High-Resolution Anorectal Manometry as a Screening Tool for Hirschsprung's Disease: A Comprehensive Retrospective Analysis.

Hirschsprung's disease (HD) is characterized by a congenital absence of enteric ganglion cells in the intestine, posing challenges in diagnosis, particularly in pediatric patients. The gold standard, rectal suction biopsy (RSB), carries risks, prompting an exploration of non-invasive alternatives such as high-resolution anorectal manometry (HR-ARM) for HD screening. We conducted a retrospective analysis of 136 patients suspected of HD between 2018 and 2022, which were stratified into three age groups: ≤12 months, ≤24 months, and >24 months. Criteria for suspicion included delayed meconium passage, unresponsive chronic constipation, and abnormal prior test results. HR-ARM, supplemented by additional tests, confirmed 16 HD cases. HR-ARM exhibited 93.75% sensitivity, 89.47% specificity, 99.03% negative predictive value (NPV), and 55.56% positive predictive value (PPV). Notably, HR-ARM consistently performed well in patients ≤ 2 years old but demonstrated reduced efficacy in older children, which was likely due to complications from chronic constipation. This study underscores HR-ARM's promise as a non-invasive HD screening tool, especially in younger patients. However, its limitations in older children warrant consideration. Establishing standardized protocols, particularly for assessing the recto-anal inhibitory reflex, is crucial. Further research is imperative to optimize HR-ARM's diagnostic role across varied age groups in HD assessment.

Short-term clinical and manometric outcomes of percutaneous tibial nerve stimulation for faecal incontinence: a large single-centre series.

BACKGROUND: Faecal incontinence (FI) is common, with a significant impact on quality of life. Percutaneous tibial nerve stimulation (PTNS) is a therapy for FI; however, its role has recently been questioned. Here we report the short-term clinical and manometric outcomes in a large tertiary centre. METHODS: A retrospective review of a prospective PTNS database was performed, extracting patient-reported FI outcome measures including bowel diary, the St Marks's Incontinence Score (SMIS) and Manchester Health Questionnaire (MHQ). Successful treatment was > 50% improvement in symptoms, whilst a partial response was 25-50% improvement. High-resolution anorectal manometry (HRAM) results before and after PTNS were recorded. RESULTS: Data were available from 135 patients [119 (88%) females; median age: 60 years (range: 27-82years)]. Overall, patients reported a reduction in urge FI (2.5-1) and passive FI episodes (2-1.5; p < 0.05) alongside a reduction in SMIS (16.5-14) and MHQ (517.5-460.0; p < 0.001). Some 76 (56%) patients reported success, whilst a further 20 (15%) reported a partial response. There were statistically significant reductions in rectal balloon thresholds and an increase in incremental squeeze pressure; however, these changes were independent of treatment success. CONCLUSION: Patients report PTNS improves FI symptoms in the short term. Despite this improvement, changes in HRAM parameters were independent of this success. HRAM may be unable to measure the clinical effect of PTNS, or there remains the possibility of a placebo effect. Further work is required to define the role of PTNS in the treatment of FI.

Relationship of Age and Gender to Motility Test Results and Symptoms in Patients with Chronic Constipation.

BACKGROUND/AIMS: Patients with chronic constipation (CC) exhibit symptoms and functional abnormalities upon testing, but their relationship to age and gender is unclear. We assessed age- and gender-related differences in symptoms, colon transit time, and anorectal motility, sensation, and expulsion. PATIENTS AND METHODS: Retrospective, post hoc data analysis of patients with CC, who underwent Wireless Motility Capsule (WMC), High-Resolution Anorectal Manometry (HR-ARM), Balloon Expulsion Test (BET) and Rectal Sensory Testing (RST). Clinical assessment was made by questionnaires. Standard WMC criteria for colonic transit time (CTT) and the London classification was used for HR-ARM analyses, and regression plots between age, gender, CTT, HR-HRM, RST and BET were calculated. RESULTS: We studied 75 women and 91 men. Abdominal pain, infrequent defecation, incomplete evacuation, defecatory straining, and multiple motility and anorectal function abnormalities were common. Abdominal pain was least frequently, and straining was most frequently associated with a motility abnormality. For each symptom, the highest prevalence was associated with failed BET. There was a significant increase in CTT with age only in men (p = 0.0006). In men, for each year of age there was a CTT increase of 1.02 h. The prevalence of abdominal pain and incomplete evacuation for females was significantly higher than that for males (both P < 0.05). The prevalence of low anal squeeze pressure for females was significantly higher than that for males, and the prevalence of poor rectal sensation for males was significantly higher than that for females (both P < 0.05). A significant decrease in basal anal and squeeze pressures with age occurred in women (p < 0.0001); an increase in age of one year was associated with a decrease in anal base pressure of 1.2 mmHg. Abnormal CTT and HR-ARM tests were associated with increased symptom frequency, but not severity. CONCLUSIONS: There are significant age- and gender-related differences in symptoms, CTT, and HR-HRM parameters, rectal sensation, and expulsion, that may influence the multifaceted management of constipation.

Rectal Sensory and Compliance Testing: A Method Comparison Study between High-Resolution Anorectal Manometry and Barostat Investigations.

Abnormal visceral perception and motor function are often observed in patients with fecal incontinence, evacuation disorders and irritable bowel syndrome. The international anorectal physiology working group has proposed a standardization for anorectal function assessment, where rectal sensitivity testing is performed using an elastic balloon attached to a high-resolution anorectal manometry (HRAM) catheter. Rectal compliance, another component of rectal function evaluation, is a pressure-volume relationship that refers to the rectum's ability to stretch and expand as it receives and holds fecal matter. There are no data available regarding the possibility of compliance testing using HRAM, although this is theoretically possible by correcting for the elastic balloon's intrinsic properties. The gold standard for measurement of visceral sensitivity and compliance is the rectal barostat, according to the procedure described by the European COST action GENIEUR group. Data on the agreement between the two different procedures are scarce. Hence, we performed a comparative study of the HRAM and barostat investigations in 26 healthy individuals. We hypothesized that by inflating the balloon before the examination, rectal compliance can be measured with HRAM investigations, and we examined correlations and levels of agreement between the methods. Our results demonstrate that assessing rectal compliance with HRAM is technically possible; however, a strong correlation with the rectal barostat was only observed at the maximum tolerable volume (Spearman's rho = 0.7, p = 0.02). We only found moderate correlations (Spearman's rho = 0.562, p = 0.019) for compliance according to the barostat methodology and for rectal sensibility testing (Spearman's rho = 0.57, p = 0.03 for maximum tolerable volume). Bland-Altman plots showed poor levels of agreement between the methods. We conclude that HRAM and the rectal barostat cannot be used interchangeably for compliance or sensitivity assessments. We suggest the development of a non-elastic balloon with a fixed size and shape to assess rectal sensory function and compliance in HRAM testing.

High Prevalence of Anorectal Dysfunction in Ambulatory Patients with Chronic Constipation, Regardless of Colon Transit Time.

BACKGROUND: Classification of chronic constipation (CC) into its three subtypes of slow transit constipation, defecation disorder and normal transit constipation, may improve its multifaceted management. We assessed the merits of the London classification in patients with CC, who were studied by both wireless motility capsule (WMC) and high-resolution anorectal manometry (HR-ARM), examining their relative utilities in decision-making.s PATIENTS AND METHODS: Retrospective, community-based study of prospectively collected data on patients with CC by Rome IV criteria, who underwent WMC and HR-ARM, Balloon Expulsion Test, and Rectal Sensory Testing. Clinical assessment was made by standard questionnaires. On WMC, standard criteria for colonic transit time (CTT) were used (normal CTT < 59 h). The hierarchical London classification was used for HR-ARM analyses. RESULTS: Of 1261 patients with CC, 166 (91 M; ages 22-86) received technically satisfactory WMC and HR-ARM, formed the analyzed study cohort, of whom 84 had normal CTT and 82 had prolonged CTT (> 59 h). Patients with slow CTT were significantly older and had longer duration and more severe disease. Using the London classification criteria for disorders of anorectal function, we noted a high prevalence of anorectal dysfunction, regardless of CTT. Except for lower rate of anal hypertonicity in patients with slow CTT, disorders of recto-anal coordination, and rectal sensation were seen at a comparable rate in patients with CC, regardless of CTT. CONCLUSION: There is a significant overlap of anorectal disorders in patients with slow CTT. There is questionable specificity and utility of WMC and HR-ARM in assessing patients with CC. More work is needed to demonstrate the value of these studies as surrogate markers of the disease and its response to multifaceted therapy.

Clinical utility of anal sphincter relaxation integral in water-perfused and solid-state high-resolution anorectal manometry.

BACKGROUND/PURPOSE: We investigated the diagnostic performance of the anal sphincter relaxation integral (ASRI) for infants with Hirschsprung's disease (HD). METHODS: We performed water-perfused high-resolution anorectal manometry (HRAM) in 18 infants (9 with HD), and solid-state HRAM in another 18 infants (4 with HD). We calculated the ASRI during the rectoanal inhibitory reflex (RAIR) maneuver at pressure cutoffs of <10 mmHg (ASRI 10) and <15 mmHg (ASRI 15). We investigated the diagnostic performance of the ASRI for HD in infants undergoing water-perfused and solid-state HRAM. RESULTS: HD infants who underwent either water-perfused or solid-state HRAM had significantly lower ASRI 10 and ASRI 15 values, compared with non-HD infants (P < 0.05 and P < 0.05, respectively). Using the water-perfused HRAM system, ASRI 10 and ASRI 15 values of <7 and <29 mmHg s.cm, respectively, exhibited good diagnostic performance for HD (88.89% and 88.89%, respectively). Receiver operating characteristic curve analysis indicated that ASRI 10 and ASRI 15 values of <5.5 and <20 mmHg s.cm, respectively, were optimal for the diagnosis of HD infants when using the solid-state HRAM system, with high diagnostic accuracies of 83.33% and 83.33%, respectively. CONCLUSION: ASRI may assist the diagnosis of HD infants using either water-perfused or solid-state HRAM. These systems require different catheter-specific ASRI cutoffs for the prediction of HD.

Colorectal motility patterns and psychiatric traits in functional constipation and constipation-predominant irritable bowel syndrome: A study from China.

BACKGROUND: Functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C) represent a spectrum of constipation disorders. However, the majority of previous clinical investigations have focused on Western populations, with limited data originating from China. AIM: To determine and compare the colorectal motility and psychiatric features of FC and IBS-C in an Eastern Chinese population. METHODS: Consecutive chronic constipation patients referred to our motility clinic from December 2019 to February 2023 were enrolled. FC and IBS-C diagnoses were established using ROME IV criteria, and patients underwent high-resolution anorectal manometry (ARM) and a colonic transmit test using the Sitz marker study. Constipation-related symptoms were obtained through questionnaires. Anxiety and depression were assessed by the Hamilton anxiety rating scale and the Hamilton Depression Rating Scale-21. The clinical characteristics and colorectal motility patterns of FC and IBS-C patients were compared. RESULTS: No significant differences in sex, age or abdominal discomfort symptoms were observed between IBS-C and FC patients (all P > 0.05). The proportion of IBS-C patients with delayed colonic transit was higher than that of patients with FC (36.63% vs 15.91%, P < 0.05), while rectosigmoid accumulation of radiopaque markers was more common in the FC group than in the IBS-C group (50% vs 26.73%, P < 0.05). Diverse proportions of these dyssynergic patterns were noted within both the FC and IBS-C groups by ARM. IBS-C patients were found to have a higher prevalence of depression than FC patients (66.30% vs 42.42%, P < 0.05). The scores for feelings of guilt, suicide, psychomotor agitation, diurnal variation, obsessive/compulsive disorder, hopelessness, self-abasedment and gastrointestinal symptoms were significantly higher in IBS-C patients than that in FC patients (P < 0.05). For IBS-C (χ2 = 5.438, P < 0.05) but not FC, patients with normal colon transit time were significantly more likely to have anxiety than those with slow colon transit time. For IBS-C patients but not FC patients, the threshold of first constant sensation, desire to defecate and sustained urgency were all weakly correlated with the degree of anxiety (r = 0.414, r = 0.404, and r = 0.418, respectively, P < 0.05). The proportion of patients with a low threshold of desire to defecate among IBS-C patients with depression was lower than that in those without depression (69.6% vs 41.9%, χ2 = 4.054, P < 0.05). CONCLUSION: Our findings highlight both overlapping and distinctive patterns of colon transit, dyssynergic patterns, anorectal sensation, psychological distress, and associations of psychiatric and colorectal motility characteristics in FC and IBS-C patients in an Eastern Chinese population, providing valuable insights into the pathophysiological underpinnings of these disorders.

Lack of improvement in anorectal manometry parameters after implementation of a pelvic floor/anal sphincter biofeedback in persons with motor-incomplete spinal cord injury.

BACKGROUND: Effect of biofeedback on improving anorectal manometric parameters in incomplete spinal cord injury is unknown. A short-term biofeedback program investigated any effect on anorectal manometric parameters without correlation to bowel symptoms. METHODS: This prospective uncontrolled interventional study comprised three study subject groups, Group 1: sensory/motor-complete American Spinal Injury Association Impairment Scale (AIS) A SCI (n = 13); Group 2 (biofeedback group): sensory incomplete AIS B SCI (n = 17) (n = 3), and motor-incomplete AIS C SCI (n = 8), and AIS D SCI (n = 6); and Group 3: able-bodied (AB) controls (n = 12). High-resolution anorectal manometry (HR-ARM) was applied to establish baseline characteristics in all subjects for anorectal pressure, volume, length of pressure zones, and duration of sphincter squeeze pressure. SCI participants with motor-incomplete SCI were enrolled in pelvic floor/anal sphincter bowel biofeedback training (2 × 6-week training periods comprised of two training sessions per week for 30-45 min per session). HR-ARM was also performed after each of the 6-week periods of biofeedback training. RESULTS: Compared to motor-complete or motor-incomplete SCI participants, AB subjects had higher mean intra-rectal pressure, maximal sphincteric pressure, residual anal pressure, recto-anal pressure gradient, and duration of squeeze (p < 0.05 for each of the endpoints). No significant difference was evident at baseline between the motor-complete and motor-incomplete SCI groups. In motor-incomplete SCI subjects, the pelvic floor/anal sphincter biofeedback protocol failed to improve HR-ARM parameters. CONCLUSION: Biofeedback training program did not improve anal manometric parameters in subjects with motor-incomplete or sensory-incomplete SCI. Biofeedback did not change physiology, and its effects on symptoms are unknown. INFERENCES: Utility of biofeedback is limited in patients with incomplete spinal cord injury in terms of improving HR-ARM parameters.

Study on 3D High-Resolution Anorectal Manometry Interrater Agreement in the Evaluation of Dyssynergic Defecation Disorders.

Anorectal manometry measurements exhibit significant interrater variability. Newer techniques like 3D high-resolution anorectal manometry (3D-HRAM) have the potential to enhance diagnostic accuracy and our understanding of defecation disorders. However, the extent of interrater variability in 3D-HRAM is still unknown. Between January 2020 to April 2022, patients referred for pelvic floor physical therapy (PFPT) due to functional defecation complaints underwent 3D-HRAM testing. In a retrospective analysis, three expert raters independently evaluated the 3D-HRAM results in a blinded matter to assess interrater agreement. The evaluation also determined the level of agreement concerning dyssynergic patterns during simulated defecation. The 3D-HRAM results of 50 patients (37 females) were included. Twenty-nine patients had complaints of fecal incontinence, eleven patients had chronic constipation, and ten patients had several other complaints. There was a substantial agreement (kappa 0.612) between the raters concerning the 3D images on dyssynergic patterns during simulated defecation. Our study emphasizes the need for standardized guidelines in evaluating 3D-HRAM test results to reduce subjectivity and further improve agreement among raters. Implementing these guidelines could improve diagnostic consistency and enhance personalized treatment strategies, increasing the reliability and usefulness of 3D-HRAM testing in clinical practice.

Differential Findings on Anorectal Manometry in Patients with Parkinson's Disease and Defecatory Dysfunction.

Introduction: Gastrointestinal dysfunction, particularly constipation, is among the most common non-motor manifestations in Parkinson's Disease (PD). We aimed to identify high-resolution anorectal manometry (HR-ARM) abnormalities in patients with PD using the London Classification. Methods: We conducted a retrospective review of all PD patients at our institution who underwent HR-ARM and balloon expulsion test (BET) for evaluation of constipation between 2015 and 2021. Using age and sex-specific normal values, HR-ARM recordings were re-analyzed and abnormalities were reported using the London Classification. A combination of Wilcoxon rank sum and Fisher's exact test were used. Results: 36 patients (19 women) with median age 71 (interquartile range [IQR]: 69-74) years, were included. Using the London Classification, 7 (19%) patients had anal hypotension, 17 (47%) had anal hypocontractility, and 3 women had combined hypotension and hypocontractility. Anal hypocontractility was significantly more common in women compared to men. Abnormal BET and dyssynergia were noted in 22 (61%) patients, while abnormal BET and poor propulsion were only seen in 2 (5%). Men had significantly more paradoxical anal contraction and higher residual anal pressures during simulated defecation, resulting in more negative recto-anal pressure gradients. Rectal hyposensitivity was seen in nearly one third of PD patients and comparable among men and women. Conclusion: Our data affirms the high prevalence of anorectal disorders in PD. Using the London Classification, abnormal expulsion and dyssynergia and anal hypocontractility were the most common findings in PD. Whether the high prevalence of anal hypocontractility in females is directly related to PD or other confounding factors will require further research.

Evaluation of Anal Sphincter with High Resolution Anorectal Manometry and 3D Reconstruction in Patients with Anorectal Malformation.

BACKGROUND: Patients with anorectal malformation (ARM) need long-term follow-up, in order to evaluate fecal continence; the main predictors of longer-term success are the type of ARM, associated anomalies and sacral integrity. Three-Dimensional High Resolution Anorectal Manometry (3D-HRAM) gives detailed information on pressure on the anal complex profile. Our objective was to analyze anal sphincter activity in ARM patients with 3D-HRAM establishing the correlation between manometric and clinical data. METHODS: Forty ARM patients were submitted to 3D-HRAM: manometric, anatomical and clinical scores were correlated with each other and with the bowel management response (BM). RESULTS: A positive correlation between all scores and types of ARM was found: in high ARM and in patients with spinal anomalies (regardless to ARM type) lower scores were reported and even after BM they did not achieve good continence. CONCLUSIONS: 3D-HRAM gives detailed data on the functional activity of the anal sphincter complex. Our study revealed a correlation between manometric parameters and clinical outcomes, confirming spinal malformations and ARM type as the most important prognostic risk factors for a bad outcome. Specific sphincteric defects can also be explored with manometry, allowing for tailored bowel management strategies.

Recto-anal Pressures in Constipated Men and Women Undergoing High-Resolution Anorectal Manometry.

BACKGROUND: In constipated individuals, high-resolution anorectal manometry (HRM) may suggest the presence of a defecatory disorder. Despite known physiological differences between men and women, our understanding of functional anorectal pathophysiology is based upon predominantly female cohorts. Results are generalized to men. AIMS: To evaluate whether recto-anal pressure patterns in constipated men are similar to those in constipated women. METHODS: The electronic health records at Mayo Clinic, Rochester were used to identify constipated adult patients, without organic anorectal disease, who had undergone HRM and balloon expulsion testing (BET) in 2018, 2019, and 2020. Comparative analyses were performed. RESULTS: Among 3,298 constipated adult patients (2,633 women, 665 men), anal and rectal pressures were higher in men. Women more likely to have HRM findings suggestive of a defecatory disorder (39% versus 20%, P < 0.001). Women were more likely to exhibit a type 4 pattern (27% versus 14%, P < 0.001), and less likely to exhibit a type 1 pattern (14% versus 38%, P < 0.001), of dyssynergia. Men were more likely to have an abnormal balloon expulsion test (BET, 34% versus 29%, P = 0.006). Nominal logistic regression demonstrates that male sex, age over 50 years, reduced recto-anal gradient during simulated evacuation, and types 2 and 4 dyssynergia are associated with an abnormal BET. CONCLUSIONS: In this large retrospective study, constipated men and women exhibited different patterns of dyssynergia both in the presence and absence of an abnormal BET. These findings were independent of sex-specific baseline physiological differences.

Role of 3D high resolution anorectal manometry compared to conventional technique in management of constipation and fecal incontinence in children.

BACKGROUND: Anorectal manometry is a valuable tool for objective assessment of motility motor and sensory function of the anorectum. The aim of this study was to investigate role of water-perfused (WP) three dimensional high-resolution anorectal manometry (3D-HRARM) compared to WP conventional manometry (CM) in the management of chronic idiopathic constipation (CIC) and faecal incontinence (FI) in children. METHODS: This was a retrospective review of 122 consecutive children, who had WP 8-channel CM or 24 channel 3D-HRARM and endosonography under ketamine anaesthesia from September 2012 to February 2019. All patients had a validated symptom severity score questionnaire ranging from 0 (best) to 65 (worst). Mann-Whitney-U test and Spearman rank test were used and p<0.05 was considered significant. RESULTS: Subjects were divided according to investigation: CM group (n = 75) and 3D-HRAM (n = 47), who were otherwise comparable. Median anal resting pressure was 50 mmHg and rectoanal inhibitory reflex (RAIR) threshold volume was 10mls across the entire cohort. There were no significant differences in resting pressure or RAIR threshold when using conventional or 3D-HRARM. Rectal capacity was significantly higher in the CM group (p = 0.002). Rectal capacity and internal anal sphincter (IAS) thickness positively correlated with symptom severity, duration and patient age. 3D-HRARM provided a more detailed depiction of the anorectal pressure profile. Botulinum toxin was injected into the external anal sphincter (EAS) muscle (n = 75, 61%) and an anterograde colonic enema (ACE) stoma was needed subsequently in 19 (16%) to treat recurrent constipation and soiling symptoms. Rectal biopsy was done in 43(35%) patients, if RAIR was absent or inconclusive. CONCLUSION: CM and 3D-HRARM are comparable in terms of resting pressure and RAIR threshold. 3D-HRAM is safe and provides detailed functional morphology of anal sphincters and it is useful to understand underlying pathophysiology of constipation and faecal incontinence in children and plan further treatment. LEVEL OF EVIDENCE: Level I.

Alterations in the Rectal Sensitivity of Children With Chronic Constipation Evaluated by High-Resolution Anorectal Manometry.

Introduction Constipation is one of the most frequent chronic disorders in children and is almost always of functional etiology. Manometric alterations in anorectal sensitivity in children with chronic constipation are described in the literature; nevertheless, the impact of the duration of constipation on the parameters of anorectal manometry sensitivity is unknown. Objective To compare the parameters of sensitivity of high-resolution anorectal manometry (first sensation, threshold volume for urgency, and maximal tolerability) in children with chronic constipation, related to the time of evolution from the beginning of the symptoms. Methods This was a retrospective observational analytic study. The data of 39 children with functional constipation who were subjected to high-resolution anorectal manometry were included to evaluate constipation. The patients were divided into three groups according to the duration of constipation: <1 year; from 1 to 2 years; and >2 years. The parameters of sensitivity of the anorectal manometry were compared between the three groups and correlation tests were performed with the duration in months from the beginning of the symptoms of constipation. Results There was no difference between the sensitivity parameters of high-resolution anorectal manometry of the three groups; no correlation of these parameters with the time of evolution of the symptoms was found. Conclusions Alterations in the anorectal distensibility could develop early in the course of the disease, even from the first year of the beginning of the symptoms.

Anorectal Function with High-Resolution Anorectal Manometry in Active Ulcerative Colitis and after Remission: A Pilot Study.

BACKGROUND: Ulcerative colitis may impair anorectal function, causing disabling symptoms such as incontinence and/or increase in the stool frequency, urgency and tenesmus. Data on anorectal function in these patients evaluated by conventional anorectal manometry are conflicting. OBJECTIVES: The aim of this prospective study was to assess by means of high resolution anorectal manometry the anorectal function in patients with mild-to-moderate ulcerative colitis at presentation and after remission. Anorectal function of ulcerative colitis patients was compared to that observed in healthy volunteers. METHODS: 20 patients with mild to moderate left-sided ulcerative colitis or proctitis and 20 healthy volunteers were prospectively enrolled. All ulcerative colitis patients underwent high resolution anorectal manometry before treatment and after clinical remission. RESULTS: Ulcerative colitis patients showed similar values for anal sphincter function as healthy volunteers, whereas rectal threshold volume for the first sensation, desire to defecate, urgency to defecate and maximum discomfort were significantly lower than in healthy volunteers (p<0.05). Rectal compliance was significantly lower in ulcerative colitis than in healthy volunteers (p<0.05). After remission, rectal threshold volumes, as well as rectal compliance, significantly increased. An inverse linear correlation was found between regression of urgency and stool frequency and rectal compliance (r=0.811; p<0.05). CONCLUSION: Ulcerative colitis patients show altered rectal function, with increased rectal sensitivity and lower compliance, compared to controls. This altered function is restored after successful treatment of the underlying inflammatory process. Finally high resolution anorectal manometry provides useful information on anorectal functionality and, in our opinion, should be preferred over conventional manometry.

Review of the indications, methods, and clinical utility of anorectal manometry and the rectal balloon expulsion test.

BACKGROUND: Anorectal manometry (ARM) comprehensively assesses anorectal sensorimotor functions. PURPOSE: This review examines the indications, techniques, interpretation, strengths, and weaknesses of high-resolution ARM (HR-ARM), 3-dimensional high-resolution anorectal manometry (3D-HR-ARM), and portable ARM, and other assessments (i.e., rectal sensation and rectal balloon expulsion test) that are performed alongside manometry. It is based on a literature search of articles related to ARM in adults. HR-ARM and 3D-HR-ARM are useful for diagnosing defecatory disorders (DD), to identify anorectal sensorimotor dysfunction and guide management in patients with fecal incontinence (FI), constipation, megacolon, and megarectum; and to screen for anorectal structural (e.g., rectal intussusception) abnormalities. The rectal balloon expulsion test is a useful, low-cost, radiation-free, outpatient assessment tool for impaired evacuation that is performed and interpreted in conjunction with ARM. The anorectal function tests should be interpreted with reference to age- and sex-matched normal values, clinical features, and results of other tests. A larger database of technique-specific normal values and newer paradigms of analyzing anorectal pressure profiles will increase the precision and diagnostic utility of HR-ARM for identifying abnormal mechanisms of defecation and continence.

Diagnostic Strategy and Tools for Identifying Defecatory Disorders.

This article reviews the indications, techniques, interpretation, strengths, and weaknesses of tests (anal manometry, anal surface electromyography, rectal balloon expulsion test, barium and MRI defecography, assessment of rectal compliance and sensation, and colonic transit) that are used diagnose defecatory disorders in constipated patients. The selection of tests and the sequence in which they are performed should be individualized to and interpreted in the context of the clinical features. Because anorectal functions are affected by age, results should be interpreted with reference to age- and sex-matched normal values for the same technique.

Clinical value of positive BET and pelvic floor dyssynergia in Chinese patients with functional defecation disorder.

BACKGROUND: Functional defecation disorder (FDD) is a common subtype of functional constipation (FC). Balloon expulsion test (BET) and high resolution anorectal manometry (HR-ARM) are significant tools but their results are not always consistent. AIMS: To investigate the characteristics of patients with positive BET and pelvic floor dyssynergia (PFD) and explore the value of both positive results in FDD diagnosis. METHODS: We retrospectively diagnosed FC subtypes and enrolled FDD patients based on Rome-IV criteria. They underwent HR-ARM, BET and CTT tests. Then they were classified to two groups and further stratified by FDD subtypes. Validated questionnaires were applied to investigate patients' constipation, anxiety/depression and quality of life. RESULTS: 335 FDD patients were finally enrolled. They were classified into two groups according to whether BET and PFD were both positive (consistent or not). 84.48% showed consistent results. These patients had significantly higher anal residual pressure, lower anal relaxation rate, manometric defecation index (MDI) and a more negative rectoanal pressure gradient (RAPG) (Ps < .05). The specific distribution of FDD phenotypes in two groups showed significant difference (p = .021). Males suffered a more negative RAPG (p < .001) and age was correlated with anal relaxation rate (p < .001). A subset (177 individuals) was investigated with validated questionnaires. Scores for Defecation Symptoms, Physical Discomfort and GAD-7 score were significantly high in Consistent Group (Ps < .05). GAD-7 score was associated with Defecation Symptoms (p < .001) while anal residual pressure, GAD-7 and Defecation Symptoms score were linked to Physical Discomfort (Ps < .05). The diagnostic specificity and PPV for FDD rose significantly with positive BET and PFD. CONCLUSION: FDD patients with positive BET and PFD suffered from severe defecation symptoms, anxiety and impaired QOL. Positive BET and PFD could be an ideal tool for screening FDD.

Intra-subject Variability in High Resolution Anorectal Manometry Using the London Classification: Diagnostic and Therapeutic Implications.

This retrospective pilot study conducted on a community-based cohort of both men and women of various ages and underlying clinical presentations examined the durability and reproducibility of HR-ARM findings influencing their potential impact on clinical decision-making at the point of care (Jameson et al. in Br J Surg 81:1689-1692, 1994). The key finding of our study was that only a minority of patients who underwent repeat anorectal manometry as analyzed by the London Classification had stable manometric findings, raising questions regarding the validity of a single manometric measurement, as currently analyzed, for clinical decision-making.

Redundancy in the International Anorectal Physiology Working Group Manometry Protocol: A Diagnostic Accuracy Study in Fecal Incontinence.

BACKGROUND: Anorectal manometry (ARM) is essential for identifying sphincteric dysfunction. The International Anorectal Physiology Working Group (IAPWG) protocol and London Classification provide a standardized format for performing and interpreting ARM. However, there is scant evidence to support timing and number of constituent maneuvers. AIMS: To assess the impact of protocol modification on diagnostic accuracy in patients with fecal incontinence. METHODS: Retrospective analysis of high-resolution ARM recordings from consecutive patients based on the current IAPWG protocol and modifications thereof: (1) baseline rest period (60 vs. 30 vs. 10 s); (2) number of abnormal short squeezes (SS) out of 3 (SS1/SS2/SS3) based on maximal incremental squeeze pressures over 5 s; (3) resting anal pressures (reflecting recovery) at 25-30 versus 15-20 s after SS1. RESULTS: One hundred patients (86 F, median age 55 [IQR: 39-65]; median St. Mark's incontinence score 14 [10-17]) were studied. 26% and 8% had anal hypotonia and hypertonia, respectively. Compared with 60-s resting pressure, measurements had perfect correlation (κ = 1.0) over 30 s, and substantial correlation (κ = 0.85) over 10 s. After SS1, SS2, and SS3, 43%, 49%, and 46% had anal hypocontractility, respectively. Correlation was substantial between SS1 and SS2 (κ = 0.799) and almost perfect between SS2 and SS3 (κ = 0.9). Compared to resting pressure of 5 s before SS1, pressure recordings at 25-30 and 15-20 s after SS1 were significantly correlated. CONCLUSIONS: A 30-s resting anal pressure, analysis of 2 short-squeezes with a 20-s between-maneuver recovery optimizes study duration without compromising diagnostic accuracy. These findings indicate the IAPWG protocol has redundancy.