Abstract
Objectives
High‐resolution anorectal manometry (HR‐ARM) is a diagnostic test assessing anorectal neuromuscular function in children with constipation and/or fecal incontinence. Interrater reliability of HR‐ARM in children has not been previously studied. The aim of this study was to assess the interrater reliability of pediatric HR‐ARM studies.
Methods
Ten pediatric gastroenterologists specialized in neurogastroenterology and motility analyzed ten deidentified pediatric HR‐ARM studies using dedicated analysis software (Solar GI HRM v9.1, MMS, Enschede, the Netherlands). Anal canal resting pressure, squeeze pressure and duration, presence of the rectoanal inhibitory reflex (RAIR), bear down maneuver (normal/abnormal), and final interpretation of the study (normal/abnormal) were evaluated. Fleiss' Kappa (κ) and intraclass correlation coefficient (ICC) were used for categorical and continuous data, respectively.
Results
Interrater reliability was excellent for resting pressure (ICC 0.97, 95% confidence interval [CI 0.93–0.99), squeeze pressure (ICC 0.97, 95% CI 0.94–0.99), and squeeze duration (ICC 0.93, 95% CI 0.85–0.98). A fair interrater agreement for the RAIR (κ = 0.35) was seen, and a moderate interrater agreement was seen for interpretation of the bear down maneuver and the final interpretation of the study either being normal or abnormal (κ = 0.50 and κ = 0.43, respectively).
Conclusions
This study demonstrated excellent interrater reliability in assessing HR‐ARM anal canal resting pressure, squeeze pressure, and squeeze duration and suboptimal reliability in interpreting the detection of a RAIR and bear down maneuver. These findings highlight the need for standardization of HR‐ARM protocols and interpretation criteria in children.
Keywords: children, diagnostic test, Hirschsprung disease
What is Known
High‐resolution anorectal manometry (HR‐ARM) is a diagnostic test used to assess anorectal neuromuscular function in the management of constipation, fecal incontinence, and conditions like Hirschsprung disease (HD) and internal anal sphincter achalasia (IASA) in children.
In recent years, there has been a significant increase in the availability of pediatric neurogastroenterology and motility services, including anorectal manometry.
What is New
In pediatric HR‐ARM studies, interrater reliability among experienced raters was found to be excellent for assessment of the anal canal resting pressure, the squeeze pressure, as well as the squeeze duration.
Only fair interrater agreement was found for detection of the rectoanal inhibitory reflex and moderate agreement on the bear down maneuver and final interpretation of the study as either being normal or abnormal.
Standardized interpretation criteria for pediatric HR‐ARM are needed.
1. INTRODUCTION
High‐resolution anorectal manometry (HR‐ARM) is a diagnostic test used to assess anorectal neuromuscular function in the management of constipation, fecal incontinence, and conditions like Hirschsprung disease (HD) and internal anal sphincter achalasia (IASA) in children. 1 HR‐ARM is also used to evaluate patients with anorectal malformations with persistent defecation problems after surgical repair. 1 The procedure involves inserting a manometry catheter through the anus and into the rectum and is used to evaluate anal sphincter characteristics and function, the presence or absence of the rectoanal inhibitory reflex (RAIR), rectal sensation, and defecation dynamics. 1 In recent years, there has been a significant increase in the availability of pediatric neurogastroenterology and motility services, including anorectal manometry (ARM), across North America. 2 An international survey among pediatric gastroenterologists revealed that ARM is currently the most frequently used diagnostic test for children with intractable constipation. 2 Although there are guidelines and consensus documents from the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN), the American Neurogastroenterology and Motility Society (ANMS), and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) on how to perform and interpret HR‐ARM studies, the utilization of diagnostic and therapeutic ARM procedures varies considerably in standard practice and among experts. 1 , 3 , 4 This variability highlights the critical importance of interrater reliability in ensuring consistent and accurate interpretation of HR‐ARM results across clinicians. Such consistency is fundamental for reliable diagnosis and effective management of anorectal disorders and constipation in the pediatric population. The objective of this study was therefore to assess the interrater reliability of HR‐ARM in children.
2. METHODS
To establish interrater reliability, we made use of a set of HR‐ARM studies from children who underwent ARM at Nationwide Children's Hospital (Columbus, OH, USA) between January 2010 and February 2024. ARM studies were performed using a high‐resolution solid‐state catheter according to the institutional protocol of Nationwide Children's Hospital. Patients were prepared with a bisacodyl suppository the day before and the morning of the study (0.2 mg/kg, rounded to either 5 mg or 10 mg). Stool retention was assessed during the HR‐ARM based on resistance to catheter insertion or difficulty performing the HR‐ARM itself. HR‐ARMs were conducted while the patient was awake and positioned on their left side for all maneuvers except the balloon expulsion test, when the patient sat on a bedside commode. Each procedure included assessment of anal canal resting pressure and involved gradual inflation of a rectal balloon to assess the presence of the RAIR. Rectal sensory thresholds during balloon inflations were also evaluated, along with the assessment of squeeze and bear down (or push) maneuvers.
HR‐ARM studies of patients meeting the following criteria were considered for inclusion: (1) HR‐ARM studies were performed awake; and (2) no technical errors occurred. From these potential studies, 10 studies representing a range of findings were chosen to assess the interrater reliability. All study data were thoroughly deidentified to ensure patient anonymity.
2.1. Ethics statement
The Nationwide Children's Hospital Institutional Review Board approved the study protocol (STUDY00003903).
2.2. Data analysis
Ten pediatric gastroenterologists with expertise in neurogastroenterology and motility from different centers in the United States and Europe were asked to analyze the 10 HR‐ARM studies. None of the 10 HR‐ARM studies had been previously reviewed or performed by the selected raters, meaning all the studies were new to them. To ensure unbiased evaluation, the raters were blinded to the patients' medical history, the initial ARM reports and to the evaluations of the other raters. For raters not familiar with the software, an explanation was provided prior to study analysis using the dedicated Medical Measurement Systems software (Solar GI HRM v9.1, MMS, Enschede, the Netherlands). Raters were instructed to analyze and interpret the studies as they normally would in clinical practice. For all 10 studies, they were asked to assess the anal canal resting pressure (in mmHg), the squeeze pressure (in mmHg) and duration (in seconds), as well as the presence of the RAIR. Raters had access to the numerical values generated by the software, but could adjust the software‐generated boxes if necessary. No predefined cut‐off values for normal pressures or RAIR criteria were provided. They were asked to determine whether the bear down maneuver was normal or abnormal, and if abnormal, to identify the type of dyssynergia based on the Rao criteria (type I–IV). 5 Finally, raters were asked to provide a final interpretation of the study as either normal or abnormal. If a study was classified as abnormal, raters were asked to indicate what aspect was abnormal, selecting from predefined options: low or high resting pressure, low or high squeeze pressure, absent RAIR, abnormal bear down maneuver, or other with the option of free text.
2.3. Statistical analysis
Data were analyzed using R, version 4.4.0. For continuous data, the intraclass correlation coefficient (ICC) was used. For categorical data, interrater reliability was calculated using Fleiss' kappa (further annotated as κ). We used the commonly used scales for ICC and κ values: 0.00: no agreement, 0.01–0.20: slight agreement, 0.21–0.40: fair agreement, 0.41–0.60: moderate agreement, 0.61–0.80: substantial agreement, and 0.81–1.00: excellent agreement.
3. RESULTS
Ten pediatric gastroenterologists specialized in neurogastroenterology and motility from nine different tertiary centers analyzed the 10 deidentified pediatric HR‐ARM studies. Years of experience were as follows: 0–5 years (10%), 10–15 years (30%), and >15 years (60%).
3.1. Patient characteristics
Of the 10 included HR‐ARM studies, patients were 60% male and had a median age of 11 years (range 6–20 years). Underlying conditions of the patients included HD s/p pull through procedure (n = 1), sacral agenesis (n = 1), IASA (n = 1), and functional constipation (FC, n = 7). The patient with sacral agenesis had a split appendix Malone appendicostomy/Mitrofanoff and a pudendal nerve stimulator for management of neurogenic bladder. One patient with FC had a Malone appendicostomy for antegrade continence enemas. Another patient with FC had a colostomy after resection of transverse colon due to colonic volvulus.
3.2. Interrater reliability
The ICC and κ values with 95% confidence intervals (CI) for all manometric parameters assessed by the 10 raters are shown in Figure 1. Interrater reliability was excellent for the assessment of the anal canal resting pressure (ICC 0.97, 95% CI 0.93–0.99), the squeeze pressure (ICC 0.97, 95% CI 0.94–0.99), and the squeeze duration (ICC 0.93, 95% CI 0.85–0.98).
Figure 1.
ICC or κ values with 95% CI for all manometric parameters assessed by the 10 raters. CI, confidence interval; ICC, intraclass correlation coefficient; RAIR, rectoanal inhibitory reflex.
For the RAIR assessment, the median number of balloon inflations per study was nine (interquartile range 6–11), and interrater reliability was fair (κ = 0.35). Disagreement among raters regarding the presence or absence of the RAIR was observed in four of the 10 studies. In the study performed on a child with HD (Study 1), seven raters agreed that the RAIR was absent, while three believed it was present. For the child with IASA (Study 8), four raters agreed on the absence of the RAIR, whereas six considered it present. In the study of a child with FC who had a colostomy (Study 6), eight raters agreed that the RAIR was present, while two believed it was absent. Additionally, in another study involving a child with FC (Study 7), the raters were evenly split, with five indicating the presence and five indicating the absence of the RAIR.
The assessment of the bear down maneuver resulted in a moderate (κ = 0.50) level of agreement. In seven of the 10 studies, disagreement among raters existed in the assessment of whether the bear down maneuver was normal or abnormal (Table 1). Disagreement in these seven studies varied between 10% and 30% of the raters and identification of dyssynergia subtype was inconsistent. In the three studies that all raters agreed that the bear down maneuver was abnormal, there was slight interrater agreement (κ = 0.03) in identifying the subtype of dyssynergia.
Table 1.
Evaluation of bear down maneuvers in the 10 HR‐ARM studies by 10 raters: Classification as normal or abnormal, and identification of dyssynergia subtype if abnormal.
| HR‐ARM study | Assessed as abnormal, n (%) | Type I, n (%) | Type II, n (%) | Type III, n (%) | Type IV, n (%) | Cannot specify, n (%) |
|---|---|---|---|---|---|---|
| 1 | 2 (20%) | 2 (100%) | ||||
| 2 | 10 (100%) | 8 (80%) | 2 (20%) | |||
| 3 | 3 (30%) | 2 (67%) | 1 (33%) | |||
| 4 | 2 (20%) | 1 (50%) | 1 (50%) | |||
| 5 | 10 (100%) | 9 (90%) | 1 (10%) | |||
| 6 | 2 (20%) | 1 (50%) | 1 (50%) | |||
| 7 | 10 (100%) | 4 (40%) | 1 (10%) | 3 (30%) | 2 (20%)a | |
| 8 | 8 (80%) | 4 (50%) | 3 (38%) | 1 (13%) | ||
| 9 | 2 (20%) | 2 (100%) | ||||
| 10 | 9 (90%) | 8 (89%) | 1 (11%) |
Abbreviation: HR‐ARM, high‐resolution anorectal manometry.
Both raters mentioned: first squeeze was type I, second squeeze was type III.
A moderate interrater agreement (κ = 0.43) was found in the final interpretation of the HR‐ARM study as either normal or abnormal. In five of the 10 studies, all 10 raters agreed that the HR‐ARM study was abnormal (Table 2). Reasons for the classification of the study being abnormal, however, were inconsistent. In none of these five studies did all raters fully agree on the reasons for classifying the study as abnormal. In three of the five studies, raters agreed that an abnormal bear down maneuver was at least one reason for the abnormal classification, although some also identified additional abnormalities, such as high resting pressure, high squeeze pressure, or an absent RAIR. In two of the five studies in which there was disagreement among raters regarding the final interpretation, all raters who considered the study to be abnormal agreed that the only reason for this classification was an abnormal bear down maneuver. In contrast, in the remaining three studies, multiple abnormalities were identified.
Table 2.
Final interpretation of the 10 HR‐ARM studies by 10 raters: Classification as normal or abnormal, and identification of abnormalities.
| HR‐ARM study | Final interpretation abnormal, n (%) | Low resting pressure, n (%) | High resting pressure, n (%) | Low squeeze pressure, n (%) | High squeeze pressure, n (%) | Absent RAIR, n (%) | Abnormal bear down maneuver, n (%) |
|---|---|---|---|---|---|---|---|
| 1 | 10 (100%) | 6 (60%) | 3 (30%) | 7 (70%) | 2 (20%) | ||
| 2 | 10 (100%) | 5 (50%) | 2 (20%) | 10 (100%) | |||
| 3 | 4 (40%) | 1 (25%) | 3 (75%) | ||||
| 4 | 10 (100%) | 2 (20%) | 9 (90%) | 2 (20%) | |||
| 5 | 10 (100%) | 3 (30%) | 10 (100%) | ||||
| 6 | 7 (70%) | 4 (57%) | 2 (29%) | 2 (29%) | |||
| 7 | 10 (100%) | 1 (10%) | 1 (10%) | 5 (50%) | 10 (100%) | ||
| 8 | 9 (90%) | 2 (22%) | 4 (44%) | 8 (89%) | |||
| 9 | 2 (20%) | 2 (100%) | |||||
| 10 | 9 (90%) | 9 (100%) |
Abbreviations: HR‐ARM, high‐resolution anorectal manometry; RAIR, rectoanal inhibitory reflex.
Table 3 depicts the agreement of the raters per HR‐ARM study for the assessment of the RAIR, bear down maneuver, and final interpretation of the study.
Table 3.
Heatmap showing agreement among 10 raters in the assessment of the rectoanal inhibitory reflex, bear down maneuver, and final interpretation across 10 high‐resolution anorectal manometry studies.
| Study 1 | Study 2 | Study 3 | Study 4 | Study 5 | Study 6 | Study 7 | Study 8 | Study 9 | Study 10 | |
|---|---|---|---|---|---|---|---|---|---|---|
| RAIR present | 30% | 100% | 100% | 100% | 100% | 80% | 50% | 60% | 100% | 100% |
| Bear down maneuver abnormal | 20% | 100% | 30% | 20% | 100% | 20% | 100% | 80% | 20% | 90% |
| Final interpretation abnormal | 100% | 100% | 40% | 100% | 100% | 70% | 100% | 90% | 20% | 90% |
Abbreviation: RAIR, rectoanal inhibitory reflex.
4. DISCUSSION
This is the first study assessing the interrater reliability of pediatric HR‐ARM studies. Our study shows suboptimal consistency in interpreting key manometric parameters even among experienced raters. Although interrater reliability was excellent for anal canal pressure, squeeze pressure, and squeeze duration, interrater agreement for detection of a RAIR was only fair and agreement on the bear down maneuver was moderate. In addition, interrater agreement for the final interpretation of the HR‐ARM study as normal or abnormal only had moderate agreement.
Anal canal resting pressure, squeeze pressure, and squeeze duration provide valuable insights into anal sphincter function, including the function of both the internal and external anal sphincters, which are essential for maintaining continence and are required for normal defecation. Resting pressure primarily reflects the function of the internal anal sphincter, while squeeze pressure and duration indicate the strength and function of the external anal sphincter. High level of agreement is fundamental for reliable diagnosis of anal sphincter disorders, and for understanding and managing persistent defecation problems especially in children who have undergone surgery for HD or anorectal malformations. 1
The assessment of the RAIR had the lowest interrater reliability among all manometric parameters with only fair agreement. The level of agreement we found is noteworthy, as the most widely accepted indication for HR‐ARM in children is to evaluate the RAIR to help exclude HD or IASA in children with constipation. 1 , 3 In our study performed on a child with HD, seven raters agreed on the absence of the RAIR, while three raters believed it was present. While rectal suction biopsy remains the gold standard for diagnosis of HD, multiple studies have shown that HR‐ARM is a safe, non‐invasive, and effective initial screening method for HD in children with reported sensitivity ranging from 89% to 93.75% and specificity from 83% to 89.47%, varying between studies. 6 , 7 , 8 , 9 It has been argued that use of ARM as the initial diagnostic tool can reduce the need for invasive rectal biopsies. 7 Moreover, assessment of the RAIR also plays a critical role in the diagnosis IASA, which is characterized by the absence of the RAIR in conjunction with the presence of ganglion cells on rectal biopsy. 10 , 11 These patients may benefit from botulinum toxin injection into the anal sphincter complex. 1 , 12 In our study performed on a child with IASA, four raters agreed on the absence of the RAIR, while six raters believed it was present. The low interrater reliability of RAIR assessment that we found raises concern for misdiagnosis and inappropriate treatment decisions.
It is important to highlight that in clinical practice, RAIR interpretation is dependent on several factors, including baseline anal sphincter pressure assessment, timing of anal sphincter pressure decrease relative to balloon insufflation, degree of relaxation, and adequate return to baseline pressure following balloon deflation. 13 RAIR parameters such as the degree of relaxation, latency before relaxation following balloon insufflation, and duration of relaxation are dependent on the frequency, rate, and volume of rectal balloon distention. 13
According to the pediatric literature, the RAIR should be evaluated by inflating the rectal balloon in 5 mL increments in infants up to 20 mL and by 10 mL increments in older children up to 250–300 mL if complete relaxation is not obtained. 1 Criteria for an intact RAIR vary in the literature from a decrease as little as 5 mmHg, 1 to a decrease of 20 mmHg with “normal morphology”, 7 to a drop of >25% of the resting pressure. 14 These inconsistencies highlight the need for standardized protocols for RAIR evaluation. Future studies may also evaluate “critical volumes” or other balloon volume thresholds and how these volumes should affect interpretation.
In HR‐ARM, the bear down maneuver is utilized to assess defecation dynamics, with a well‐executed bear down maneuver being crucial for effective rectal evacuation. A normal bear down maneuver is characterized by an increase in rectal pressure accompanied by a decrease in anal canal pressure, reflecting the coordinated relaxation of the external anal sphincter and pelvic floor muscles. Conversely, paradoxical contraction of the external anal sphincter and pelvic floor muscles during attempted defecation leads to an elevation in anal canal pressure, a response indicative of pelvic floor dyssynergia. Despite the importance of this test as part of the HR‐ARM study, our study revealed only moderate interrater agreement in the classification of the bear down maneuver as either normal or abnormal, resulting in variability that could impact diagnoses and treatment decisions. Interrater analysis for subtyping dyssynergia (types I–IV) was feasible only for those studies in which all raters agreed on the classification of the bear down maneuver being abnormal. The agreement in these three studies was minimal, with only slight agreement observed among raters. Moreover, when examining the responses for the remaining seven studies, significant inconsistency in dyssynergia subtyping was evident. In practice, however, many pediatric gastroenterologists use the term “pelvic floor dyssynergia” more broadly and may not routinely distinguish between different subtypes of dyssynergia, potentially explaining the inconsistency between raters. In addition, it can be discussed if differentiating the different subtypes of dyssynergia is clinically relevant in children. In the new London classification of anorectal disorders in adults, the traditional dyssynergia subtypes (types I–IV) have been replaced with a combination of two descriptive terms. 15 , 16 These are “propulsion,” which refers to the adequacy of the increase in rectal pressure during the bear down maneuver, and “dyssynergia,” which describes abnormal anal contraction. Additionally, any abnormal manometric finding (e.g., poor propulsion or dyssynergia) must be accompanied by abnormal expulsion, as can be seen with a balloon expulsion test or defecography, in order to be considered clinically relevant. This change was influenced by a pivotal study in which ARM studies were analyzed by multiple blinded observers which revealed that traditional dyssynergia subtypes (types I–IV) could not distinguish between healthy control subjects and patients with functional constipation, prompting the shift in classification. 17 It will be interesting for future research to examine whether the adult London classification can also be validated in children. In addition, a standardized protocol for the bear‐down maneuver is essential. Such protocols should provide clear guidance on balloon inflation and outline how the balloon expulsion test should be performed and integrated into pediatric assessment. A standard protocol and diagnostic criteria will ensure that this parameter provides meaningful guidance for diagnosis and management in practice.
Although interrater agreement was only fair for the RAIR and moderate for both the bear down maneuver and the final interpretation of the HR‐ARM study, this level of reliability should be interpreted in the context of other commonly used diagnostic tests. For example, interrater reliability for the differentiation of normal or abnormal motility on antroduodenal manometry in children was found to be moderate, with even lower agreement for major diagnostic categories, for example, myopathy or neuropathy. 18 Similarly, another study found moderate interrater agreement among clinicians using the pediatric Rome IV criteria to diagnose disorders of gut‐brain interaction. 19 In the context of esophageal motility disorders, diagnoses based on the automated software‐based Chicago Classification demonstrated good inter‐ and intrarater reliability among both experts and non‐experts. 20 However, the clinical diagnosis of achalasia and distal esophageal spasm was less reliable. 20 In adults, interrater reliability of ARM has only been evaluated for 3D‐HR‐ARM studies in patients referred for pelvic floor physical therapy due to functional defecation complaints. In that study, moderate agreement was found for the assessment of anal resting pressure, while evaluation of a dyssynergic pattern during three straining maneuvers showed good agreement. 21 However, interrater reliability for the maximum squeeze pressure was only fair. 21
In the present study, raters assessed completely de‐identified HR‐ARM studies, without access to any information regarding the patients' medical history, results from other diagnostic tests or procedural conditions. It is important to highlight that, while this approach ensured standardized interpretation and minimized bias, it diverges from typical clinical practice, where such contextual information is integral to interpreting ARM findings which could have influenced the results. Similarly, a study assessing reliability of electrocardiogram interpretation in critically ill patients, found only slight interrater agreement for the detection of myocardial ischemia and infarction when raters were unaware of the troponin values. 22 However, when this important contextual information was provided, the interrater reliability significantly increased to moderate. 22
A limitation of our study is that we were unable to conduct an intrarater reliability analysis. This was due to logistical constraints, as all raters were from different centers and were only present at the same location for a single session. Intrarater reliability, which assesses the consistency of a single rater's measurements over time, would have provided additional valuable information about the stability and reproducibility of individual assessments. Another limitation of our study is the relatively small sample size of only 10 HR‐ARM studies evaluated. We limited the sample size due to practical considerations. A larger sample would have significantly increased the burden on each rater given the time‐intensive nature of the analysis, potentially leading to fatigue or reduced participation, which could have affected the quality of the assessments. Therefore, we deliberately kept the sample size modest to maintain high rater engagement while still generating meaningful data for evaluating interrater reliability. Finally, not all raters were familiar with the analysis software, which may have influenced the results.
5. CONCLUSION
In conclusion, in this first evaluation of pediatric HR‐ARM interrater reliability in ten experienced raters, we found excellent interrater agreement for anal canal resting pressure, squeeze pressure, as well as the squeeze duration. We identified fair interrater agreement for the detection of a RAIR and moderate agreement on the bear down maneuver. These findings highlight the need for standardization of HR‐ARM protocols and interpretation criteria.
CONFLICT OF INTEREST STATEMENT
Julia M. J. van der Zande received financial support from the Cultuurfonds with support from the Jadefonds, and Amsterdam University Fund to conduct this research. The other authors declare no conflicts of interest.
REFERENCES
- 1. Rodriguez L, Sood M, Di Lorenzo C, Saps M. An ANMS‐NASPGHAN consensus document on anorectal and colonic manometry in children. Neurogastroenterol Motility. 2017;29(1):nmo.12944. [DOI] [PubMed] [Google Scholar]
- 2. van der Zande JMJ, Koppen IJN, Yacob D, et al. Current practice in the care of children with functional constipation: what is the hold up? J Pediatr Gastroenterol Nutr. 2024;79(2):301‐308. [DOI] [PubMed] [Google Scholar]
- 3. Strisciuglio C, Banasiuk M, Salvatore S, et al. Anorectal manometry in children: the update on the indications and the protocol of the procedure. J Pediatr Gastroenterol Nutr. 2022;74(4):440‐445. [DOI] [PubMed] [Google Scholar]
- 4. Carrington EV, Heinrich H, Knowles CH, Rao SS, Fox M. Scott SM. methods of anorectal manometry vary widely in clinical practice: results from an international survey. Neurogastroenterol Motil. 2017;29(8):e13016. [DOI] [PubMed] [Google Scholar]
- 5. Rao SSC, Patcharatrakul T. Diagnosis and treatment of dyssynergic defecation. J Neurogastroenterol Motil. 2016;22(3):423‐435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Sowulewski O, Bubińska M, Zagierska A, Zagierski M, Szlagatys‐Sidorkiewicz A. High‐Resolution anorectal manometry as a screening tool for Hirschsprung's disease: a comprehensive retrospective analysis. J Clin Med. 2024;13(5):1268. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7. Meinds RJ, Trzpis M, Broens PMA. Anorectal manometry may reduce the number of rectal suction biopsy procedures needed to diagnose hirschsprung disease. J Pediatr Gastroenterol Nutr. 2018;67(3):322‐327. [DOI] [PubMed] [Google Scholar]
- 8. de Lorijn F, Kremer LCM, Reitsma JB, Benninga MA. Diagnostic tests in Hirschsprung disease: a systematic review. J Pediatr Gastroenterol Nutr. 2006;42(5):496‐505. [DOI] [PubMed] [Google Scholar]
- 9. Tang YF, Chen JG, An HJ, et al. High‐resolution anorectal manometry in newborns: normative values and diagnostic utility in Hirschsprung disease. Neurogastroenterol Motility. 2014;26(11):1565‐1572. [DOI] [PubMed] [Google Scholar]
- 10. Ciamarra P, Nurko S, Barksdale E, Fishman S, Di Lorenzo C. Internal anal sphincter achalasia in children: clinical characteristics and treatment with Clostridium botulinum toxin. J Pediatr Gastroenterol Nutr. 2003;37(3):315‐319. [DOI] [PubMed] [Google Scholar]
- 11. Baaleman DF, Malamisura M, Benninga MA, et al. The not‐so‐rare absent RAIR: internal anal sphincter achalasia in a review of 1072 children with constipation undergoing high‐resolution anorectal manometry. Neurogastroenterol Motility. 2021;33(4):e14028. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Halleran DR, Lu PL, Ahmad H, et al. Anal sphincter botulinum toxin injection in children with functional anorectal and colonic disorders: A large institutional study and review of the literature focusing on complications. J Pediatr Surg. 2019;54(11):2305‐2310. [DOI] [PubMed] [Google Scholar]
- 13. Cheeney G, Nguyen M, Valestin J, Rao SSC. Topographic and manometric characterization of the recto‐anal inhibitory reflex. Neurogastroenterol Motility. 2012;24(3):e147‐e154. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Gala T, Johnston L, Solanki D, et al. Anorectal manometry — how to perform and interpret manometry. Continence. 2024;10:101214. [Google Scholar]
- 15. Scott SM, Carrington EV. The london classification: improving characterization and classification of anorectal function with anorectal manometry. Curr Gastroenterol Rep. 2020;22(11):55. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Carrington EV, Heinrich H, Knowles CH, et al. The international anorectal physiology working group (IAPWG) recommendations: standardized testing protocol and the London classification for disorders of anorectal function. Neurogastroenterol Motility. 2020;32(1):e13679. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17. Grossi U, Carrington EV, Bharucha AE, Horrocks EJ, Scott SM, Knowles CH. Diagnostic accuracy study of anorectal manometry for diagnosis of dyssynergic defecation. Gut. 2016;65(3):447‐455. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. Connor FL, Hyman PE, Faure C, et al. Interobserver variability in antroduodenal manometry. Neurogastroenterol Motility. 2009;21(5):500‐7.e3. [DOI] [PubMed] [Google Scholar]
- 19. Ginton L, Budhathoki R, Saps M. Reliability of pediatric Rome IV criteria for the diagnosis of disorders of gut‐brain interaction. Neurogastroenterol Motility. 2024;36(7):e14813. [DOI] [PubMed] [Google Scholar]
- 20. Singendonk MMJ, Smits MJ, Heijting IE, et al. Inter‐ and intrarater reliability of the Chicago classification in pediatric high‐resolution esophageal manometry recordings. Neurogastroenterol Motility. 2015;27(2):269‐276. [DOI] [PubMed] [Google Scholar]
- 21. van Oostendorp JY, van Hagen P, van der Mijnsbrugge GJH, Han‐Geurts IJM. Study on 3D high‐resolution anorectal manometry interrater agreement in the evaluation of dyssynergic defecation disorders. Diagnostics. 2023;13(16):2657. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22. Lim W, Qushmaq I, Cook DJ, et al. Reliability of electrocardiogram interpretation in critically ill patients. Crit Care Med. 2006;34(5):1338‐1343. [DOI] [PubMed] [Google Scholar]