and by CCv3.0 who are now considered normal (Normal group). Demographics, manometric and reflux parameters, and clinical outcomes were compared.

Results

A total of 594 manometries were analyzed. Of those, 66 (11.1%) met criteria for IEM by CCv3.0 (CC3), 41 (62.0%) retained an IEM diagnosis using CCv4.0 criteria (CC4), while 25 (38.0%) patients no longer met criteria for IEM (Normal). The CC4 group had higher esophageal acid exposure, especially supine (% time - 18.9% vs 2.2%; P = 0.005), less adequate peristaltic reserve (22.0% vs 88.0%; P = 0.003), and higher Demeester score (49.0 vs 21.2; P = 0.017) compared to the Normal group. There was no difference in bolus clearance between the groups.

Conclusions

IEM under CCv4.0 has a stronger association with pathologic reflux, especially supine reflux, and inadequate peristaltic reserve, but impairment in bolus clearance is unchanged when compared with IEM diagnosed based on CCv3.0. Further studies are required to determine the implications of these findings on management strategies.

Assessment of Esophageal Motility in Patients With Eosinophilic Esophagitis: A Scoping Review

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated condition causing esophageal symptoms, particularly dysphagia. Despite the important progress in the treatment of EoE, a significant proportion of patients continue to report symptoms that negatively impact quality of life. Esophageal manometry is used to assess motility and function, but is not routinely used in EoE. We aimed to systematically review and describe current literature evaluating esophageal manometry in EoE. Forty-eight studies meeting the criteria were identified, describing 802 patients. Using standard water swallow protocols, the proportion of abnormalities detected was not dissimilar to other populations, apart from disorders of esophago-gastric outflow, which were found in 5%. Twelve studies described pretreatment and posttreatment manometry, with motility normalization after pharmacological therapy reported in 20%. Early, brief panesophageal pressurization was described in a number of studies and was more prevalent in the few studies utilizing additional provocation testing. Reports in the literature regarding temporal relationships between manometric findings and symptoms are variable. Esophageal manometry may be capable of detecting clinically relevant changes to esophageal function in EoE. Possible mechanisms are altered neuromuscular function because of secretory products of EoE and/or fibroinflammatory processes, manifesting as pressurization because of altered esophageal compliance. Some changes may be reversible with therapy. Drawing strong conclusions from the literature is difficult, with bias toward case reports and retrospective observation. Adaptations to assessment protocols to include provocation testing may provide more robust evaluation and detect clinically relevant, subtle changes in esophageal function, earlier within the patient pathway.

Association of Bolus Transit Time on Barium Esophagram With Esophageal Peristalsis on High-resolution Manometry and Nonobstructive Dysphagia

GOAL

The goal of this study was to correlate upright and prone bolus transit time (BTT) on barium esophagography (BE) with esophageal peristalsis on high-resolution manometry (HRM) and self-reported dysphagia in patients with normal lower esophageal sphincter parameters on HRM.

BACKGROUND

BTT on BE could be the gold standard for assessing the effectiveness of esophageal peristalsis if it can be quantified.

MATERIALS AND METHODS

Patients with normal lower esophageal sphincter parameters and standard-protocol BE from 2017 to 2020 were included. Patients were divided, based on the number of normal swallows (distal contractile integral >450 mm Hg-s-cm), into 11 groups (10 normal swallows to 0 normal swallows). Liquid barium swallows in prone position were objectively evaluated for prone BTT. Patients reported difficulty in swallowing on a scale from 0 (none) to 4 (very severe). Fractional polynomial and logistic regression analysis were used to study the association (along with the rate of change) between BTT, peristalsis, and dysphagia.

RESULTS

A total of 146 patients were included. Prone BTT increased as the number of normal swallows decreased ( P <0.001). Two deflection points were noted on the association between peristalsis and prone BTT at 50% normal swallows, 40 seconds and 30% normal swallows, 80 seconds, after which peristaltic function declined independently of prone BTT. Patients with prone BTT>40 seconds had nearly 6-fold higher odds of 0% normal swallows on HRM than patients with prone BTT<40 seconds ( P =0.002). Increasing prone BTT was associated with increasing dysphagia grades 1 and 2 ( P ≤0.036).

CONCLUSIONS

Esophageal motility can be quantified by BE. Prone BTT correlates with the proportion of normal esophageal swallows and dysphagia.

The Supportive Role of Provocative Maneuvers and Impedance Clearance in Detecting Ineffective Esophageal Motility

BACKGROUND

Ineffective esophageal motility (IEM) is one of the most common esophageal motility disorders. However, the definition of IEM has evolved. Chicago classification version 4.0 (CCv4.0) made IEM parameters more stringent with greater than 70% of ineffective wet swallows (WS) necessary to diagnose conclusive IEM. Of the ineffective swallows, 50-70% are deemed "inconclusive cases". This study sought to determine whether provocative maneuvers, including multiple rapid swallows (MRS) and apple viscous swallows (AVS), and impedance clearance can provide supportive information for inconclusive IEM disorders based on CCv4.0.

METHODS

Esophageal motility data on 100 patients were analyzed. All patients completed WS and at least one additional swallow test (MRS and/or AVS). Patients were classified as having conclusive IEM, inconclusive IEM, or normal motility. IEM features detected on MRS/AVS and incomplete bolus clearance were recorded. Percentage of agreement between IEM features and incomplete bolus clearance was calculated for each motility group.

RESULTS

Ten patients had conclusive IEM, nine had inconclusive IEM, and 32 had normal motility. There was 70% agreement between IEM features and incomplete bolus clearance with conclusive IEM, 33% agreement with inconclusive IEM, and 9% agreement with normal motility. There was significantly more agreement in the conclusive and inconclusive IEM groups than in the normal motility group (P = 0.0003).

CONCLUSIONS

Combinational follow-up testing with provocative maneuvers and impedance clearance may assist with risk stratification of IEM patients and assist in further management of inconclusive IEM. MRS and AVS can detect unique IEM features that may help with preoperative management of inconclusive IEM.

Dysphagia Worsens With Increasing Ineffective Swallows Among Patients With Ineffective Esophageal Motility

INTRODUCTION

Ineffective esophageal motility (IEM) is the most common motility disorder identified on esophageal high-resolution manometry (HRM), but patients with this finding may be asymptomatic. Therefore, we aimed to identify specific HRM findings predictive of symptoms in IEM.

METHODS

Adult patients (≥18 y) who underwent HRM between March 2016 and July 2019 were retrospectively evaluated and reclassified according to Chicago Classification 4.0 (CC4.0). Demographic information, HRM parameters, and gastroesophageal reflux disease Health-Related Quality of Life Questionnaire responses were captured among those with normal manometry or IEM. We evaluated the association between heartburn, regurgitation, and dysphagia, with respect to HRM findings including ineffective swallows.

RESULTS

Of 379 patients, 243 (64.1%) had a normal manometry, 136 (35.9%) were on IEM spectrum, and 73 (19.3%) had conclusive IEM by CC4.0. Mean dysphagia scores were significantly higher in those with conclusive IEM compared with those with normal HRM (2.00 vs. 1.36, P=0.002), as was the percentage of individuals reporting dysphagia affecting daily activities (21.9% vs. 11.4%, P=0.02). Heartburn and regurgitation symptoms did not differ between groups. In a multivariable model of IEM patients, the percentage of ineffective swallows independently predicted a higher dysphagia burden (β regression coefficient: 0.032, P=0.04).

CONCLUSIONS

Applying the CC4.0 definition for conclusive IEM identifies a group of patients with worse dysphagia symptoms. Within this group, the percentage of ineffective swallows was an independent predictor of dysphagia severity. These findings may help practitioners and patients contextualize the heterogeneous diagnosis of IEM.

Advancing high-resolution manometry: evaluating the use of multiple rapid swallows versus apple viscous swallows in clinical practice

BACKGROUND

High-Resolution Manometry (HRM) with provocative maneuvers, such as Multiple Rapid Swallows (MRS) and Apple Viscous Swallows (AVS), is commonly utilized to diagnose esophageal disorders. Increasing standardization in HRM protocol can help save time and reduce patient discomfort. This study assesses AVS and MRS to determine their respective benefits and limitations.

METHODS

Retrospective reviews were performed on 100 patients to analyze their AVS and/or MRS results. Parameters included abnormal motility patterns, tolerance, and DCI. Diagnostic benefits from MRS and AVS were assessed. Based on the previous studies, additional benefit from MRS was defined as detection of good peristaltic reserve, weak peristaltic reserve, or an abnormal motility/pressurization pattern. Additional benefit from AVS was defined as detection of IEM features or abnormal motility/pressurization pattern.

RESULTS

When patients completed both MRS and AVS (n = 70), MRS provided additional benefit in assessing 36% of patients, while AVS provided additional benefit in 19% of patients (p < 0.0001). Furthermore, MRS detected significantly more abnormal motility/pressurization patterns than AVS (27% MRS; 8% AVS; p = 0.0005). Two unique strengths of AVS were higher tolerance for test completion (p = 0.009) and better detection of severe hypokinetic disorders in 4% of patients, which were missed by MRS.

CONCLUSIONS

MRS may uniquely identify abnormal motility/pressurization patterns, such as paradoxical LES response, distal pressurization, hypercontractile, and spasm patterns. These findings argue for a tailored approach when selecting provocative testing. MRS may be more useful for patients with abnormal pathophysiology, while AVS may help to supplement MRS in detecting severe hypokinetic disorders in preoperative management.

[Chicago Classification ver. 4.0: Diagnosis of Peristaltic Disorder]

The Chicago Classification is being revised continuously for the accurate diagnosis of esophageal peristaltic disorders in which the etiology is unclear, and the disease behavior is heterogeneous. The ver. 4.0 was recently updated. A representative change in the diagnosis of esophageal peristaltic disorders of the ver. 4.0 showed that the distinction between major and minor disorders was eliminated and was divided into the following four diagnoses: absent contractility, distal esophageal spasm (DES), hypercontractile esophagus (HE), and ineffective esophageal motility. Compared to the ver. 3.0, it recommended a more detailed protocol of high-resolution esophageal manometry and methods of interpreting manometric. In addition, it emphasized the clinically relevant symptoms in diagnosing DES and HE, and presented provocative tests (e.g., multiple rapid swallow and rapid drinking challenge), as well as additional testing, including impedance, timed barium esophagogram and functional lumen imaging probe, which may provide more standardized and rigorous criteria for peristaltic patterns and to minimize the ambiguity in diagnosis. Although it will take time and effort to apply this revised Chicago Classification in clinical practice, it may help diagnose and manage patients with esophageal peristalsis disorder in the future.

Making Sense of Nonachalasia Esophageal Motor Disorders

Achalasia is the prototypical obstructive motor disorder diagnosed using HRM, but non-achalasia motor disorders are often identified in symptomatic patients. The clinical relevance of these disorders are assessed using ancillary HRM maneuvers (multiple rapid swallows, rapid drink challenge, solid swallows) that augment the standard supine HRM evaluation by challenging peristaltic function. Finding obstructive motor physiology in non-achalasia motor disorders may raise the option of invasive management akin to achalasia. Certain non-achalasia disorders, particularly hypermotility disorders, may manifest as epiphenomena seen with esophageal hypersensitivity. Symptomatic management is offered for superimposed reflux disease, psychological disorders, functional esophageal disorders, and behavioral disorders.

Chicago Classification update (V4.0): Technical review on diagnostic criteria for ineffective esophageal motility and absent contractility

Esophageal hypomotility disorders manifest with abnormal esophageal body contraction vigor, breaks in peristaltic integrity, or failure of peristalsis in the context of normal lower esophageal sphincter relaxation on esophageal high-resolution manometry (HRM). The Chicago Classification version 4.0 recognizes two hypomotility disorders, ineffective esophageal motility (IEM) and absent contractility, while fragmented peristalsis has been incorporated into the IEM definition. Updated criteria for ineffective swallows consist of weak esophageal body contraction vigor measured using distal contractile integral (DCI, 100-450 mmHg·cm·s), transition zone defects >5 cm measured using a 20 mmHg isobaric contour, or failure of peristalsis (DCI < 100 mmHg·cm·s). More than 70% ineffective swallows and/or ≥50% failed swallows are required for a conclusive diagnosis of IEM. When the diagnosis is inconclusive (50%-70% ineffective swallows), supplementary evidence from multiple rapid swallows (absence of contraction reserve), barium radiography (abnormal bolus clearance), or HRM with impedance (abnormal bolus clearance) could support a diagnosis of IEM. Absent contractility requires 100% failed peristalsis, consistent with previous versions of the classification. Consideration needs to be given for the possibility of achalasia in absent contractility with dysphagia despite normal IRP, and alternate complementary tests (including timed upright barium esophagram and functional lumen imaging probe) are recommended to confirm or refute the presence of achalasia. Future research to quantify esophageal bolus retention on stationary HRM with impedance and to understand contraction vigor thresholds that predict bolus clearance will provide further refinement to diagnostic criteria for esophageal hypomotility disorders in future iterations of the Chicago Classification.

Impact of ineffective esophageal motility on secondary peristalsis: Studies with high-resolution manometry

BACKGROUND/AIM

The aim was to investigate whether there is a difference in secondary peristalsis on high-resolution manometry (HRM) among gastroesophageal reflux disease (GERD) patients with and without ineffective esophageal motility (IEM), and healthy individuals.

METHODS

Twenty-eight GERD patients and seventeen healthy controls were included. Secondary peristalsis was stimulated by a rapid injection of 20 ml air in mid-esophagus. We compared HRM metrics and the response and effective rate of triggering secondary peristalsis between patients with and without IEM and healthy controls.

RESULTS

Sixteen patients had IEM, and the remaining 12 had normal manometry. By triggering of secondary peristalsis, patients without IEM and healthy controls had significantly higher distal contractile integral (DCI) values than IEM patients (p = 0.006). A successful secondary peristalsis was triggered more frequently in healthy controls than in GERD patients with normal peristalsis or IEM (56.9% vs. 20.2% vs. 9.1%, all p < 0.001). The effective rate which determined as DCI > 450 mm Hg.cm.s was higher in healthy controls compared to patients with normal peristalsis (36.5% vs. 19.4%, p < 0.001) and IEM (36.5% vs. 6.3%, p < 0.001). Patients with IEM had lower successful triggering response (9.1% vs. 20.2%) and effective secondary peristalsis (6.3% vs. 19.4%) compared with patients without IEM (p < 0.001).

CONCLUSIONS

Our work has demonstrated that GERD patients, in particular those with IEM, have significant defects in the triggering of secondary peristalsis on HRM. HRM helps characterize esophageal secondary peristalsis which exhibits differently in patients with and without IEM.

Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0©

Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). Fifty-two diverse international experts separated into seven working subgroups utilized formal validated methodologies over two-years to develop CCv4.0. Key updates in CCv.4.0 consist of a more rigorous and expansive HRM protocol that incorporates supine and upright test positions as well as provocative testing, a refined definition of esophagogastric junction (EGJ) outflow obstruction (EGJOO), more stringent diagnostic criteria for ineffective esophageal motility and description of baseline EGJ metrics. Further, the CCv4.0 sought to define motility disorder diagnoses as conclusive and inconclusive based on associated symptoms, and findings on provocative testing as well as supportive testing with barium esophagram with tablet and/or functional lumen imaging probe. These changes attempt to minimize ambiguity in prior iterations of Chicago Classification and provide more standardized and rigorous criteria for patterns of disorders of peristalsis and obstruction at the EGJ.