Digital Rectal Examination and Balloon Expulsion Test in the Study of Defecatory Disorders: Are They Suitable as Screening or Excluding Tests?

Review document of the Spanish Association of Neurogastroenterology and Motility on the management of opioid-induced constipation

Opioid-induced constipation (OIC) is a rising problem due to the progressive increase in opioid prescription. In contrast to functional constipation, opioid-induced constipation is not a functional gut disorder but a side effect of opioid use. Opioids produce constipation due to a decrease in gastrointestinal motility and a reduction in gastrointestinal secretions. The treatment of OIC focuses on three basic pillars: optimizing opioid drug indication, preventing constipation onset, and treating constipation should it develop. As with any other cause of constipation, lifestyle adjustments and laxatives should be the first-line option in the pharmacological management of OIC. Osmotic laxatives such as polyethylene glycol (PEG) are the agents of choice. PEG is inert and is neither fermented nor absorbed in the gastrointestinal tract. Furthermore, it has broad clinical applicability due to its favourable safety profile. If first-line treatments fail, peripheral μ-opioid receptor antagonists (PAMORA) are the drugs of choice. They reduce the peripheral effects of OIC with a minimal potential to diminish analgesia or induce a centrally mediated withdrawal syndrome. Different PAMORA are available in the market both for oral and subcutaneous administration, with demonstrated efficacy for the management of OIC in different clinical trials.

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.

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.

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.

Current Overview on Clinical Management of Chronic Constipation

Constipation is one of the major gastrointestinal disorders diagnosed in clinical practice in Western countries. Almost 20% of population suffer from this disorder, which means constipation is a substantial utilization of healthcare. Pathophysiology of constipation is complex and multifactorial, where aspects like disturbance in colonic transit, genetic predisposition, lifestyle habits, psychological distress, and many others need to be taken into consideration. Diagnosis of constipation is troublesome and requires thorough accurate examination. A nonpharmacological approach, education of the patient about the importance of lifestyle changes like diet and sport activity state, are the first line of therapy. In case of ineffective treatment, pharmacological treatments such as laxatives, secretagogues, serotonergic agonists, and many other medications should be induced. If pharmacologic treatment fails, the definitive solution for constipation might be surgical approach. Commonness of this disorder, costs of medical care and decrease in quality life cause constipation is a serious issue for many specialists. The aim of this review is to present current knowledge of chronic constipation and management of this disorder.

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.

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.

Pretest and Post-test Probabilities of Diagnoses of Rectal Evacuation Disorders Based on Symptoms, Rectal Exam, and Basic Tests: a Systematic Review

BACKGROUND & AIMS

There is controversy over the utility of symptoms, examination, and tests for diagnosis of rectal evacuation disorders (REDs) or slow-transit constipation (STC). We aimed to ascertain the pooled prevalence, sensitivity, specificity, and likelihood ratios for clinical parameters to determine pretest and post-test probabilities of diagnoses of RED and STC without RED.

METHODS

We searched the MEDLINE and PUBMED databases since 1999 for studies that used binary data to calculate sensitivity, specificity, and likelihood ratios to determine the diagnostic utility of history, symptoms, and tests for RED and STC. RED and STC were defined based on confirmation by at least 1 objective anorectal test or colonic transit test. Controls had normal test results based on the specific protocol in each study.

RESULTS

We reviewed 100 articles; 63 studies of RED and 61 studies of STC met the inclusion criteria. Among 3364 patients with chronic constipation, objective tests demonstrated RED alone, 27.2%; normal transit constipation alone, 37.2%; STC alone, 19.0%; and RED with STC, 16.6%. To diagnose RED, discriminant features were urinary symptoms (specificity, 100%; likelihood ratio, above 10; 58 patients), less than 2 findings of dyssynergia in a digital rectal exam (sensitivity, 83.2%; negative likelihood ratio, 0.2; 462 patients) and rectoanal pressure gradient below -40 mm Hg with high anal pressure during straining (specificity, 100%; likelihood ratio, above 10; 101 patients). The features most strongly associated with STC alone were call to stool (specificity, 91.5%; likelihood ratio, 10.5; 75 patients) and absence of abdominal distension, fullness, or bloating (sensitivity, 92.9%; negative likelihood ratio, 0.1; 93 patients).

CONCLUSIONS

In a systematic review, we found specific symptoms, lack of dyssynergia in a digital rectal exam, and findings on anorectal manometry to be highly informative and critical in evaluation of RED and STC.

Diagnostic value of the balloon expulsion test compared with anorectal manometry in Indian patients with dyssynergic defecation

INTRODUCTION

Digital rectal examination (DRE) and balloon expulsion test (BET) are simple tests to diagnose dyssynergic defecation (DD).

AIM

To determine differences in symptoms and manometry findings in patients with abnormal BET and normal BET. The secondary objective was to ascertain the sensitivity and specificity of BET and DRE + BET for the diagnosis of DD in an Indian setting using ARM findings as the gold standard.

MATERIAL AND METHODS

Retrospective analysis of patients with chronic constipation referred for anorectal manometry (ARM) between December 2012 and March 2019. DD was diagnosed using ARM. Findings on BET and, in a subset of cases, on DRE + BET were compared with ARM findings. The data were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Agreement of BET and DRE + BET with ARM was calculated using Cohen's κ coefficient. A p-value of < 0.05 was considered significant.

RESULTS

A total of 1006 cases (734 males, 73%) formed the study cohort. Patients with abnormal BET more frequently reported digitation, bleeding per rectum, and straining (p < 0.00001). Moreover, they had a significantly higher median basal pressure compared to those with normal BET (80 vs. 67, p = 0.03). DD was significantly more common in those with abnormal BET. The sensitivity, specificity, PPV, and NPV of BET in detecting DD were 28.29%, 97.15%, 81.13%, and 75.78%, respectively. The percentage of agreement was 76.34%, and there was fair degree of correlation between the two tests. In a smaller subset of cases (166), DRE and BET findings were both available for analysis. We noted that the sensitivity, specificity, PPV, and NPV of combined DRE + BET were 57.63%, 88.79%, 73.91%, and 79.17%, respectively. The Cohen's κ correlation coefficient was 0.49, suggesting moderate agreement.

CONCLUSIONS

Patients with abnormal BET more frequently report digitation, straining, and bleeding per rectum, and have higher resting anal pressure. BET is a good screening test for DD in an Indian setting.

European society of neurogastroenterology and motility guidelines on functional constipation in adults

INTRODUCTION

Chronic constipation is a common disorder with a reported prevalence ranging from 3% to 27% in the general population. Several management strategies, including diagnostic tests, empiric treatments, and specific treatments, have been developed. Our aim was to develop European guidelines for the clinical management of constipation.

DESIGN

After a thorough review of the literature by experts in relevant fields, including gastroenterologists, surgeons, general practitioners, radiologists, and experts in gastrointestinal motility testing from various European countries, a Delphi consensus process was used to produce statements and practical algorithms for the management of chronic constipation.

KEY RESULTS

Seventy-three final statements were agreed upon after the Delphi process. The level of evidence for most statements was low or very low. A high level of evidence was agreed only for anorectal manometry as a comprehensive evaluation of anorectal function and for treatment with osmotic laxatives, especially polyethylene glycol, the prokinetic drug prucalopride, secretagogues, such as linaclotide and lubiprostone and PAMORAs for the treatment of opioid-induced constipation. However, the level of agreement between the authors was good for most statements (80% or more of the authors). The greatest disagreement was related to the surgical management of constipation.

CONCLUSIONS AND INFERENCES

European guidelines on chronic constipation, with recommendations and algorithms, were developed by experts. Despite the high level of agreement between the different experts, the level of scientific evidence for most recommendations was low, highlighting the need for future research to increase the evidence and improve treatment outcomes in these patients.

IS THE PHYSICIAN EXPERTISE IN DIGITAL RECTAL EXAMINATION OF VALUE IN DETECTING ANAL TONE IN COMPARISON TO ANORECTAL MANOMETRY?

BACKGROUND

Digital rectal examination (DRE) is part of the physical examination, is also essential for the colorectal surgeon evaluation. A good DRE offers precious information related to the patient's complaints, which will help in decision making. It is simple, quick and minimally invasive. In many centers around the world, the DRE is still the only method to evaluate the anal sphincter prior to patient's management. On the other hand, anorectal manometry (ARM) is the main method for objective functional evaluation of anal sphincter pressures. The discrepancy of DRE depending on the examiner to determine sphincter tonus in comparison to ARM motivated this study.

OBJECTIVE

To compare the DRE performed by proficient and non-experienced examiners to sphincter pressure parameters obtained at ARM, depending on examiners expertise.

METHODS

Thirty-six consecutive patients with complaints of fecal incontinence or chronic constipation, from the anorectal physiology clinic of the University of São Paulo School of Medicine, were prospectively included. Each patient underwent ARM and DRE performed by two senior colorectal surgeons and one junior colorectal surgeon prior to the ARM. Patient's history was blinded for the examiner's knowledge, also the impressions of each examiner were blinded from the others. For the DRE rest and squeeze pressures were classified by an objective scale (DRE scoring system) that was compared to the parameters of the ARM for the analysis. The results obtained at the ARM were compared to the DRE performed by the seniors and the junior colorectal surgeons.

STATISTICAL ANALYSIS

Descriptive analysis was performed for all parameters. For the rest and squeeze pressures the Gamma index was used for the comparison between the DRE and ARM, which varied from 0 to 1. The closer to 1 the better was the agreement.

RESULTS

The mean age was 48 years old and 55.5% of patients were female. The agreement of rest anal pressures between the ARM and the DRE performed by the senior proficient examiners was 0.7 (CI 95%; 0.32-1.0), while for the junior non-experienced examiner was 0.52 (CI 95%; 0.09-0.96). The agreement of squeeze pressures was 0.96 (CI 95%; 0.87-1.0) for the seniors and 0.52 (CI 95%; 0.16-0.89) for the junior examiner.

CONCLUSION

More experienced colorectal surgeons used to DRE had a more significant agreement with the ARM, thereafter would have more appropriate therapeutic management to patients with sphincter functional problems. ARM, therefore, persists as an important exam to objectively evaluate the sphincter complex, justifying its utility in the clinical practice.

Audit of the diagnosis of rectal evacuation disorders in chronic constipation

BACKGROUND

Balloon expulsion test (BET) and high-resolution anorectal manometry (HRM) are used in diagnosis of rectal evacuation disorders (REDs); their performance characteristics are suboptimal.

METHODS

We audited records of 449 consecutive patients with chronic constipation (CC). We documented anal sphincter tone and contraction, puborectalis tenderness, and perineal descent on digital rectal exam (DRE); maximum resting and squeeze pressures, and rectoanal pressure gradient on HRM; weight or time to balloon expulsion; colonic transit, and area of rectal area on radiograph (RASF). We based the diagnosis of RED on ≥2 abnormalities on both DRE and HRM, excluding results of BET, as the performance of BET is being investigated. Results of RED vs non-RED and results obtained using tbBET vs wbBET groups were compared. We used multivariate logistic regressions to identify predictors of RED using different diagnostic modalities.

KEY RESULTS

Among 449 individuals, 276 were included (74 RED and 202 non-RED). Predominant exclusions were for no HRM (n = 79) or use of low resolution anorectal manometry (n = 77). Logistic regression models for abnormal tbBET showed time >60 seconds, RASF and age-predicted RED. For tbBET, the current cutoff of 60 seconds had sensitivity of 39.0% and specificity 93.0% to diagnose RED; on the other hand, applying the cutoff at 22 seconds, the sensitivity was 77.8% and specificity 69.8%.

CONCLUSIONS & INFERENCES

The clinical diagnosis of RED in patients with CC is achieved with combination of DRE, HRM and an optimized, time-based BET. Prospective studies are necessary to confirm the proposed 22 second cutoff for tbBET.

Fecobionics: A Novel Bionics Device for Studying Defecation

During defecation, solid, semisolid or liquid stools are eliminated via the anus in a complex physiological process. Up to 25% of the population are affected by anorectal disorders that are poorly recognized and treated. We developed a new bionics device, a simulated stool named Fecobionics, to replace several current tests of anorectal function. Fecobionics was developed to simulate the defecation process that depends on rectal forces, the anorectal size angle, and anorectal size and sensitivity. Fecobionics provided axial pressure signatures, measurement of bending (anorectal angle) and geometric mapping in a single examination. It had the consistency and shape of normal stool. The device had a soft core with embedded electronics and a bag for distension. The paper describes the device development and validation. Furthermore, data were obtained in preliminary experiments in pigs, healthy human subjects and patients with focus on four important features of the system, i.e. measurements of pressure signatures, bending characteristics, impedance measurements and data transmission. Accurate pressure and orientation data as well as geometric profiles were successfully obtained on the bench as well as in vivo in pigs and human subjects during defecation. Fecobionics is a novel technology imitating defecation. The clinical future ultimately depends on its ability to impact on daily treatment of anorectal disorders. A potential long-term clinical application is use of the device for biofeedback training for dyssynergic defecation.

Clinical and manometric characteristics of women with paradoxical puborectalis syndrome

Background

A subset of patients with functional defecation disorders have predominance of the puborectalis muscle (PRM) on three-dimensional high definition anorectal manometry (HDARM), known as paradoxical puborectalis syndrome (PPS). The aim of this study was to assess clinical and manometric differences between patients with and without PPS.

Methods

A total of 227 women with functional defecation disorders undergoing HDARM between December 2012 and October 2016 at a single center were included in this study. All completed the Rome III constipation module and Pelvic Floor Distress Inventory 20 (PFDI-20).

Results

Eighty-seven out of 227 women had a 3D pressure topographic profile consistent with PPS. They had higher mean PDFI-20 scores for straining and incomplete evacuation symptoms than those without PPS. In addition, they demonstrated higher mean resting anal pressure, a more negative mean anorectal pressure differential, and a greater proportion with prolonged balloon expulsion test. These findings were more pronounced in a subgroup of 58 PPS patients with a distinct pattern of both posterior and posterolateral wall indentation.

Conclusion

Among female patients with functional defecation disorders, those with PPS demonstrated clinical and manometric differences compared to those without PPS. These differences may be driven by predominant posterolateral wall indentation in a subgroup of PPS patients.

The Mexican consensus on chronic constipation

INTRODUCTION

Significant advances have been made in the knowledge and understanding of the epidemiology, pathophysiology, diagnosis, and treatment of chronic constipation, since the publication of the 2011 guidelines on chronic constipation diagnosis and treatment in Mexico from the Asociación Mexicana de Gastroenterología.

AIMS

To present a consensus review of the current state of knowledge about chronic constipation, providing updated information and integrating the new scientific evidence.

METHODS

Three general coordinators reviewed the literature published within the time frame of January 2011 and January 2017. From that information, 62 initial statements were formulated and then sent to 12 national experts for their revision. The statements were voted upon, using the Delphi system in 3 voting rounds (2 electronic and one face-to-face). The statements were classified through the GRADE system and those that reached agreement >75% were included in the consensus.

RESULTS AND CONCLUSIONS

The present consensus is made up of 42 final statements that provide updated knowledge, supplementing the information that had not been included in the previous guidelines. The strength of recommendation and quality (level) of evidence were established for each statement. The current definitions of chronic constipation, functional constipation, and opioid-induced constipation are given, and diagnostic strategies based on the available diagnostic methods are described. The consensus treatment recommendations were established from evidence on the roles of diet and exercise, fiber, laxatives, new drugs (such as prucalopride, lubiprostone, linaclotide, plecanatide), biofeedback therapy, and surgery.

The assessment and management of defecatory dysfunction: a critical appraisal

PURPOSE OF REVIEW

To summarize the advances in diagnostic modalities and management options for defecatory dysfunction and highlight the areas in need of further research.

RECENT FINDINGS

The diagnostic utility of high-resolution anorectal manometry (ARM), which has emerged as a promising tool for the diagnosis of defecatory dysfunction, appears to be questionable in differentiating disease from normal physiology. There also seems to be discrepancy between results of various tests of anorectal function in the diagnosis of defecatory dysfunction. New revisions in diagnostic criteria for defecatory dysfunction by Rome IV consortium, may enhance its diagnostic yield. Biofeedback remains to be the most effective evidence-based treatment option for patients with defecatory dysfunction. Anorectal pressure profile cannot predict or mediate the success of biofeedback. Biofeedback may improve the symptoms through central effects.

SUMMARY

Despite the advances in the ARM and defecography techniques, no one test has been able to be considered as the 'gold standard' for diagnosis of defecatory dysfunction. The mechanism of action of biofeedback in defecatory dysfunction remains poorly understood.