BACKGROUND: Whether patients with defecatory disorders (DDs) with favorable response to a footstool have distinctive anorectal pressure characteristics is unknown. We aimed to identify the clinical phenotype and anorectal pressure profile of patients with DDs who benefit from a footstool.
METHODS: This is a retrospective review of patients with high resolution anorectal manometry (HR-ARM) and balloon expulsion test (BET) from a tertiary referral center. BET was repeated with a 7-inch-high footstool in those who failed it after 120 s. Data were compared among groups with respect to BET results.
RESULTS: Of the 667 patients with DDs, a total of 251 (38%) had failed BET. A footstool corrected BET in 41 (16%) of those with failed BET. Gender-specific differences were noted in anorectal pressures, among patients with and without normal BET, revealing gender-based nuances in pathophysiology of DDs. Comparing patients who passed BET with footstool with those who did not, the presence of optimal stool consistency, with reduced instances of loose stools and decreased reliance on laxatives were significant. Additionally, in women who benefited from a footstool, lower anal pressures at rest and simulated defecation were observed. Independent factors associated with a successful BET with a footstool in women included age <50, Bristol 3 or 4 stool consistency, lower anal resting pressure and higher rectoanal pressure gradient.
CONCLUSIONS: Identification of distinctive clinical and anorectal phenotype of patients who benefited from a footstool could provide insight into the factors influencing the efficacy of footstool utilization and allow for an individualized treatment approach in patients with DDs.

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.
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.
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.
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.

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.
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.
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.
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.
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.

BACKGROUND: Perianal Crohn\'s disease is a disabling condition, with little known about anorectal function in healed/inactive perianal Crohn\'s disease; Aim: To evaluate anorectal function in a cohort of patients with treated/healed perianal Crohn\'s disease; Methods: Prospective cohort study, including high-resolution anorectal manometry, balloon expulsion test, and 3D-endoanal ultrasound in all patients; Results: Of the 16 patients studied (mean age ± SD, 42 ± 13 years), 12 (75%) were men. A laceration of the internal anal sphincter and/or anal scarring was seen in nine (56%) patients; there was no laceration of the external anal sphincter. Five (56%) of these nine patients had never experienced faecal incontinence. All had normal anal resting and squeeze pressures. Manometry suggested dyssynergia in 11 (69%) patients, with only one (6%) fulfilling the criteria for obstructed defecation. Hyposensitivity for at least one sensory parameter was seen in 11 (69%) patients and hypersensitivity in five (31%) patients; Conclusions: This study detected sphincter abnormalities in more than half of patients, many of whom were asymptomatic. Alterations in rectal sensation were frequently seen, more commonly with rectal hyposensitivity.
BACKGROUND: ClinicalTrials.gov (NCT03819257).

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.
OBJECTIVE: 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.

Symptoms such as a feeling of incomplete evacuation, straining, absence of the call to stool, anal blockage, or digitation suggest the presence a functional defecation disorder. As symptoms do not distinguish between patients with and without functional defecation disorder, Rome IV criteria recommend that this disorder is diagnosed when two of three tests are positive: balloon expulsion test (BET), anorectal manometry (ARM), and defecography. However, previous studies have demonstrated that the agreement among these tests is limited. In this issue of Neurogastroenterology and Motility, Sharma et al tested the hypothesis that conducting the ARM in a seated position would increase the diagnostic accuracy of the test in discriminating between patients with normal and prolonged BET. This minireview discusses the current knowledge on the role of the techniques to diagnose defecation disorder and the potential role of the ARM in a seated position.

This manuscript summarizes consensus reached by the International Anorectal Physiology Working Group (IAPWG) for the performance, terminology used, and interpretation of anorectal function testing including anorectal manometry (focused on high-resolution manometry), the rectal sensory test, and the balloon expulsion test. Based on these measurements, a classification system for disorders of anorectal function is proposed.
Twenty-nine working group members (clinicians/academics in the field of gastroenterology, coloproctology, and gastrointestinal physiology) were invited to six face-to-face and three remote meetings to derive consensus between 2014 and 2018.
The IAPWG protocol for the performance of anorectal function testing recommends a standardized sequence of maneuvers to test rectoanal reflexes, anal tone and contractility, rectoanal coordination, and rectal sensation. Major findings not seen in healthy controls defined by the classification are as follows: rectoanal areflexia, anal hypotension and hypocontractility, rectal hyposensitivity, and hypersensitivity. Minor and inconclusive findings that can be present in health and require additional information prior to diagnosis include anal hypertension and dyssynergia.
This framework introduces the IAPWG protocol and the London classification for disorders of anorectal function based on objective physiological measurement. The use of a common language to describe results of diagnostic tests, standard operating procedures, and a consensus classification system is designed to bring much-needed standardization to these techniques.

Functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C) have significant healthcare impact. Clinical and investigative data of patients with these disorders in Indian population is scarce. We aimed to compare the clinical and anorectal manometric profile of patients with FC and IBS-C.
Consecutive patients with chronic constipation undergoing anorectal manometry (ARM) and balloon expulsion test (BET) were enrolled. Thirty healthy volunteers served as controls (HC). Functional defecatory disorder (FDD) was diagnosed according to ROME IV criteria if both ARM and BET were abnormal.
Of the 231 patients enrolled (median age 47 years, 87.8% males), FC and IBS-C were diagnosed in 132 (57.1%) and 99 (42.9%) patients, respectively. Significant clinical differences between FC and IBS-C patients included older age, lower stool frequency/week, higher frequency of straining, and greater frequency  of incomplete evacuation (p < 0.001). ARM revealed abnormal defecatory pattern in 55.3% (n = 73) FC patients and 47.5% (n = 47) IBS-C patients. Of them, 54.7% (40/73) of FC patients had inadequate defecatory propulsion while 89.4% (42/47) of the IBS-C patients had dyssynergic defecation (p < 0.001). Abnormal BET was seen in 67.4% of FC patients and 43.4% of IBS-C patients. Thus, FDD was diagnosed in 55.3% and 46.5% of FC and IBS-C patients, respectively. Rectal hyposensitivity was present in 60.6% of FC patients compared with 2% of IBS-C patients (p < 0.001).
There were significant differences in clinical and manometric profile of FC and IBS-C patients. Compared with IBS-C patients, FC patients were older, had higher prevalence of FDD, less often had dyssynergic defecation, and had higher prevalence of rectal hyposensitivity.

High-resolution manometry (HRM) is used to measure rectoanal pressures in defecatory disorders and fecal incontinence. This study sought to define normal values for rectoanal HRM, ascertain the effects of age and BMI on rectoanal pressures, and compare pressures in asymptomatic women with normal and prolonged balloon expulsion time (BET).
High-resolution manometry pressures and BET were measured in 163 asymptomatic healthy participants. Women (96) and men (47) with normal BET were used to estimate normal values and the effects of age/BMI on pressures using a Medtronic 4.2-mm-diameter rectoanal catheter.
Age is associated with lower resting pressure, higher rectal pressure during evacuation, and a higher rectoanal gradient during evacuation in women and men. In women, the BET is also inversely correlated with age while the BMI is correlated with a higher threshold volume for discomfort and a longer BET. The anal squeeze pressure increment, squeeze duration, and HPZ length are higher in men than women. The rectoanal gradient during evacuation is also lower (ie, more negative) in asymptomatic women with an abnormal than a normal BET.
These findings provide an expanded database of normal values for anorectal HRM in men and women. Age and sex affect anal resting and squeeze pressures, respectively; rectal pressure during evacuation is also higher in older people. Less than 15% of asymptomatic people have BET >60 seconds, which is associated with manometry features of impaired evacuation.

Anorectal manometry (ARM) is typically preformed in a lateral position. This non-physiological testing position has produced an unexpected negative rectoanal pressure gradient (RAPG, i.e. difference between rectal and anal pressure) with normal defecation. This study was designed (i) to study differences in ARM parameters between water-perfused and solid-state sensors and between lateral and seated positions and (ii) to investigate the roles of ARM parameters in predicting balloon expulsion.
ARM was performed in 18 healthy volunteers (HV) and 60 patients with functional constipation (FC) under three randomized conditions: water-perfused in lateral position, solid-state in lateral position, and solid-state in seated position, followed by a balloon expulsion test in seated position.
i) Under the same lateral position, solid-state sensors produced higher rectal resting pressure and RAPG than water-perfused sensors. ii) Using the solid-state sensors, ARM in the seated position revealed higher resting rectal pressure (34.9 vs 10.9 mmHg in HV, 30.9 vs 10.6 mmHg in FC, both P<.001) and higher RAPG (22.6 vs -6.2 mmHg in HV, 17.1 vs -8.1 mmHg in FC, both P<.001) than the lateral position. iii) When ARM was performed using solid-state sensors in seated position, RAPG was predictive of balloon expulsion; using 10 mmHg as a threshold, RAPG could predict balloon expulsion with specificity of 82% and sensitivity 77%.
ARM performed in a seated position using solid-state sensors seems more accurate in assessing rectal pressure, and the RAPG measured under these conditions is predictive of balloon expulsion in FC patients.