An update on anorectal disorders for gastroenterologists

Gut Microecological Prescription: A Novel Approach to Regulating Intestinal Micro-Ecological Balance

The intestinal microecology is comprises intestinal microorganisms and other components constituting the entire ecosystem, presenting characteristics of stability and dynamic balance. Current research reveals intestinal microecological imbalances are related to various diseases. However, fundamental research and clinical applications have not been effectively integrated. Considering the importance and complexity of regulating the intestinal microecological balance, this study provides an overview of the high-risk factors affecting intestinal microecology and detection methods. Moreover, it proposes the definition of intestinal microecological imbalance and the definition, formulation, and outcomes of gut microecological prescription to facilitate its application in clinical practice, thus promoting clinical research on intestinal microecology and improving the quality of life of the population.

Characterization of obstructive defecation from a structural and a functional perspective

BACKGROUND/AIMS

Defecation disorders can occur as a consequence of functional or structural anorectal dysfunctions during voiding. The aims of this study is to assess the prevalence of structural (SDD) vs functional (FDD) defecation disorders among patients with clinical complaints of obstructive defecation (OD) and their relationship with patients' expulsive capacity.

PATIENTS AND METHODS

Retrospective study of 588 patients with OD studied between 2012 and 2020 with evacuation defecography (ED), and anorectal manometry (ARM) in a subgroup of 294.

RESULTS

90.3% patients were women, age was 58.5±12.4 years. Most (83.7%) had SDD (43.7% rectocele, 45.3% prolapse, 19.3% enterocele, and 8.5% megarectum), all SDD being more prevalent in women except for megarectum. Functional assessments showed: (a) absence of rectification of anorectal angle in 51% of patients and poor pelvic descent in 31.6% at ED and (b) dyssynergic defecation in 89.9%, hypertonic IAS in 44%, and 33.3% rectal hyposensitivity, at ARM. Overall, 46.4% of patients were categorized as pure SDD, 37.3% a combination of SDD+FDD, and 16.3% as having pure FDD. Rectal emptying was impaired in 66.2% of SDD, 71.3% of FDD and in 78% of patients with both (p=0.017).

CONCLUSIONS

There was a high prevalence of SDD in middle-aged women with complaints of OD. Incomplete rectal emptying was more prevalent in FDD than in SDD although FDD and SDD frequently coexist. We recommend a stepwise therapeutic approach always starting with therapy directed to improve FDD and relaxation of striated pelvic floor muscles.

Fecal incontinence patients categorized based on anal pressure and electromyography: Anal sphincter damage and clinical symptoms

BACKGROUND

Disruption of external anal sphincter muscle (EAS) is an important factor in the multifactorial etiology of fecal incontinence (FI).

OBJECTIVES

We categorize FI patients into four groups based on the location of lesion in neuromuscular circuitry of EAS to determine if there are differences with regards to fecal incontinence symptoms severity (FISI) score, age, BMI, obstetrical history, and anal sphincter muscle damage.

METHODS

Female patients (151) without any neurological symptoms, who had undergone high-resolution manometry, anal sphincter EMG, and 3D ultrasound imaging of the anal sphincter were assessed. Patients were categorized into four groups: Group 1 (normal)-normal cough EMG (>10 μV), normal squeeze EMG (>10 μV), and normal anal squeeze pressure (>124 mmHg); Group 2 (cortical apraxia, i.e., poor cortical activation)-normal cough EMG, low squeeze EMG, and low anal squeeze pressure; Group 3 (muscle damage)-normal cough EMG, normal squeeze EMG, and low anal squeeze pressure; and Group 4 (pudendal nerve damage)-low cough EMG, low squeeze EMG, and low anal squeeze pressure.

RESULTS

The four patient groups were not different with regards to the patient's age, BMI, parity, and FISI scores. 3D ultrasound images of the anal sphincter complex revealed significant damage to the internal anal sphincter, external anal sphincter, and puborectalis muscles in all four groups.

CONCLUSION

The FI patients are a heterogeneous group; majority of these patients have significant damage to the muscles of the anal sphincter complex. Whether biofeedback therapy response is different among different patient groups requires study.

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.

Brain-derived neurotrophic factor - a key player in the gastrointestinal system

Brain-derived neurotrophic factor (BDNF) is highly expressed throughout the gastrointestinal (GI) tract and plays a critical role in the regulation of intestinal motility, secretion, sensation, immunity, and mucosal integrity. Dysregulation of BDNF signalling has been implicated in the pathophysiology of various GI disorders including inflammatory bowel disease, irritable bowel syndrome, functional dyspepsia, and diabetic gastroenteropathy. This review provides a comprehensive overview of BDNF localization, synthesis, receptors, and signalling mechanisms in the gut. In addition, current evidence on the diverse physiologic and pathophysiologic roles of BDNF in the control of intestinal peristalsis, mucosal transport processes, visceral sensation, neuroimmune interactions, gastrointestinal mucosal healing, and enteric nervous system homeostasis are discussed. Finally, the therapeutic potential of targeting BDNF for the treatment of functional GI diseases is explored. Advancing knowledge of BDNF biology and mechanisms of action may lead to new therapies based on harnessing the gut trophic effects of this neurotrophin.

Bowel dysfunctions after acquired brain injury: a scoping review

Bowel dysfunction is a common consequence of neurological diseases and has a major impact on the dignity and quality of life of patients. Evidence on neurogenic bowel is focused on spinal cord injury and multiple sclerosis; few studies have focused on patients with acquired brain injury (ABI). Neurogenic bowel dysfunction is related to a lifelong condition derived from central neurological disease, which further increases disability and social deprivation. The manifestations of neurogenic bowel dysfunction include fecal incontinence and constipation. Almost two out of three patients with central nervous system disorder have bowel impairment. This scoping review aims to comprehend the extent and type of evidence on bowel dysfunction after ABI and present conservative treatment. For this scoping review, the PCC (population, concept, and context) framework was used: patients with ABI and bowel dysfunction; evaluation and treatment; and intensive/extensive rehabilitation path. Ten full-text articles were included in the review. Oral laxatives are the most common treatment. The Functional Independence Measure (FIM) subscale is the most common scale used to assess neurogenic bowel disease (60%), followed by the Rome II and III criteria, and the colon transit time is used to test for constipation; however, no instrumental methods have been used for incontinence. An overlapping between incontinence and constipation, SCI and ABI increase difficulties to manage NBD. The need for a consensus between the rehabilitative and gastroenterological societies on the diagnosis and medical care of NBD.

Systematic review registration

Open Science Framework on August 16, 2022 https://doi.org/10.17605/OSF.IO/NEQMA.

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.

Fecal Incontinence and Defecatory Disorders in Patients With Ileal Pouch-Anal Anastomosis

Functional anorectal disorders are common in patients with ileal pouch-anal anastomosis (IPAA) and often have a debilitating impact on quality of life. The diagnosis of functional anorectal disorders, including fecal incontinence (FI) and defecatory disorders, requires a combination of clinical symptoms and functional testing. Symptoms are generally underdiagnosed and underreported. Commonly utilized tests include anorectal manometry, balloon expulsion test, defecography, electromyography, and pouchoscopy. The treatment for FI begins with lifestyle modifications and medications. Sacral nerve stimulation and tibial nerve stimulation have been trialed on patients with IPAA and FI, resulting in improvement in symptoms. Biofeedback therapy has also been used in patients with FI but is more commonly utilized in defecatory disorders. Early diagnosis of functional anorectal disorders is important because a response to treatment may significantly improve a patient's quality of life. To date, there is limited literature describing the diagnosis and treatment of functional anorectal disorders in patients with IPAA. This article focuses on the clinical presentation, diagnosis, and treatment of FI and defecatory disorders in patients with IPAA.

Clinical significance and related factors of rectal hyposensitivity in patients with functional defecation disorder

Background

Rectal hyposensitivity (RH) is not uncommon in patients with functional defecation disorder (FDD). FDD patients with RH are usually unsatisfied with their treatment.

Aims

The aim of this study was to find the significance of RH in patients with FDD and the related factors of RH.

Methods

Patients with FDD first completed clinical questionnaires regarding constipation symptoms, mental state, and quality of life. Then anorectal physiologic tests (anorectal manometry and balloon expulsion test) were performed. Rectal sensory testing (assessing rectal response to balloon distension using anorectal manometry) was applied to obtain three sensory thresholds. Patients were separated into three groups (non-RH, borderline RH, and RH) based on the London Classification. The associations between RH and clinical symptoms, mental state, quality of life, and rectal/anal motility were investigated.

Results

Of 331 included patients with FDD, 87 patients (26.3%) had at least one abnormally elevated rectal sensory threshold and 50 patients (15.1%) were diagnosed with RH. Patients with RH were older and mostly men. Defecation symptoms were more severe (p = 0.013), and hard stool (p < 0.001) and manual maneuver (p = 0.003) were more frequently seen in the RH group. No difference in rectal/anal pressure was found among the three groups. Elevated defecatory desire volume (DDV) existed in all patients with RH. With the number of elevated sensory thresholds increasing, defecation symptoms got more severe (r = 0.35, p = 0.001). Gender (male) (6.78 [3.07-15.00], p < 0.001) and hard stool (5.92 [2.28-15.33], p < 0.001) were main related factors of RH.

Conclusion

Rectal hyposensitivity plays an important role in the occurrence of FDD and is associated with defecation symptom severity. Older male FDD patients with hard stool are prone to suffer from RH and need more care.

Flow simulations of rectal evacuation: towards a quantitative evaluation from video defaecography

Mechanistic understanding of anorectal (patho)physiology is missing to improve the medical care of patients suffering from defaecation disorders. Our objective is to show that complex fluid dynamics modelling of video defaecography may open new perspectives in the diagnosis of defaecation disorders. Based on standard X-ray video defaecographies, we developed a bi-dimensional patient-specific simulation of the expulsion of soft materials, the faeces, by the rectum. The model quantified velocity, pressure and stress fields during the defaecation of a neostool with soft stool-like rheology for patients showing normal and pathological defaecatory function. In normal defaecation, the proximal-distal pressure gradient resulted from both the anorectal junction which formed a converging channel and the anal canal. The flow of the neostool through these anatomical parts was dominated by its shear-thinning viscous properties, rather than its yield stress. Consequently, the evacuation flow rate was significantly affected by variations in pressure applied by the rectum, and much less by the geometry of the anorectal junction. Lastly, we simulated impaired defaecations in the absence of obvious obstructive phenomena. Comparison with normal defaecation allowed us to discuss critical elements which should lead to effective medical management.

Functional bowel disorders with diarrhoea: Clinical guidelines of the United European Gastroenterology and European Society for Neurogastroenterology and Motility

Irritable bowel syndrome with diarrhoea (IBS-D) and functional diarrhoea (FDr) are the two major functional bowel disorders characterized by diarrhoea. In spite of their high prevalence, IBS-D and FDr are associated with major uncertainties, especially regarding their optimal diagnostic work-up and management. A Delphi consensus was performed with experts from 10 European countries who conducted a literature summary and voting process on 31 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation criteria. Consensus (defined as >80% agreement) was reached for all the statements. The panel agreed with the potential overlapping of IBS-D and FDr. In terms of diagnosis, the consensus supports a symptom-based approach also with the exclusion of alarm symptoms, recommending the evaluation of full blood count, C-reactive protein, serology for coeliac disease, and faecal calprotectin, and consideration of diagnosing bile acid diarrhoea. Colonoscopy with random biopsies in both the right and left colon is recommended in patients older than 50 years and in presence of alarm features. Regarding treatment, a strong consensus was achieved for the use of a diet low fermentable oligo-, di-, monosaccharides and polyols, gut-directed psychological therapies, rifaximin, loperamide, and eluxadoline. A weak or conditional recommendation was achieved for antispasmodics, probiotics, tryciclic antidepressants, bile acid sequestrants, 5-hydroxytryptamine-3 antagonists (i.e. alosetron, ondansetron, or ramosetron). A multinational group of European experts summarized the current state of consensus on the definition, diagnosis, and management of IBS-D and FDr.

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

BACKGROUND

Functional defecation disorder (FDD) is a common subtype of functional constipation (FC). Balloon expulsion test (BET) and high resolution anorectal manometry (HR-ARM) are significant tools but their results are not always consistent.

AIMS

To investigate the characteristics of patients with positive BET and pelvic floor dyssynergia (PFD) and explore the value of both positive results in FDD diagnosis.

METHODS

We retrospectively diagnosed FC subtypes and enrolled FDD patients based on Rome-IV criteria. They underwent HR-ARM, BET and CTT tests. Then they were classified to two groups and further stratified by FDD subtypes. Validated questionnaires were applied to investigate patients' constipation, anxiety/depression and quality of life.

RESULTS

335 FDD patients were finally enrolled. They were classified into two groups according to whether BET and PFD were both positive (consistent or not). 84.48% showed consistent results. These patients had significantly higher anal residual pressure, lower anal relaxation rate, manometric defecation index (MDI) and a more negative rectoanal pressure gradient (RAPG) (Ps < .05). The specific distribution of FDD phenotypes in two groups showed significant difference (p = .021). Males suffered a more negative RAPG (p < .001) and age was correlated with anal relaxation rate (p < .001). A subset (177 individuals) was investigated with validated questionnaires. Scores for Defecation Symptoms, Physical Discomfort and GAD-7 score were significantly high in Consistent Group (Ps < .05). GAD-7 score was associated with Defecation Symptoms (p < .001) while anal residual pressure, GAD-7 and Defecation Symptoms score were linked to Physical Discomfort (Ps < .05). The diagnostic specificity and PPV for FDD rose significantly with positive BET and PFD.

CONCLUSION

FDD patients with positive BET and PFD suffered from severe defecation symptoms, anxiety and impaired QOL. Positive BET and PFD could be an ideal tool for screening FDD.

Three-dimensional High-resolution Anorectal Manometry in Children With Non-retentive Fecal Incontinence

Background/Aims

Three-dimensional high-resolution anorectal manometry (3D-HRAM) is a precise tool to assess the function of the anorectum. Our aim is to evaluate children diagnosed with non-retentive fecal incontinence (NRFI) using 3D-HRAM.

Methods

In all children diagnosed with NRFI, manometric parameters and 3-dimensional reconstructions of the anal canal subdivided into 8 segments were recorded. All data were compared to raw data that were obtained from asymptomatic children, collected in our laboratory and published previously (C group).

Results

Forty children (31 male; median age, 8 years; range, 5-17) were prospectively included in the study. Comparison of the NRFI group and C group revealed lower values of mean resting pressure (74.4 mmHg vs 89.2 mmHg, P < 0.001) and maximum squeeze pressure (182 mmHg vs 208.5 mmHg, P = 0.018) in the NRFI group. In the NRFI group, the thresholds of sensation, urge and discomfort (40 cm³, 70 cm³, and 140 cm³, respectively) were significantly higher than those in the C group (20 cm³, 30 cm³, and 85 cm³, respectively; P < 0.001). In the NRFI group, 62.5% presented a mean resting pressure above the fifth percentile, and 82.5% of patients presented a maximum squeeze pressure above the fifth percentile. The comparisons between segments obtained from these patients and those obtained from the C group revealed several segments with significantly decreased pressure values in the NRFI group.

Conclusions

Our study demonstrated lower pressure parameters in children with NRFI. In patients with normal resting pressures, 3D-HRAM may reveal segments with decreased pressures, which may play a potential role in the pathomechanism of incontinence.

Anorectal Anatomy and Function

Anatomy of pelvic floor muscles has long been controversial. Novel imaging modalities, such as three-dimensional transperineal ultrasound imaging, MRI, and diffusion tensor imaging, have revealed unique myoarchitecture of the external anal sphincter and puborectalis muscle. High-resolution anal manometry, high-definition anal manometry, and functional luminal imaging probe are important new tools to assess anal sphincter and puborectalis muscle function. Increased understanding of the structure and function of anal sphincter complex/pelvic floor muscle has improved the ability to diagnose patients with pelvic floor disorders. New therapeutic modalities to treat anal/fecal incontinence and other pelvic floor disorders will emerge in the near future.

Do resistance exercises during biofeedback therapy enhance the anal sphincter and pelvic floor muscles in anal incontinence?

AIM

To determine if a biofeedback therapy that includes concentric resistance exercise for the anal sphincter muscles can improve muscle strength/function and improve AI symptoms compared to the traditional/non-resistance biofeedback therapy.

BACKGROUND

Biofeedback therapy is the current gold standard treatment for patients with anal incontinence (AI). Lack of resistance exercise biofeedback programs is a limitation in current practice.

METHODS

Thirty-three women with AI (mean age 60 years) were randomly assigned to concentric (resistance) or isometric (non-resistance) biofeedback training. Concentric training utilized the Functional Luminal Imaging Probe to provide progressive resistance exercises based on the patient's ability to collapse the anal canal lumen. Isometric training utilized a non-collapsible 10 mm diameter probe. Both groups performed a biofeedback protocol once per week in the clinic for 12 weeks and at home daily. High definition anal manometry was used to assess anal sphincter strength; symptoms were measured using FISI and UDI-6. 3D transperineal ultrasound imaging was used to assess the anal sphincter muscle integrity.

RESULTS

Concentric and isometric groups improved FISI and UDI-6 scores to a similar degree. Both the concentric and isometric groups showed small improvement in the anal high-pressure zone; however, there was no difference between the two groups. Ultrasound image analysis revealed significant damage to the anal sphincter muscles in both patient groups.

CONCLUSIONS

Concentric resistance biofeedback training did not improve the anal sphincter muscle function or AI symptoms beyond traditional biofeedback training. Anal sphincter muscle damage may be an important factor that limits the success of biofeedback training.

Development of colonic transit time and ultrasound imaging tools as objective indicators for assessing abnormal defecation associated with food intake: a narrative review based on previous scientific knowledge

Background

Functional gastrointestinal disorders (FGIDs) involve chronic or persistent gastrointestinal symptoms. Laboratory tests show no organic lesions, and the symptoms are due to dysfunction. The most typical FGID is irritable bowel syndrome (IBS). In IBS patients, defecation disorders are common and have adverse effects on daily life. The proper evaluation and analysis of colonic transit are important for the management of defecation disorders in IBS patients. In addition, dietary intake and lifestyle affect colonic transit. An accurate assessment of such factors can guide management, leading to improvements in colonic transit and the resolution of defecation disorders.

Main topic

The Rome IV diagnostic criteria for IBS are based on subjective symptoms, which must be communicated and explained by the patient, limiting their application. Colonic transit time and ultrasonography are objective tools that can be used to diagnose IBS. In particular, previous studies used colonic transit to accurately distinguish between constipation and normal stool passage and to assess delayed gastrointestinal motility. Diet and lifestyle modifications can improve colonic transit and ameliorate bowel dysfunction.

Conclusion

Colonic transit can be improved by modifying lifestyle factors. Defecation disorders in IBS patients may be resolved by focusing on such factors. In the future, methods of visualizing defecation disorders due to impaired gastrointestinal motility and objective indicators of the associated abdominal symptoms need to be investigated.

Digital Rectal Examination Is a Valuable Bedside Tool for Detecting Dyssynergic Defecation: A Diagnostic Study and a Meta-Analysis

BACKGROUND

Accurate dyssynergic defecation (DD) diagnosis depends on anorectal physiological tests that are not widely available.

AIM

The purpose of this study is to evaluate the diagnostic yield of digital rectal examination (DRE) compared with anorectal physiological tests in diagnosing DD in patients with constipation.

METHODS

A total of 218 chronic constipation patients who fulfilled the Rome IV diagnostic criteria for functional constipation (FC) and underwent a standardized DRE and high-resolution anorectal manometry (HRAM) test were enrolled in this study. The diagnostic accuracy of DRE compared with HRAM was evaluated, and the agreement between DRE and HRAM was calculated. Furthermore, a comprehensive literature search on PubMed, Web of Science, Cochrane Library, and Embase database was conducted to further elucidate the pooled diagnostic accuracy of DRE in DD patients.

RESULTS

A total of 101 patients (46.33%) had a DD pattern using HRAM, while 117 patients (53.67%) were diagnosed without DD. The sensitivity of DRE in diagnosing dyssynergia was 71.3%, and the specificity was 76.1%. There was a moderate agreement between DRE and HRAM for diagnosing DD (κ-coefficient = 0.474, P < 0.001). Meanwhile, six studies (including our study) comprising 964 constipated patients were included in our meta-analysis. The outcomes demonstrated that the AUC was 0.85 (95% CI 0.82-0.88) with 77% summary sensitivity (95% CI 65-86) and 80% summary specificity (95% CI 71-86) to diagnose DD.

CONCLUSIONS

DRE could be a valuable tool for screening DD. Our study revealed acceptable sensitivity and specificity of DRE in detecting dyssynergia compared with the physiological tests. Meanwhile, our study highlights that DRE remains an important tool in clinical practice.

Imaging modalities for the detection of posterior pelvic floor disorders in women with obstructed defaecation syndrome

BACKGROUND

Obstructed defaecation syndrome (ODS) is difficulty in evacuating stools, requiring straining efforts at defaecation, having the sensation of incomplete evacuation, or the need to manually assist defaecation. This is due to a physical blockage of the faecal stream during defaecation attempts, caused by rectocele, enterocele, intussusception, anismus or pelvic floor descent. Evacuation proctography (EP) is the most common imaging technique for diagnosis of posterior pelvic floor disorders. It has been regarded as the reference standard because of extensive experience, although it has been proven not to have perfect accuracy. Moreover, EP is invasive, embarrassing and uses ionising radiation. Alternative imaging techniques addressing these issues have been developed and assessed for their accuracy. Because of varying results, leading to a lack of consensus, a systematic review and meta-analysis of the literature are required.

OBJECTIVES

To determine the diagnostic test accuracy of EP, dynamic magnetic resonance imaging (MRI) and pelvic floor ultrasound for the detection of posterior pelvic floor disorders in women with ODS, using latent class analysis in the absence of a reference standard, and to assess whether MRI or ultrasound could replace EP. The secondary objective was to investigate differences in diagnostic test accuracy in relation to the use of rectal contrast, evacuation phase, patient position and cut-off values, which could influence test outcome.

SEARCH METHODS

We ran an electronic search on 18 December 2019 in the Cochrane Library, MEDLINE, Embase, SCI, CINAHL and CPCI. Reference list, Google scholar. We also searched WHO ICTRP and clinicaltrials.gov for eligible articles. Two review authors conducted title and abstract screening and full-text assessment, resolving disagreements with a third review author.

SELECTION CRITERIA

Diagnostic test accuracy and cohort studies were eligible for inclusion if they evaluated the test accuracy of EP, and MRI or pelvic floor ultrasound, or both, for the detection of posterior pelvic floor disorders in women with ODS. We excluded case-control studies. If studies partially met the inclusion criteria, we contacted the authors for additional information.

DATA COLLECTION AND ANALYSIS

Two review authors performed data extraction, including study characteristics, 'Risk-of-bias' assessment, sources of heterogeneity and test accuracy results. We excluded studies if test accuracy data could not be retrieved despite all efforts. We performed meta-analysis using Bayesian hierarchical latent class analysis. For the index test to qualify as a replacement test for EP, both sensitivity and specificity should be similar or higher than the historic reference standard (EP), and for a triage test either specificity or sensitivity should be similar or higher. We conducted heterogeneity analysis assessing the effect of different test conditions on test accuracy. We ran sensitivity analyses by excluding studies with high risk of bias, with concerns about applicability, or those published before 2010. We assessed the overall quality of evidence (QoE) according to GRADE.

MAIN RESULTS

Thirty-nine studies covering 2483 participants were included into the meta-analyses. We produced pooled estimates of sensitivity and specificity for all index tests for each target condition. Findings of the sensitivity analyses were consistent with the main analysis. Sensitivity of EP for diagnosis of rectocele was 98% (credible interval (CrI)94%-99%), enterocele 91%(CrI 83%-97%), intussusception 89%(CrI 79%-96%) and pelvic floor descent 98%(CrI 93%-100%); specificity for enterocele was 96%(CrI 93%-99%), intussusception 92%(CrI 86%-97%) and anismus 97%(CrI 94%-99%), all with high QoE. Moderate to low QoE showed a sensitivity for anismus of 80%(CrI 63%-94%), and specificity for rectocele of 78%(CrI 63%-90%) and pelvic floor descent 83%(CrI 59%-96%). Specificity of MRI for diagnosis of rectocele was 90% (CrI 79%-97%), enterocele 99% (CrI 96%-100%) and intussusception 97% (CrI 88%-100%), meeting the criteria for a triage test with high QoE. MRI did not meet the criteria to replace EP. Heterogeneity analysis showed that sensitivity of MRI performed with evacuation phase was higher than without for rectocele (94%, CrI 87%-98%) versus 65%, CrI 52% to 89%, and enterocele (87%, CrI 74%-95% versus 62%, CrI 51%-88%), and sensitivity of MRI without evacuation phase was significantly lower than EP. Specificity of transperineal ultrasound (TPUS) for diagnosis of rectocele was 89% (CrI 81%-96%), enterocele 98% (CrI 95%-100%) and intussusception 96% (CrI 91%-99%); sensitivity for anismus was 92% (CrI 72%-98%), meeting the criteria for a triage test with high QoE. TPUS did not meet the criteria to replace EP. Heterogeneity analysis showed that sensitivity of TPUS performed with rectal contrast was not significantly higher than without for rectocele(92%, CrI 69%-99% versus 81%, CrI 58%-95%), enterocele (90%, CrI 71%-99% versus 67%, CrI 51%-90%) and intussusception (90%, CrI 69%-98% versus 61%, CrI 51%-86%), and was lower than EP. Specificity of endovaginal ultrasound (EVUS) for diagnosis of rectocele was 76% (CrI 54%-93%), enterocele 97% (CrI 80%-99%) and intussusception 93% (CrI 72%-99%); sensitivity for anismus was 84% (CrI 59%-96%), meeting the criteria for a triage test with very low to moderate QoE. EVUS did not meet the criteria to replace EP. Specificity of dynamic anal endosonography (DAE) for diagnosis of rectocele was 88% (CrI 62%-99%), enterocele 97% (CrI 75%-100%) and intussusception 93% (CrI 65%-99%), meeting the criteria for a triage test with very low to moderate QoE. DAE did not meet the criteria to replace EP. Echodefaecography (EDF) had a sensitivity of 89% (CrI 65%-98%) and specificity of 92% (CrI 72%-99%) for intussusception, meeting the criteria to replace EP but with very low QoE. Specificity of EDF for diagnosis of rectocele was 89% (CrI 60%-99%) and for enterocele 97% (CrI 87%-100%); sensitivity for anismus was 87% (CrI 72%-96%), meeting the criteria for a triage test with low to very low QoE.

AUTHORS' CONCLUSIONS

In a population of women with symptoms of ODS, none of the imaging techniques met the criteria to replace EP. MRI and TPUS met the criteria of a triage test, as a positive test confirms diagnosis of rectocele, enterocele and intussusception, and a negative test rules out diagnosis of anismus. An evacuation phase increased sensitivity of MRI. Rectal contrast did not increase sensitivity of TPUS. QoE of EVUS, DAE and EDF was too low to draw conclusions. More well-designed studies are required to define their role in the diagnostic pathway of ODS.

BDNF rescues aging-associated internal anal sphincter dysfunction

Aging can lead to rectoanal incontinence due to internal anal sphincter (IAS) dysfunction, which is characterized by a decrease in IAS tone and contractility and an increase in nonadrenergic noncholinergic (NANC) relaxation. We aimed to determine whether brain-derived neurotropic factor (BDNF) rescues this aging-associated IAS dysfunction (AAID). To do so, we studied the effects of BDNF on the basal and G protein-coupled receptors (GPCR)-stimulated IAS smooth muscle tone and on NANC relaxation in Fischer 344 rats representing different age groups [26-mo-old (aging) vs. 6-mo-old (young)], before and after tyrosine kinase receptor B (TrkB) antagonist K252a. We also used isolated smooth muscle cells (SMCs) to determine the effects of BDNF before and after different agonists. For some studies, we monitored NO release using smooth muscle perfusates. BDNF reversed AAID by rescuing the basal IAS tone and agonists [thromboxane A₂ analog (U46619) and angiotensin II (ANG II)]-induced contractility, and NANC relaxation. These rescue effects of BDNF were selective as K252a attenuated the changes in the IAS without modifying the effects of K⁺depolarization. Because of the direct association between the basal and GPCR-stimulated IAS tone and RhoA/ROCK activation, we speculate that this pathway in the rescue effects of BDNF. Conversely, our data suggest that aging-associated increased NANC relaxation is reversed by decreased release of NO and decrease in the sensitivity of the released inhibitory neurotransmitter. In summary, BDNF rescue of AAID involves RhoA/ROCK and inhibitory neurotransmission. These data have direct implications for the role of BDNF in the pathophysiology and therapeutic targeting of aging-associated rectoanal motility disorders.NEW & NOTEWORTHY These studies demonstrate that brain-derived neurotropic factor (BDNF) rescues the aging-associated internal anal sphincter (IAS) dysfunction, characterized by a decrease in IAS tone, and increase in non-adrenergic noncholinergic relaxation. We determined the effects of BDNF on the basal and GPCR (TXA₂ and ANG II)-stimulated IAS tone, and on NANC relaxation, before and after TrkB inhibitor K252a. BDNF may have an important role in the pathophysiology and therapeutic targeting of certain rectoanal motility disorders.

ANORECTAL MANOMETRY STANDARD OF A BRAZILIAN POPULATION AT PRODUCTIVE AGE WITHOUT PELVIC FLOOR DISORDERS: A PROSPECTIVE VOLUNTEERED STUDY

Background:

Due to the lack of normal standards of anorectal manometry in Brazil, data used are subject to normality patterns described at different nationalities.

Aim:

To determine the values and range of the parameters evaluated at anorectal manometry in people, at productive age, without pelvic floor disorders comparing the parameters obtained between male and female.

Methods:

Prospective analysis of clinical data, such as gender, age, race, body mass index (BMI) and anorectal manometry, of volunteers from a Brazilian university reference in pelvic floor disorders.

Results:

Forty patients were included, with a mean age of 45.5 years in males and 37.2 females (p=0.43). According to male and female, respectively in mmHg, resting pressures were similar (78.28 vs. 63.51, p=0.40); squeeze pressures (153.89 vs. 79.78, p=0.007) and total squeeze pressures (231.27 vs. 145.63, p=0.002). Men presented significantly higher values of anorectal squeeze pressures, as well as the average length of the functional anal canal (2.85 cm in male vs. 2.45 cm in female, p=0.003).

Conclusions:

Normal sphincter pressure levels in Brazilians differ from those used until now as normal literature standards. Male gender has higher external anal sphincter tonus as compared to female, in addition a greater extension of the functional anal canal

Gastrointestinal motility disorders in neurologic disease

The extrinsic and autonomic nervous system intricately controls the major functions of the gastrointestinal tract through the enteric nervous system; these include motor, secretory, sensory, storage, and excretory functions. Disorders of the nervous system affecting gastrointestinal tract function manifest primarily as abnormalities in motor (rather than secretory) functions. Common gastrointestinal symptoms in neurologic disorders include sialorrhea, dysphagia, gastroparesis, intestinal pseudo-obstruction, constipation, diarrhea, and fecal incontinence. Diseases of the entire neural axis ranging from the cerebral hemispheres to the peripheral autonomic nerves can result in gastrointestinal motility disorders. The most common neurologic diseases affecting gastrointestinal function are stroke, parkinsonism, multiple sclerosis, and diabetic neuropathy. Diagnosis involves identification of the neurologic disease and its distribution, and documentation of segmental gut dysfunction, typically using noninvasive imaging, transit measurements, or intraluminal measurements of pressure activity and coordination of motility. Apart from treatment of the underlying neurologic disease, management focuses on restoration of normal hydration and nutrition and pharmacologic treatment of the gut neuromuscular disorder.

Functional Constipation: Individualising Assessment and Treatment

Chronic constipation is one of the five most common symptoms seen by gastroenterologist. In the absence of alarm symptoms, a confident symptom-based diagnosis can often be made using the Rome criteria. Three different subtypes have been identified to date: normal transit constipation, defaecatory disorders and slow transit constipation. Differentiation between these subtypes can be made through functional testing using tests such as anorectal manometry with balloon expulsion and a radio-opaque marker test. In general, patients are initially advised to increase their fluid and fibre intake. When these general lifestyle recommendations do not improve patients' symptoms, a step-wise and add-on treatment approach should be applied. This review summarises the diagnostic criteria to differentiate functional constipation from other causes of chronic constipation. In addition, current drug treatment options, including discussion of new therapeutic targets are discussed. Further, practical treatment approaches (choice and dosing), include discussion of combination/augmentation, treatment failure (adherence/expectations), and relapse prevention are mentioned. Finally, treatment and management of pain and bloating aspects are included.

External Anal Sphincter Fatigability: An Electromyographic and Manometric Study in Patients With Anorectal Disorders

Background/Aims

External anal sphincter (EAS) plays an important role in fecal and gas voluntary continence. Like every muscle, it can be affected by repeated efforts due to fatigability (physiological response) and/or fatigue (pathological response). No standardized fatiguing protocol and measure method to assess EAS fatigability has existed. The aim is to test a simple, standardized protocol for fatiguing and measuring EAS fatigability and fatigue to understand better the part of EAS fatigability in the pathophysiology of fecal incontinence.

Methods

Patients with anorectal disorders evaluated with anorectal manometry were included. They had to perform 10 repetitions of maximum voluntary contraction (MVC) of 20 seconds. Measurement was made with an anorectal manometry catheter and a surface recording electromyography (EMG). The primary outcome was the difference in EMG root mean square between the first and the last MVC. Secondary outcomes were differences in other EMG and manometry parameters between the first and the last MVC. Difficulties and adverse effects were recorded.

Results

Nineteen patients underwent the fatiguing protocol. All patients completed the entire protocol and no complications were found. No difficulty was declared by the examiner. A significant decrease in root mean square was found between the first and last MVC (0.01020 ± 0.00834 mV vs 0.00661 ± 0.00587 mV; P = 0.002), in maximum anal pressure area under the curve of continuous recordings of anal pressure and mean and total EMG power (P < 0.05).

Conclusions

This protocol is simple and minimally invasive to measure EAS fatigue and fatigability. We highlighted a fatigue of EAS in many patients with anorectal disorders.

Anatomical feasibility of peripheral nerve transfer to reestablish external anal sphincter control - cadaveric study

PURPOSE

Motor deficits affecting anal sphincter control can severely impair quality of life. Peripheral nerve transfer has been proposed as an option to reestablish anal sphincter motor function. We assessed, in human cadavers, the anatomical feasibility of nerve transfer from a motor branch of the tibialis portion of the sciatic nerve to two distinct points on pudendal nerve (PN), through transgluteal access, as a potential approach to reestablish anal sphincter function.

METHODS

We dissected 24 formalinized specimens of the gluteal region and posterior proximal third of the thigh. We characterized the motor fascicle (donor nerve) from the sciatic nerve to the long head of the biceps femoris muscle and the PN (recipient nerve), and measured nerve lengths required for direct coaptation from the donor nerve to the recipient in both the gluteal region (proximal) and perineal cavity (distal).

RESULTS

We identified three anatomical variations of the donor nerve as well as three distinct branching patterns of the recipient nerve from the piriformis muscle to the pudendal canal region. Donor nerve lengths (proximal and distal) were satisfactory for direct coaptation in all cases.

CONCLUSIONS

Transfer of a motor fascicle of the sciatic nerve to the PN is anatomically feasible without nerve grafts. Donor nerve length was sufficient and donor nerve functionally compatible (motor). Anatomical variations in the PN could also be accommodated.

Translumbosacral Neuromodulation Therapy for Fecal Incontinence: A Randomized Frequency Response Trial

INTRODUCTION

Treatments for fecal incontinence (FI) remain unsatisfactory because they do not remedy the underlying multifactorial dysfunction(s) including anorectal neuropathy. The aim of this study was to investigate the optimal dose frequency, clinical effects, and safety of a novel treatment, translumbosacral neuromodulation therapy (TNT), aimed at improving neuropathy.

METHODS

Patients with FI were randomized to receive 6 sessions of weekly TNT treatments consisting of 600 repetitive magnetic stimulations over each of 2 lumbar and 2 sacral sites with either 1, 5, or 15 Hz frequency. Stool diaries, FI severity indices, anorectal neurophysiology and sensorimotor function, and quality of life were compared. Primary outcome measure was the change in FI episodes/week. Responders were patients with ≥50% decrease in weekly FI episodes.

RESULTS

Thirty-three patients with FI participated. FI episodes decreased significantly (∆ ±95% confidence interval, 4.2 ± 2.8 (1 Hz); 2 ± 1.7 (5 Hz); 3.4 ± 2.5 (15 Hz); P < 0.02) in all 3 groups when compared with baseline. The 1 Hz group showed a significantly higher (P = 0.04) responder rate (91 ± 9.1%) when compared with the 5 Hz group (36 ± 18.2%) or 15 Hz (55 ± 18.2%); no difference was found between the 5 and 15 Hz groups (P = 0.667). Anal neuropathy, squeeze pressure, and rectal capacity improved significantly only in the 1 Hz (P < 0.05) group compared with baseline, but not in other groups. Quality of life domains improved significantly (P < 0.05) with 1 and 5 Hz groups. No device-related serious adverse events were noted.

DISCUSSION

TNT significantly improves FI symptoms in the short term, and the 1 Hz frequency was overall better than 5 and 15 Hz. Both anorectal neuropathy and physiology significantly improved, demonstrating mechanistic improvement. TNT is a promising, novel, safe, efficacious, and noninvasive treatment for FI (see Visual Abstract, Supplementary Digital Content 3, http://links.lww.com/AJG/B598).

Belgian consensus guideline on the management of hemorrhoidal disease

Introduction

Hemorrhoidal disease is a common problem that arises when hemorrhoidal structures become engorged and/or prolapse through the anal canal. Both conservative and invasive treatment options are diverse and guidance to their implementation is lacking.

Methods

A Delphi consensus process was used to review current literature and draft relevant statements. These were reconciliated until sufficient agreement was reached. The grade of evidence was determined. These guidelines were based on the published literature up to June 2020.

Results

Hemorrhoids are normal structures within the anorectal region. When they become engorged or slide down the anal canal, symptoms can arise. Every treatment for symptomatic hemorrhoids should be tailored to patient profile and expectations. For low-grade hemorrhoids, conservative treatment should consist of fiber supplements and can include a short course of venotropics. Instrumental treatment can be added case by case : infrared coagulation or rubber band ligation when prolapse is more prominent. For prolapsing hemorrhoids, surgery can be indicated for refractory cases. Conventional hemorrhoidectomy is the most efficacious intervention for all grades of hemorrhoids and is the only choice for non-reducible prolapsing hemorrhoids.

Conclusions

The current guidelines for the management of hemorrhoidal disease include recommendations for the clinical evaluation of hemorrhoidal disorders, and their conservative, instrumental and surgical management.

Progress in Endoscopic Treatment of Hemorrhoids

Hemorrhoids are one of the most common diseases of the anorectal region. Previously, treatment for hemorrhoids included conservative treatment, outpatient treatment, and surgical treatment. The development of flexible reversible endoscopes has provided precise controllability and imaging, enabling further improvement and development of various endoscopic techniques to treat hemorrhoids. This article discusses several of these endoscopic techniques: rubber band ligation, sclerotherapy, and electrocoagulation. The development, efficacy, and advantages of these treatments are summarized and evaluated. It is expected that going forward, endoscopic technology will be further applied in clinical practice and may become the first-line method for the treatment of hemorrhoids.

The Macro- and Micro-Mechanics of the Colon and Rectum II: Theoretical and Computational Methods

Abnormal colorectal biomechanics and mechanotransduction associate with an array of gastrointestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, diverticula disease, anorectal disorders, ileus, and chronic constipation. Visceral pain, principally evoked from mechanical distension, has a unique biomechanical component that plays a critical role in mechanotransduction, the process of encoding mechanical stimuli to the colorectum by sensory afferents. To fully understand the underlying mechanisms of visceral mechanical neural encoding demands focused attention on the macro- and micro-mechanics of colon tissue. Motivated by biomechanical experiments on the colon and rectum, increasing efforts focus on developing constitutive frameworks to interpret and predict the anisotropic and nonlinear biomechanical behaviors of the multilayered colorectum. We will review the current literature on computational modeling of the colon and rectum as well as the mechanical neural encoding by stretch sensitive afferent endings, and then highlight our recent advances in these areas. Current models provide insight into organ- and tissue-level biomechanics as well as the stretch-sensitive afferent endings of colorectal tissues yet an important challenge in modeling theory remains. The research community has not connected the biomechanical models to those of mechanosensitive nerve endings to create a cohesive multiscale framework for predicting mechanotransduction from organ-level biomechanics.

Low preoperative maximum squeezing pressure evaluated by anorectal manometry is a risk factor for non-reversal of diverting stoma

PURPOSE

A diverting stoma is created to prevent anastomotic leakage and related complications impairing sphincteric function in rectal surgery. However, diverting stoma may be left unclosed. This study is aimed to analyze preoperative factors including anorectal manometric data associated with diverting stoma non-reversal before rectal surgery. We also addressed complications related to diverting stoma in patients undergoing surgery for rectal malignant tumor.

METHODS

A total of 203 patients with rectal malignant tumor who underwent sphincter-preserving surgery with diverting stoma were retrospectively evaluated. The risk factors for non-reversal of diverting stoma were identified by univariate and multivariate analyses. For these analyses, anorectal manometric data were measured before rectal surgery. The association between stoma-related complications and other clinicopathological features was also analyzed.

RESULTS

During the median follow-up of 46.4 months, 24% (49 patients) did not undergo stoma reversal. Among parameters that were available before rectal surgery, age ≥ 75 years, albumin < 3.5 g/dl, tumor size ≥ 30 mm, tumor distance from the anal verge < 4 cm, and maximum squeezing pressure (MSP) < 130 mmHg measured by anorectal manometry (ARM) were independent factors associated with stoma non-reversal. The most common stoma-related complication was peristomal skin irritation (25%). Ileostomy was the only factor associated with peristomal skin irritation.

CONCLUSION

The current study demonstrated that low preoperative MSP evaluated by ARM, old age, hypoalbuminemia, and a large tumor close to the anus were predictive of diverting stoma non-reversal. Stoma site should be well deliberated when patients have the aforementioned risk factors for diverting stoma non-reversal.

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.

Improvements in Self-Reported Depression Following Treatment of Fecal Incontinence with Sacral Neuromodulation

OBJECTIVE

To evaluate changes in self-reported depression after treatment of fecal incontinence (FI) with sacral neuromodulation.

MATERIALS AND METHODS

This is a subanalysis of data collected from March 2016 to October 2017 for an Institutional Review Board-approved retrospective cohort study. Demographic information, medical history, psychiatric comorbidities, and the Patient-Reported Outcomes Measurement Information System item bank t-scores were extracted from the electronic medical record. The differences in t-scores were compared with a two-sided paired t-test, and a p value <0.05 was considered statistically significant.

RESULTS

Of the cohort (n = 24), most were Caucasian (88%), female (92%), nonsmokers (92%). Median age was 63.5 years (interquartile range 57.5-71.0 years) and median body mass index was 27.7 kg/m² (range 18.3-42.9 kg/m² ). A significant decrease in mean depression t-scores occurred after implantation of a sacral neuromodulation device, -4.5 (95% confidence interval [CI]: -8.7, -0.2, p = 0.04). Self-reported pain interference (p = 0.37) and physical function (p = 0.47) scores were similar following implantation. Individuals with comorbid anxiety reported the greatest improvement in depression (-6.5, 95% CI: -11.8, -1.1, p = 0.02).

CONCLUSIONS

Treatment of FI with sacral neuromodulation was associated with improvement in self-reported depression with the greatest improvement in those with anxiety. Further prospective research is needed to corroborate these findings.

Latest Advances in Intersphincteric Resection for Low Rectal Cancer

Background

Intersphincteric resection (ISR) has been a preferable alternative to abdominoperineal resection (APR) for anal preservation in patients with low rectal cancer. Laparoscopic ISR and robotic ISR have been widely used with the proposal of 2 cm or even 1 cm rule of distal free margin and the development of minimally invasive technology. The aim of this review was to describe the newest advancements of ISR.

Methods

A comprehensive literature review was performed to identify studies on ISR techniques, preoperative chemoradiotherapy (PCRT), complications, oncological outcomes, and functional outcomes and thereby to summarize relevant information and controversies involved in ISR.

Results

Although PCRT is employed to avoid positive circumferential resection margin (CRM) and decrease local recurrence, it tends to engender damage of anorectal function and patients' quality of life (QoL). Common complications after ISR include anastomotic leakage (AL), anastomotic stricture (AS), urinary retention, fistula, pelvic sepsis, and prolapse. CRM involvement is the most important predictor for local recurrence. Preoperative assessment and particularly rectal endosonography are essential for selecting suitable patients. Anal dysfunction is associated with age, PCRT, location and growth of anastomotic stoma, tumour stage, and resection of internal sphincter.

Conclusions

The ISR technique seems feasible for selected patients with low rectal cancer. However, the postoperative QoL as a result of functional disorder should be fully discussed with patients before surgery.

A novel combined anorectal biofeedback and percutaneous tibial nerve stimulation protocol for treating fecal incontinence

BACKGROUND/AIMS

Fecal incontinence (FI) is a common, debilitating condition that causes major impact on quality of life for those affected. Non-surgical treatment options include anorectal biofeedback therapy (BF) and percutaneous tibial nerve stimulation (PTNS), usually performed separately. The aims of the current study were to determine the feasibility, tolerability, safety, and efficacy of performing a combined BF and PTNS treatment protocol.

METHODS

Female patients with urge FI were offered a novel pilot program combining BF with PTNS. The treatment protocol consisted of 13 weekly sessions: an educational session, followed by 5 combined BF and PTNS sessions, 6 PTNS and a final combined session. Anorectal physiology and clinical outcomes were assessed throughout the program. For efficacy, patients were compared with BF only historical FI patients matched for age, parity, and severity of symptoms.

RESULTS

A total of 12/13 (93%) patients completed the full program. Overall attendance rate was 93% (157/169 sessions). Patient comfort score with treatment was rated high at 9.8/10 (SD 0.7) for PTNS and 8.6/10 (SD 1.7) for the BF component. No major side effects were reported. A reduction of at least 50% in FI episodes/week was achieved by 58% of patients by visit 6, and 92% by visit 13. No physiology changes were evident immediately following PTNS compared with before, but pressure during sustained anal squeeze improved by the end of the treatment course. Comparing outcomes with historical matched controls, reductions in weekly FI episodes were more pronounced in the BF only group at visit 6, but not week 13.

CONCLUSIONS

In this pilot study, concurrent PTNS and anorectal biofeedback therapy has been shown to be feasible, comfortable, and low risk. The combined protocol is likely to be an effective treatment for FI, but future research could focus on optimizing patient selection.

Obstructed defecation syndrome: a diagnostic and therapeutic challenge

Obstructed defecation syndrome produces constipation with anal blockage and a feeling of incomplete evacuation, due to either anatomic and functional causes. This is a complex and multifactorial entity due to diverse etiological factors that may coexist in many patients. Therefore, a diagnostic approach requires structural and functional assessment. The concordance between findings of diagnostic tests is suboptimal, thus an individualized analysis is mandatory in each patient. Therapeutic strategies require the best understanding of anatomic and functional aspects. Consequently, this entity is a diagnostic and therapeutic challenge.

Anorectal Functional Outcomes Following Doppler-Guided Transanal Hemorrhoidal Dearterialization: Evidence from Vietnam

INTRODUCTION

Doppler-guided transanal hemorrhoidal dearterialization (THD) was considered a less invasive and innovative method to treat hemorrhoidal disease, but it may impact the anal area during dearterialization and mucopexy. Thus, this study aimed to assess any changes in anorectal manometry of grade III and IV hemorrhoidal patients following THD treatment.

METHODS

This prospective observational study was conducted with patients who had grades III and IV hemorrhoidal disease. The patients were treated using THD at the Department of Surgery in the National Hospital of Traditional Medicine (Hanoi, Vietnam) between June 2012 and December 2013. Anorectal manometry was performed prior to THD and again between 6 and 12 months following the procedure.

RESULTS

A total of 40 patients were enrolled in the study, including 32 with grade III hemorrhoids and 8 with grade IV hemorrhoids. The proportion of male patients (65%) was higher than that of female patients (35%), and the majority of patients (82.5%) were > 40 years old. The mean duration of symptoms prior to treatment was 12.3 years. The mean length of the anal sphincter was unchanged before and after THD (3.64 ± 0.40 cm prior to treatment vs. 3.66 ± 0.48 cm following treatment; p = 0.57). Significant differences in treatment-related changes were detected for all anorectal manometric measurements except maximum squeezing pressure (p < 0.05). No patient showed anal stenosis or fecal incontinence.

CONCLUSION

The THD technique did not change the length of the anal sphincter 6 months after hemorrhoid treatment. The values of anal pressure and rectal sensation decreased almost significantly between treatment and the follow-up visit. We suggest that further studies, which include larger sample sizes, should be conducted to confirm THD effectiveness in terms of anorectal functions.

BDNF augments rat internal anal sphincter smooth muscle tone via RhoA/ROCK signaling and nonadrenergic noncholinergic relaxation via increased NO release

Presently, there are no studies examining the neuromodulatory effects of brain-derived neurotropic factor (BDNF) on the basal internal anal sphincter (IAS) tone and nonadrenergic noncholinergic (NANC) relaxation. To examine this, we determined the neuromuscular effects of BDNF on basal IAS smooth muscle tone and the smooth muscle cells (SMCs) and the effects of NANC nerve stimulation before and after high-affinity receptor tyrosine kinase receptor B (TrkB) antagonist K252a. We also investigated the mechanisms underlying BDNF-augmented increase in the IAS tone and NANC relaxation. We found that BDNF-increased IAS tone and SMC contractility were TTX resistant and attenuated by K252a. TrkB-specific agonist 7,8-dihydroxyflavone, similar to BDNF, also produced a concentration-dependent increase in the basal tone, whereas TrkB inhibitors K252a and ANA-12 produced a decrease in the tone. In addition, BDNF produced leftward shifts in the concentration-response curves with U46619 and ANG II (but not with bethanechol and K⁺ depolarization), and these shifts were reversed by K252a. Effects of Y27632 and Western blot data indicated that the BDNF-induced increase in IAS tone was mediated via RhoA/ROCK. BDNF-augmented NANC relaxation by electrical field stimulation was found to be mediated via the nitric oxide (NO)/soluble guanylate cyclase (sGC) pathway rather than via increased sensitivity to NO. In conclusion, the net effect of BDNF was that it caused an increase in the basal IAS tone via RhoA/ROCK signaling. BDNF also augmented NANC relaxation via NO/sGC. These findings may have relevance to the role of BDNF in the pathophysiology and therapeutic targeting of the IAS-associated rectoanal motility disorders.NEW & NOTEWORTHY These studies for the first time to our knowledge demonstrate that increased levels of brain-derived neurotrophic factor (BDNF; conceivably released from smooth muscle cells and/or the enteric neurons) has two major effects. First, BDNF augments the internal anal sphincter (IAS) tone via tyrosine kinase receptor B/thromboxane A2-receptor, angiotensin II receptor type 1/RhoA/ROCK signaling; and second, it increases nonadrenergic noncholinergic relaxation via nitric oxide/soluble guanylate cyclase. These studies may have relevance in therapeutic targeting in the anorectal motility disorders associated with the IAS.

Loop analysis of the anal sphincter complex in fecal incontinent patients using functional luminal imaging probe

Cardiac loops have been used extensively to study myocardial function. With changes in cardiac pump function, loops are shifted to the right or left. Functional luminal imaging probe (FLIP) recordings allow for loop analysis of the anal sphincter and puborectalis muscle (PRM) function. The goal was to characterize anal sphincter area-pressure/tension loop changes in fecal incontinence (FI) patients. Fourteen healthy subjects and 14 patients with FI were studied. A custom-designed FLIP was placed in the vagina and then in the anal canal, and deflated in 20-ml steps, from 90 to 30 ml. At each volume, subjects performed maximal voluntary squeezes. Area-pressure (AP) and area-tension (AT) loops were generated for each squeeze cycle. Three-dimensional ultrasound imaging of the anal sphincter and PRM were obtained to determine the relationship between anal sphincter muscle damage and loop movements. With the increase in bag volume, AP loops and AT loops shifted to the right and upward in normal subjects (both anal and vaginal). The shift to the right was greater, and the upward movement was less in FI patients. The difference in the location of AP loops and AT loops was statistically significant at volumes of 50 ml to 90 ml (P < 0.05). A similar pattern was found in the vaginal loops. There is a significant relationship between the damage to the anal sphincter and PRM, and loop location of FI patients. We propose AP and AT loops as novel ways to assess the anal sphincter and PRM function. Such loops can be generated by real-time measurement of pressure and area within the anal canal.NEW & NOTEWORTHY We describe the use of area-pressure (AP) and area-tension (AT)-loop analysis of the anal sphincters and puborectalis muscles in normal subjects and fecal incontinent patients using the functional luminal imaging probe (FLIP). There are differences in the magnitude of the displacement of the loops with increase in the FLIP bag volume between normal subjects and patients with fecal incontinence. The latter group shifts more to the right in AP and AT space.

Preoperative incremental maximum squeeze pressure as a predictor of fecal incontinence after very low anterior resection for low rectal cancer

PURPOSE

Very low anterior resection (VLAR) is performed widely, but some patients are left with fecal incontinence (FI), which compromises their quality of life (QOL) severely. This study sought to identify the predictive factors of postoperative FI after VLAR, which remain unclear.

METHODS

We evaluated the anorectal manometry data of patients who underwent VLAR to identify the risk factors for postoperative FI among the various clinicopathological factors and manometric characteristics. FI and QOL were analyzed using the Wexner score and EORTC QLQ-C30, respectively.

RESULTS

The subjects of this study were 40 patients who underwent VLAR for low rectal cancer between April, 2015 and May, 2018. There were 11 (27%) patients in the major-FI group and 29 (73%) in the minor-FI group. Multivariate analysis revealed that low preoperative incremental maximum squeeze pressure (iMSP) was an independent risk factor for postoperative major-FI. Postoperative QOL tended to be worse in the major-FI group.

CONCLUSIONS

Preoperative low iMSP increases the risk of major-FI and impaired QOL after VLAR. This highlights the importance of performing preoperative anorectal manometry to evaluate the patient's anal function as well as to select the most appropriate operative procedure and early multifaceted treatment such as medication, rehabilitation, and biofeedback for postoperative FI.

Downregulation of thromboxane A2 and angiotensin II type 1 receptors associated with aging-related decrease in internal anal sphincter tone

Aging-associated decrease in internal anal sphincter (IAS) tone (AADI) is a major contributor in the rectoanal incontinence (RI). To determine the pathogenesis of AADI, we investigated the effect of aging on GPCR activation and related downstream signaling. We particularly investigated two GPCRs that characterize IAS smooth muscle cells (SMCs): thromboxane A2 and angiotensin II type 1. Two groups of Fischer 344 rats (6-month-old [young group] and 26-month-old [old group]) were employed to determine the GPCR function by isometric contraction, the expressions of GPCRs, and their downstream regulatory signaling proteins (regulator of G-protein signaling 2, RGS2; GPCR Kinase 5, GRK5; and β-arrestin, Arrb2) using RT-PCR, qPCR, and western blot analyses. We used reversible biotinylation to monitor the GPCR trafficking using SMCs. Aging selectively attenuated thromboxane A2 and Ang II-induced IAS contraction. RT-PCR, qPCR, and WB data revealed a significant decrease in the expressions of the GPCRs and increase in the expression of RGS2, GRK5, and Arrb2. The increased GPCR internalization and decreased recycling under aging were validated by reversible biotinylation. We conclude that downregulation of GPCR, accompanied by upregulation of regulatory proteins, plays an important role in receptor desensitization and may be important underlying mechanisms of RI in certain aging patients.

Clinical and physiological risk factors for fecal incontinence in chronically constipated women

BACKGROUND

Fecal incontinence (FI) and chronic constipation (CC) are disabling symptoms that cause a significant public health problem. The pathophysiology of combined constipation and FI is not fully understood. Our aim was to delineate the clinical, physiological and anatomical factors that may contribute to the association of FI and CC.

METHODS

A retrospective study was performed in a pelvic floor unit in a tertiary medical center. Consecutive female patients diagnosed with CC were included, and further divided into two groups according to the co-occurrence of FI. Demographic characteristics, anorectal physiology (obtained by manometry) and pelvic anatomical pathology (as assessed by dynamic pelvic ultrasound) were recorded and subsequently compared.

RESULTS

A total of 267 women were included in the study. Of those, 62 patients (23%) had an associated FI (CCFI). The CCFI group had higher body mass index (BMI) levels and a trend toward younger average age as compared to the group without FI (CCNFI). The number of vaginal and instrumental deliveries was similar in both groups. Anal resting and squeeze pressures were significantly lower in the CCFI group (64 ± 21 vs 48 ± 18, p = 0.004 and 141 ± 136.2 vs. 97.5 ± 38.6, p = 0.02, respectively). Rectal sensation abnormalities were common, but did not differ between both groups. Dyssynergic defecation and rectocele were more common in the CCNFI group (68% vs. 51%, p = 0.04 and 39% vs. 24%, p = 0/045, respectively.

CONCLUSIONS

Lower anal pressures and higher BMI were found among women with coexisting FI and CC. Pelvic floor anatomical and functional abnormalities are common in women diagnosed with CC and FI, but dyssynergia and diagnosis of significant rectocele, which cause obstructed defecation, were more common in the CCNFI group.

A Comprehensive Approach to Pouch Disorders

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical procedure of choice for patients with medically refractory ulcerative colitis (UC) or indeterminate colitis, UC with colonic dysplasia or neoplasia, and familial adenomatous polyposis. In general, patients experience good function outcomes and quality of life with an IPAA. Although pouchitis is the most well-recognized and frequent complication after IPAA, a number of additional inflammatory, postsurgical, structural, neoplastic, and functional complications may occur, resulting in pouch dysfunction. We herein provide a comprehensive review of pouch function and an approach to diagnosis and management of pouch complications.

Pelvic floor rehabilitation for defecation disorders

Pelvic floor rehabilitation is frequently recommended for defecation disorders, in both constipation and fecal incontinence. However, the lack of patient selection, together with the variety of rehabilitation methods and protocols, often jeopardize the results of this approach, causing difficulty in evaluating outcomes and addressing proper management, and above all, in obtaining scientific evidence for the efficacy of these methods for specific indications. The authors represent different gastroenterological and surgical scientific societies in Italy, and their aim was to identify the indications and agree on treatment protocols for pelvic floor rehabilitation of patients with defecation disorders. This was achieved by means of a modified Delphi method, utilizing a working team (10 members) which developed the statements and a consensus group (15 members, different from the previous ones) which voted twice also suggesting modifications of the statements.

Systematic review with meta-analysis: defecography should be a first-line diagnostic modality in patients with refractory constipation

BACKGROUND

Defecography is considered the reference standard for the assessment of pelvic floor anatomy and function in patients with a refractory evacuation disorder. However, the overlap of radiologically significant findings seen in patients with chronic constipation (CC) and healthy volunteers is poorly defined.

AIM

To systematically review rates of structural and functional abnormalities diagnosed by barium defecography and/or magnetic resonance imaging defecography (MRID) in patients with symptoms of CC and in healthy volunteers.

METHODS

Electronic searches of major databases were performed without date restrictions.

RESULTS

From a total of 1760 records identified, 175 full-text articles were assessed for eligibility. 63 studies were included providing data on outcomes of 7519 barium defecographies and 668 MRIDs in patients with CC, and 225 barium defecographies and 50 MRIDs in healthy volunteers. Pathological high-grade (Oxford III and IV) intussuscepta and large (>4 cm) rectoceles were diagnosed in 23.7% (95% CI: 16.8-31.4) and 15.9% (10.4-22.2) of patients, respectively. Enterocele and perineal descent were observed in 16.8% (12.7-21.4) and 44.4% (36.2-52.7) of patients, respectively. Barium defecography detected more intussuscepta than MRID (OR: 1.52 [1.12-2.14]; P = 0.009]). Normative data for both barium defecography and MRID structural and functional parameters were limited, particularly for MRID (only one eligible study).

CONCLUSIONS

Pathological structural abnormalities, as well as functional abnormalities, are common in patients with chronic constipation. Since structural abnormalities cannot be evaluated using nonimaging test modalities (balloon expulsion and anorectal manometry), defecography should be considered the first-line diagnostic test if resources allow.

Endoflip vs high-definition manometry in the assessment of fecal incontinence: A data-driven unsupervised comparison

BACKGROUND

How much anal sphincter dysfunction contributes to fecal incontinence (FI) is not clear. High-definition anorectal manometry (HDAM) and functional luminal imaging probe (Endoflip) are two new techniques to study anal sphincter function.

AIMS

The goal was to compare the diagnostic utility of HDAM and Endoflip using optimal feature(s) in each modality for FI diagnosis.

METHODS

Blinded classification was carried out on 70 female subjects (32 FI & 38 controls), using 3 prominent machine-learning clustering techniques, with 3 distance metrics. For HDAM, descriptive statistics, shape, and textural features characterizing the spatial relationship of pixels in the HDAM high-pressure zone, and for Endoflip, permutations of pressure and CSA combinations (ie, multiplication, division, or individually) at rest and squeeze were tested.

RESULTS

Intramodality: (a) Endoflip: Best clustering was obtained using the combination of the ratio of CSA over pressure at 40 and 50 mL at rest, which had significantly better specificity (P < 0.001) than using only pressure at 50 mL, no difference in sensitivity (P = 0.68). (b) HDAM: clustering using textural information at rest had significantly higher specificity compared to using only the maximal pressure at rest (P < 0.001). Intermodality: Clustering results using optimal features were not significantly different with respect to sensitivity or specificity (P > 0.05). Optimal Endoflip feature set differed significantly in specificity compared to HDAM maximal pressure at both rest (P < 0.001) and squeeze (P < 0.001).

CONCLUSION

Defective anal closure function is fairly sensitive and highly specific in diagnosing FI. Using optimal feature sets, HDAM and Endoflip perform in a similar fashion in diagnosing FI, but are not complementary.

A Protocol-Driven Assessment Promotes a More Accurate Diagnosis of Irritable Bowel Syndrome

A diverse range of conditions share symptoms commonly identified with irritable bowel syndrome. The objective of this study was to examine the diagnostic process in identifying additional diagnoses in women who are attending a clinic for evaluation of symptoms suggestive of irritable bowel syndrome. A retrospective audit was conducted of anonymous data gathered on consecutive female patients presenting to a specialist nurse-led service in Christchurch, New Zealand, with a provisional diagnosis of irritable bowel syndrome. A protocol containing routine pathology investigations and physical examination was used. Alarm features were identified and pertinent investigations were implemented. Rectocele was detected on rectal examination. Final diagnosis was noted and compared with baseline symptom data. Of 231 patients, 187 initially met Rome III criteria for irritable bowel syndrome. Red flags and abnormal investigations led to an alternate diagnosis in a further 27 patients. Of the 160 patients with irritable bowel syndrome, 31% were found to have a rectocele. They were seven times more likely to report a symptom associated with pelvic floor dysfunction (p < .0001) and four times more likely to report constipation (p = .0003). The use of a protocol including routine investigations and physical examination improves diagnostic yield. Pelvic floor dysfunction should be considered in those with unique symptom patterns and rectocele in the setting of irritable bowel syndrome.