High-resolution anorectal manometry and barium defecography in suspected functional defecation disorders: agreement and impact of structural findings

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No single diagnostic test reliably identifies FDD, and guidelines recommend that pathological results from two investigations are required for diagnosis. Commonly used tests include high-resolution anorectal manometry (HRAM), barium defecography (BD), and the balloon expulsion test (BET). Their agreement is uncertain, and structural abnormalities may influence HRAM metrics. We assessed diagnostic agreement between HRAM and BD in patients with suspected FDD and explored relationships between key variables and the influence of structural findings on HRAM parameters. Methods We included 80 patients with constipation and suspected FDD who underwent HRAM and BD. HRAM recordings were reinterpreted using pattern-based and threshold-based approaches. Radiologists evaluated BD for puborectalis relaxation and structural abnormalities, and in a subsequent assessment, we quantified rectal barium evacuation and anorectal angles. We used Cohen’s kappa (κ) to assess agreement, Spearman's rho to assess correlations, and the Mann-Whitney U test to compare distributions. Results Rectoceles were present in 71% of women. Agreement between HRAM and BD was only fair and similar across interpretation methods (κ = 0.27–0.31). Continuous HRAM and BD measures were not correlated. Rectocele was associated with higher anal resting pressure and greater anal relaxation (p = 0.005 and 0.023). Among patients with normal barium evacuation (N = 56), 41% had both a non-relaxing puborectalis and an abnormal HRAM pattern, with moderate agreement (κ ≈ 0.44–0.45). Conclusion Overall agreement between HRAM and BD is limited, indicating that they assess complementary aspects of anorectal function. Different HRAM interpretation approaches perform similarly. Rectoceles influence HRAM metrics. In patients with normal barium evacuation, puborectalis assessment on BD may support the interpretation of abnormal HRAM and identify a relevant patient group. Functional defecation disorders high-resolution anorectal manometry barium defecography constipation rectocele Figures Figure 1 Figure 2 Figure 3 Introduction Functional defecation disorders (FDD) affect a large proportion of patients with chronic constipation and are defined by difficulty emptying the rectum despite adequate urge. They are usually functional rather than caused by an obstruction, and many patients improve with pelvic floor biofeedback when impaired coordination is present [ 1 – 4 ]. FDD comprises dyssynergic defecation (DD), characterised by inappropriate contraction or insufficient relaxation of the pelvic floor and anal sphincter during attempted defecation, and inadequate defecatory propulsion [ 5 ]. Diagnosis remains challenging because symptoms are nonspecific and there is a considerable overlap in test results between patients and healthy controls [ 6 – 12 ]. No single “gold standard” diagnostic test exists. Current guidelines, therefore, recommend combining clinical evaluation with at least two objective tests [ 5 , 13 ]. Commonly used tests include the balloon expulsion test (BET), high-resolution anorectal manometry (HRAM), and barium defecography (BD). BET measures the ability to expel a water-filled rectal balloon [ 14 ]. HRAM records rectoanal pressures at rest, during squeeze, and during simulated defecation [ 8 , 12 , 15 , 16 ]. BD assesses evacuation of barium paste and visualizes anorectal dynamics during defecation [ 17 , 18 ]. However, impaired evacuation is also reported in up to 16% of healthy controls, which means that a single test cannot reliably distinguish normal from abnormal function [ 6 , 7 , 9 – 11 ]. The London consensus considers a pathological evacuation test (BET or BD) together with an abnormal HRAM pattern of rectoanal coordination as a minor finding, whereas a single abnormal test is considered inconclusive [ 13 ]. The London consensus does not define any “major” rectoanal coordination disorders, which reflects how weakly symptoms match test results. In daily practice, diagnostic inconsistency is common. Around one-third of patients with constipation have a prolonged BET, but fewer than half of these also show abnormal HRAM findings, and up to half of HRAM recordings in patients with constipation are interpreted as normal [ 13 , 19 ]. The role of BD is less clear in current guidelines. It can help reclassify otherwise inconclusive results and may therefore be useful as part of routine anorectal function assessment. The clinical value of BD in this setting depends on how well BD agrees with HRAM and whether structural abnormalities influence the interpretation of HRAM measurements. Recent studies have described HRAM patterns associated with prolonged BET, and the rectoanal pressure gradient has most often been associated with impaired evacuation on defecography [ 19 , 20 ]. However, most of this work relied on magnetic resonance imaging or mixed imaging methods rather than conventional BD. The agreement between HRAM and conventional barium defecography (BD) remains incompletely described. In addition, there is no consensus on HRAM- or BD-based diagnostic criteria for FDD, and radiologic features such as puborectalis relaxation and anorectal angle changes during defecation may relate to manometric findings. In this study, we aimed to assess agreement between HRAM and BD, determine how different HRAM interpretation methods affect classification, and test whether BD parameters and structural findings (particularly rectoceles) are associated with specific HRAM metrics. We hypothesized that the agreement would be, at best, moderate and that structural findings would have measurable effects on HRAM metrics. Materials and methods Study design We conducted a retrospective study to evaluate the agreement between HRAM and BD in patients with constipation and possible FDD. The analysis focused on relationships between predefined HRAM- and BD variables and on the influence of coexisting anorectal pathology on HRAM findings. First, we used the original clinical interpretations to classify DD as present or absent. Then, to reduce variation caused by differences in the initial analyses and interpretations, we reassessed HRAM recordings using both pattern- and threshold-based approaches. Radiologists evaluated BD for puborectalis relaxation and structural abnormalities, and in a subsequent assessment, we quantified rectal barium evacuation and anorectal angles. Reporting follows STARD 2015 guidelines where applicable [21]. The primary focus of the study was the utility of these investigations in a clinical setting. Hence, we did not include healthy volunteers in the study cohort. HRAM values were interpreted using published reference ranges from healthy adults investigated with an identical HRAM catheter to the one we used (sex- and parity-stratified; 5th–95th percentiles used as normal) [8]. For variables not reported there, we used reference data from 26 healthy volunteers examined at our center with the same equipment and protocol. Compliance with Ethical Standards This study was approved by the Regional Ethics Committee in Uppsala (Dnr 2023-03776-02) and was conducted in accordance with the Declaration of Helsinki and applicable Swedish regulations. The Regional Ethical Review Authority granted a waiver of informed consent due to the retrospective design, minimal risk, and use of de-identified data prior to analysis. Data processing complied with the General Data Protection Regulation and the Swedish Patient Data Act; only authorised personnel accessed identifiable records. Data collection We analysed HRAM investigations conducted at the motility lab between May 2018 and December 2024. Patients who had not undergone BD were excluded. The remaining investigations were sorted by indication, and those involving patients with constipation symptoms and suspected FDD were included. Constipation symptoms comprised hard stools, fewer than three bowel movements per week, intense straining, the sensation of incomplete evacuation, the sensation of anorectal blockage, or the need for manual maneuvers. Following inclusion, patient records were reviewed for previously diagnosed functional gastrointestinal disorders, use of medication for constipation and neuromodulators, history of vaginal births, obstetrical injury, and prior surgery involving the pelvic floor. HRAM was performed using the Solar GI HRAM equipment (MMS/Laborie, Enschede, the Netherlands) and a Solar Solid-State HRAM catheter (12 French, eight circumferential pressure zones and one for the balloon). The investigations adhered to the standardized testing protocol recommended by the International Anorectal Physiology Working Group (IAPWG) [13], except for the BET, which was implemented later at our motility unit. Specialized nurses conducted the HRAM procedures, and the results were interpreted by two specialized gastroenterologists using the QuickView analysis program. BD studies were performed and interpreted at the Radiology Department in accordance with established protocols [17, 18, 22, 23]. The BD variables were reassessed using the Sectra Radiology PACS software (Sectra AB, Linköping, Sweden). Variables: Original interpretations HRAM: Findings interpreted by the gastroenterologist as suggestive of FDD or not. BD: Findings interpreted by the radiologist as suggestive of FDD or not. Concomitant pathology on BD: Presence of rectocele ≥ 2 cm, rectocele with barium retention, enterocele, rectal prolapse, or intussusception. Reassessed parameters All investigations were reassessed by a single investigator blinded to the original interpretations. HRAM parameters (best values from three simulated defecations): Anal resting pressure (mmHg); anal push pressure (mmHg); anal relaxation during simulated defecation (%); maximal rectal pressure during simulated defecation (mmHg); and rectoanal pressure gradient (rectal–anal pressure difference during simulated defecation, mmHg). There is currently no consensus on HRAM-based diagnostic criteria for FDD. In conventional manometry, a negative rectoanal pressure gradient has been considered a key feature of dyssynergia. In HRAM studies, however, the rectoanal gradient during evacuation is often negative even in healthy individuals, and there is significant overlap between patients with constipation and healthy individuals [19, 20]. Normal values for the rectoanal pressure gradient have not been established. HRAM can be interpreted in three main ways: Traditional dyssynergia patterns as described by Rao et al.: Four dyssynergia subtypes (types I–IV) are defined, based on rectoanal coordination during simulated defecation rather than static pressure values. These patterns were originally described using conventional manometry in patients with constipation, but their discriminative value for distinguishing between healthy controls and constipated patients remains uncertain [24]. Parameter-based thresholds: Uses catheter-, age-, sex-, and parity-adjusted reference values for key variables like rectal pressure increase and anal relaxation. Both the Rome IV criteria and the London consensus classify FDD based on rectal and anal pressures during simulated defecation [5, 13]. Novel dyssynergia patterns as described by Ratuapli et al.: HRAM patterns were identified that distinguish patients with constipation from healthy controls and those with normal versus pathological BET [20]. Four defecatory patterns were identified; three correspond to Rao types I, II, and IV. The different methods for diagnosing DD on HRAM are presented in Supplementary Table 1. BD parameters Barium paste evacuation: normative data indicate that expulsion 2.5 min is not observed in healthy participants [9]. Other studies have proposed alternative thresholds (<25% or <50%). [12, 18, 25]. Assessing volume in two-dimensional images has limitations; to avoid misclassification, we used a conservative definition of normal evacuation (50% as the threshold) when comparing HRAM to BD in patients with normal barium evacuation. Non-relaxing puborectalis: Binary variable (present/absent). Dynamic measures (at rest and peak evacuation): posterior anorectal angle (PARA), and central anorectal angle (CARA). The definitions of rectal wall, rectal center, and rectal angles follow previously published standards [9, 22, 23, 25]. Comparing HRAM and BD: challenges and considerations: The diagnostic outputs from HRAM and BD depend on how multiple measured variables are interpreted to determine whether an FDD is present. There is currently no standardized method for direct comparison between these methods, nor is there a gold standard for diagnosing FDD. Consequently, it is unclear whether the diagnostic outputs of each investigation should be compared or whether specific HRAM findings correlate more closely with specific BD findings. Thus, we analyzed correlations between: Rectal pressure on HRAM and evacuation performance on BD. Anal relaxation on HRAM and changes in the anorectal angle on BD. Statistical analysis All statistical analyses were performed using JASP open-source software (version 0.19.0, JASP Team, 2024) [26]. The tables and figures were created using Microsoft Excel and Microsoft Word. Agreement for binary variables obtained from HRAM and BD was assessed using Cohen’s kappa (κ). Interpretation of κ-values followed the following thresholds: ≤ 0.00: No agreement 0.01 to 0.19: None to slight agreement 0.20 to 0.39: Fair agreement 0.40 to 0.59: Moderate agreement 0.60 to 0.79: Substantial agreement 0.80 to 1.00: Almost perfect agreement Previous literature has questioned the utility of κ-values <0.6 in medical research. In this study, a κ value of 0.6 or greater was considered acceptable [27]. For sample size considerations, existing guidelines for kappa-based reliability studies recommend a minimum of 54 participants to achieve 90% power for detecting a statistically significant κ coefficient [28]. For continuous variables, we used Spearman’s rho for non-normally distributed data to assess correlations, and we used the Mann-Whitney U test to compare distributions. A p-value of <0.05 was considered statistically significant for all tests. Results Patient inclusion and characteristics Among 344 HRAM investigations screened, 81 lacked a corresponding BD, and 176 were performed for faecal incontinence. Three additional cases with full-thickness rectal prolapse and four non-interpretable BD studies were excluded, leaving 80 patients (68 women, 12 men) with constipation and suspected DD for analysis. The data collection and inclusion flowchart are illustrated in Figure 1, and patient demographics and clinical characteristics are presented in Table 1. T able 1 Demographic and clinical characteristics of patients with constipation and suspected FDD Demographics value % of sample Mean age (years) 50 - Sex (female) 68 86 Obstetric history % of females Vaginal birth 40 59 Known obstetrical complications 8 12 Interventions for pelvic prolapse 12 19 Hysterectomy 9 13 Surgical history Bowel resection 2 3 Interventions on the anal sphincter or hemorrhoids 2 3 Medication Antidepressants 21 27 Prucalopride/linaclotide 10 13 Concomitant pathology observed with BD Structural abnormalities were frequent. Rectoceles ≥ 2 cm were observed in 48 (71%), and rectoceles ≥ 4 cm in 9 (13%) women. Rectoceles with barium retention were found in 34 women (50%), including all with a rectocele ≥ 4 cm. Intussusception was observed in 17 patients (22%), enterocele in 7 (8%), and rectal prolapse in 3 (4%) patients, respectively. Agreement of DD diagnosis between HRAM and BD Radiologists assessed DD primarily based on the presence of a non-relaxing puborectalis muscle during defecation. The ARAs were inconsistently reported, and the evacuation of barium paste was only interpreted in the context of concomitant pathology and its impact on defecation. Additional evaluations were performed to assess HRAM patterns of anorectal coordination, barium paste evacuation, and ARAs as described in the Methods section. The prevalence of DD across the different assessment methods is presented in Table 2. Table 2 The prevalence of FDD using HRAM and BD. For additional information about the interpretation methods, see supplementary Table 1 Method of assessing FDD Number of cases Percentage (%) Original interpretation HRAM 25 32 Non-relaxing puborectalis on BD 37 47 Reassessed parameters FDD on HRAM after Rao 36 46 Type I 4 5 Type II 7 9 Type III 13 16 Type IV 12 15 FDD on HRAM after Ratuapli 36 45 High anal 0 0 Hybrid 3 4 Low rectal 11 14 Short HPZ 27 34 FDD on HRAM after Rome IV 22 28 Inadequate rectal propulsion 15 23 Dyssynergia after Rome IV 7 9 Barium evacuation <35% 17 22 Any BD finding indicative of FDD 44 57 Two HRAM investigations were considered inconclusive regarding DD in the initial interpretation. Among the 78 remaining cases, the initial clinical interpretations of HRAM and BD showed almost no agreement (κ = 0.007). The agreement between the reinterpreted HRAM and any BD findings indicative of DD (non-relaxing puborectalis or impaired barium evacuation) was only fair (κ values of 0.307, 0.272, and 0.294 for interpretations according to the Rao et al., Ratuapli et al., and Rome IV criteria, respectively). The analysis of the relationship between rectal propulsion (HRAM) and rectal evacuation (BD) showed almost no agreement (κ = 0.057), while there was a slight agreement between anal relaxation (HRAM) and puborectalis relaxation (BD) (κ = 0.213 for the agreement between patterns I, II, and III according to Rao indicative of failed anal relaxation and a non-relaxing puborectalis on BD). The complete results are available in Supplementary Table 2. Comparison of HRAM and binary BD parameters: Patients with a persistent puborectalis impression on BD had lower anal relaxation and lower maximal rectal pressure during simulated defecation (p = 0.004 and p = 0.011, respectively) (Figure 2). Correlations between the reassessed HRAM and BD continuous parameters. The reassessed continuous parameters for HRAM and BD are summarized in Supplementary Table 3, with detailed correlation results presented in Supplementary Table 4. Since several parameters were not normally distributed, Spearman’s ρ was used to analyze their correlations. No significant correlations were found between the reassessed continuous parameters. The effect of concomitant pathology on HRAM parameters. Patients with rectocele had higher anal resting pressure and greater anal relaxation than those without rectocele (p = 0.005 and p = 0.023). After excluding large rectoceles (> 4 cm), the difference in anal relaxation was no longer significant (p = 0.08) (Figure 3). No significant HRAM differences were observed in patients with enterocele, intussusception, or rectal prolapse. Patients with a normal barium evacuation test. In the subgroup of patients who had at least 50% barium evacuation (N=56), 23 (41%) had a non-relaxing puborectalis muscle on BD. Abnormal HRAM patterns were found in 24 (43%) cases according to the Rao et al. interpretation, and in 16 (29%) cases according to the Rome IV classification. The kappa for the agreement between the initial HRAM interpretation and a non-relaxing puborectalis on BD was 0.015, while after HRAM reinterpretation, the kappa was 0.450 and 0.444 for the interpretations after Rao and Rome IV, respectively. The combination of abnormal puborectalis relaxation and abnormal HRAM pattern was present in 16 (29%) patients using the Rao classification and 12 (21%) patients using the ROME IV classification. In this group, there were no significant differences in HRAM parameters between patients with and without rectocele. Discussion In this cohort of patients investigated for suspected FDD, agreement between HRAM and BD was only fair, and structural pathology in the rectum affected HRAM measurements. Key findings Consistent with clinical experience, we observed little agreement between the initial interpretations of HRAM and BD investigations. This study demonstrates that even when standardized criteria are applied, HRAM and BD exhibit only fair agreement in diagnosing FDD. We found no meaningful agreement between impaired rectal propulsion on HRAM and barium retention on BD or between impaired anal relaxation on HRAM and a non-relaxing puborectalis. This suggests that classification bias (subjective interpretation) does not fully explain the discrepancies in agreement between these methods either. Instead, it indicates that the two tests measure different physiological processes. The different interpretations of HRAM We could not find clear differences in agreement with BD between the pattern recognition methods based on the Rao or Rome IV criteria. The classification proposed by the IAPWG group is similar to Rome IV, except that in Rome IV there is no “poor propulsion and dyssynergia”. We could not draw any conclusions using the Ratuapli method, as, with these definitions, there were no cases of the first dyssynergia type in our study group. This may be explained by the different normal-range intervals used (5th to 95th percentile vs 10th to 90th percentile) and by the different solid-state catheters. Other variables We found a significant difference in anal relaxation between patients with and without persistent puborectalis contraction; however, we found no evidence that HRAM parameters during simulated defecation correlate with changes in anorectal parameters on BD, further supporting the notion that these methods measure different physiological processes. Influence of structural pathology A key finding was the relation between structural abnormalities in BD investigations and HRAM measurements. Rectocele was frequent and was associated with differences in anal pressure measures. When large rectoceles were excluded, the association weakened, suggesting that the effect is strongest in more pronounced structural change. These results support that structural pathology can influence HRAM metrics and may lead to misclassification if HRAM is interpreted in isolation. Therefore, BD adds value by identifying anatomy and evacuation mechanics that HRAM cannot show. Patients with normal barium evacuation A substantial subgroup had normal barium paste evacuation despite a suspected evacuation disorder. In this subgroup, we found moderate agreement between HRAM and a non-relaxing puborectalis muscle on BD, which was nonetheless better than in the larger cohort. This supports the conclusion that normal barium evacuation does not exclude abnormal findings on other tests, and that while HRAM and BD should not be used interchangeably, together they may identify a small group of patients with normal evacuation who nevertheless have two abnormal tests of anorectal function and might benefit from biofeedback therapy. Clinical implications These findings have practical implications for the clinical interpretation of HRAM. In cases with abnormal evacuation and normal HRAM, BD can identify structural abnormalities (e.g., large rectoceles) that may explain the apparent discrepancy. This is particularly relevant in older patients, in whom structural findings are common. Conversely, when evacuation testing is normal, but HRAM is abnormal, BD may help corroborate HRAM findings and support the indication for therapy. Overall, our data support a combined assessment when the diagnosis is uncertain or when HRAM findings do not align with symptoms. Comparison with previous research Prior studies have reported limited agreement between anorectal manometry and BD [29]. Our results extend this by focusing on BD in routine clinical referrals and by examining how structural abnormalities on BD relate to HRAM measurements. Taken together, the findings support using HRAM and BD together when possible rather than expecting strong agreement between them. Strengths and limitations The study’s strengths include its focus on the typical patient population seen in clinical practice. The systematic reassessment of HRAM and BD parameters aimed to reduce subjectivity and interobserver variability. The sample size provided adequate power to detect moderate agreement. Limitations include the retrospective design and potential selection bias. In contrast, concerns about multiple comparisons are less critical given the overall low level of agreement. There is no accepted gold standard for evacuation disorders, so we could only assess agreement rather than diagnostic accuracy. BET data were mainly missing and could not be included in the main comparisons. Conclusion In summary, HRAM and BD showed only fair agreement in suspected evacuation disorders. Structural findings on BD, especially rectocele, were common and were associated with differences in HRAM measurements. These results support considering structural pathology when interpreting HRAM and support a combined testing approach when findings are inconclusive. Declarations Founding Open access funding provided by Örebro University. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Conflict of Interests All authors declare that they have no conflicts of interest. Competing interests The authors declare that they have no known competing interests or personal relationships that could have appeared to influence the work reported in this paper. Author Contribution L.M.G. and M.v.N. conceptualized the study. L.M.G., M.A.R., and M.v.N. developed the methodology. L.M.G. and M.A.R. performed data curation. L.M.G. and M.A.R. prepared the original draft. L.M.G. and M.v.N. contributed to review and editing. L.M.G. and M.v.N. were responsible for resources and project administration. All authors reviewed and approved the final manuscript.All authors declare that they have no conflicts of interest, and no external funding was received for this study. The authors declare that they have no known competing interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgement We thank Professor Jonas Halfvarson for his support in finalizing this manuscript, as well as the nurses from our motility lab, Hanna Falck, Johanna Lundgren, Karina Varas Rende, and Victoria Johansson, for performing the HRAM investigations. Open-access publishing is facilitated by Örebro University. Data Availability The datasets generated and/or analysed during the current study are not publicly available due to ethical and legal restrictions related to patient privacy and data protection (including compliance with applicable data protection regulations such as the General Data Protection Regulation [GDPR]). De-identified data may be made available from the corresponding author on reasonable request. References Mertz H, Naliboff B, Mayer EA. Physiology of refractory chronic constipation. Am J Gastroenterol. 1999;94:609–615. Videlock EJ, Lembo A, Cremonini F. Diagnostic testing for dyssynergic defecation in chronic constipation: meta-analysis. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9225339","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":617203986,"identity":"8fe178d0-cbe5-4302-9628-8e57f49216c8","order_by":0,"name":"Lucian Marinica Grando","email":"data:image/png;base64,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","orcid":"","institution":"Örebro University","correspondingAuthor":true,"prefix":"","firstName":"Lucian","middleName":"Marinica","lastName":"Grando","suffix":""},{"id":617203987,"identity":"87758653-b3a2-47b1-b156-47028d037a1e","order_by":1,"name":"Mohammed Abdul Razzaq","email":"","orcid":"","institution":"Örebro University","correspondingAuthor":false,"prefix":"","firstName":"Mohammed","middleName":"Abdul","lastName":"Razzaq","suffix":""},{"id":617203988,"identity":"f2d4b0f8-0771-48fa-bf8f-6c23f713e435","order_by":2,"name":"Michiel van Nieuwenhoven","email":"","orcid":"","institution":"Örebro University","correspondingAuthor":false,"prefix":"","firstName":"Michiel","middleName":"van","lastName":"Nieuwenhoven","suffix":""}],"badges":[],"createdAt":"2026-03-25 16:08:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9225339/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9225339/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106309734,"identity":"c814e105-9fa3-4655-a165-4d54461e188b","added_by":"auto","created_at":"2026-04-07 10:19:25","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":32585,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eFlowchart of data collection and patient inclusion. HRAM: high-resolution anorectal manometry. BD: barium defecography.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9225339/v1/5ad3f942de4eecf5d44108ba.jpg"},{"id":106309732,"identity":"a7a836ca-6b10-4d9f-8dd1-bb0f017ecb02","added_by":"auto","created_at":"2026-04-07 10:19:24","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":26311,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eThe Mann-Whitney test shows a significant difference between anal relaxation (a) and maximal rectal pressure during simulated defecation (b) for patients with a non-relaxing puborectalis compared to patients with normal relaxation. The effect size is represented by the rank-biserial correlation (R).*: p \u0026lt;0.05. **: p \u0026lt;0.01\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9225339/v1/ac03334b615a67deeb7f9243.jpg"},{"id":106309733,"identity":"12b60b51-0605-4f3f-93dc-741361739a50","added_by":"auto","created_at":"2026-04-07 10:19:24","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":32437,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eTop row: The Mann-Whitney test comparing patients with rectoceles \u003c/em\u003e≥\u003cem\u003e 2 cm (yes) and without (no) reveals significant differences in anal resting pressure and anal relaxation during defecation. Bottom row: After excluding large rectoceles (\u003c/em\u003e≥\u003cem\u003e 4 cm), the Mann-Whitney test reveals a significant difference in anal resting pressure but not in anal relaxation between patients with rectoceles (yes) and those without rectoceles (no). The effect size is represented by the rank-biserial correlation (R). *: p \u0026lt;0.05. **: p\u0026lt;0.01\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9225339/v1/a78aa0e1d97df2fa429d6193.jpg"},{"id":106960695,"identity":"d2ff67e4-e7d9-4529-b902-528f0b2fa7be","added_by":"auto","created_at":"2026-04-15 09:22:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":993815,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9225339/v1/ab7aa440-d244-46f7-852f-019c9da10d34.pdf"},{"id":106309731,"identity":"4db12c54-379b-4c02-91c8-d469bb67e66d","added_by":"auto","created_at":"2026-04-07 10:19:24","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":23077,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-9225339/v1/c0de42797928ecdbd6c8ff84.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"High-resolution anorectal manometry and barium defecography in suspected functional defecation disorders: agreement and impact of structural findings","fulltext":[{"header":"Introduction","content":"\u003cp\u003eFunctional defecation disorders (FDD) affect a large proportion of patients with chronic constipation and are defined by difficulty emptying the rectum despite adequate urge. They are usually functional rather than caused by an obstruction, and many patients improve with pelvic floor biofeedback when impaired coordination is present [\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. FDD comprises dyssynergic defecation (DD), characterised by inappropriate contraction or insufficient relaxation of the pelvic floor and anal sphincter during attempted defecation, and inadequate defecatory propulsion [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Diagnosis remains challenging because symptoms are nonspecific and there is a considerable overlap in test results between patients and healthy controls [\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10 CR11\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. No single \u0026ldquo;gold standard\u0026rdquo; diagnostic test exists. Current guidelines, therefore, recommend combining clinical evaluation with at least two objective tests [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Commonly used tests include the balloon expulsion test (BET), high-resolution anorectal manometry (HRAM), and barium defecography (BD). BET measures the ability to expel a water-filled rectal balloon [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. HRAM records rectoanal pressures at rest, during squeeze, and during simulated defecation [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. BD assesses evacuation of barium paste and visualizes anorectal dynamics during defecation [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. However, impaired evacuation is also reported in up to 16% of healthy controls, which means that a single test cannot reliably distinguish normal from abnormal function [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe London consensus considers a pathological evacuation test (BET or BD) together with an abnormal HRAM pattern of rectoanal coordination as a minor finding, whereas a single abnormal test is considered inconclusive [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The London consensus does not define any \u0026ldquo;major\u0026rdquo; rectoanal coordination disorders, which reflects how weakly symptoms match test results. In daily practice, diagnostic inconsistency is common. Around one-third of patients with constipation have a prolonged BET, but fewer than half of these also show abnormal HRAM findings, and up to half of HRAM recordings in patients with constipation are interpreted as normal [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The role of BD is less clear in current guidelines. It can help reclassify otherwise inconclusive results and may therefore be useful as part of routine anorectal function assessment. The clinical value of BD in this setting depends on how well BD agrees with HRAM and whether structural abnormalities influence the interpretation of HRAM measurements.\u003c/p\u003e \u003cp\u003eRecent studies have described HRAM patterns associated with prolonged BET, and the rectoanal pressure gradient has most often been associated with impaired evacuation on defecography [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, most of this work relied on magnetic resonance imaging or mixed imaging methods rather than conventional BD.\u003c/p\u003e \u003cp\u003eThe agreement between HRAM and conventional barium defecography (BD) remains incompletely described. In addition, there is no consensus on HRAM- or BD-based diagnostic criteria for FDD, and radiologic features such as puborectalis relaxation and anorectal angle changes during defecation may relate to manometric findings.\u003c/p\u003e \u003cp\u003eIn this study, we aimed to assess agreement between HRAM and BD, determine how different HRAM interpretation methods affect classification, and test whether BD parameters and structural findings (particularly rectoceles) are associated with specific HRAM metrics. We hypothesized that the agreement would be, at best, moderate and that structural findings would have measurable effects on HRAM metrics.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted a retrospective study to evaluate the agreement between HRAM and BD in patients with constipation and possible FDD. The analysis focused on relationships between predefined HRAM- and BD variables and on the influence of coexisting anorectal pathology on HRAM findings. First, we used the original clinical interpretations to classify DD as present or absent. Then, to reduce variation caused by differences in the initial analyses and interpretations, we reassessed\u0026nbsp;HRAM recordings using both pattern- and threshold-based approaches. Radiologists evaluated BD for puborectalis relaxation and structural abnormalities, and in a subsequent assessment, we quantified rectal barium evacuation and anorectal angles.\u0026nbsp;\u0026nbsp;Reporting follows STARD 2015 guidelines where applicable [21].\u003c/p\u003e\n\u003cp\u003eThe primary focus of the study was the utility of these investigations in a clinical setting. Hence, we did not include healthy volunteers in the study cohort. HRAM values were interpreted using published reference ranges from healthy adults investigated with an identical HRAM catheter to the one we used (sex- and parity-stratified; 5th\u0026ndash;95th percentiles used as normal) [8]. For variables not reported there, we used reference data from 26 healthy volunteers examined at our center with the same equipment and protocol.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompliance with Ethical Standards\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Regional Ethics Committee in Uppsala (Dnr 2023-03776-02) and was conducted in accordance with the Declaration of Helsinki and applicable Swedish regulations. The Regional Ethical Review Authority granted a waiver of informed consent due to the retrospective design, minimal risk, and use of de-identified data prior to analysis. Data processing complied with the General Data Protection Regulation and the Swedish Patient Data Act; only authorised personnel accessed identifiable records.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData collection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe analysed HRAM investigations conducted at the motility lab between May 2018 and December 2024. Patients who had not undergone BD were excluded. The remaining investigations were sorted by indication, and those involving patients with constipation symptoms and suspected FDD were included.\u003c/p\u003e\n\u003cp\u003eConstipation symptoms comprised hard stools, fewer than three bowel movements per week, intense straining, the sensation of incomplete evacuation, the sensation of anorectal blockage, or the need for manual maneuvers.\u003c/p\u003e\n\u003cp\u003eFollowing inclusion, patient records were reviewed for previously diagnosed functional gastrointestinal disorders, use of medication for constipation and neuromodulators, history of vaginal births, obstetrical injury, and prior surgery involving the pelvic floor.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHRAM was performed using the Solar GI HRAM equipment (MMS/Laborie, Enschede, the Netherlands) and a Solar Solid-State HRAM catheter (12 French, eight circumferential pressure zones and one for the balloon). The investigations adhered to the standardized testing protocol recommended by the International Anorectal Physiology Working Group (IAPWG) [13], except for the BET, which was implemented later at our motility unit. Specialized nurses conducted the HRAM procedures, and the results were interpreted by two specialized gastroenterologists using the QuickView analysis program. BD studies were performed and interpreted at the Radiology Department in accordance with established protocols\u0026nbsp;[17, 18, 22, 23]. The BD variables were reassessed using the Sectra Radiology PACS software (Sectra AB, Link\u0026ouml;ping, Sweden).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eVariables:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOriginal interpretations\u003c/strong\u003e\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eHRAM: Findings interpreted by the gastroenterologist as suggestive of FDD or not.\u003c/li\u003e\n \u003cli\u003eBD: Findings interpreted by the radiologist as suggestive of FDD or not.\u003c/li\u003e\n \u003cli\u003eConcomitant pathology on BD: Presence of rectocele \u0026ge; 2 cm, rectocele with barium retention, enterocele, rectal prolapse, or intussusception.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eReassessed parameters\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll investigations were reassessed by a single investigator blinded to the original interpretations.\u003c/p\u003e\n\u003cp\u003eHRAM parameters (best values from three simulated defecations):\u003cbr\u003e\u0026nbsp;Anal resting pressure (mmHg); anal push pressure (mmHg); anal relaxation during simulated defecation (%); maximal rectal pressure during simulated defecation (mmHg); and rectoanal pressure gradient (rectal\u0026ndash;anal pressure difference during simulated defecation, mmHg).\u003c/p\u003e\n\u003cp\u003eThere is currently no consensus on HRAM-based diagnostic criteria for FDD. In conventional manometry, a negative rectoanal pressure gradient has been considered a key feature of dyssynergia. In HRAM studies, however, the rectoanal gradient during evacuation is often negative even in healthy individuals, and there is significant overlap between patients with constipation and healthy individuals [19, 20]. Normal values for the rectoanal pressure gradient have not been established. HRAM can be interpreted in three main ways:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eTraditional dyssynergia patterns as described by Rao et al.: Four dyssynergia subtypes (types I\u0026ndash;IV) are defined, based on rectoanal coordination during simulated defecation rather than static pressure values. These patterns were originally described using conventional manometry in patients with constipation, but their discriminative value for distinguishing between healthy controls and constipated patients remains uncertain [24].\u003c/li\u003e\n\u003c/ol\u003e\n\u003col start=\"2\" type=\"1\"\u003e\n \u003cli\u003eParameter-based thresholds: Uses catheter-, age-, sex-, and parity-adjusted reference values for key variables like rectal pressure increase and anal relaxation. Both the Rome IV criteria and the London consensus classify \u0026nbsp;FDD based on rectal and anal pressures during simulated defecation [5, 13].\u003c/li\u003e\n \u003cli\u003eNovel dyssynergia patterns as described by Ratuapli et al.: \u0026nbsp;HRAM patterns were identified that distinguish patients with constipation from healthy controls and those with normal versus pathological BET [20]. Four defecatory patterns were identified; three correspond to Rao types I, II, and IV.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eThe different methods for diagnosing DD on HRAM are presented in Supplementary Table 1.\u003c/p\u003e\n\u003cp\u003eBD parameters\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eBarium paste evacuation: normative data indicate that expulsion \u0026lt;35 % or an evacuation time \u0026gt; 2.5 min is not observed in healthy participants [9]. Other studies have proposed alternative thresholds (\u0026lt;25% or \u0026lt;50%). [12, 18, 25]. Assessing volume in two-dimensional images has limitations; to avoid misclassification, we used a conservative definition of normal evacuation (50% as the threshold) when comparing HRAM to BD in patients with normal barium evacuation.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eNon-relaxing puborectalis: Binary variable (present/absent).\u003c/li\u003e\n \u003cli\u003eDynamic measures (at rest and peak evacuation): posterior anorectal angle (PARA), and central anorectal angle (CARA). The definitions of rectal wall, rectal center, and rectal angles follow previously published standards [9, 22, 23, 25].\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eComparing HRAM and BD: challenges and considerations:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe diagnostic outputs from HRAM and BD depend on how multiple measured variables are interpreted to determine whether an FDD is present. There is currently no standardized method for direct comparison between these methods, nor is there a gold standard for diagnosing FDD. Consequently, it is unclear whether the diagnostic outputs of each investigation should be compared or whether specific HRAM findings correlate more closely with specific BD findings. Thus, we analyzed correlations between:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eRectal pressure on HRAM and evacuation performance on BD.\u003c/li\u003e\n \u003cli\u003eAnal relaxation on HRAM and changes in the anorectal angle on BD.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll statistical analyses were performed using JASP open-source software (version 0.19.0, JASP Team, 2024) [26]. The tables and figures were created using Microsoft Excel and Microsoft Word. Agreement for binary variables obtained from HRAM and BD was assessed using Cohen\u0026rsquo;s kappa (\u0026kappa;). Interpretation of \u0026kappa;-values followed the following thresholds:\u003c/p\u003e\n\u003cul class=\"decimal_type\"\u003e\n \u003cli\u003e\u0026nbsp; \u0026le; 0.00: No agreement\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e0.01 to 0.19: None to slight agreement\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e0.20 to 0.39: Fair agreement\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e0.40 to 0.59: Moderate agreement\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e0.60 to 0.79: Substantial agreement\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e0.80 to 1.00: Almost perfect agreement\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003ePrevious literature has questioned the utility of \u0026kappa;-values \u0026lt;0.6 in medical research. In this study, a \u0026kappa; value of 0.6 or greater was considered acceptable [27].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor sample size considerations, existing guidelines for kappa-based reliability studies recommend a minimum of 54 participants to achieve 90% power for detecting a statistically significant \u0026kappa; coefficient [28].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor continuous variables, we used Spearman\u0026rsquo;s rho for non-normally distributed data to assess correlations, and we used the Mann-Whitney U test to compare distributions. \u0026nbsp;A p-value of \u0026lt;0.05 was considered statistically significant for all tests.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePatient inclusion and characteristics\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong 344 HRAM investigations screened, 81 lacked a corresponding BD, and 176 were performed for faecal incontinence. Three additional cases with full-thickness rectal prolapse and four non-interpretable BD studies were excluded, leaving 80 patients (68 women, 12 men) with constipation and suspected DD for analysis. The data collection and inclusion flowchart are illustrated in Figure 1, and patient demographics and clinical characteristics are presented in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eT\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003eable 1\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;Demographic and clinical characteristics of patients with constipation and suspected FDD\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"510\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eDemographics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003evalue\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e% of sample\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eMean age (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eSex (female)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eObstetric history\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e% of females\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eVaginal birth\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eKnown obstetrical complications\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eInterventions for pelvic prolapse\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eHysterectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eSurgical history\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eBowel resection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eInterventions on the anal sphincter or hemorrhoids\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eMedication\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eAntidepressants\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003ePrucalopride/linaclotide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eConcomitant pathology observed with BD\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStructural abnormalities were frequent. Rectoceles ≥ 2 cm were observed in 48 (71%), and rectoceles ≥ 4 cm in 9 (13%) women. Rectoceles with barium retention were found in 34 women (50%), including all with a rectocele ≥ 4 cm. Intussusception was observed in 17 patients (22%), enterocele in 7 (8%), and rectal prolapse in 3 (4%) patients, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAgreement of DD diagnosis between HRAM and BD\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRadiologists assessed DD primarily based on the presence of a non-relaxing puborectalis muscle during defecation. The ARAs were inconsistently reported, and the evacuation of barium paste was only interpreted in the context of concomitant pathology and its impact on defecation. Additional evaluations were performed to assess HRAM patterns of anorectal coordination, barium paste evacuation, and ARAs as described in the Methods section. The prevalence of DD across the different assessment methods is presented in Table 2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 2\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;The prevalence of FDD using HRAM and BD. For additional information about the interpretation methods, see supplementary Table 1\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"501\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eMethod of assessing FDD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eNumber of cases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003ePercentage (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eOriginal interpretation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eHRAM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eNon-relaxing puborectalis on BD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eReassessed parameters\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFDD on HRAM after Rao\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eType I\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eType II\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eType III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eType IV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFDD on HRAM after Ratuapli\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eHigh anal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eHybrid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLow rectal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eShort HPZ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFDD on HRAM after Rome IV\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eInadequate rectal propulsion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eDyssynergia after Rome IV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eBarium evacuation \u0026lt;35%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAny BD finding indicative of FDD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTwo HRAM investigations were considered inconclusive regarding DD in the initial interpretation. Among the 78 remaining cases, the initial clinical interpretations of HRAM and BD showed almost no agreement (κ = 0.007).\u003c/p\u003e\n\u003cp\u003eThe agreement between the reinterpreted HRAM and any BD findings indicative of DD (non-relaxing puborectalis or impaired barium evacuation) was only fair (κ values of 0.307, 0.272, and 0.294 for interpretations according to the Rao et al., Ratuapli et al., and Rome IV criteria, respectively).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe analysis of the relationship between rectal propulsion (HRAM) and rectal evacuation (BD) showed almost no agreement (κ = 0.057), while there was a slight agreement between anal relaxation (HRAM) and puborectalis relaxation (BD) (κ = 0.213 for the agreement between patterns I, II, and III according to Rao indicative of failed anal relaxation and a non-relaxing puborectalis on BD).\u003c/p\u003e\n\u003cp\u003eThe complete results are available in Supplementary Table 2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison of HRAM and binary BD parameters:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients with a persistent puborectalis impression on BD had lower anal relaxation and lower maximal rectal pressure during simulated defecation (p = 0.004 and p = 0.011, respectively) (Figure 2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelations between the reassessed HRAM and BD continuous parameters.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe reassessed continuous parameters for HRAM and BD are summarized in Supplementary Table 3, with detailed correlation results presented in Supplementary Table 4. Since several parameters were not normally distributed, Spearman’s ρ was used to analyze their correlations.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;No significant correlations were found between the reassessed continuous parameters.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe effect of concomitant pathology on HRAM parameters.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients with rectocele had higher anal resting pressure and greater anal relaxation than those without rectocele (p = 0.005 and p = 0.023). After excluding large rectoceles (\u0026gt; 4 cm), the difference in anal relaxation was no longer significant (p = 0.08) (Figure 3). No significant HRAM differences were observed in patients with enterocele, intussusception, or rectal prolapse.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatients with a normal barium evacuation test. \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the subgroup of patients who had at least 50% barium evacuation (N=56), 23 (41%) had a non-relaxing puborectalis muscle on BD. Abnormal HRAM patterns were found in 24 (43%) cases according to the Rao et al. interpretation, and in 16 (29%) cases according to the Rome IV classification. The kappa for the agreement between the initial HRAM interpretation and a non-relaxing puborectalis on BD was 0.015, while after HRAM reinterpretation, the kappa was 0.450 and 0.444 for the interpretations after Rao and Rome IV, respectively. The combination of abnormal puborectalis relaxation and abnormal HRAM pattern was present in 16 (29%) patients using the Rao classification and 12 (21%) patients using the ROME IV classification. \u0026nbsp; In this group, there were no significant differences in HRAM parameters between patients with and without rectocele.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this cohort of patients investigated for suspected FDD, agreement between HRAM and BD was only fair, and structural pathology in the rectum affected HRAM measurements.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey findings\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConsistent with clinical experience, we observed little agreement between the initial interpretations\u0026nbsp;of HRAM and BD investigations. This study demonstrates that even when standardized criteria are applied, HRAM and BD exhibit only fair agreement in diagnosing FDD. We found no meaningful agreement between impaired rectal propulsion on HRAM and barium retention on BD or between impaired anal relaxation on HRAM and a non-relaxing puborectalis. This suggests that classification bias (subjective interpretation) does not fully explain the discrepancies in agreement between these methods either. Instead, it indicates that the two tests measure different physiological processes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe different interpretations of HRAM\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe could not find clear differences in agreement with BD between the pattern recognition methods based on the Rao or Rome IV criteria. The classification proposed by the IAPWG group is similar to Rome IV, except that in Rome IV there is no “poor propulsion and dyssynergia”. We could not draw any conclusions using the Ratuapli method, as, with these definitions, there were no cases of the first dyssynergia type in our study group. This may be explained by the different normal-range intervals used (5th to 95th percentile vs 10th to 90th percentile) and by the different solid-state catheters. \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther variables\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe found a significant difference in anal relaxation between patients with and without persistent puborectalis contraction; however, we found no evidence that HRAM parameters during simulated defecation correlate with changes in anorectal parameters on BD, further supporting the notion that these methods measure different physiological processes. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInfluence of structural pathology\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA key finding was the relation between structural abnormalities in BD investigations and HRAM measurements. Rectocele was frequent and was associated with differences in anal pressure measures. When large rectoceles were excluded, the association weakened, suggesting that the effect is strongest in more pronounced structural change. These results support that structural pathology can influence HRAM metrics and may lead to misclassification if HRAM is interpreted in isolation. Therefore, BD adds value by identifying anatomy and evacuation mechanics that HRAM cannot show.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatients with normal barium evacuation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA substantial subgroup had normal barium paste evacuation despite a suspected evacuation disorder. In this subgroup, we found moderate agreement between HRAM and a non-relaxing puborectalis muscle on BD, which was nonetheless better than in the larger cohort. This supports the conclusion that normal barium evacuation does not exclude abnormal findings on other tests, and that while HRAM and BD should not be used interchangeably, together they may identify a small group of patients with normal evacuation who nevertheless have two abnormal tests of anorectal function and might benefit from biofeedback therapy.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical implications\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThese findings have practical implications for the clinical interpretation of HRAM. In cases with abnormal evacuation and normal HRAM, BD can identify structural abnormalities (e.g., large rectoceles) that may explain the apparent discrepancy. This is particularly relevant in older patients, in whom structural findings are common. Conversely, when evacuation testing is normal, but HRAM is abnormal, BD may help corroborate HRAM findings and support the indication for therapy. Overall, our data support a combined assessment when the diagnosis is uncertain or when HRAM findings do not align with symptoms.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison with previous research\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePrior studies have reported limited agreement between anorectal manometry and BD [29]. Our results extend this by focusing on BD in routine clinical referrals and by examining how structural abnormalities on BD relate to HRAM measurements. Taken together, the findings support using HRAM and BD together when possible rather than expecting strong agreement between them.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStrengths and limitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study’s strengths include its focus on the typical patient population seen in clinical practice. The systematic reassessment of HRAM and BD parameters aimed to reduce subjectivity and interobserver variability. The sample size provided adequate power to detect moderate agreement. Limitations include the retrospective design and potential selection bias. In contrast, concerns about multiple comparisons are less critical given the overall low level of agreement.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThere is no accepted gold standard for evacuation disorders, so we could only assess agreement rather than diagnostic accuracy. BET data were mainly missing and could not be included in the main comparisons.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, HRAM and BD showed only fair agreement in suspected evacuation disorders. Structural findings on BD, especially rectocele, were common and were associated with differences in HRAM measurements. These results support considering structural pathology when interpreting HRAM and support a combined testing approach when findings are inconclusive.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFounding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOpen access funding provided by Örebro University. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors declare that they have no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no known competing interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eL.M.G. and M.v.N. conceptualized the study. L.M.G., M.A.R., and M.v.N. developed the methodology. L.M.G. and M.A.R. performed data curation. L.M.G. and M.A.R. prepared the original draft. L.M.G. and M.v.N. contributed to review and editing. L.M.G. and M.v.N. were responsible for resources and project administration. All authors reviewed and approved the final manuscript.All authors declare that they have no conflicts of interest, and no external funding was received for this study. The authors declare that they have no known competing interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003ch2\u003eAcknowledgement\u003c/h2\u003e\n\u003cp\u003eWe thank Professor Jonas Halfvarson for his support in finalizing this manuscript, as well as the nurses from our motility lab, Hanna Falck, Johanna Lundgren, Karina Varas Rende, and Victoria Johansson, for performing the HRAM investigations. Open-access publishing is facilitated by Örebro University.\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe datasets generated and/or analysed during the current study are not publicly available due to ethical and legal restrictions related to patient privacy and data protection (including compliance with applicable data protection regulations such as the General Data Protection Regulation [GDPR]). De-identified data may be made available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMertz H, Naliboff B, Mayer EA. Physiology of refractory chronic constipation. Am J Gastroenterol. 1999;94:609\u0026ndash;615. \u003c/li\u003e\n\u003cli\u003eVidelock EJ, Lembo A, Cremonini F. Diagnostic testing for dyssynergic defecation in chronic constipation: meta-analysis. Neurogastroenterol Motil. 2013;25:509\u0026ndash;520. \u003c/li\u003e\n\u003cli\u003eRao SSC, Patcharatrakul T. Diagnosis and treatment of dyssynergic defecation. J Neurogastroenterol Motil. 2016;22:423\u0026ndash;435. \u003c/li\u003e\n\u003cli\u003eChiarioni G, Heymen S, Whitehead WE. Biofeedback therapy for dyssynergic defecation. World J Gastroenterol. 2006;12:7069\u0026ndash;7074. \u003c/li\u003e\n\u003cli\u003eSimr\u0026eacute;n M, P\u0026aacute;lsson OS, Whitehead WE. Update on Rome IV criteria for colorectal disorders: implications for clinical practice. Curr Gastroenterol Rep. 2017;19:15. \u003c/li\u003e\n\u003cli\u003eDedeli O, et al. Normative values of the balloon expulsion test in healthy adults. Turk J Gastroenterol. 2007;18:177\u0026ndash;181. \u003c/li\u003e\n\u003cli\u003eGrossi U, et al. Diagnostic accuracy study of anorectal manometry for diagnosis of dyssynergic defecation. Gut. 2016;65:447\u0026ndash;455. \u003c/li\u003e\n\u003cli\u003eCarrington EV, et al. Traditional measures of normal anal sphincter function using high-resolution anorectal manometry (HRAM) in 115 healthy volunteers. Neurogastroenterol Motil. 2014;26:625\u0026ndash;635. \u003c/li\u003e\n\u003cli\u003ePalit S, et al. Evacuation proctography: a reappraisal of normal variability. Colorectal Dis. 2014;16:538\u0026ndash;546. \u003c/li\u003e\n\u003cli\u003eRao SSC, et al. Manometric tests of anorectal function in healthy adults. Am J Gastroenterol. 1999;94:773\u0026ndash;783. \u003c/li\u003e\n\u003cli\u003eRao SSC, Welcher KD, Leistikow JS. Obstructive defecation: a failure of rectoanal coordination. Am J Gastroenterol. 1998;93:1042\u0026ndash;1050. \u003c/li\u003e\n\u003cli\u003eCarrington EV, et al. Expert consensus document: advances in the evaluation of anorectal function. Nat Rev Gastroenterol Hepatol. 2018;15:309\u0026ndash;323. \u003c/li\u003e\n\u003cli\u003eCarrington EV, et al. The international anorectal physiology working group (IAPWG) recommendations: standardized testing protocol and the London classification for disorders of anorectal function. Neurogastroenterol Motil. 2020;32:e13679. \u003c/li\u003e\n\u003cli\u003eMinguez M, et al. Predictive value of the balloon expulsion test for excluding the diagnosis of pelvic floor dyssynergia in constipation. Gastroenterology. 2004;126:57\u0026ndash;62. \u003c/li\u003e\n\u003cli\u003eRao SSC, et al. Minimum standards of anorectal manometry. Neurogastroenterol Motil. 2002;14:553\u0026ndash;559. \u003c/li\u003e\n\u003cli\u003eLee TH, Bharucha AE. How to perform and interpret a high-resolution anorectal manometry test. J Neurogastroenterol Motil. 2016;22:46\u0026ndash;59. \u003c/li\u003e\n\u003cli\u003eKim AY. How to interpret a functional or motility test: defecography. J Neurogastroenterol Motil. 2011;17:416\u0026ndash;420. \u003c/li\u003e\n\u003cli\u003eMahieu P, Pringot J, Bodart P. Defecography: I. Description of a new procedure and results in normal patients. Gastrointest Radiol. 1984;9:247\u0026ndash;251. \u003c/li\u003e\n\u003cli\u003eBlackett JW, et al. Comparison of anorectal manometry, rectal balloon expulsion test, and defecography for diagnosing defecatory disorders. Gastroenterology. 2022;163:1582\u0026ndash;1592.e2. \u003c/li\u003e\n\u003cli\u003eRatuapli SK, et al. Phenotypic identification and classification of functional defecatory disorders using high-resolution anorectal manometry. Gastroenterology. 2013;144:314\u0026ndash;322.e2. \u003c/li\u003e\n\u003cli\u003eCohen JF, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. BMJ Open. 2016;6:e012799. \u003c/li\u003e\n\u003cli\u003ePenninckx F, et al. Intraobserver variation in the radiological measurement of the anorectal angle. Gastrointest Radiol. 1991;16:73\u0026ndash;76. \u003c/li\u003e\n\u003cli\u003eYang X, et al. Reproducibility of five anorectal morphologic measurements in defecography. Acad Radiol. 1994;1:224\u0026ndash;228. \u003c/li\u003e\n\u003cli\u003eRao SSC. Dyssynergic defecation. Gastroenterol Clin North Am. 2001;30:97\u0026ndash;114. \u003c/li\u003e\n\u003cli\u003eChoi JS, et al. Intraobserver and interobserver measurements of the anorectal angle and perineal descent in defecography. Dis Colon Rectum. 2000;43:1121\u0026ndash;1126. \u003c/li\u003e\n\u003cli\u003eJASP Team. JASP (Version 0.19.0) [computer software]. 2024. Available from: https://jasp-stats.org/ \u003c/li\u003e\n\u003cli\u003eMcHugh ML. Interrater reliability: the kappa statistic. Biochem Med (Zagreb). 2012;22:276\u0026ndash;282. \u003c/li\u003e\n\u003cli\u003eSim J, Wright CC. The kappa statistic in reliability studies: use, interpretation, and sample size requirements. Phys Ther. 2005;85:257\u0026ndash;268. \u003c/li\u003e\n\u003cli\u003ePalit S, et al. Diagnostic disagreement between tests of evacuatory function: a prospective study of 100 constipated patients. Neurogastroenterol Motil. 2016;28:1589\u0026ndash;1598.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Functional defecation disorders, high-resolution anorectal manometry, barium defecography, constipation, rectocele","lastPublishedDoi":"10.21203/rs.3.rs-9225339/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9225339/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eFunctional defecation disorders (FDD) affect approximately one-third of patients with functional constipation. No single diagnostic test reliably identifies FDD, and guidelines recommend that pathological results from two investigations are required for diagnosis. Commonly used tests include high-resolution anorectal manometry (HRAM), barium defecography (BD), and the balloon expulsion test (BET). Their agreement is uncertain, and structural abnormalities may influence HRAM metrics. We assessed diagnostic agreement between HRAM and BD in patients with suspected FDD and explored relationships between key variables and the influence of structural findings on HRAM parameters.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe included 80 patients with constipation and suspected FDD who underwent HRAM and BD. HRAM recordings were reinterpreted using pattern-based and threshold-based approaches. Radiologists evaluated BD for puborectalis relaxation and structural abnormalities, and in a subsequent assessment, we quantified rectal barium evacuation and anorectal angles. We used Cohen\u0026rsquo;s kappa (κ) to assess agreement, Spearman's rho to assess correlations, and the Mann-Whitney U test to compare distributions.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eRectoceles were present in 71% of women. Agreement between HRAM and BD was only fair and similar across interpretation methods (κ\u0026thinsp;=\u0026thinsp;0.27\u0026ndash;0.31). Continuous HRAM and BD measures were not correlated. Rectocele was associated with higher anal resting pressure and greater anal relaxation (p\u0026thinsp;=\u0026thinsp;0.005 and 0.023). Among patients with normal barium evacuation (N\u0026thinsp;=\u0026thinsp;56), 41% had both a non-relaxing puborectalis and an abnormal HRAM pattern, with moderate agreement (κ\u0026thinsp;\u0026asymp;\u0026thinsp;0.44\u0026ndash;0.45).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eOverall agreement between HRAM and BD is limited, indicating that they assess complementary aspects of anorectal function. Different HRAM interpretation approaches perform similarly. Rectoceles influence HRAM metrics. In patients with normal barium evacuation, puborectalis assessment on BD may support the interpretation of abnormal HRAM and identify a relevant patient group.\u003c/p\u003e","manuscriptTitle":"High-resolution anorectal manometry and barium defecography in suspected functional defecation disorders: agreement and impact of structural findings","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-07 10:19:20","doi":"10.21203/rs.3.rs-9225339/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a12798c4-053d-4ea8-875f-099f5d754572","owner":[],"postedDate":"April 7th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-14T18:10:17+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-07 10:19:20","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9225339","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9225339","identity":"rs-9225339","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}