An update on anorectal disorders for gastroenterologists

New Metrics in High-Resolution and High-Definition Anorectal Manometry

PURPOSE OF REVIEW

To review recently published diagnostic methods that use high-resolution (HR-) or high-definition- (HD-) anorectal manometry (ARM) techniques.

RECENT FINDINGS

The integrated pressurized volume (IPV) is a new measure based on spatiotemporal plots obtained from HR-ARM. The IPV may be clinically useful for improving the prediction of abnormal balloon expulsion test in patients with constipation and for discriminating patients with anorectal disorders from asymptomatic controls. Combination of IPV parameters was superior to conventional manometric parameters in predicting the responsiveness to biofeedback therapy. Moreover, several novel parameters including the HR-ARM resting integral, HR-ARM squeeze profile, and anorectal asymmetry index may each be useful as predictive factors for identifying patients with fecal incontinence. HR- and HD-ARM are increasingly performed worldwide for evaluation of anorectal function. Here, we describe new metrics whose clinical significance has not been fully established. Further standardization and validation of these metrics could provide clinically important new information and could help improve our understanding of the pathophysiology of anorectal disorders.

Measuring length-tension function of the anal sphincters and puborectalis muscle using the functional luminal imaging probe

The functional luminal imaging probe (FLIP) has been used to measure the distensibility of the anal canal. We hypothesized that with increasing distension of the anal canal with FLIP there will be an increase in length of the anal sphincter muscle allowing measurement of the length-tension function of anal sphincter and puborectalis muscles (PRM). We studied 14 healthy nulliparous women. A custom-designed FLIP bag (30-mm diameter) was placed in the vagina and then in the anal canal, distended in 10-ml steps with volumes ranging from 30 to 90 ml. At each volume, subject performed maximal voluntary squeezes. Length-tension measurements were also made with a manometric probe system. Tension was calculated (pressure × radius) in Newtons per meter using a custom software program. Peak tensions at different FLIP volumes were compared with the manometric data. No change in the luminal CSA was noted at low fluid volumes; the sphincter muscles were able to fully collapse the FLIP bag within the anal canal/vagina even at rest. At larger volumes, with each squeeze there was an increase in the bag pressure and reduction in the cross-sectional area, which represents concentric contraction of the muscle. Both rest and squeeze tension increased with the increase in volume in the anal as well as vaginal canal indicating that the external anal sphincter and puborectalis muscles produce more tension when lengthened. FLIP device, which has been used to describe the distensibility of the anal canal can also provide information on the length-tension function of the anal sphincters and PRM. NEW & NOTEWORTHY The functional luminal imaging probe (FLIP) has been used to describe the distensibility of the anal canal. This report is the first to describe the use of the FLIP in the vaginal canal and the anal canal to provide information on the length-tension function of the anal sphincter and puborectalis muscles, which may provide clinicians with additional information regarding the active components of muscle contraction involved in the anal closure function.

High-resolution and high-definition anorectal manometry: rediscovering anorectal function

Anorectal motor and functional disorders are common among the general population. Anorectal manometry allows the study of anorectal motor activity both at rest and mimicking different physiological situations. High-resolution anorectal manometry (HR-ARM) and high-definition anorectal manometry (HD-ARM) are increasingly used in clinical practice. In comparison with the conventional technique, HR-ARM and HD-ARM catheters provide a higher number of recording points because of their many, closely packed circumferential sensors. This allows time-space visualization (topographic or 2-3-plane mode) as spatially continuous measurements are obtained by interpolation between near sensors. HR-ARM and HD-ARM allow a more standardized, reproducible technique, and a better assessment and understanding of the functional anatomy of the sphincter complex. Newer specific parameters are now being developed for use with these systems. They are being currently assessed by multiple research teams, and many of them remain unavailable for clinical practice as of today. However, they provide highly relevant information, which is now prompting a redefinition of anorectal anatomy and physiology. The goal of the present review was to describe the currently available HR-ARM and HD-ARM techniques, to discuss the normal values so far reported, and to analyze the newer parameters that may be assessed with these techniques, and which will likely be highly useful for clinical practice in the upcoming future.

Evaluation and management of defecatory dysfunction in women

PURPOSE OF REVIEW

To summarize the current recommendations for the evaluation and management of defecatory dysfunction in women and highlight key relationships between defecatory dysfunction and other pelvic floor disorders, including pelvic organ prolapse, fecal incontinence, and voiding dysfunction.

RECENT FINDINGS

Conservative measures including lifestyle modifications, pharmacotherapy, and biofeedback continue to be the mainstay of treatment with newer therapies emerging. Physiologic testing and/or radiologic imaging should be considered for those who fail conservative therapy or are clinically complex. Surgical management is appropriate for carefully selected patients with anatomic causes of defecatory dysfunction. Further research is needed on surgical outcomes and patient expectations.

SUMMARY

Pelvic floor disorders, including defecatory dysfunction, have a significant societal impact and are highly prevalent among women. Given its potential complexity, a broader focus is needed when evaluating women with defecatory symptoms and effective treatment may require multidisciplinary care.

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.

Clinical measurement of gastrointestinal motility and function: who, when and which test?

Symptoms related to abnormal gastrointestinal motility and function are common. Oropharyngeal and oesophageal dysphagia, heartburn, bloating, abdominal pain and alterations in bowel habits are among the most frequent reasons for seeking medical attention from internists or general practitioners and are also common reasons for referral to gastroenterologists and colorectal surgeons. However, the nonspecific nature of gastrointestinal symptoms, the absence of a definitive diagnosis on routine investigations (such as endoscopy, radiology or blood tests) and the lack of specific treatments make disease management challenging. Advances in technology have driven progress in the understanding of many of these conditions. This Review serves as an introduction to a series of Consensus Statements on the clinical measurements of gastrointestinal motility, function and sensitivity. A structured, evidence-based approach to the initial assessment and empirical treatment of patients presenting with gastrointestinal symptoms is discussed, followed by an outline of the contribution of modern physiological measurement on the management of patients in whom the cause of symptoms has not been identified with other tests. Discussions include the indications for and utility of high-resolution manometry, ambulatory pH-impedance monitoring, gastric emptying studies, breath tests and investigations of anorectal structure and function in day-to-day practice and clinical management.

A high-resolution anorectal manometry parameter based on integrated pressurized volume: A study based on 204 male patients with constipation and 26 controls

BACKGROUND

Conventional anorectal manometric parameters based on linear waves cannot properly predict balloon expulsion (BE) time. We aimed to determine the correlation between integrated pressurized volume (IPV) parameters during simulated evacuation (SE) and BE time in healthy individuals and constipated patients and to assess the correlation between each parameter and symptoms.

METHODS

A total of 230 male participants (including 26 healthy volunteers and 204 chronically constipated patients) underwent high-resolution anorectal manometry (HRAM) and BE tests. The IPV was calculated by multiplying the amplitude, distance, and time from the HRAM profile. Receiver operating characteristic curve (ROC) analysis and partial least square regression (PLSR) were performed.

KEY RESULTS

ROC analysis indicated that the IPV ratio between the upper 1 cm and lower 4 cm of the anal canal was more effective for predicting BE time (area under the curve [AUC]: 0.74, 95% confidence interval [CI]: 0.67-0.80, P < .01) than the conventional anorectal parameters, including defecation index and rectoanal gradient (AUC: 0.60, 95% CI: 0.52-0.67, P = .01). PLSR analysis of a linear combination of IPV parameters yielded an AUC of 0.79. Moreover, the IPV ratio showed a greater clinical correlation with patient symptoms than conventional parameters.

CONCLUSIONS AND INFERENCES

The IPV parameters and the combination of IPV parameters via PLSR were more significantly correlated with BE time than the conventional parameters. Thus, this study presents a useful diagnostic tool for the evaluation of pathophysiologic abnormalities in dyssynergic defecation using IPV and BE time.

Anorectal Manometry in Defecatory Disorders: A Comparative Analysis of High-resolution Pressure Topography and Waveform Manometry

Background/Aims

Whether high-resolution anorectal pressure topography (HRPT), having better fidelity and spatio-temporal resolution is comparable to waveform manometry (WM) in the diagnosis and characterization of defecatory disorders (DD) is not known.

Methods

Patients with chronic constipation (Rome III) were evaluated for DD with HRPT and WM during bearing-down “on-bed” without inflated rectal balloon and “on-commode (toilet)” with 60-mL inflated rectal balloon. Eleven healthy volunteers were also evaluated.

Results

Ninety-three of 117 screened participants (F/M = 77/16) were included. Balloon expulsion time was abnormal (> 60 seconds) in 56% (mean 214.4 seconds). A modest correlation between HRPT and WM was observed for sphincter length (R = 0.4) and likewise agreement between dyssynergic subtypes (κ = 0.4). During bearing down, 2 or more anal pressure-segments (distal and proximal) could be appreciated and their expansion measured with HRPT but not WM. In constipated vs healthy participants, the proximal segment was more expanded (2.0 cm vs 1.0 cm, P = 0.003) and of greater pressure (94.8 mmHg vs 54.0 mmHg, P = 0.010) during bearing down on-commode but not on-bed.

Conclusions

Because of its better resolution, HRPT may identify more structural and functional abnormalities including puborectal dysfunction (proximal expansion) than WM. Bearing down on-commode with an inflated rectal balloon may provide additional dimension in characterizing DD.

Real-time Visualisation and Analysis of Clinicians' Performance during Palpation in Physical Examinations

OBJECTIVE

Motivated by the fact that palpation skills are challenging to learn and teach, particularly during Digital Rectal Examinations (DRE), and the lack of understanding of what constitutes adequate performance, we present a visualisation and analysis system that uses small position and pressure sensors located on the examining finger, allowing the quantitative analysis of duration, steps and pressure applied.

METHODS

The system is first described, followed by an experimental study of twenty experts from four clinical specialties performing ten DREs each on a benchtop model using the proposed system. Analysis of the constitutive steps was conducted to improve understanding of the examination. A Markov model representing executed tasks and analysis of pressure applied is also introduced.

RESULTS

The proposed system successfully allowed the visualisation and analysis during the experimental study. General Practitioners and Nurses were found to execute more tasks compared to Urologists and Colorectal Surgeons. Urologists executed the least number of tasks and were the most consistent group compared to others.

CONCLUSION

The ability to "see through" allowed us to better characterise the performance of experts when conducting a DRE on a benchtop model, comparing the performance of relevant specialties, and studying executed tasks and the pressure applied. The Markov model presented summarises task execution of experts and could be used to compare performance of novices against that of experts.

SIGNIFICANCE

This approach allows for the analysis of performance based on continuous sensor data recording that can be easily extended to real subjects and other types of physical examinations.

Functional and histologic effects after implanting pluripotent stem cells in a murine model with sphincterotomy

INTRODUCTION AND AIMS

Fecal incontinence is a disabling condition with devastating consequences for the patients. Medical and surgical options are not very satisfactory, reason by which regenerative medicine has been considered in this field. In the present research, we analyzed functional and histologic effects after implanting pluripotent stem cells (PSCs) in a murine model with sphincterotomy.

MATERIALS AND METHODS

Female Wistar rats were subjected to sphincterotomy and divided into three groups. Group 1 (control group) was treated with 300μL of balanced saline solution and group 2 (late treatment) and group 3 (early treatment) received 50,000 PSCs resuspended in 300μL of balanced saline solution. All animals were evaluated through high-resolution anorectal manometry 24hours before and after sphincterotomy and every month for three months. Finally, the rats were euthanized and histopathologic sections from the anal canal were obtained.

RESULTS

All groups showed a decrease in resting anal pressure and squeeze anal pressure 24hours after sphincterotomy. At the third month, higher anal pressures in the groups treated with PSCs were detected. Regarding the histologic effects, the microscopic architecture was restored and there was a significant decrease in the inflammatory response in the groups treated with PSCs.

CONCLUSION

PSCs implantation improves anal tone, as well as histologic structure, presenting better regenerative results when implanted as early treatment.

Intsy: a low-cost, open-source, wireless multi-channel bioamplifier system

OBJECTIVE

Multi-channel electrical recordings of physiologically generated signals are common to a wide range of biomedical fields. The aim of this work was to develop, validate, and demonstrate the practical utility of a high-quality, low-cost 32/64-channel bioamplifier system with real-time wireless data streaming capability.

APPROACH

The new 'Intsy' system integrates three main off-the-shelf hardware components: (1) Intan RHD2132 bioamplifier; (2) Teensy 3.2 microcontroller; and (3) RN-42 Bluetooth 2.1 module with a custom LabView interface for real-time data streaming and visualization. Practical utility was validated by measuring serosal gastric slow waves and surface EMG on the forearm with various contraction force levels. Quantitative comparisons were made to a gold-standard commercial system (Biosemi ActiveTwo).

MAIN RESULTS

Intsy signal quality was quantitatively comparable to that of the ActiveTwo. Recorded slow wave signals had high SNR (24  ±  2.7 dB) and wavefront propagation was accurately mapped. EMG spike bursts were characterized by high SNR (⩾10 dB) and activation timing was readily identified. Stable data streaming rates achieved were 3.5 kS s^-1 for wireless and 64 kS s^-1 for USB-wired transmission.

SIGNIFICANCE

Intsy has the highest channel count of any existing open-source, wireless-enabled module. The flexibility, portability and low cost ($1300 for the 32-channel version, or $2500 for 64 channels) of this new hardware module reduce the entry barrier for a range of electrophysiological experiments, as are typical in the gastrointestinal (EGG), cardiac (ECG), neural (EEG), and neuromuscular (EMG) domains.

Diagnostic Role of Anal Sphincter Relaxation Integral in High-Resolution Anorectal Manometry for Hirschsprung Disease in Infants

OBJECTIVE

To investigate the possible diagnostic role of anal sphincter relaxation integral (ASRI) in high-resolution anorectal manometry (HRAM) for Hirschsprung disease.

STUDY DESIGN

We performed conventional anorectal manometry (ARM) in 24 infants (8 with Hirschsprung disease and 16 without Hirschsprung disease) and HRAM in another 21 infants (9 with Hirschsprung disease and 12 without Hirschsprung disease) before and after October 2014. All infants underwent rectal suction biopsy for confirmation of Hirschsprung disease. We quantified rectoanal inhibitory reflex (RAIR) adequacy by calculating the ASRI in HRAM study at pressure cutoffs of less than 10, 15, and 20 mm Hg (ASRI10, ASRI15, and ASRI20, respectively) and investigated the diagnostic utility.

RESULTS

Patients with Hirschsprung disease who underwent HRAM had significantly lower ASRI10, ASRI15, and ASRI20 values than did infants without Hirschsprung disease (P = .0002, .0002, and .0003, respectively), indicating significant difference in internal anal sphincter relaxation during RAIR test between these 2 groups. ASRI10 exhibited a greater diagnostic accuracy, area under the curve, sensitivity, and specificity than did ASRI15 and ASRI20 for Hirschsprung disease. Moreover, the diagnostic accuracy of HRAM for Hirschsprung disease based on ASRI10 <7 mm Hg.s.cm was significantly greater than that of conventional ARM (P = .02).

CONCLUSIONS

ASRI10 may be indicative of the adequacy of RAIR by HRAM in infants, thus assisting the diagnosis of Hirschsprung disease. The diagnostic accuracy of HRAM (based on the ASRI10 value) is greater than that of conventional ARM for Hirschsprung disease. ASRI10 may be used in an automatic HRAM analysis system for the diagnosis of anorectal motility disorders.

Fecal incontinence and parity in the Dutch population: A cross-sectional analysis

Background

It is assumed that pregnancy and childbirth increase the risk of developing fecal incontinence (FI).

Objective

We investigated the incidence of FI in groups of nulliparous and parous women.

Methods

Retrospectively, we studied a cross-section of the Dutch female population (N = 680) who completed the Groningen Defecation & Fecal Continence questionnaire. We also analyzed a subgroup of healthy women (n = 572) and a subgroup of women with comorbidities (n = 108).

Results

The prevalence of FI and the Vaizey and Wexner scores did not differ significantly between nulliparous and parous women. Parous women were 1.6 times more likely to experience fecal urgency than nulliparous women (95% CI, 1.0–2.6, p = 0.042). Regression analyses showed that parity, mode of delivery, duration of second stage of labor, obstetrical laceration or episiotomy, and birth weight seem not to be associated with the likelihood of FI.

Conclusions

Pregnancy and childbirth seem not to be associated with the prevalence and severity of FI in the Dutch population. Vacuum and forceps deliveries, however, might result in a higher prevalence of FI. Although the duration of being able to control bowels after urge sensation is comparable between nulliparous and parous women, parous women experience fecal urgency more often.

In vivo magnetofection: a novel approach for targeted topical delivery of nucleic acids for rectoanal motility disorders

In these studies, we developed a novel approach of in vivo magnetofection for localized delivery of nucleic acids such as micro-RNA-139-5p (miR-139-5p; which is known to target Rho kinase2) to the circular smooth muscle layer of the internal anal sphincter (IAS). The IAS tone is known to play a major role in the rectoanal continence via activation of RhoA-associated kinase (RhoA/ROCK2). These studies established an optimized protocol for efficient gene delivery using an assembly of equal volumes of in vivo PolyMag and miR139-5p or anti-miR-139-5p (100 nM each) injected in the circular smooth muscle layer in the pinpointed areas of the rat perianal region and then incubated for 20 min under magnetic field. Magnetofection efficiency was confirmed and analyzed by confocal microscopy of FITC-tagged siRNA. Using physiological and biochemical approaches, we investigated the effects of miR-139-5p and anti-miR-139-5p on basal intraluminal IAS pressure (IASP), fecal pellet count, IAS tone, agonist-induced contraction, contraction-relaxation kinetics, and RhoA/ROCK2 signaling. Present studies demonstrate that magnetofection-mediated miR-139-5p delivery significantly decreased RhoA/ROCK2, p-MYPT1, and p-MLC₂₀ signaling, leading to decreases in the basal IASP and IAS tone and in rates of contraction and relaxation associated with increase in fecal pellet output. Interestingly, anti-miR-139-5p transfection had opposite effects on these parameters. Collectively, these data demonstrate that magnetofection is a promising novel method of in vivo gene delivery and of nucleotides to the internal anal sphincter for the site-directed and targeted therapy for rectoanal motility disorders. NEW & NOTEWORTHY These studies for the first time demonstrate the success of topical in vivo magnetofection (MF) of nucleic acids using perianal injections. To demonstrate its effectiveness, we used FITC-tagged siRNA via immunofluorescence microcopy and functional and biochemical evidence using miR-139-5p (which is known to target ROCK2). In conclusion, MF allows safe, convenient, efficient, and targeted delivery of oligonucleotides such as siRNAs and microRNAs. These studies have direct therapeutic implications in rectoanal motility disorders especially associated with IAS.

Chronic constipation

Chronic constipation is a prevalent condition that severely impacts the quality of life of those affected. Several types of primary chronic constipation, which show substantial overlap, have been described, including normal-transit constipation, rectal evacuation disorders and slow-transit constipation. Diagnosis of primary chronic constipation involves a multistep process initiated by the exclusion of 'alarm' features (for example, unintentional weight loss or rectal bleeding) that might indicate organic diseases (such as polyps or tumours) and a therapeutic trial with first-line treatments such as dietary changes, lifestyle modifications and over-the-counter laxatives. If symptoms do not improve, investigations to diagnose rectal evacuation disorders and slow-transit constipation are performed, such as digital rectal examination, anorectal structure and function testing (including the balloon expulsion test, anorectal manometry or defecography) or colonic transit tests (such as the radiopaque marker test, wireless motility capsule test, scintigraphy or colonic manometry). The mainstays of treatment are diet and lifestyle interventions, pharmacological therapy and, rarely, surgery. This Primer provides an introduction to the epidemiology, pathophysiological mechanisms, diagnosis, management and quality of life associated with the commonly encountered clinical problem of chronic constipation in adults unrelated to opioid abuse.

Surgical Interventions and the Use of Device-Aided Therapy for the Treatment of Fecal Incontinence and Defecatory Disorders

The purpose of this clinical practice update expert review is to describe the key principles in the use of surgical interventions and device-aided therapy for managing fecal incontinence (FI) and defecatory disorders. The best practices outlined in this review are based on relevant publications, including systematic reviews and expert opinion (when applicable). Best Practice Advice 1: A stepwise approach should be followed for management of FI. Conservative therapies (diet, fluids, techniques to improve evacuation, a bowel training program, management of diarrhea and constipation with diet and medications if necessary) will benefit approximately 25% of patients and should be tried first. Best Practice Advice 2: Pelvic floor retraining with biofeedback therapy is recommended for patients with FI who do not respond to the conservative measures indicated above. Best Practice Advice 3: Perianal bulking agents such as intra-anal injection of dextranomer may be considered when conservative measures and biofeedback therapy fail. Best Practice Advice 4: Sacral nerve stimulation should be considered for patients with moderate or severe FI in whom symptoms have not responded after a 3-month or longer trial of conservative measures and biofeedback therapy and who do not have contraindications to these procedures. Best Practice Advice 5: Until further evidence is available, percutaneous tibial nerve stimulation should not be used for managing FI in clinical practice. Best Practice Advice 6: Barrier devices should be offered to patients who have failed conservative or surgical therapy, or in those who have failed conservative therapy who do not want or are not eligible for more invasive interventions. Best Practice Advice 7: Anal sphincter repair (sphincteroplasty) should be considered in postpartum women with FI and in patients with recent sphincter injuries. In patients who present later with symptoms of FI unresponsive to conservative and biofeedback therapy and evidence of sphincter damage, sphincteroplasty may be considered when perianal bulking injection and sacral nerve stimulation are not available or have proven unsuccessful. Best Practice Advice 8: The artificial anal sphincter, dynamic graciloplasty, may be considered for patients with medically refractory severe FI who have failed treatment or are not candidates for barrier devices, sacral nerve stimulation, perianal bulking injection, sphincteroplasty and a colostomy. Best Practice Advice 9: Major anatomic defects (eg, rectovaginal fistula, full-thickness rectal prolapse, fistula in ano, or cloaca-like deformity) should be rectified with surgery. Best Practice Advice 10: A colostomy should be considered in patients with severe FI who have failed conservative treatment and have failed or are not candidates for barrier devices, minimally invasive surgical interventions, and sphincteroplasty. Best Practice Advice 11: A magnetic anal sphincter device may be considered for patients with medically refractory severe FI who have failed or are not candidates for barrier devices, perianal bulking injection, sacral nerve stimulation, sphincteroplasty, or a colostomy. Data regarding efficacy are limited and 40% of patients had moderate or severe complications. Best Practice Advice 12: For defecatory disorders, biofeedback therapy is the treatment of choice. Best Practice Advice 13: Based on limited evidence, sacral nerve stimulation should not be used for managing defecatory disorders in clinical practice. Best Practice Advice 14: Anterograde colonic enemas are not effective in the long term for management of defecatory disorders. Best Practice Advice 15: The stapled transanal rectal resection and related procedures should not be routinely performed for correction of structural abnormalities in patients with defecatory disorders.

Efficacy and Predictors for Biofeedback Therapeutic Outcome in Patients with Dyssynergic Defecation

Aim

To evaluate the short-term efficacy of biofeedback therapy (BFT) for dyssynergic defecation (DD) and to explore the predictors of the efficacy of BFT.

Methods

Clinical symptoms, psychological state, and quality of life of patients before and after BFT were investigated. All patients underwent lifestyle survey and anorectal physiology tests before BFT. Improvement in symptom scores was considered proof of clinical efficacy of BFT. Thirty-eight factors that could influence the efficacy of BFT were studied. Univariate and multivariate analysis was conducted to identify the independent predictors.

Results

Clinical symptoms, psychological state, and quality of life of DD patients improved significantly after BFT. Univariate analysis showed that efficacy of BFT was positively correlated to one of the 36-item Short-Form Health Survey terms, the physical role function (r = 0.289; P = 0.025), and negatively correlated to the stool consistency (r = −0.220; P = 0.032), the depression scores (r = −0.333; P = 0.010), and the first rectal sensory threshold volume (r = −0.297; P = 0.022). Multivariate analysis showed depression score (β = −0.271; P = 0.032) and first rectal sensory threshold volume (β = −0.325; P = 0.013) to be independent predictors of BFT efficacy.

Conclusion

BFT improves the clinical symptoms of DD patients. Depression state and elevated first rectal sensory threshold volume were independent predictors of poor outcome with BFT.

Intractable Constipation in the Elderly

OPINION STATEMENT

Chronic constipation is a common gastrointestinal disorder disproportionately affecting the elderly. Immobility, polypharmacy, and physiologic changes contribute to its increased prevalence in this population. Unidentified and undertreated constipation leads to a significant negative impact on quality of life and an increase in healthcare spending. Careful physical examination and exploration of the clinical history can unmask primary and secondary forms of constipation, guiding diagnostic and therapeutic considerations. Non-pharmacologic treatment options include bowel training and biofeedback as well as the addition of fiber. Laxatives are safe and can be used long term; thus, they remain the mainstay of therapy. Newer agents with specific physiologic targets have proven to be effective in adults with chronic constipation, but data is lacking for safety profile in the elderly. Consideration for surgery in medically refractory cases should be entertained, while use of neuromodulation is not ready for prime time. This is a review of the currently available treatment options for chronic constipation in adults and specifically tailored towards the elderly.

3D High-definition anorectal manometry: Values obtained in asymptomatic volunteers, fecal incontinence and chronic constipation. Results of a prospective multicenter study (NOMAD)

BACKGROUND

3D-high definition anorectal manometry (3DARM) may aid the diagnosis of functional anorectal disorders, but data comparing asymptomatic and symptomatic subjects are scarce. We aimed to describe 3DARM values in asymptomatic volunteers and those with fecal incontinence (FI) or chronic constipation (CC), and identify which variables differentiate best these groups.

METHODS

Asymptomatic subjects were stratified by sex, age, and parity. Those with FI or CC were included according to anorectal symptom questionnaires. Endoanal ultrasound examination and 3DARM were performed the same day. Anal pressures were analyzed at rest, during voluntary squeeze, and during push maneuver, and compared between the 3 groups. Anal pressure defects were defined and compared to ultrasound defects.

KEY RESULTS

A total of 126 subjects (113 female, mean age 52 years, range 18-83) were included; 36 asymptomatic, 38 FI, 42 CC. Anal resting and squeeze pressures, and rectal sensitivity values were lower in FI women than in the other groups. Typical anal sphincter asymmetry during squeezing was less frequently observed in FI women. A dyssynergic pattern during push maneuver was found in 70% of asymptomatic subjects, and with a similar frequency in the 2 symptomatic groups. There was slight concordance between 3D-pressure defects and ultrasound defects.

CONCLUSIONS & INFERENCES

3D anal pressures in asymptomatic women were significantly lower than in men, and in FI compared to asymptomatic women. The classical dyssynergic pattern during push maneuver was found as frequently in asymptomatic and symptomatic patients. Further studies should try to identify 3DARM variables that could reliably identify dyssynergic defecation.

Nonrelaxing Pelvic Floor Dysfunction Is an Underestimated Complication of Ileal Pouch-Anal Anastomosis

BACKGROUND & AIMS

Nonrelaxing pelvic floor dysfunction (N-RPFD), or dyssynergic defecation, is the paradoxical contraction and/or impaired relaxation of pelvic floor and anal muscles during defecation. Few studies have evaluated this disorder in patients with an ileal pouch-anal anastomosis (IPAA). We investigated the frequency of N-RPFD in patients with and without chronic pouchitis following IPAA and the effectiveness of biofeedback therapy within this population.

METHODS

We conducted a retrospective study of all patients with an IPAA who underwent anorectal manometry between January 2000 and March 2015 (n = 111). N-RPFD was diagnosed in patients with symptoms consistent with a pouch evacuation disorder and 1 or more of the following abnormal tests: anorectal manometry, balloon expulsion test, barium or magnetic resonance defecography, or external anal sphincter electromyography. Patients who completed biofeedback therapy were identified and assessed to determine symptomatic response.

RESULTS

Of the 111 patients evaluated, 83 (74.8%) met criteria for N-RPFD. A significantly higher proportion of patients with chronic pouchitis were diagnosed with N-RPFD than patients without chronic pouchitis (83.3% vs 62.2%, respectively; P = .012). Most patients diagnosed with N-RPFD had abnormal results from the balloon expulsion test (78.3%); 53.0% of patients diagnosed with N-RPFD had abnormal findings from external anal sphincter electromyography, 25.3% had abnormal defecography findings, and 20.5% had abnormal findings from anorectal manometry. Twenty-two patients completed biofeedback therapy: 15 patients (68.2%) had mild-moderate improvement and 5 patients (22.7%) had significant improvement of symptoms.

CONCLUSIONS

N-RPFD occurs in almost 75% of patients with an IPAA, especially in patients with chronic pouchitis. Biofeedback seems to be an effective therapy for patients with an IPAA and N-RPFD, but further studies are needed for validation.

Methods of anorectal manometry vary widely in clinical practice: Results from an international survey

BACKGROUND

Ano-rectal manometry (ARM) is the most commonly performed investigation for assessment of anorectal dysfunction. Its use is supported by expert consensus documents and international guidelines. Variation in technology, data acquisition, and analysis affect results and clinical interpretation. This study examined variation in ARM between institutions to establish the status of current practice.

METHODS

A 50-item web-based questionnaire assessing analysis and interpretation of ARM was distributed by the International Anorectal Physiology Working Group via societies representing practitioners that perform ARM. Study methodology and performance characteristics between institutions were compared.

KEY RESULTS

One hundred and seven complete responses were included from 30 countries. Seventy-nine (74%) institutions performed at least two studies per week. Forty-nine centers (47%) applied conventional ARM (≤8 pressure sensors) and 57 (53%) high-resolution ARM (HR-ARM). Specialist centers were most likely to use HR-ARM compared to regional hospitals and office-based practice (63% vs 37%). Most conventional ARM systems used water-perfused technology (34/49); solid-state hardware was more frequently used in centers performing HR-ARM (44/57). All centers evaluated rest and squeeze. There was marked variation in the methods used to report results of maneuvers. No two centers had identical protocols for patient preparation, setup, study, and data interpretation, and no center fully complied with published guidelines.

CONCLUSIONS & INFERENCES

There is significant discrepancy in methods for data acquisition, analysis, and interpretation of ARM. This is likely to impact clinical interpretation, transfer of data between institutions, and research collaboration. There is a need for expert international co-operation to standardize ARM.

Rectal gas volume: Defining cut-offs for screening for evacuation disorders in patients with constipation

BACKGROUND

Diagnosis of rectal evacuation disorders (RED) is currently based on anorectal manometry (ARM) and evacuation tests in specialized laboratories; we recently showed higher rectal gas volume (RGV) and maximum rectal gas transaxial area (MRGTA) measured on abdominal and pelvic computed tomography (CT) in patients with documented RED.The aim of this study was to obtain cut-off values of RGV, MRGTA, and rectal area on scout film (RASF) to differentiate constipated patients with RED from those without RED, based on ARM, balloon expulsion test (BET), and colon transit test.

METHODS

We identified 118 constipated patients (65 with RED) with prior record of CT. Using standard CT software, we used a variable region of interest (ROI) program to measure RGV, MRTGA, and RASF, as previously described. We constructed receiver operating characteristics curves based on different values, and we estimated AUC, specificity, and positive predictive value (PPV) to detect RED in patients with constipation.

KEY RESULTS

Receiver operating characteristics of the models to predict RED showed AUC 0.751 for RGV and 0.737 for MRGTA (both P<.001), and 0.623 for RASF (P=.029). At specificity of 90%, RGV of 30 mL had a PPV 77.3%, MRGTA of 10 cm² had a PPV 75.0%, and RFAS of 9 cm² had a PPV of 68.8% for identifying constipated patients with RED.

CONCLUSIONS & INFERENCES

Rectal gas measurements on abdominal imaging may indicate RED in patients with constipation. At ~90% specificity for RED, RGV of 20 or 30 mL or MRGTA of 10 cm² on CT has PPV ~75%, and RASF of >9 cm² has PPV of ~69%.

Can three-dimensional high-resolution anorectal manometry detect anal sphincter defects in patients with faecal incontinence?

AIM

Endoanal ultrasound (EAUS) is the gold standard for detecting anal sphincter defects in patients with faecal incontinence (FI), while anorectal manometry evaluates sphincter function. Three-dimensional high-resolution anorectal manometry (3D HRAM) is a newer modality with the potential to assess both sphincter function and anatomy. The purpose of the present study was to compare 3D HRAM with 3D EAUS for the detection of anal sphincter defects in patients with FI.

METHOD

A linkage analysis was performed between the 3D HRAM and 3D EAUS databases of a tertiary referral centre to identify patients with FI who underwent both 3D EAUS and 3D HRAM. With 3D HRAM, a defect was defined as any pressure measurement below 25 mmHg at rest with at least 18° of continuous expansion. The 3D HRAM findings were compared with those of 3D EAUS.

RESULTS

The study cohort included 39 patients with a mean age of 64.7 ± 15.2 years (SD); and 31 (79%) were female. Eight (21%) patients had an anal sphincter defect on EAUS with a median size of 93° (range 40°-136°). Fourteen (36%) had a defect shown by 3D HRAM with a median size of 144° (36°-180°). The sensitivity, specificity and positive and negative predictive values of 3D HRAM in detecting a sphincter defect were 75%, 74%, 43% and 92%, respectively.

CONCLUSION

With a negative predictive value of 92%, 3D HRAM may be a useful screening method for ruling out a sphincter defect in patients with FI, thereby avoiding both EAUS and manometry in selected patients.

Update on Rome IV Criteria for Colorectal Disorders: Implications for Clinical Practice

PURPOSE OF REVIEW

The purpose of the review was to provide an update of the Rome IV criteria for colorectal disorders with implications for clinical practice.

RECENT FINDINGS

The Rome diagnostic criteria are expert consensus criteria for diagnosing functional gastrointestinal disorders (FGIDs). The current version, Rome IV, was released in May of 2016 after Rome III had been in effect for a decade. It is the collective product of committees that included more than 100 leading functional GI experts. For functional bowel and anorectal disorders, the majority of changes relative to Rome III are relatively minor and will have little impact on clinical practice. However, notable changes with potential impact on clinical practice and research include the changes in the diagnostic criteria for IBS, the modified approach for subtyping of IBS, the view on functional bowel disorders as a spectrum of disorders, and the new definition of fecal incontinence. New features in the Rome IV diagnostic criteria for functional bowel and anorectal disorders will likely have modest influence on clinical practice, with a few exceptions.

Effect of biofeedback therapy on anorectal physiological parameters among patients with fecal evacuation disorder

BACKGROUND

Though biofeedback therapy is often effective in patients with fecal evacuation disorder (FED), a common cause of chronic constipation (CC) in tertiary practice, data on anorectal physiological parameters following it are scanty.

METHODS

Consecutive patients with FED with CC diagnosed by abnormalities in at least two of the three tests (anorectal manometry, defecography, and balloon expulsion test [BET]) undergoing biofeedback (two sessions per day, 30 min each, for 2 weeks) during a 3-year period were analyzed. Clinical evaluation, anorectal manometry (ARM), and BET were performed at the beginning and after biofeedback.

RESULTS

Incomplete evacuation 42/43 (98%), straining 40/43 (93%), and feeling of outlet obstruction 35/43 (81%) were the most common symptoms among these 43 patients (median age 44 years, range 18-76, 30 [71%] male). All the three tests (defecography, BET, and ARM) were abnormal in 17 (40%) patients and the others had two abnormal tests. Improvement in physiological parameters was noted following biofeedback (median residual anal pressure during defecation 99 mmHg (range 52-148) vs. 78 mmHg (37-182), p = 0.03; maximum intra-rectal pressure 60 mmHg (90-110) vs. 76 mmHg (31-178); p = 0.01; defecation index 1.1 (0.1-23.0) vs. 3.2 (0.5-29.0); p = 0.001). Dyssynergia on ARM and BET got corrected in 22/34 (65%) and 18/30 (60%) patients. At a 1-month follow up, 23/37 (62%) patients reported satisfactory symptomatic improvement.

CONCLUSIONS

Biofeedback not only improves symptoms but also anorectal physiological parameters in patients with FED.

The importance of a high rectal pressure on strain in constipated patients: implications for biofeedback therapy

BACKGROUND

A subset of patients with chronic constipation display a relatively high manometric rectal pressure on strain. We hypothesized that these patients represent a unique phenotype of functional defecatory disorder (FDD) and would benefit from undergoing anorectal biofeedback (BF).

METHODS

Of 138 consecutive patients with chronic constipation and symptoms of FDD, 19 were defined as having a high rectal pressure on strain, using a statistically derived cut-off of 78 mm Hg. This subset was compared with remaining patients in regard to baseline clinical profile and physiology, and outcome of BF.

KEY RESULTS

There was a greater representation of males in the high rectal pressure group. Their constipation score, impact of bowel dysfunction on quality of life and satisfaction with bowel habits did not differ from the remaining patients. Eighty-four percent of patients in the high group successfully expelled the rectal balloon and 95% displayed paradoxical anal contraction on strain (P<.05 compared with the remaining patients). Following BF, 89% of patients in the high group reduced their rectal pressure to normal. End of BF treatment outcomes improved significantly, and to a similar degree, in both groups.

CONCLUSIONS & INFERENCES

We have identified a subgroup of patients with dyssynergic symptoms but without a formal Rome III diagnosis of FDD, who were characterized by a high straining rectal pressure. Although these patients displayed some physiological differences to the patients with lower straining rectal pressure, they suffer similarly. Importantly, we have shown that these patients can respond favorably to anorectal BF.

Reproducibility of high-definition (3D) manometry and its agreement with high-resolution (2D) manometry in women with fecal incontinence

BACKGROUND

While widely used in clinical practice, the reproducibility of high-definition anorectal manometry (HD-ARM) remains unclear. We evaluated the intra-individual reproducibility of HD-ARM and compared pressures measured with HD-ARM and high-resolution anorectal manometry (HR-ARM).

METHODS

Thirty-six women with fecal incontinence had an initial HD-ARM (HD-ARM1); on the same day, after randomization, 21 had a second (HD-ARM2). Sixteen women had a third (HD-ARM3) 4 weeks later. Twenty-five had also been evaluated by HR-ARM previously. Rectoanal pressures were assessed at rest, during squeeze and simulated evacuation. Concordance among pressures was assessed with Lin's concordance correlation coefficient (CCC).

KEY RESULTS

Anal resting and squeeze pressures measured with HD-ARM were reproducible on the same and different days; for average resting pressures of HD-ARM1 vs HD-ARM2, CCC = 0.73 (95% confidence interval [CI]: 0.53-0.94), and for HD-ARM1 vs HD-ARM3, CCC = 0.60 (95% CI: 0.28-0.93). For maximum squeeze pressures of HD-ARM1 vs HD-ARM2, CCC = 0.86 (95% CI: 0.75-0.97), and for HD-ARM1 vs HD-ARM3, CCC = 0.56 (95% CI: 0.21-0.91). The rectoanal gradient during evacuation was significantly concordant between HD-ARM1 and HD-ARM2 but not HD-ARM1 and HD-ARM3. Resting (CCC = 0.38 [95% CI: 0.14-0.62]) and squeeze pressures (CCC = 0.73 [95% CI: 0.57-0.89]) measured with HD-ARM1 and HR-ARM were also concordant.

CONCLUSIONS & INFERENCES

Among women with fecal incontinence, measurements with HD-ARM were reproducible on the same (anal resting and squeeze pressures and rectoanal gradient during evacuation) and different days (anal resting and squeeze pressures) and correlated with HR-ARM measurements. These findings support use of HD-ARM and HR-ARM for longitudinal assessments of anal resting and squeeze pressures.

Improving biofeedback for the treatment of fecal incontinence in women: implementation of a standardized multi-site manometric biofeedback protocol

BACKGROUND

Standardized training and clinical protocols using biofeedback for the treatment of fecal incontinence (FI) are important for clinical care. Our primary aims were to develop, implement, and evaluate adherence to a standardized protocol for manometric biofeedback to treat FI.

METHODS

In a Pelvic Floor Disorders Network (PFDN) trial, participants were enrolled from eight PFDN clinical centers across the United States. A team of clinical and equipment experts developed biofeedback software on a novel tablet computer platform for conducting standardized anorectal manometry with separate manometric biofeedback protocols for improving anorectal muscle strength, sensation, and urge resistance. The training protocol also included education on bowel function, anal sphincter exercises, and bowel diary monitoring. Study interventionists completed online training prior to attending a centralized, standardized certification course. For the certification, expert trainers assessed the ability of the interventionists to perform the protocol components for a paid volunteer who acted as a standardized patient. Postcertification, the trainers audited interventionists during trial implementation to improve protocol adherence.

KEY RESULTS

Twenty-four interventionists attended the in-person training and certification, including 46% advanced practice registered nurses (11/24), 50% (12/24) physical therapists, and 4% physician assistants (1/24). Trainers performed audio audits for 88% (21/24), representing 84 audited visits. All certified interventionists met or exceeded the prespecified 80% pass rate for the audit process, with an average passing rate of 93%.

CONCLUSIONS & INFERENCES

A biofeedback protocol can be successfully imparted to experienced pelvic floor health care providers from various disciplines. Our process promoted high adherence to a standard protocol and is applicable to many clinical settings.

Methods of Evaluation of Anorectal Causes of Obstructed Defecation

Obstructed defecation is a complex disorder that results in impaired propagation of stool from the rectum. It is one of the major subtypes of functional constipation and can be secondary to either functional or anatomic etiologies. Patients with obstructed defecation typically present with symptoms of abdominal discomfort, a sensation of incomplete evacuation and rectal obstruction, passage of hard stools, the need for rectal or vaginal digitation, excessive straining, and reduced stool frequency. Evaluation of obstructed defecation is multimodal, starting with a thorough history and physical examination with focus on the abdominal, perineal, and rectal examination. Additional modalities to elicit the diagnosis of obstructed defecation include proctoscopy, colonic transit time studies, anorectal manometry, a rectal balloon expulsion test, defecography, electromyography, and ultrasound. The results from these studies should be taken in the context of each patient's clinical situation, as there is no single criterion standard for the diagnosis of obstructed defecation. Surgery is typically a last resort for these patients and the majority of patients will have good symptomatic management with diet and lifestyle changes. Patients who are found to have functional mechanisms behind their obstructed defecation also benefit from pelvic floor exercises and biofeedback therapy.

A Predictive Model to Identify Patients With Fecal Incontinence Based on High-Definition Anorectal Manometry

BACKGROUND & AIMS

Three-dimensional high-definition anorectal manometry (3D-HDAM) is used to assess anal sphincter function; it determines profiles of regional pressure distribution along the length and circumference of the anal canal. There is no consensus, however, on the best way to analyze data from 3D-HDAM to distinguish healthy individuals from persons with sphincter dysfunction. We developed a computer analysis system to analyze 3D-HDAM data and to aid in the diagnosis and assessment of patients with fecal incontinence (FI).

METHODS

In a prospective study, we performed 3D-HDAM analysis of 24 asymptomatic healthy subjects (control subjects; all women; mean age, 39 ± 10 years) and 24 patients with symptoms of FI (all women; mean age, 58 ± 13 years). Patients completed a standardized questionnaire (FI severity index) to score the severity of FI symptoms. We developed and evaluated a robust prediction model to distinguish patients with FI from control subjects using linear discriminant, quadratic discriminant, and logistic regression analyses. In addition to collecting pressure information from the HDAM data, we assessed regional features based on shape characteristics and the anal sphincter pressure symmetry index.

RESULTS

The combination of pressure values, anal sphincter area, and reflective symmetry values was identified in patients with FI versus control subjects with an area under the curve value of 1.0. In logistic regression analyses using different predictors, the model identified patients with FI with an area under the curve value of 0.96 (interquartile range, 0.22). In discriminant analysis, results were classified with a minimum error of 0.02, calculated using 10-fold cross-validation; different combinations of predictors produced median classification errors of 0.16 in linear discriminant analysis (interquartile range, 0.25) and 0.08 in quadratic discriminant analysis (interquartile range, 0.25).

CONCLUSIONS

We developed and validated a novel prediction model to analyze 3D-HDAM data. This system can accurately distinguish patients with FI from control subjects.

The incidence rate and characteristics of clinically diagnosed defecatory disorders in the community

BACKGROUND

Defecatory disorders (DD) are defined by clinical and objective features of impaired rectal evacuation. The epidemiology of DD in the population is unknown, partly because many constipated patients do not undergo anorectal tests. Our objectives were to estimate the incidence rate and clinical features of DD in the community.

METHODS

We reviewed the medical records of all patients older than 16 years in Olmsted County, MN, who had constipation and underwent anorectal manometry from 1999 through 2008. Criteria for diagnosing DD were constipation for 6 months or longer and one of the following: (i) abnormal rectal balloon expulsion test; (ii) reduced or increased perineal descent; or (iii) two or more abnormal features with defecography or surface electromyography.

KEY RESULTS

Of 11 112 constipated patients, 516 had undergone anorectal tests; 245 of these (209 women, 36 men) had a DD. The mean (±SD) age at diagnosis was 44 years (±18) among women and 49 years (±19) among men. The overall age- and sex-adjusted incidence rate per 100 000 person-years was 19.3 (95% CI: 16.8-21.8). The age-adjusted incidence per 100 000 person-years was greater (p < 0.0001) in women (31.8, 95% CI: 27.4-36.1) than in men (6.6, 95% CI: 4.4-8.9). Prior to the diagnosis of DD, nearly 30% of patients had irritable bowel syndrome (IBS), 48% had a psychiatric diagnosis, 18% had a history of abuse, and 21% reported urinary and/or fecal incontinence.

CONCLUSIONS & INFERENCES

Among constipated patients, DD are fourfold more common in women than men and often associated with IBS and psychiatric diagnoses.

Aging-associated changes in microRNA expression profile of internal anal sphincter smooth muscle: Role of microRNA-133a

A comprehensive genomic and proteomic, computational, and physiological approach was employed to examine the (previously unexplored) role of microRNAs (miRNAs) as regulators of internal anal sphincter (IAS) smooth muscle contractile phenotype and basal tone. miRNA profiling, genome-wide expression, validation, and network analyses were employed to assess changes in mRNA and miRNA expression in IAS smooth muscles from young vs. aging rats. Multiple miRNAs, including rno-miR-1, rno-miR-340-5p, rno-miR-185, rno-miR-199a-3p, rno-miR-200c, rno-miR-200b, rno-miR-31, rno-miR-133a, and rno-miR-206, were found to be upregulated in aging IAS. qPCR confirmed the upregulated expression of these miRNAs and downregulation of multiple, predicted targets (Eln, Col3a1, Col1a1, Zeb2, Myocd, Srf, Smad1, Smad2, Rhoa/Rock2, Fn1, Tagln v2, Klf4, and Acta2) involved in regulation of smooth muscle contractility. Subsequent studies demonstrated an aging-associated increase in the expression of miR-133a, corresponding decreases in RhoA, ROCK2, MYOCD, SRF, and SM22α protein expression, RhoA-signaling, and a decrease in basal and agonist [U-46619 (thromboxane A₂ analog)]-induced increase in the IAS tone. Moreover, in vitro transfection of miR-133a caused a dose-dependent increase of IAS tone in strips, which was reversed by anti-miR-133a. Last, in vivo perianal injection of anti-miR-133a reversed the loss of IAS tone associated with age. This work establishes the important regulatory effect of miRNA-133a on basal and agonist-stimulated IAS tone. Moreover, reversal of age-associated loss of tone via anti-miR delivery strongly implicates miR dysregulation as a causal factor in the aging-associated decrease in IAS tone and suggests that miR-133a is a feasible therapeutic target in aging-associated rectoanal incontinence.

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

Background. Rome III criteria add physiological criteria to symptom-based criteria of chronic constipation (CC) for the diagnosis of defecatory disorders (DD). However, a gold-standard test is still lacking and physiological examination is expensive and time-consuming. Aim. Evaluate the usefulness of two low-cost tests-digital rectal examination (DRE) and balloon expulsion test (BET)-as screening or excluding tests of DD. Methods. We performed a systematic search in PUBMED and MEDLINE. We selected studies where constipated patients were evaluated by DRE or BET. Heterogeneity was assessed and random effect models were used to calculate the sensitivity, specificity, and negative predictive value (NPV) of the DRE and the BET. Results. Thirteen studies evaluating BET and four studies evaluating DRE (2329 patients) were selected. High heterogeneity (I2 > 80%) among studies was demonstrated. The studies evaluating the BET showed a sensitivity and specificity of 67% and 80%, respectively. Regarding the DRE, a sensitivity of 80% and specificity of 84% were calculated. NPV of 72% for the BET and NPV of 64% for the DRE were estimated. The sensitivity and specificity were similar when we restrict the analysis to studies using Rome criteria to define CC. The BET seems to perform better when a cut-off time of 2 minutes is used and when it is compared with a combination of physiological tests. Considering the DRE, strict criteria seem to improve the sensitivity but not the specificity of the test. Conclusion. Neither of the low-cost tests seems suitable for screening or excluding DD.

Determinants and clinical impact of pressure drift in manoscan anorectal high resolution manometry system

BACKGROUND

Pressure drift (PD), resulting from differences between room and body temperature, reduces the accuracy of pressure measurements with the Manoscan high resolution manometry (HRM) system. Our aims were to assess PD during anorectal HRM.

METHODS

Defined as the residual pressure measured immediately after the catheter was removed, PD was calculated for each sensor and averaged across all 12 sensors in 454 anorectal consecutive studies recorded with 3 HRM catheters. The relationship between PD and study duration, number of prior uses of a catheter, and peak and average pressure exposure during a study were evaluated. The correction of PD with a software algorithm (thermal compensation) was evaluated in 76 studies where the most distal sensor was outside the body.

KEY RESULTS

The PD varied among sensors and across catheters. The average PD (7.3 ± 0.2 mmHg) was significantly greater for newer catheters, during longer studies, or when sensors were exposed to higher pressures. Together, these factors explained 81% of the variance in overall PD. After thermal compensation, the uncorrected median PD for the most distal sensor was 2.5-5 mmHg over the study duration. Correcting this changed the interpretation (e.g., as abnormal instead of normal) of at least 1 anorectal parameter in eight of 76 studies.

CONCLUSIONS & INFERENCES

During anorectal HRM, PD declines with catheter use and is greater for newer catheters, when sensors are exposed to higher pressures, and for studies of longer duration. While PD is partially corrected with thermal compensation algorithms, the impact on interpretation is modest.

Bioengineering the gut: future prospects of regenerative medicine

Functions of the gastrointestinal tract include motility, digestion and absorption of nutrients. These functions are mediated by several specialized cell types including smooth muscle cells, neurons, interstitial cells and epithelial cells. In gastrointestinal diseases, some of the cells become degenerated or fail to accomplish their normal functions. Surgical resection of the diseased segments of the gastrointestinal tract is considered the gold-standard treatment in many cases, but patients might have surgical complications and quality of life can remain low. Tissue engineering and regenerative medicine aim to restore, repair, or regenerate the function of the tissues. Gastrointestinal tissue engineering is a challenging process given the specific phenotype and alignment of each cell type that colonizes the tract - these properties are critical for proper functionality. In this Review, we summarize advances in the field of gastrointestinal tissue engineering and regenerative medicine. Although the findings are promising, additional studies and optimizations are needed for translational purposes.

Endpoints for therapeutic interventions in faecal incontinence: small step or game changer

Faecal incontinence (FI) is common and its pathophysiology and treatments continue to evolve. However, a standard measure(s) for assessing its clinical outcome has been elusive. Consequently, over 100 measures and scoring systems, each with intrinsic biases have been reported. These include adequate relief or global satisfaction, ≥50% reduction in episodes or days without FI, quality of life (QOL), FI severity scales and composite indices. Earlier scales relied on the frequency and type of solid, liquid or flatus incontinence and effects on life style whereas newer scales have incorporated urgency, use of pads, antidiarrhoeals and amount of leakage, using prospective daily stool diaries or retrospective weekly or single point assessments. Such a plethora of measures have negatively impacted the assessment and outcome of clinical trials, and have made comparisons difficult. So, how does one sort out the grain from the chaff? In a provocative, post-hoc analysis published in this issue, the minimal clinically important difference, i.e. the smallest change detected by an instrument that is associated with a clinically meaningful change was used to assess FI endpoint. Based on this a ≥50% reduction in FI episodes is recommended as a clinically meaningful outcome measure when assessed by prospective stool diary, and it correlates with symptoms and severity. However, this requires further validation in multi-centre, longer duration and therapeutically effective clinical trial(s). Simultaneous assessment of coping strategies, QOL and psychosocial domains can provide further insights regarding the overall impact of treatments. This mini-review discusses the advances and controversies in defining meaningful FI endpoints.

High-resolution Anorectal Manometry in Parkinson Disease With Defecation Disorder: A Comparison With Functional Defecation Disorder

GOAL

To investigate the characteristics of high-resolution anorectal manometry (HR-ARM) in Parkinson disease (PD) patients with defecation disorder (DD) compared with patients with functional defecation disorder (FDD).

BACKGROUND

DD is a common gastrointestinal symptom in PD. HR-ARM is a relatively new and reliable method for detecting DD.

STUDY

A cohort of PD patients with DD was matched with FDD patients. Defecatory symptoms were investigated by questionnaire. Anorectal motility and sensation were evaluated by HR-ARM. Differences in defecatory symptoms, sensorimotor parameters, and DD type were analyzed. Defecatory symptoms and manometric variables obtained in early-stage PD were compared with advanced stage, and relationships between manometric parameters and evacuatory symptoms explored.

RESULTS

Straining and sensation of blockage was experienced significantly more in PD than FDD, and stool consistency more severely affected. Maximum squeeze and intrarectal pressure during defecation in PD was lower than in FDD. Anal resting and residual pressures, duration of sustained squeeze, threshold volumes for first sensation, urgency, and maximum discomfort were similar between groups. PD patients presented predominantly with inadequate propulsive forces, whereas FDD patients showed dyssynergic defecation. Defecatory symptoms and manometric parameters did not differ between stages of PD.

CONCLUSIONS

PD patients with DD experienced more straining and sensation of blockage than FDD patients, possibly related to inadequate anorectal motility and paradoxical anal contraction of pelvic floor. Impaired squeeze response and inadequate propulsive forces are specific to anorectal function of PD patients with DD, compared with FDD, with abnormalities unchanged between early and advanced PD.

Values From Three-dimensional High-resolution Anorectal Manometry Analysis of Children Without Lower Gastrointestinal Symptoms

BACKGROUND & AIMS

Three-dimensional high-resolution anorectal manometry (3DHRAM) provides a topographic image of pressure along the anal canal. We aimed to determine normal 3DHRAM values in children.

METHODS

We performed a prospective study of 61 children (34 male; mean age, 8.28 years) without any symptoms arising from the lower gastrointestinal tract who were evaluated at the Department of Pediatric Gastroenterology and Nutrition, Medical University of Warsaw, Poland. Manometry procedures were performed by using a rigid probe without medication. Pressure within the anal canal and 3D images of sphincters were measured. If possible, squeeze pressure and thresholds of sensation were evaluated. The population was divided into age groups of <5 years, 5-8 years, 9-12 years, and older than 12 years.

RESULTS

The mean resting and squeeze sphincter pressures were 83 ± 23 mm Hg and 191 ± 64 mm Hg, respectively. The mean length of the anal canal was 2.62 ± 0.68 cm and correlated with age (r = 0.49, P < .0001). The mean rectal balloon volume to elicit rectoanal inhibitory reflex was 15.7 ± 10.9 cm(3). The first sensation, urge, and discomfort were observed at balloon volumes of 24.4 ± 23.98 cm(3), 45.9 ± 34.55 cm(3), and 91.6 ± 50.17 cm(3), respectively. The mean resting pressure of the puborectalis muscle was 69 ± 14 mm Hg, whereas the mean squeeze pressure was 124 ± 33 mm Hg. There was no statistically significant difference in pressure parameters between age groups. We observed a positive correlation between age and balloon volume needed to elicit discomfort (r = 0.49, P < .001).

CONCLUSIONS

In a prospective study, we determined normal values from 3DHRAM analysis of children without symptoms arising from the lower gastrointestinal tract. There were no significant differences in pressure results between children of different sexes or ages. ClinicalTrials.gov number: NCT02236507.

Rectal Hyposensitivity Is Associated With a Defecatory Disorder But Not Delayed Colon Transit Time in a Functional Constipation Population

The physiological mechanism of functional constipation (FC) includes defecatory disorders and delayed colon transit. About 18% to 68% constipated patients may have rectal hyposensitivity (RH). We performed this study to investigate the association between RH and functional defecatory disorder (FDD) as well as that between RH and delayed colon transit in FC patients.A total of 218 FC patients were enrolled. The constipation severity instrument (CSI) was used to assess constipation symptoms. High-resolution anorectal manometry (HR-ARM), defecography, balloon expulsion tests, and colon transit studies were performed for each patient. RH was defined as 1 or more sensory threshold pressures raised beyond the normal range based on HR-ARM. We investigated the association between RH and constipation symptoms, and the occurrence of FDD and delayed CTT. Ninety FDD patients completed the initial phase of biofeedback treatment (BFT). We investigated the association between RH and the effect of BFT.Totally 122 (56.0%) patients had RH. The total CSI (49.82 ± 1.09 vs 41.25 ± 1.55, P = 0.023) and obstructive defecation subscale scores (23.19 ± 0.69 vs 17.07 ± 0.90, P < 0.001) were significantly higher in RH than in non-RH patients. No significant difference was observed in slow transit symptoms (21.77 ± 0.72 vs 19.90 ± 0.85, P = 0.121) or abdominal pain (6.85 ± 2.61 vs 5.00 ± 1.04, P = 0.380). The frequency of prolonged CTT was not significantly different between RH and non-RH groups (54.1% vs 58.3%, P = 0.403). RH patients rated more occurrence of FDD (72.1% vs 53.1%, P = 0.014) and dysynergic defecation (79.8% vs 50.2%, P = 0.004) than non-RH patients, whereas no differences were seen for inadequate defecatory propulsion (59.2% vs 55.0%, P = 0.589). After BFT, the proportion of "no effect" was significantly higher in the RH group than in the non-RH group (22.4% vs 9.4%, P = 0.010).RH is associated with obstructive defecation symptoms and the occurrence of FDD. Further studies are needed to detect the mechanism of RH's effect on BFT and FC.

Functional Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of common anorectal disorders: fecal incontinence (FI), functional anorectal pain and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into three subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome (LAS) and unspecified anorectal pain the pain lasts more than 30 minutes, but in LAS there is puborectalis tenderness. Functional defecation disorders are defined by >2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with >2 features of impaired evacuation i.e., abnormal evacuation pattern on manometry, abnormal balloon expulsion test or impaired rectal evacuation by imaging. It includes two subtypes; dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating LAS and defecatory disorders.

Functional Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of common anorectal disorders: fecal incontinence (FI), functional anorectal pain and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into three subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome (LAS) and unspecified anorectal pain the pain lasts more than 30 minutes, but in LAS there is puborectalis tenderness. Functional defecation disorders are defined by >2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with >2 features of impaired evacuation i.e., abnormal evacuation pattern on manometry, abnormal balloon expulsion test or impaired rectal evacuation by imaging. It includes two subtypes; dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating LAS and defecatory disorders.

Diagnostic accuracy study of anorectal manometry for diagnosis of dyssynergic defecation

OBJECTIVE

The diagnostic accuracy of anorectal manometry (AM), which is necessary to diagnose functional defecatory disorders (FDD), is unknown. Using blinded analysis and standardised reporting of diagnostic accuracy, we evaluated whether AM could discriminate between asymptomatic controls and patients with functional constipation (FC).

DESIGN

Derived line plots of anorectal pressure profiles during simulated defecation were independently analysed in random order by three expert observers blinded to health status in 85 women with FC and 85 age-matched asymptomatic healthy volunteers (HV). Using accepted criteria, these pressure profiles were characterised as normal (ie, increased rectal pressure coordinated with anal relaxation) or types I-IV dyssynergia. Interobserver agreement and diagnostic accuracy were determined.

RESULTS

Blinded consensus-based assessment disclosed a normal pattern in 16/170 (9%) of all participants and only 11/85 (13%) HV. The combined frequency of dyssynergic patterns (I-IV) was very similar in FC (80/85 (94%)) and HV (74/85 (87%)). Type I dyssynergia ('paradoxical' contraction) was less prevalent in FC (17/85 (20%) than in HV (31/85 (36.5%), p=0.03). After statistical correction, only type IV dyssynergia was moderately useful for discriminating between FC (39/85 (46%)) and HV (17/85 (20%)) (p=0.001, positive predictive value=70.0%, positive likelihood ratio=2.3). Interobserver agreement was substantial or moderate for identifying a normal pattern, dyssynergia types I and IV, and FDD, and fair for types II and III.

CONCLUSIONS

While the interpretation of AM patterns is reproducible, nearly 90% of HV have a pattern that is currently regarded as 'abnormal' by AM. Hence, AM is of limited utility for distinguishing between FC and HV.

How to Perform and Interpret a High-resolution Anorectal Manometry Test

High-resolution anorectal manometry (HR-ARM) and high-definition anorectal manometry (HD-ARM) catheters have closely spaced water-perfused or solid state circumferentially-oriented pressure sensors that provide much better spatiotemporal pressurization than non-high resolution catheters. This is a comprehensive review of HR-ARM and HD-ARM anorectal manometry catheter systems, the methods for conducting, analyzing, and interpreting HR-ARM and HD-ARM, and a comparison of HR-ARM with non-high resolution anorectal manometry. Compared to non-high resolution techniques, HR-ARM and HD-ARM studies take less time and are easier to interpret. However, HR-ARM and HD-ARM catheters are more expensive and fragile and have a shorter lifespan. Further studies are needed to refine our understanding of normal values and to rigorously evaluate the incremental clinical utility of HR-ARM or HD-ARM compared to non-high resolution manometry.

Impact of fecal incontinence and its treatment on quality of life in women

Fecal incontinence (FI) is a physically and psychosocially debilitating disorder which negatively impacts quality of life (QOL). It bears a significant burden not only on patients but also on their families, caretakers as well as society as a whole. Even though it is considered a somewhat common condition, especially as women age, the prevalence is often underestimated due to patients' reluctance to report symptoms or seek care. The evaluation and treatment of FI can be also hindered by lack of understanding of the current management options among healthcare providers and how they impact on QOL. This article provides a comprehensive review on the impact of FI and its treatment on QOL in women.

Food, fibre, bile acids and the pelvic floor: An integrated low risk low cost approach to managing irritable bowel syndrome

Patients presenting with abdominal pain and diarrhea are often labelled as suffering from irritable bowel syndrome, and medications may be used often without success. Advances in the understanding of the causes of the symptoms (including pelvic floor weakness and incontinence, bile salt malabsorption and food intolerance) mean that effective, safe and well tolerated treatments are now available.

A novel technique for bedside anorectal manometry in humans

BACKGROUND

Currently, anorectal manometry (ARM), which is used to diagnose defecatory disorders and identify anal weakness in fecal incontinence (FI) is generally conducted in specialized laboratories. Our aims were to compare anorectal functions measured with high-resolution manometry (HRM) and a novel portable manometry device.

METHODS

Anal pressures at rest, during squeeze, and simulated evacuation, and rectal sensation were evaluated with portable and HRM in 20 healthy women, 19 women with constipation, and 11 with FI. The relationship between anal pressures measured with portable and HRM was assessed by the concordance correlation coefficient (CCC), Bland Altman test, and paired t-tests.

KEY RESULTS

Anal pressures at rest (CCC 0.45; 95% CI: 0.29, 0.58) and during squeeze (CCC 0.60; 95% CI: 0.46, 0.72) measured with portable and HRM were correlated and inversely associated with the risk of FI. During simulated evacuation, the CCC for rectal pressure (0.62; 95% CI: 0.43, 0.76) was greater than that for anal pressure (CCC 0.22; 95% CI: 0.04, 0.39) and the rectoanal gradient (CCC 0.22; 95% CI: 0.02, 0.41). Rectal sensory thresholds for first sensation, the desire to defecate, and urgency measured by portable and HRM were also significantly correlated between techniques. For several parameters, differences between portable and HRM were statistically significant and the Bland Altman test was positive.

CONCLUSIONS & INFERENCES

Anorectal pressures and rectal sensation can be conveniently measured by portable manometry and are significantly correlated with high-resolution manometry.