Normal values for high-resolution anorectal manometry in healthy women: effects of age and significance of rectoanal gradient

Rectal sensory-motor alterations: a clinical perspective on anorectal disorders. The correlation between rectal sensation and motility in different anorectal diseases

BACKGROUND

Patients with anorectal diseases commonly exhibit abnormalities in rectal sensation and/or rectal motility. However, the relationship between rectal sensation and motility in these pathological processes is unclear. We aim to explore this association.

METHODS

We conducted a retrospective review of clinical data from 954 patients with anorectal disorders and defecation problems who had undergone anorectal functional testing. We investigated the correlation between rectal sensation and motility across various conditions and assessed the impact of physiological factors.

RESULTS

Significant rectal sensation differences were seen across constipation, fecal incontinence, rectal cancer, and postoperative patients, with the highest sensitivity in postoperative patients (P<0.05). Stratified analysis showed constipated patients with rectal hyposensitivity had higher anal resting and maximum squeeze pressures, lower rectoanal gradients, manometric defecation index, and anal relaxation rate (P<0.05). Further analysis revealed that rectal sensory parameters in constipated patients positively correlated with anal resting and maximum squeeze pressures, and negatively correlated with rectoanal gradients, manometric defecation index, and anal relaxation rate (P<0.05), with the influence of age and gender being synergistic (P<0.05). In rectal cancer, the maximum tolerable volume positively correlates with anal resting pressure and negatively with the rectoanal gradient and manometric defecation index (P<0.05). This negative correlation is also observed in postoperative patients (P<0.05).

CONCLUSIONS

In patients with anorectal disorders and defecation problems, there is a significant correlation between rectal sensory abnormalities and dynamic changes induced by varying levels of rectal sensitivity, with these changes being modulated by physiological factors.

Enhancing standardization in anorectal manometry testing: the impact of a national position paper

BACKGROUND

The 2019 International Anorectal Physiology Working Group published the 'London Classification', providing recommendations for anorectal manometry (ARM) and balloon expulsion testing (BET). Despite this, the extent of guideline adoption in clinical settings was unclear. This study aimed to evaluate ARM and BET practices across Israel, identify deviations from these international guidelines, and measure the impact of a newly instated national position paper.

METHODS

In late 2020, gastroenterologists from 95% of Israeli centers performing ARM responded to a comprehensive 61-item survey. The survey highlighted discrepancies with international standards, prompting the formation of a national task force. This task force drafted a position paper incorporating international recommendations, followed by an educational course on ARM and BET. A subsequent survey assessed practice changes 1 year later.

RESULTS

Initial findings showed considerable variation in practices, including inconsistent application of the London classification, lack of standardized reference values, selective reporting on parameters like anal squeeze pressure, and differences in ARM and BET methodologies. Following the introduction of the position paper, 87% of centers altered their practices to include standardized reporting, consistent use of normal values, and uniform execution of tests like the rectoanal inhibitory reflex. Despite these improvements, variations in BET techniques persisted, particularly regarding balloon use and patient positioning.

CONCLUSION

The implementation of a national position paper and subsequent educational initiatives markedly enhanced the standardization of ARM and BET procedures in Israel, demonstrating the value of targeted educational and policy interventions in harmonizing medical practices with established international guidelines.

Frequency of detection of dyssynergic defecation in patients with overlap syndrome of functional disorders of the digestive organs associated with constipation

Introduction. The presence of dyssynergic defecation in a cohort of patients with overlap syndrome of functional disorders is poorly studied.

Aim. To assess the motor function and sensitivity parameters of the anorectal zone, to identify dyssynergic defecation and to analyze the frequency of correlation in patients with overlap syndrome of functional gastrointestinal disorders associated with constipation.

Materials and methods. A one-stage examination was conducted in four parallel groups. The study included 100 patients aged 30 to 40 years with the following diagnoses: constipation-p redominance irritable bowel syndrome (IBS-C) (group 1), IBS-C combined with functional dyspepsia (group 2), IBS-C combined with functional biliary disorder (group 3) and healthy volunteers (group 0). All patients underwent a balloon expulsion test and high-resolution anorectal manometry to determine the presence of dyssynergic defecation.

Results. Based on the analysis of parameters according to anorectal manometry data, dyssynergic defecation was not detected in group 0, in group 1 dyssynergic defecation was detected in 8 people – 32.0% (95% CI 12.3–51.6), in group 2 – in 14 people – 56.0% (95% CI 35.0–76.9), in group 3 – in 16 people – 64.0% (95% CI 43.7–84.2). A negative evacuation test was detected in 8 (32%) patients in group 1, in 14 (56%) patients in group 2, and in 17 (68%) patients in group 3, which confirmed the presence of dyssynergic defecation.

Conclusions. This study demonstrated the presence of dyssynergic defecation in three groups of subjects, more often with a combination of irritable bowel syndrome with predominant constipation with functional dyspepsia, and most often with a functional disorder of the gallbladder.

The Clinical Utility of Anorectal Manometry: A Review of Current Practices

Anorectal manometry (ARM) is a diagnostic test that utilizes pressure sensors to dynamically measure intraluminal anal and rectal pressures, thus providing an objective evaluation of anorectal functional parameters (tone, contractility, and relaxation), coordination and reflex activity, and sensation. ARM is a useful test for numerous indications including for the assessment and management of functional anorectal disorders such as fecal incontinence, functional defecatory disorders, and functional anorectal pain, preoperative assessment of anorectal function, and in facilitating/assessing response to biofeedback training. In addition, while many functional anorectal disorders present with overlapping symptoms (ie constipation, anorectal pain), ARM allows delineation of more specific disease processes and may guide treatment more effectively. In recent years the development of advanced manometric methodologies such as high-resolution anorectal manometry has also led to improved spatial resolution of data acquisition, further increasing the potential for the expansion of ARM. However, despite its ability to provide detailed information on anorectal and pelvic floor muscle function and synergy as well as the endorsements of several national and international organizations, ARM is still infrequently utilized in clinical practice. The purpose of this review is to address the current clinical applications and limitations of ARM for various disorders of the lower gastrointestinal tract. In so doing, we will provide clinicians with a framework for the use of ARM in clinical practice. This review will also discuss potential barriers to widespread adoption of ARM in clinical practice and propose possible solutions to these challenges.

Effect of neoadjuvant chemoradiation on anorectal function assessed with anorectal manometry: A systematic review and meta-analysis

AIM

Improvement in oncological survival for rectal cancer increases attention to anorectal dysfunction. Diagnostic questionnaires can evaluate quality of life but are subjective and dependent on patients' compliance. Anorectal manometry can objectively assess the continence mechanism and identify functional sphincter weakness and rectal compliance. Neoadjuvant chemoradiotherapy is presumed to affect anorectal function. We aim to assess anorectal function in rectal cancer patients who undergo total mesorectal excision, with or without neoadjuvant chemoradiation, using anorectal manometry measurements.

METHOD

MEDLINE, Embase, and Cochrane databases were searched for studies comparing perioperative anorectal manometry between neoadjuvant chemoradiation and upfront surgery for rectal cancers. Primary outcomes were resting pressure, squeeze pressure, sensory threshold volume and maximal tolerable volume.

RESULTS

Eight studies were included in the systematic review, of which seven were included for metanalysis. 155 patients (45.3%) had neoadjuvant chemoradiation before definitive surgery, and 187 (54.6%) underwent upfront surgery. Most patients were male (238 vs. 118). The standardized mean difference of mean resting pressure, mean and maximum squeeze pressure, maximum resting pressure, sensory threshold volume, and maximal tolerable volume favored the upfront surgery group but without statistical significance.

CONCLUSION

Currently available evidence on anorectal manometry protocols failed to show any statistically significant differences in functional outcomes between neoadjuvant chemoradiation and upfront surgery. Further large-scale prospective studies with standardized neoadjuvant chemoradiation and anorectal manometry protocols are needed to validate these findings.

Comparison of etiological and physiological characteristics of fecal incontinence in men and women

Fecal incontinence (FI) is often underreported and underestimated in men. Our aims were to clarify the causes and the physiological characteristics of FI in men and to underline the differences between etiological and physiological factors in men and women diagnosed with FI. The study cohort encompassed 200 men and 200 women who underwent anatomical and physiological evaluation for FI in a tertiary referral center specializing in pelvic floor disorders. All patients underwent endoanal ultrasound and anorectal manometry. Evacuation proctography was performed in some patients. Demographic, medical, anatomical, and physiological parameters were compared between the two study groups. Urge incontinence was the most frequent type of FI in both genders. In men, anal fistula, history of anal surgeries, rectal tumors, and pelvic radiotherapy were common etiologic factors, whereas history of pelvic surgeries was more common in women. Associated urinary incontinence was reported more frequently by women. External anal sphincter defects, usually anterior, were more common in women (M: 1.5%, F: 24%, P < 0.0001), whereas internal anal sphincter defect prevalence was similar in men and women (M: 6%, F: 12%, P = 0.19). Decreased resting and squeeze pressures were less common in men (M: 29%, F: 46%, P < 0.0001: M: 44%, F: 66%, P < 0.0001). The incidence of rectal hyposensitivity was higher in men (M: 11.1%, F: 2.8%, P < 0.0001), whereas rectal hypersensitivity was higher in women (M: 5.8%, F: 10.8%, P < 0.0001). Anorectal dyssynergia was more common in men (M: 66%, F: 37%, P < 0.0001). Significantly different etiological factors and physiological characteristics for FI were found in men. Acknowledging these differences is significant and may yield better treatment options.NEW & NOTEWORTHY Fecal incontinence (FI) in men has different etiological factors when compared with women. The prevalence of internal anal sphincter defect among men with FI was similar to women. Different manometric measurements were found among men with FI: decreased anal pressures were less common among men, whereas rectal hyposensitivity and anorectal dyssynergia were more common among men.

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.

High-resolution anorectal manometry for diagnosing obstructed defecation syndrome associated with moderate rectocele compared to healthy individuals

BACKGROUND

Few studies have investigated healthy female individuals (HFI) and those with obstructed defecation syndrome associated with moderate rectocele in women (MRW), identified using three-dimensional high-resolution anorectal manometry (3D HRAM) parameters that correlate with age stratification.

OBJECTIVE

We aimed to explore the clinical diagnostic values of the MRW and HFI groups using 3D HRAM parameters related to age stratification.

METHODS

A prospective non-randomized controlled trial involving 128 cases from the MRW (treatment group, 68 cases) and HFI (control group, 60 cases) groups was conducted using 3D HRAM parameters at Tianjin Union Medical Center between January 2017 and June 2022, and patients were divided into two subgroups based on their ages: the ≥50 and < 50 years subgroups.

RESULTS

Multivariate binary logistic regression analysis showed that age (P = 0.024) and rectoanal inhibitory reflex (P = 0.001) were independent factors affecting the disease in the MRW group. Compared to the HFI group, the receiver operating characteristic (ROC) curve demonstrated that the 3D HRAM parameters exhibited a higher diagnostic value for age (Youden index = 0.31), urge to defecate (Youden index = 0.24), and rectoanal pressure differential (Youden index = 0.21) in the MRW group.

CONCLUSIONS

Compared to the HFI group, the ROC curve of the 3D HRAM parameters suggests that age, urge to defecate, and rectoanal pressure differential in the MRW group have a significant diagnostic value. Because the Youden index is lower, 3D HRAM cannot be considered the gold standard method for diagnosing MRW.

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.

Rectal Prolapse Pathological Features: Findings in Patients With Outlet Obstruction Treated With Stapled Transanal Rectal Resection

BACKGROUND

Obstructed defecation syndrome is a common multifactorial disease for which treatment is based primarily on clinic presentation for the lack of reliable instrumental and anatomopathological criteria.

OBJECTIVE

The study aimed to analyze the pathological findings of the resected rectal specimens after stapled transanal rectal resection in patients affected by outlet obstruction.

DESIGN

Retrospective cohort study.

SETTINGS

University hospital.

PATIENTS

Patients who underwent rectal resection for obstructed defecation syndrome due to internal rectal prolapse were included.

INTERVENTIONS

Specimens of patients with obstructed defecation syndrome were analyzed through conventional histology and morphometric image analysis and compared with those of rectal specimens excised for oncological diseases.

MAIN OUTCOME MEASURES

Analysis of the anatomopathological impairments underlying rectal prolapse.

RESULTS

From January 2017 to December 2020, 46 specimens from the stapled transanal rectal resection group were compared with 40 specimens from the control group. In the stapled transanal rectal resection group, conventional histology revealed 34 samples (73.9%) had moderate- to severe-grade fibrosis with moderate-grade nerve degeneration in 33 cases (71.7%). In the control group, conventional histology revealed the absence of fibrosis in 31 specimens (77.5%), whereas the absence of nerve degeneration was detected in 37 specimens (92.5%). In the stapled transanal rectal resection group, morphometric image analysis showed severe-grade fibrosis in 25 cases (54.4%) compared to only low-grade fibrosis in 11 cases (27.5%).

LIMITATIONS

The small sample size and the retrospective design of the study were limitations. Moreover, there was no chance to use specimens from healthy volunteers as the control group.

CONCLUSIONS

Stapled transanal rectal resection specimens showed a higher rate of fibrosis and nerve dysplasia, an important parameter that is typically not considered preoperatively and could lead patients with rectal prolapse to the best treatment approach. See Video Abstract at http://links.lww.com/DCR/B928 .

CARACTERSTICAS ANATOMOPATOLGICAS EN EL PROLAPSO DE RECTO HALLAZGOS EN PACIENTES CON OBSTRUCCIN DEL TRACTO DE SALIDA TRATADOS CON RESECCIN RECTAL TRANSANAL CON GRAPAS

ANTECEDENTES:El síndrome de obstrucción del tracto de salida, es una afección multifactorial común, cuyo tratamiento está basado principalmente en la presentación clínica, ésto, debido a la falta de criterios confiables tanto instrumentales como anatomopatológicos.OBJETIVO:Analizamos los hallazgos histopatológicos de las piezas de resección rectal obtenidas por vía transanal mediante grapas, realizadas en pacientes que presentaban obstrucción del tracto de salida.DISEÑO:Este fue un estudio de cohorte retrospectivo.AJUSTE:El escenario fue un hospital universitario.PACIENTES:Aquellos sometidos a resección rectal por síndrome obstructivo del tracto de salida causada por un prolapso rectal interno.INTERVENCIONES:Los especímenes de pacientes con síndrome obstructivo defecatorio fueron analizados mediante histología convencional y análisis de imágenes morfométricas, comparados con especímenes rectales resecados por enfermedad oncológica.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario se concentró en la investigación de las deficiencias anatomopatológicas subyacentes del prolapso rectal interno.RESULTADOS:Desde enero de 2017 hasta diciembre de 2020, se compararon 46 especímenes del grupo de resección rectal transanal con grapas con 40 especímenes del grupo de control. En histología convencional, el grupo de resección rectal transanal con grapas, 34 muestras (73,9%) presentaron un grado de fibrosis moderada-severa con un grado moderado de degeneración neurógena en 33 casos (71,7%). En el grupo control, la histología convencional reveló ausencia de fibrosis en 31 especímenes (77,5 %), mientras que la ausencia de degeneración neurógena se detectó en 37 controles (92,5 %). En el grupo de resección rectal transanal con grapas, el análisis de imágenes morfométricas mostró fibrosis moderada y fibrosis severa en 19 (41,3%) y 25 (54,4%) casos, respectivamente. En el grupo control, el análisis de imágenes morfométricas mostró solo un bajo grado de fibrosis en 11 casos (27,5%). Se encontró una diferencia significativa en todos los grados de fibrosis y displasia neurógena entre los grupos en las evaluaciones de análisis de imagen morfométrica e histología convencional (p < 0,001).LIMITACIONES:El pequeño tamaño de la muestra y el diseño retrospectivo del estudio. Además, no existe la posibilidad de utilizar un grupo de control con muestras de voluntarios sanos.CONCLUSIONES:Los especímenes de resección rectal transanal con grapas mostraron una mayor tasa de fibrosis y displasia neurógena, parámetro importante que actualmente no está considerado antes de la operación y en un futuro muy cercano podría orientar a los pacientes con prolapso rectal interno hacia un mejor enfoque de tratamiento. Consulte Video Resumen en http://links.lww.com/DCR/B928 . (Traducción-Dr. Xavier Delgadillo ).

Ethnic Differences in Anorectal Manometry Findings in Patients With Fecal Incontinence: Results From a Multiethnic Cohort According to the London Classification

BACKGROUND/AIMS

Clinical rates of fecal incontinence (FI) are known to vary based on race and ethnicity. It is unclear if anorectal manometry (ARM) findings in patients with FI differ based on ethnicity.

METHODS

High-resolution ARM studies performed between 2014-2021 due to FI at 2 hospitals with multiethnic populations were retrospectively reviewed.

RESULTS

Four hundred and seventy-nine subjects were included--87 (18.2%) Arab Israelis, 76 (15.9%) immigrants from the former Soviet Union, and 316 (66.0%) Jewish Israelis. Median age was 67 years old (76.0% women: 90.4% were parous). The Arab Israeli group had higher rates of smoking, diabetes, and obesity. Over 95% of ARM's were abnormal per the London classification including 23% with "combined anal hypotension and hypocontractility," 36% with "anal normotension with anal hypocontractility," 67% with "dyssynergia," and 65% with either "rectal hyposensation" or "borderline rectal hyposensation." On univariate analyses, significant differences between the ethnic groups were noted in the rates of "anal hypotension with normal contractility," "combined anal hypotension with anal hypocontractility," and "dyssynergia." In multivariate logistic regression analyses controlling for age, gender, parity, smoking, diabetes, and obesity, the Arab Israeli group remained several times more likely to have "combined anal hypotension and hypocontractibility" compared to the other groups.

CONCLUSIONS

Ethnicity impacts ARM findings in patients with FI. The reason for this is unclear and future studies on ethnically diverse populations evaluating the clinical relevance of these findings are warranted.

State of the Art Bowel Management for Pediatric Colorectal Problems: Functional Constipation

BACKGROUND

Functional constipation (FC) affects up to 32% of the pediatric population, and some of these patients are referred to pediatric surgery units to manage their constipation and/or fecal incontinence. The aim of the current paper is to report the recent updates on the evaluation and management of children with FC as a part of a manuscript series on bowel management in patients with anorectal malformations, Hirschsprung disease, spinal anomalies, and FC.

METHODS

A literature search was performed using Medline/PubMed, Google Scholar, Cochrane, and EMBASE databases and focusing on the manuscripts published within the last 5-10 years.

RESULTS

The first step of management of children with FC is to exclude Hirschsprung disease with a contrast study, examination under anesthesia, anorectal manometry (AMAN). If AMAN shows absent rectoanal inhibitory reflex, a rectal biopsy is performed. Internal sphincter achalasia or high resting pressures indicate botulinum toxin injection. Medical management options include laxatives, rectal enemas, transanal irrigations, and antegrade flushes. Those who fail conservative treatment require further assessment of colonic motility and can be candidates for colonic resection. The type of resection (subtotal colonic resection vs. Deloyer's procedure) can be guided with a balloon expulsion test.

CONCLUSION

Most of the patients with FC referred for surgical evaluation can be managed conservatively. Further studies are required to determine an optimal strategy of surgical resection in children unresponsive to medical treatment.

Using a footstool does not aid simulated defecation in undifferentiated constipation: A randomized trial

INTRODUCTION

The use of a footstool has been advocated to optimize posture when sitting on the toilet and thus facilitate bowel evacuation. We aimed to assess the alterations in defecatory posture, and the changes in simulated defecation with use of a footstool in patients with constipation.

METHODS

Forty-one patients (female 93%, mean 52 year, SD 14 year) with constipation referred to a tertiary neurogastroenterology unit were enrolled. A bowel questionnaire, Hospital Anxiety and Depression Scale, and Rome questionnaire were administered prior to anorectal manometry. Each patient underwent three rectal balloon expulsion tests in randomized order with no footstool, a 7-inch, and a 9-inch footstool. Additional assessments included angle between spine and femur, and visual analogue scales assessing ease of evacuation, urge to defecate, and discomfort with expulsion.

KEY RESULTS

Defecatory posture was significantly altered by footstool use, with progressive narrowing of the angle between the spine and femur as footstool height increased (p < 0.001 for all comparisons). Compared with no footstool, the use of a footstool was not associated with a change in balloon expulsion time and there was no difference between the two footstool heights. Subjectively, no significant change was identified in any of the three perceptions of balloon expulsion between no footstool and footstool use.

CONCLUSIONS AND INFERENCES

Although the use of a footstool led to changes in defecatory posture, it did not improve subjective or objective measures of simulated defecation in patients with undifferentiated constipation. Therefore, the recommendation for its use during evacuation cannot be applied to all patients with constipation.

Dyssynergic Defecation: A Comprehensive Review on Diagnosis and Management

About one-third of chronically constipated patients have an evacuation disorder, and dyssynergic defecation is a common cause of the evacuation disorder. In dyssynergic defecation, the coordination between abdominal and pelvic floor muscles during defecation is disrupted and patients cannot produce a normal bowel movement. The etiology of dyssynergic defecation is still unknown. Although a detailed history taking and a careful examination including digital rectal examination could be useful, other modalities such as anorectal manometry and balloon expulsion test are necessary for the diagnosis. Biofeedback therapy is one of the most effective and safe treatments. Here, we provide an overview of dyssynergic defecation as well as how to diagnose and manage this condition.

To what extent are anorectal function tests comparable? A study comparing digital rectal examination, anal electromyography, 3-dimensional high-resolution anal manometry, and transperineal ultrasound

BACKGROUND

Anorectal function tests are helpful for objective investigation of anorectal (dys)function. A variety of tests are available, but there is no recommendation when to perform which test. Furthermore, which test is the most accurate is controversial and the correlation between these tests is not very clear. The aim of our study was to examine the correlation of anal pressures and the possibility to diagnose pelvic floor dyssynergia between digital rectal examination (DRE) and several anorectal function tests.

METHODS

Between January 2020 and April 2022, all men and women aged 18 to 80 years, treated at the Proctos Clinic, who were referred for pelvic floor physical therapy (PFPT) by the surgeon and underwent anorectal function tests, were included. DRE was performed to establish the anal pressure at rest and during squeeze and straining. Anorectal function tests included 3D high-resolution anal manometry (3D-HRAM), balloon expulsion test (BET), transperineal ultrasound (TPUS), and surface electromyography (s-EMG).

RESULTS

A total of 50 patients, 37 (74%) females, were included. Median age was 51 years. Twenty-three (62%) females had a history of two or more vaginal deliveries. The most frequent reason for referral for PFPT was fecal incontinence in 27 (54%) patients. The assessed pressures and pelvic floor function measured with DRE by the surgeon and the pelvic floor physical therapist during rest, squeeze, and straining correlated in 78%, 78%, and 84%, respectively. Correlation between DRE and 3D-HRAM or s-EMG was better for squeeze pressures than resting pressures. The correlation between s-EMG and 3D-HRAM was better during squeeze than at rest with an agreement of 59% and 37%, respectively.

CONCLUSION

DRE by an experienced investigator is of sufficient value for daily clinical practice to detect dyssynergia and to measure sphincter tone. Commonly performed anorectal function tests correlate poorly with DRE and with other anorectal function tests. When conservative treatment fails, further investigation is warranted; however, these results should be interpreted with caution. WHAT DOES THIS PAPER ADD TO THE LITERATURE?: Anorectal function tests such as the 3D high-resolution anorectal manometry, balloon expulsion test, surface electromyography, and transperineal ultrasound are all frequently performed in the diagnostic workup in patients with defecation disorders. No previous study has compared these tests regarding their outcomes, nor has the interrater agreement been measured regarding the digital rectal examination by two experienced observers. Furthermore, transperineal ultrasound is in all probability not frequently used and therefore underexposed in the diagnostic workup of patients with dyssynergic defecation.

Novel insights into physiological mechanisms underlying fecal continence

The machinery maintaining fecal continence prevents involuntary loss of stool and is based on the synchronized interplay of multiple voluntary and involuntary mechanisms, dependent on cooperation between motor responses of the musculature of the colon, pelvic floor, and anorectum, and sensory and motor neural pathways. Knowledge of the physiology of fecal continence is key toward understanding the pathophysiology of fecal incontinence. The idea that involuntary contraction of the internal anal sphincter is the primary mechanism of continence and that the external anal sphincter supports continence only by voluntary contraction is outdated. Other mechanisms have come to the forefront, and they have significantly changed viewpoints on the mechanisms of continence and incontinence. For instance, involuntary contractions of the external anal sphincter, the puborectal muscle, and the sphincter of O'Beirne have been proven to play a role in fecal continence. Also, retrograde propagating cyclic motor patterns in the sigmoid and rectum promote retrograde transit to prevent the continuous flow of content into the anal canal. With this review, we aim to give an overview of primary and secondary mechanisms controlling fecal continence and evaluate the strength of evidence.

Effects of Aging and Gender on the Anorectal Function of Healthy Subjects Assessed with Conventional Anorectal Manometry

Background/Aims

Anorectal functions are influenced by gender and age. This study sought to define the normal anorectal pressure values measured with conventional anorectal manometry (ARM) and to evaluate the effects of age and gender on anorectal function in asymptomatic subjects.

Methods

Conventional ARM was used to measure the anorectal pressures of 164 asymptomatic healthy subjects, including 86 males and 76 females.

Results

The resting anal pressures of males and females aged >60 years were significantly lower than those ≤60 years (males, 44.09±14.22 vs. 57.45±17.69, p<0.001; females, 44.09±14.22 vs. 57.45±17.69, p<0.001). The anal high-pressure zone was significantly lower in older males than in younger males (2.42±0.93 vs. 2.82±0.739, p=0.048). In both age groups (<60 and ≥60 years), the anal squeezing pressures of males were significantly higher than those of females (<60 years old, 168.40±75.94 vs. 119.15±57.53, p=0.001; ≥60 years, 149.61±64.68 vs. 101.3±54.92, p=0.006).

Conclusions

The normal anorectal pressure values measured with ARM in males and females were different. Older males and females had lower anal resting pressures than those of the younger subjects, but squeezing pressure was not affected by age.

Predicting Responsiveness to Biofeedback Therapy Using High-resolution Anorectal Manometry With Integrated Pressurized Volume

BACKGROUND/AIMS

Biofeedback therapy is widely used to treat patients with chronic constipation, especially those with dyssynergic defecation. Yet, the utility of high-resolution manometry with novel parameters in the prediction of biofeedback response has not been reported. Thus, we constructed a model for predicting biofeedback therapy responders by applying the concept of integrated pressurized volume in patients undergoing high-resolution anorectal manometry.

METHODS

Seventy-one female patients (age: 48-68 years) with dyssynergic defecation who underwent initial high-resolution anorectal manometry and subsequent biofeedback therapy were enrolled. The manometry profiles were used to calculate the 3-dimensional integrated pressurized volumes by multiplying the distance, time, and amplitude during simulated evacuation. Partial least squares regression was performed to generate a predictive model for responders to biofeedback therapy by using the integrated pressurized volume parameters.

RESULTS

Fifty-five (77.5%) patients responded to biofeedback therapy. The responders and non-responders did not show significant differences in the conventional manometric parameters. The partial least squares regression model used a linear combination of eight integrated pressurized volume parameters and generated an area under the curve of 0.84 (95% confidence interval: 0.76-0.95, P < 0.01), with 85.5% sensitivity and 62.1% specificity.

CONCLUSIONS

Integrated pressurized volume parameters were better than conventional parameters in predicting the responsiveness to biofeedback therapy, and the combination of these parameters and partial least squares regression was particularly promising. Integrated pressurized volume parameters can more effectively explain the physiology of the anorectal canal compared with conventional parameters.

Anorectal volume-pressure relations, contraction work, and flow during defecation

Fecobionics is an integrated device that has shown promise for assessment of anorectal function. We used a wireless Fecobionics prototype to visualize defecatory patterns and to compute volume-pressure, contraction work, and flow. Twelve normal subjects were studied. The probe was 10 cm-long and contained pressure sensors and electrodes for impedance planimetry. Pressures, diameters, and volume data during defecation were analyzed. The bag was distended inside rectum to the urge-to-defecate level where after the subjects were asked to evacuate. The contraction work and defecatory flow were computed from the volume changes during expulsion. The minimum anal diameter during the evacuation was 17.6 ± 1.5 mm. The middle diameter recording was 10-20% lower than the front diameter channels and 10-20% bigger than the rear channels. The bag volume at urge correlated with the minimum diameter (r = 0.63). The diameter-pressure and volume-pressure loops were counterclockwise with phases of bag filling, isometric contraction, ejection and anal passage. The defecatory contraction work was 3520 ± 480 mL × cmH2O. The maximum flow during defecation was 302 ± 33 mL/s. The flow was associated with the anal diameter (r = 0.84) but not with the rectoanal pressure gradient (r = 0.14). Volume-pressure loops have a tremendous impact on the understanding of cardiopulmonary pathophysiology. Future studies will shed light on potential clinical impact in defecatory pathophysiology.

Optimizing techniques for measuring anal resting and squeeze pressures with high-resolution manometry

BACKGROUND

The optimal methods for measuring and analyzing anal resting and squeeze pressure with high-resolution manometry (HRM) are unclear.

METHODS

Anal resting and squeeze pressures were measured with HRM in 90 healthy women, 35 women with defecatory disorders (DD), and 85 with fecal incontinence (FI). Pressures were analyzed with Manoview™ software and a customized approach. Resting pressures measured for 20, 60, and 300 s were compared. During the squeeze period, (3 maneuvers, 20 s each), the squeeze increment, which was averaged over 5, 10, 15, and 20 s, and squeeze duration were evaluated.

RESULTS

Compared to healthy women, the anal resting pressure, squeeze pressure increment, and squeeze duration were lower in FI (p ≤ 0.04) but not in DD. The 20, 60, and 300 s resting pressures were strongly correlated (concordance correlation coefficients = 0.96-0.99) in healthy and DD women. The 5 s squeeze increment was the greatest; 10, 15, and 20 s values were progressively lower (p < 0.001). The squeeze pressure increment and duration differed (p < 0.01) among the three maneuvers in healthy and DD women but not in FI women. The upper 95th percentile limit for squeeze duration was 19.5 s in controls, 19.9 s in DD, and 19.3 s in FI. Adjusted for age, resting pressure, and squeeze duration, a greater squeeze increment was associated with a lower risk of FI versus health (OR, 0.96; 95% CI, 0.94-0.97).

CONCLUSIONS

These findings suggest that anal resting and squeeze pressures can be accurately measured over 20 s. In most patients, one squeeze maneuver is probably sufficient.

Feasibility study of defecation studied with a wireless Fecobionics probe in normal subjects

Several technologies have been developed for assessing anorectal function including the act of defecation. We used a new prototype of the Fecobionics technology, a multi-sensor simulated feces, to visualize defecatory patterns and introduced new metrics for anorectal physiology assessment in normal subjects. Fourteen subjects with normal fecal incontinence and constipation questionnaire scores were studied. The 10-cm-long Fecobionics device provided measurements of axial pressures, orientation, bending, and shape. The Fecobionics bag was distended to the urge-to-defecate level inside rectum where after the subjects were asked to evacuate. Physiological evacuation parameters were assessed. Special attention was paid to the Fecobionics rectoanal pressure gradient (F-RAPG) during evacuation. Anorectal manometry (ARM) and balloon expulsion test (BET) were done as references. The user interface displayed the fine coordination between pressures, orientation, bending angle, and shape. The pressures showed that Fecobionics was expelled in 11.5 s (quartiles 7.5 and 18.8s), which was shorter than the subjectively reported expulsion time of the BET balloon. Six subjects did not expel the BET balloon within 2 min. The F-RAPG was 101 (79-131) cmH₂ O, whereas the ARM-RAPG was -28 (-5 to -47) cmH₂ 0 (p < 0.001). There was no association between the two RAPGs (r²  = 0.19). Fecobionics showed paradoxical contractions in one subject (7%) compared to 12 subjects with ARM (86%). Fecobionics obtained novel physiological data. Defecatory patterns and data are reported and can be used to guide larger-scale studies in normal subjects and patients with defecatory disorders. In accordance with other studies, this Fecobionics study questions the value of the ARM-RAPG.

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.

Manometric parameters, when measured with the 3-dimensional high-definition anorectal manometry probe, poorly predict prolonged balloon expulsion time

BACKGROUND

There are little data evaluating the performance of the 3-dimensional high-definition anorectal manometry (3D-HDAM) system in the diagnosis of dyssynergic defecation. Physical properties of the thicker, rigid, 3D-HDAM probe may have implications on the measurements of anorectal pressures.

AIM

Our aim was to compare 3D-HDAM to balloon expulsion test and magnetic resonance (MR) defecography.

METHODS

Consecutive constipated patients referred for anorectal function testing at the Calgary Gut Motility Centre (Calgary, Canada) between 2014 and 2019 were assessed. All patients underwent anorectal manometry with the 3D-HDAM probe, and a subset underwent BET or MR defecography. Anorectal manometric variables were compared between patients who had normal and abnormal BET.

RESULTS

Over the study period, 81 patients underwent both 3D-HDAM and BET for symptoms of constipation. 52 patients expelled the balloon within 3 minutes. Patients with abnormal BET had significantly lower rectoanal pressure differential (RAPD) (-61 vs. -31 mmHg for normal BET, p = 0.03) and defecation index (0.29 vs. 0.56, p = 0.03). On logistic regression analysis, RAPD (OR: 0.99, 95% CI: 0.97-0.99, p = 0.03) remained a negative predictor of abnormal BET. On ROC analysis, RAPD had an AUC of 0.65. There was good agreement between dyssynergic patterns on 3D-HDAM and defecographic evidence of dyssynergia (sensitivity 80%, specificity 90%, PLR 9, NLR 0.22, accuracy 85%).

CONCLUSIONS

Manometric parameters, when measured with the 3D-HDAM probe, poorly predict prolonged balloon expulsion time. RAPD remains the best predictor of prolonged balloon expulsion time. The 3D-HDAM probe may not be the ideal tool to diagnose functional defecatory disorders.

Anorectal dysfunction in multiple sclerosis patients: A pilot study on the effect of an individualized rehabilitation approach

BACKGROUND:

Anorectal dysfunction (ARD), especially bowel incontinence, frequently compromises the quality of life in multiple sclerosis (MS) patients. The effect of rehabilitation procedures has not been clearly established.

OBJECTIVE:

To determine the effect of an individualized rehabilitation approach on bowel incontinence and anorectal pressures.

METHODS:

MS patients with ARD underwent 6-months of individually targeted biofeedback rehabilitation. High resolution anorectal manometry (HRAM) and St. Mark’s Fecal Incontinence Scores (SMIS) were completed prior to rehabilitation, after 10 weeks of supervised physiotherapy, and after 3 months of self-treatment.

RESULTS:

Ten patients (50%) completed the study. Repeated measures analysis of variance (ANOVA) demonstrated significant improvement in the SMIS questionnaire over time [14.00 baseline vs. 9.70 after supervised physiotherapy vs. 9.30 after self-treatment (p = 0.005)]. No significant improvements over time were noted in any HRAM readings: maximal pressure [49.85 mmHg baseline vs. 57.60 after supervised physiotherapy vs. 60.88 after self-treatment (p = 0.58)], pressure endurance [36.41 vs. 46.89 vs. 49.95 (p = 0.53)], resting pressure [55.83, vs 52.69 vs. 51.84 (p = 0.704)], or area under the curve [230.0 vs. 520.8 vs. 501.9 (p = 0.16)].

CONCLUSIONS:

The proposed individualized rehabilitation program supports a positive overall effect on anorectal dysfunction in MS patients.

Anorectal manometry to diagnose dyssynergic defecation: Systematic review and meta-analysis of diagnostic test accuracy

BACKGROUND

Chronic constipation is a common condition, and dyssynergic defecation underlies up to 40% of cases. Anorectal manometry is recommended to assess for dyssynergic defecation among chronically constipated patients but remains poorly standardized. We aimed to evaluate the diagnostic accuracy of anorectal manometry and determine optimal testing parameters.

METHODS

We performed a systematic review with meta-analysis of diagnostic test accuracy including cohort studies of chronically constipated patients and case-control studies of patients with dyssynergic defecation or healthy controls. Meta-analysis was performed to determine summary sensitivity, specificity, and area under the curve (AUC) with 95% confidence intervals (CI).

KEY RESULTS

A total of 15 studies comprising 2140 patients were included. Including all studies (estimating optimal diagnostic accuracy), the AUC was 0.78 [95% CI 0.72-0.82], summary sensitivity was 79% [61%-90%], and summary specificity was 64% [44%-79%] to diagnose dyssynergic defecation. In cohort studies only (estimating real-world diagnostic accuracy), the AUC was 0.72 [0.66-0.77], summary sensitivity was 86% [64%-95%], and summary specificity was 49% [30%-68%]. Employing three consecutive simulated defecation attempts improved sensitivity to 94%. A fourth simulated defecation maneuver with air insufflation may improve accuracy. Measuring anorectal pressures to identify complex dyssynergic patterns did not improve real-world diagnostic accuracy estimates over anal pressure measurement alone. Choice of manometry system did not impact diagnostic accuracy.

CONCLUSIONS & INFERENCES

Following the current iteration of the London consensus protocol (three simulated defecation attempts measuring anal relaxation), the role of anorectal manometry in evaluating dyssynergic defecation appears limited. Future iterations of this protocol may improve diagnostic accuracy.

Understanding the physiology of human defaecation and disorders of continence and evacuation

The act of defaecation, although a ubiquitous human experience, requires the coordinated actions of the anorectum and colon, pelvic floor musculature, and the enteric, peripheral and central nervous systems. Defaecation is best appreciated through the description of four phases, which are, temporally and physiologically, reasonably discrete. However, given the complexity of this process, it is unsurprising that disorders of defaecation are both common and problematic; almost everyone will experience constipation at some time in their life and many will develop faecal incontinence. A detailed understanding of the normal physiology of defaecation and continence is critical to inform management of disorders of defaecation. During the past decade, there have been major advances in the investigative tools used to assess colonic and anorectal function. This Review details the current understanding of defaecation and continence. This includes an overview of the relevant anatomy and physiology, a description of the four phases of defaecation, and factors influencing defaecation (demographics, stool frequency/consistency, psychobehavioural factors, posture, circadian rhythm, dietary intake and medications). A summary of the known pathophysiology of defaecation disorders including constipation, faecal incontinence and irritable bowel syndrome is also included, as well as considerations for further research in this field.

Diagnosis of Functional Gastrointestinal Disorders and Choice of Treatment Regimen in Constipation Patients

Aim. A practical review of functional gastrointestinal disorder diagnosis in constipation patients and the rationale for opting treatment.

Key points. Functional constipation commonly afflicts different ages and negatively impacts the quality of life. The current diagnostic algorithm in chronic constipation includes the disease identification according to Rome Criteria IV, red-flag symptom detection and instrumental laboratory examination. Functional constipation is notably often associated with anorectal abnormalities that bear a diagnostic value to elaborate an apt treatment strategy. Anorectal manometry, rectal sensation and balloon expulsion tests are the well-studied and significant probing techniques for objective anorectal zone sensorimotor function assessment in patients with functional constipation. The article reviews modern diagnostic methods in functional defecation disorders.

Conclusion. The examination and treatment algorithms presented will help improve diagnosis and apply the most suitable management in a constipation-associated functional digestive pathology.

Do Age and Sex Influence Anorectal Manometry Parameters?

Background

High-resolution anorectal manometry (HRM) is widely used in the evaluation of anal incontinence and constipation, which become increasingly prevalent with age. However, the impact of age and comorbidities on physiological digestive parameters remains poorly understood. In this study, we aimed to evaluate the effect of age on anorectal function.

Methods

We conducted a retrospective study on patients at our digestive motility clinic between January 2016 and May 2019. All patients with a normal HRM were included. Clinical data and HRM parameters were collected in a database. Multivariate regression analyses were performed to evaluate the effects of age, sex, medical comorbidities and obstetric history on anorectal HRM parameters.

Key Results

One hundred and forty-four patients were included (mean age: 53 ± 16 years, 72% females). The main indications for anorectal HRM were incontinence (44%), constipation (37%) and anorectal pain (9%). Age was significantly associated with higher maximum tolerable volume (β = +0.48 mL year^-1, P = 0.04) and higher rectal compliance (β = +0.04 mL year^-1, P = 0.01). Independently from age and medical comorbidities, female demonstrated significantly lower mean endurance squeeze pressure (β = −44.4 mmHg, P < 0.001), maximal squeeze pressure (β = −62.3 mmHg; P < 0.001), volume at first urge (β = −16.7 mL, P = 0.02) and maximum tolerable volume (β = −16.1 mL, P = 0.046). Vaginal birth was associated with lower tolerable maximum pressure (β = −39.4 mmHg, P = 0.046).

Conclusion

Age and sex are independent factors which influence anorectal HRM parameters. These findings should be taken into consideration when interpreting anorectal HRM.

Diagnostics of functional disorders of the gastrointestinal tract in patients with constipation

The purpose of the review is to acquaint general practitioners, therapists, gastroenterologists with the possibilities of diagnosing functional disorders of the gastrointestinal tract associated with constipation, as well as to draw attention to the need for additional examination methods for a comprehensive assessment of functional disorders of the gastrointestinal tract in patients with constipation on pathogenesis.

Functional constipation is an urgent problem today due to its prevalence among different age groups, a negative impact on the quality of life, as well as the variability of the clinical forms of diseases associated with this symptom. The modern diagnostic algorithm for chronic constipation consists of several stages, including the identification of signs of the disease, according to the Rome criteria of the IV revision (2016), the identification of symptoms of “red flags” and laboratory and instrumental research. It should be borne in mind that functional constipation is often based on the pathology of the anorectal zone, which is an important factor in the diagnosis and development of further therapeutic strategies. The article provides an overview of modern and promising methods for diagnosing functional disorders of defecation, taking into account functional disorders of the anorectal zone associated with constipation.

Functional methods such as anorectal manometry, rectal sensory test and balloon expulsion test are the  most studied and obligatory tests for an objective assessment of the sensorimotor function of the anorectal zone. In Russia, these methods are used very little, which requires extensive familiarization of practitioners with the advantages of these techniques. Knowledge and application of the presented examination algorithms will help the clinician to increase the overall diagnostic efficiency and apply the most justified tactics of managing patients with functional pathology of the digestive system associated with constipation. 

Defecatory Dysfunction

Normal defecation is a complex and coordinated physiologic process that involves the rectum, anus, anal sphincter complex, and pelvic floor muscles. Any alteration of this process can be considered defecatory dysfunction, a term that covers a broad range of disorders, including slow-transit constipation, functional constipation, and functional or anatomic outlet obstruction. Evaluation should include history, physical, and consideration of additional testing such as colonoscopy, colonic transit studies, defecography, and/or anorectal manometry. Depending on the etiology, management options can include conservative measures such as dietary or lifestyle modifications, medications, pelvic floor physical therapy, or surgical repair.

Comparison of Anorectal Function as Measured with High-Resolution and High-Definition Anorectal Manometry

INTRODUCTION

Anorectal manometry (ARM) provides comprehensive assessment of pressure activity in the rectum and anal canal. Absolute pressure values might depend on the catheter used.

OBJECTIVE

Our aim was to compare the results obtained by different anorectal catheters in children with functional anorectal disorders.

METHODS

Children diagnosed with functional defecation disorders based on the Rome IV criteria were prospectively enrolled. ARM was performed in the supine position successively using 2 different probes in each patient in random order. Resting, squeeze pressures, and bear-down maneuver variables obtained by high-resolution (2-dimensional [2D]) and high-definition (3-dimensional [3D]) catheters were compared.

RESULTS

We prospectively included 100 children {mean age 7.5 [standard deviation (SD) ± 4.3] years; 62 boys}. Mean resting pressures were significantly higher when measured with the 3D than with the 2D catheter (71 [SD ± 19.4] vs. 65 [SD ± 20.1] mm Hg, respectively; p = 0.000). Intrarectal pressure measured by 3D and 2D catheters was similar (35 vs. 39 mm Hg, respectively; p = 0.761), but the percent of anal relaxation appeared to be higher for the 3D than for the 2D probe (12 vs. 5%, respectively; p = 0.002). Dyssynergic defecation (DD) was diagnosed in 41/71 patients (57.7%) using the 3D probe and in 51/71 children (71.8%) using the 2D probe (p = 0.044). Cohen's kappa showed only fair agreement between the catheters (κ = 0.40) in diagnosis of DD.

CONCLUSIONS

Our study demonstrated significantly different values of pressures obtained with different types of catheters. Normal ranges for conventional manometry cannot be applied to high-resolution systems, and results obtained by different types of manometry cannot be compared without adjustments (NCT02812823).

Normal values for high-resolution anorectal manometry in healthy young adults: evidence from Vietnam

BACKGROUND

High-resolution anorectal manometry (HRAM) has been developed to improve measurement of anorectal functions. This study aims to identify normal HRAM values in healthy young Vietnamese adults.

METHODS

We conducted a cross-sectional study at the National Hospital of Traditional Medicine (Hanoi, Vietnam) from July through December 2014. Healthy young adults were invited to participate in the study. All anorectal measurement values were performed using the ISOLAB high-resolution manometry system. Differences between groups were analyzed using Student's t-tests.

RESULTS

Thirty healthy young adults, including 15 males and 15 females aged 19-26 years, were recruited. Mean functional anal canal length was 3.4 ± 0.5 cm (range: 2.4-4.8 mm). Mean maximum resting pressure, mean maximum squeezing pressure, mean maximum coughing pressure, and mean maximum strain pressure were 65.5, 168.0, 125.9, and 84.2 mm Hg, respectively. All anal pressure values were significantly different between males and females. For rectal sensation measurements, only the volume at first sensation was significantly higher in males than in females.

CONCLUSIONS

This study provides normal HRAM value for healthy young adults in Vietnam. Sex may influence anal pressure and first rectal sensation values in this cohort. Further studies should be conducted in order to improve the quality of HRAM normal values and to confirm the effects of sex.

Rectal Distension Increased the Rectoanal Gradient in Patients with Normal Rectal Sensory Function

BACKGROUND

Frequent observation of abnormal manometric patterns consistent with dyssynergia in healthy volunteers has warranted the need for reassessment of the current methods to enhance the diagnostic value of anorectal manometry in functional defecatory disorders. Whether rectal distention at simulated evacuation will affect anorectal pressure profile and increase rectoanal gradient is not known.

METHODS

One hundred and eight consecutive patients with chronic constipation, 93 females, median age 53 years (interquartile range: 40-65), were studied. Simulated evacuation was performed firstly with empty balloon and subsequently after balloon distention to 50 and 100 ml. Anorectal pressures were compared. We also performed subgroup analysis in relation to outcome of balloon expulsion test (BET). In addition, we studied the effect of rectal distension on the rectoanal pressure gradient with respect to rectal sensory function.

RESULTS

Rectal balloon distension at simulated evacuation improved rectoanal gradient and decreased the rate of dyssynergia during high-resolution anorectal manometry. In subgroup analysis, the increase in rectoanal gradient and correction of dyssynergia with rectal distension was limited to the patients who had normal BET and normal rectal sensory function. Rate of anal relaxation, residual anal pressures, and rectoanal gradient were significantly different between patients with and without normal BET at 50 ml of rectal distension. Rectoanal gradient recorded only after rectal distension, along with BMI and maximum tolerable volumes, could predict BET results independently in patients with chronic constipation.

CONCLUSIONS

Rectal distension during simulated evacuation will affect the anorectal pressure profile. Increase in rectoanal gradient and correction of dyssynergia was only significant in patients with normal rectal sensory function and normal BET.

A multicenter study of anorectal pressures and rectal sensation measured with portable manometry in healthy women and men

BACKGROUND

The equipment and methods for performing anorectal manometry and biofeedback therapy are different and not standardized. Normal values are influenced by age and sex. Our aims were to generate reference values, examine effects of gender and age, and compare anorectal pressures measured with diagnostic and biofeedback catheters and a portable manometry system.

METHODS

In this multicenter study, anorectal pressures at rest, during squeeze, and evacuation were measured with diagnostic and biofeedback catheters using Mcompass^™ portable device in healthy subjects. Balloon expulsion time and rectal sensation were evaluated. The effects of age and gender were assessed.

RESULTS

The final dataset comprised 108 (74 women) of 124 participants with normal rectal balloon expulsion time (less than 60 s). During squeeze, anal resting pressure increased by approximately twofold in women and threefold in men. During evacuation, anal pressure exceeded rectal pressure in 87 participants (diagnostic catheter). The specific rectoanal pressures (e.g., resting pressure) were significantly correlated and not different between diagnostic and biofeedback catheters. With the diagnostic catheter, the anal squeeze pressure and rectal pressure during evacuation were greater in men than women (p ≤ 0.02). Among women, women aged 50 years and older had lower anal resting pressure; rectal pressure and the rectoanal gradient during evacuation were greater in older than younger women (p ≤ 0.01).

CONCLUSIONS

Anal and rectal pressures measured with diagnostic and biofeedback manometry catheters were correlated and not significantly different. Pressures were influenced by age and sex, providing reference values in men and women.

Anorectal manometry in pediatric settings: A systematic review of 227 studies

BACKGROUND

There is wide variation in the clinical use of diagnostic tools for children with chronic constipation and functional/structural fecal incontinence (CCFSFI). Anorectal manometry (ARM) is a well-recognized technique to assess the function of the anorectum.

PURPOSE

Our aim was to perform an up-to-date review on ARM in pediatric patients with CCFSFI, with specific focus on the indication of use and protocol. Variation of its use in pediatrics will be explored.

METHODS

A systematic search was conducted for empirical studies utilizing ARM with a pediatric sample. A keyword search of literature published in English before July 2018 was conducted and updated to October 2019. Data on demographics, clinical information, study aims, ARM parameters and use of sedation/anesthesia were collected.

KEY RESULTS

A total of 227 studies were included in this systematic review. The age of study participants at the time of ARM ranged from birth to 18 years. ARM was most commonly used in patients with organic conditions (65%) compared to functional constipation (41%). In almost half [108/227 (48%)] of the studies, ARM was performed awake. The ARM parameters most frequently assessed were the rectoanal inhibitory reflex, which was evaluated in 198/227 studies (87%) and the anal resting pressure [166/227 studies (73%)].

CONCLUSIONS AND INFERENCES

This systematic review has highlighted the vast variation of ARM use within pediatrics and the need to strive toward standardization and use of consensus guidelines. We anticipate this will further advance our understanding of the pathophysiological mechanisms involved in children with defecation disorders.

Clinical Impact of Rectal Hyposensitivity: A Cross-Sectional Study of 2,876 Patients With Refractory Functional Constipation

INTRODUCTION

Normal bowel function requires intact sensory pathways. Diminished rectal sensation (rectal hyposensitivity [RH]) is associated with constipation, although its clinical importance remains unclear.

METHODS

Consecutive patients (aged 18-80) attending a tertiary center (2004-2016) for investigation of refractory functional constipation (Rome IV core criteria defined, applied post hoc) were included. Patients completed a clinical symptom questionnaire and underwent anorectal physiologic investigations, including rectal sensory testing (balloon distension) to determine 3 well-established sensory thresholds. Multivariate regression analyses were performed to evaluate associations between RH, symptomology, and allied physiologic investigations.

RESULTS

Of 2,876 patients meeting inclusion criteria, 722 (25%) had RH based on ≥1 elevated sensory thresholds (0: n = 2,154 [74.9%]; 1: n = 327 [11.4%]; 2: n = 209 [7.3%]; and 3: n = 186 [6.5%]). A linear relationship existed between increasing number of elevated sensory thresholds and constipation severity (Cleveland Clinic constipation score: mean difference per threshold [95% confidence interval] 0.69 [0.48-0.90]; P < 0.001). Several symptoms were significantly (P < 0.05) associated with RH including: infrequent defecation (odds ratio 1.29 [1.17-1.42]), painful evacuation (1.15 [1.05-1.27]), prolonged toileting (1.14 [1.05-1.24]), and digitation or enema use (1.18 [1.08-1.30]). On defecography, a "functional" evacuation disorder was also associated with RH (1.37 [1.25-1.50], P < 0.001), as was megarectum (2.52 [2.08-3.05], P < 0.001).

DISCUSSION

RH occurs in 25% of patients with refractory functional constipation. Increased number of elevated sensory thresholds is associated with more severe constipation phenotype. These data, in the largest study to date, provide for the first time evidence to show that RH is a major pathophysiologic mechanism in constipation, with recognized clinical impact (http://links.lww.com/AJG/B765).(Equation is included in full-text article.).

Bionic measurement of defecation in a swine model

OBJECTIVE

Fecobionics was used to assess pressures, orientation, bending, shape, and cross-sectional area (CSA) changes during defecation. This study aimed to evaluate the device feasibility and performance in swine.

APPROACH

Twelve pigs had wired or wireless Fecobionics devices inserted in the rectum. The bag was distended to simulate feces in the rectum. Fecobionics data were acquired simultaneously during the whole experiment. Six pigs were euthanized immediately after the procedure for evaluation of acute injury to anorectum (acute group). The remaining pigs lived two weeks before euthanasia for evaluation of long-term tissue damage and inflammation (chronic group). Signs of discomfort were monitored.

MAIN RESULTS

All animals tolerated the experiment well. The chronic animals showed normal behavior after the procedure. Mucosal damage, bleeding, or inflammation was not found in either group. Fecobionics was defecated 1 min 35 s-61 min 0 s (median 8 min 58 s) after insertion. The defecation lasted 0 min 20 s-4 min 25 s (median 1 min 52 s). The device was almost straight inside rectum (160°-180°) but usually bended 5°-20° during contractions. The three pressure sensors showed simultaneous and identical increase during rectal or abdominal muscle contractions, indicating the location inside rectum. During defecation, the maximum rear pressure was 114.1 ± 14.3 cmH₂O whereas the front pressure gradually decreased to 0 cmH₂O, indicating the front passed anus. CSA decreased from 1017.1 ± 191.0 mm² to 530.7 ± 46.5 mm² when the probe passed from the rectum through the anal canal.

SIGNIFICANCE

Fecobionics provides defecatory measurements under physiological conditions in pigs without inducing tissue damage.

Fecal Urgency: Clinical and Manometric Characteristics in Patients With and Without Diarrhea

BACKGROUND

Fecal urgency is classically associated with diarrhea, but is also common in individuals with normal bowel habits or constipation. Its etiology, particularly in non-diarrhea individuals, is unclear.

METHODS

We examined data from 368 individuals with and without diarrhea who underwent three-dimensional high-resolution anorectal manometry and balloon expulsion test. All patients completed the Rome III constipation module and the pelvic floor distress inventory (PDFI-20) survey. Patients were considered to have fecal urgency if they reported being bothered "moderately" or "quite a bit" by it in the past 3 months.

RESULTS

A total of 103 patients (28.0%) met our definition of fecal urgency. These patients were significantly more likely to meet criteria for irritable bowel syndrome and to report fecal incontinence, urinary incontinence, and diarrhea. Fecal urgency was associated with rectal hypersensitivity in those with diarrhea, but not in those without diarrhea. Fecal urgency was associated with urinary urge incontinence in those without diarrhea, but not those with diarrhea.

CONCLUSIONS

In patients with diarrhea, fecal urgency is associated with rectal hypersensitivity, whereas in patients without diarrhea, fecal urgency is associated with urinary urge incontinence. This suggests that fecal urgency has different pathophysiological mechanisms in patients with different underlying bowel habits.

Dyssynergic patterns of defecation in constipated adolescents and young adults with anorectal malformations

We aimed to evaluate the etiologies of constipation in patients with anorectal malformations having a good prognosis for bowel control but a high risk of constipation. We included twenty-five patients from the Odense university hospital in Denmark. Patients were subjected to colon transit time examination and high resolution anorectal manometry (HRAM). The median age was 18 (14-24) and 48% (12/25) were females. Fifty-two % (13/25) of patients were diagnosed with constipation. Types of anorectal malformation were perineal fistula (9/25), rectovestibular fistula (8/25), rectourethral bulbar fistula (5/25) and no fistula (3/25). No difference in neither total colon transit time nor segmental colon transit times were found based on the presence of constipation. Only four of the constipated patients fulfilled criteria for dyssynergic defecation with a dyssynergic pattern at HRAM and prolonged colon transit time. A Type I dyssynergic pattern was dominant in constipated patients (7/13). A Dyssynergic defecation pattern was due to isolated contraction of puborectalis muscle in 9 out of 13constipated patients. We found a dyssynergic pattern during attempted defecation in patients with anorectal malformations disregarded the presence of constipation. In the majority of constipated patients an isolated contraction of the puborectalis muscle was visualized with HRAM.

Does sequential balloon expulsion test improve the screening of defecation disorders?

Background

A defecation disorder (DD) is a difficulty in evacuation documented by physiological exams. However, this physiological evaluation can be cumbersome, inaccessible and costly. Three “low-cost” tools to evaluate DD—a clinical DD score, the balloon expulsion test (BET) and a digital rectal examination (DRE) score were evaluated as separate or combined tests for DD screening.

Methods

This prospective study occurred between January 2015 and March 2019 in the Gastroenterology Department of a tertiary hospital. Besides the gold standard physiological tests, constipated patients answered the clinical DD score and were evaluated by DRE and BET [standard and variable volume (VV)].

Results

From 98 constipated patients, 35 (38.9%) were diagnosed with DD according to Rome IV criteria, mainly female (n = 30, 86%) with a median age of 60 years old. The clinical DD score revealed an AUC of 0.417 (SE = 0.07, p = 0.191). The DRE score displayed an AUC of 0.56 (SE = 0.063, p = 0.301). The standard BET displayed a sensitivity of 86%, specificity of 58%, positive predictive value (PPV) of 57% and negative predictive value (NPV) of 86%. The sequential VVBET followed by standard BET improved the BET performance regarding the evaluation of DD, with a sensitivity of 86%, specificity of 67%, PPV of 63% and NPV of 87%. The sequential BET had an OR 8.942, p > 0.001, CI 3.18–25.14, revealing to be the most significant predictor for DD screening.

Conclusion

The sequential BET is a low cost, well-performing DD screening tool, appropriate to the Primary Care Setting.

Comparison of anorectal function measured using wearable digital manometry and a high resolution manometry system

There is a need for a lower cost manometry system for assessing anorectal function in primary and secondary care settings. We developed an index finger-based system (termed "digital manometry") and tested it in healthy volunteers, patients with chronic constipation, and fecal incontinence. Anorectal pressures were measured in 16 participants with the digital manometry system and a 23-channel high-resolution anorectal manometry system. The results were compared using a Bland-Altman analysis at rest as well as during maximum squeeze and simulated defecation maneuvers. Myoelectric activity of the puborectalis muscle was also quantified simultaneously using the digital manometry system. The limits of agreement between the two methods were -7.1 ± 25.7 mmHg for anal sphincter resting pressure, 0.4 ± 23.0 mmHg for the anal sphincter pressure change during simulated defecation, -37.6 ± 50.9 mmHg for rectal pressure changes during simulated defecation, and -20.6 ± 172.6 mmHg for anal sphincter pressure during the maximum squeeze maneuver. The change in the puborectalis myoelectric activity was proportional to the anal sphincter pressure increment during a maximum squeeze maneuver (slope = 0.6, R2 = 0.4). Digital manometry provided a similar evaluation of anorectal pressures and puborectalis myoelectric activity at an order of magnitude less cost than high-resolution manometry, and with a similar level of patient comfort. Digital Manometry provides a simple, inexpensive, point of service means of assessing anorectal function in patients with chronic constipation and fecal incontinence.

The London Classification: Improving Characterization and Classification of Anorectal Function with Anorectal Manometry

PURPOSE OF REVIEW

Objective measurement of anorectal sensorimotor function is a requisite component in the clinical evaluation of patients with intractable symptoms of anorectal dysfunction. Regrettably, the utility of the most established and widely employed investigations for such measurement (anorectal manometry (ARM), rectal sensory testing and the balloon expulsion test) has been limited by wide variations in clinical practice.

RECENT FINDINGS

This article summarizes the recently published International Anorectal Physiology Working Group (IAPWG) consensus and London Classification of anorectal disorders, together with relevant allied literature, to provide guidance on the indications for, equipment, protocol, measurement definitions and results interpretation for ARM, rectal sensory testing and the balloon expulsion test. The London Classification is a standardized method and nomenclature for description of alterations in anorectal motor and sensory function using office-based investigations, adoption of which should bring much needed harmonization of practice.

Assessing Anorectal Function in Constipation and Fecal Incontinence

Constipation and fecal incontinence are commonly encountered complaints in the gastrointestinal clinic. Assessment of anorectal function includes comprehensive history, rectal examination, and prospective stool diary or electronic App diary that accurately captures bowel symptoms, evaluation of severity, and quality of life of measure. Evaluation of a suspected patient with dyssynergic constipation includes anorectal manometry, balloon expulsion test, and defecography. Investigation of a suspected patient with fecal incontinence includes high-resolution anorectal manometry; anal ultrasound or MRI; and neurophysiology tests, such as translumbosacral anorectal magnetic stimulation or pudendal nerve latency. This article provides an approach to the assessment of anorectal function.

Gastrointestinal motility evaluation in children with orthostatic intolerance: Mayo Clinic experience

OBJECTIVE

Orthostatic intolerance (OI) and autonomic dysfunction (AD) are common in adolescents and young adults. Patients experience multisystem symptoms including gastrointestinal (GI), postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension (OH), or only symptoms of OI (SOI) without significant findings on 70-degree head-up tilt testing (HUT). We hypothesize that patients with POTS, OH, and SOI show differences in GI symptoms and motility test and that heart rate (HR) changes on HUT predict severity of GI dysmotility.

STUDY DESIGN

From medical records of patients (<18 years) with OI, we collected demographics, presenting symptoms, GI manifestations, and GI motility testing. Data were compared between the 3 groups (POTS, OH, and SOI). We assessed changes in HR on HUT with changes on GI motility evaluation.

RESULTS

Two hundred twenty-nine patients were included (73% females). Abdominal pain (65%), nausea (49%), vomiting (18%), and constipation (24%) were the most common GI symptoms. In patients who had motility evaluation, there were 27% (53/193) with delayed gastric emptying (GE) at 4 hours, 35% (32/92) with delayed colonic transit (CT), 55% (17/31) with reduced gastric accommodation (GA), and 75% (21/28) with dyssynergic defecation (DD). Among 100 POTS, 34 OH, and 95 SOI patients, no significant differences in GI symptoms or motility tests were identified and HR changes on HUT were not associated with changes on motility tests.

CONCLUSION

GI symptoms are frequent in adolescents with OI and are associated with delayed GE, reduced GA, delayed CT, and presence of DD.

Improvement of Patient Satisfaction and Anorectal Manometry Parameters After Biofeedback Therapy in Patients with Different Types of Dyssynergic Defecation

Biofeedback is a well-known and effective treatment for patients with fecal evacuation disorder (FED). The main purpose of this study was to investigate the outcome and the effects of biofeedback therapy on physiological parameters as assessed by manometry in patients with FED. Data from 114 consecutive patients with FED who underwent biofeedback therapy in Sara Gastrointestinal clinic in Tehran, Iran during 2015-2018 were retrospectively reviewed and analyzed. All participants underwent a comprehensive evaluation of anorectal function that included anorectal manometry and a balloon expulsion test at the baseline and after biofeedback therapy. Maximum anal squeeze pressure and sustained anal squeeze pressure were improved up to 100% and 94.7% of normal values in the patients after biofeedback, respectively (P < 0.001). First rectal sensation, was significantly decreased (25 ± 18.5 vs. 15.5 ± 5.2) while the maximum tolerable volume was significantly increased (233.6 ± 89.7 vs. 182.4 ± 23.1) after biofeedback therapy (P < 0.001). Type I dyssynergia was the most common type, effecting 82 cases (71.9%) of our patients. Dyssynergia parameters were improved 50-80% in 34 (41.5%) and 10 (31.3%) type I and non-type I patients, respectively. Over 80% improvement of dyssynergia parameters occurred in 48 (58.5%) and 22 (68.8%) type I and non-type I patients, respectively. These differences were not statistically significant between the two groups (P = 0.3). In addition, the ability to reject the balloon was significantly better in post intervention measurements (P < 0.001). Biofeedback not only improves the symptoms in patients of FED but also reverses more than 80% the dyssynergic parameters of defecation. However, due to the general effectiveness of biofeedback treatment in different types of DD, there were no significant differences between their improvement scores.