Anal sphincteric neurogenic injury in asymptomatic nulliparous women and fecal incontinence

Global Prevalence of Fecal Incontinence in Community-Dwelling Adults: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Fecal incontinence (FI) can considerably impair quality of life. Through a systematic review and meta-analysis, we sought to determine the global prevalence and geographic distribution of FI and to characterize its relationship with sex and age.

METHODS

We searched PubMed, Web of Science, and Cochrane Library databases to identify population-based surveys of the prevalence of FI.

RESULTS

Of the 5175 articles identified, the final analysis included 80 studies; the median response rate was 66% (interquartile range [IQR], 54%-74%). Among 548,316 individuals, the pooled global prevalence of FI was 8.0% (95% confidence interval [CI], 6.8%-9.2%); by Rome criteria, it was 5.4% (95% CI, 3.1%-7.7%). FI prevalence was greater for persons aged 60 years and older (9.3%; 95% CI, 6.6%-12.0%) compared with younger persons (4.9%; 95% CI, 2.9%-6.9%) (odds ratio [OR], 1.75; 95% CI, 1.39-2.20), and it was more prevalent among women (9.1%; 95% CI, 7.6%-10.6%) than men (7.4%; 95% CI, 6.0%-8.8%]) (OR, 1.17; 95% CI, 1.06-1.28). The prevalence was highest in Australia and Oceania, followed by North America, Asia, and Europe, but prevalence could not be estimated in Africa and the Middle East. The risk of bias was low, moderate, and high for 19 (24%), 46 (57%), and 15 (19%) studies, respectively. Exclusion of studies with high risk of bias did not affect the prevalence of FI or heterogeneity. In the meta-regression, the high study heterogeneity (I2 = 99.61%) was partly explained by age.

CONCLUSIONS

Approximately 1 in 12 adults worldwide have FI. The prevalence is greater among women and older people.

Faecal incontinence in adults

Faecal incontinence, which is defined by the unintentional loss of solid or liquid stool, has a worldwide prevalence of ≤7% in community-dwelling adults and can markedly impair quality of life. Nonetheless, many patients might not volunteer the symptom owing to embarrassment. Bowel disturbances, particularly diarrhoea, anal sphincter trauma (obstetrical injury or previous surgery), rectal urgency and burden of chronic illness are the main risk factors for faecal incontinence; others include neurological disorders, inflammatory bowel disease and pelvic floor anatomical disturbances. Faecal incontinence is classified by its type (urge, passive or combined), aetiology (anorectal disturbance, bowel symptoms or both) and severity, which is derived from the frequency, volume, consistency and nature (urge or passive) of stool leakage. Guided by the clinical features, diagnostic tests and therapies are implemented stepwise. When simple measures (for example, bowel modifiers such as fibre supplements, laxatives and anti-diarrhoeal agents) fail, anorectal manometry and other tests (endoanal imaging, defecography, rectal compliance and sensation, and anal neurophysiological tests) are performed as necessary. Non-surgical options (diet and lifestyle modification, behavioural measures, including biofeedback therapy, pharmacotherapy for constipation or diarrhoea, and anal or vaginal barrier devices) are often effective, especially in patients with mild faecal incontinence. Thereafter, perianal bulking agents, sacral neuromodulation and other surgeries may be considered when necessary.

A systematic review of translation and experimental studies on internal anal sphincter for fecal incontinence

The complexity in the molecular mechanism of the internal anal sphincter (IAS) limits preclinical or clinical outcomes of fecal incontinence (FI) treatment. So far, there are no systematic reviews of IAS translation and experimental studies that have been reported. This systematic review aims to provide a comprehensive understanding of IAS critical role in FI. Previous studies revealed the key pathway for basal tone and relaxation of IAS in different properties as follows; calcium, Rho-associated, coiled-coil containing serine/threonine kinase, aging-associated IAS dysfunction, oxidative stress, renin-angiotensin-aldosterone, cyclooxygenase, and inhibitory neurotransmitters. Previous studies have reported improved functional outcomes of cellular treatment for regeneration of dysfunctional IAS, using various stem cells, but did not demonstrate the interrelationship between those results and basal tone or relaxation-related molecular pathway of IAS. Furthermore, these results have lower specificity for IAS-incontinence due to the included external anal sphincter or nerve injury regardless of the cell type. An acellular approach using bioengineered IAS showed a physiologic response of basal tone and relaxation response similar to human IAS. However, in both cellular and acellular approaches, the lack of human IAS data still hampers clinical application. Therefore, the IAS regeneration presents more challenges and warrants more advances.

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

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

ACG Clinical Guidelines: Management of Benign Anorectal Disorders

Benign anorectal disorders of structure and function are common in clinical practice. These guidelines summarize the preferred approach to the evaluation and management of defecation disorders, proctalgia syndromes, hemorrhoids, anal fissures, and fecal incontinence in adults and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was assessed using the Grading of Recommendations Assessment, Development and Evaluation process. When the evidence was not appropriate for Grading of Recommendations Assessment, Development and Evaluation, we used expert consensus to develop key concept statements. These guidelines should be considered as preferred but are not the only approaches to these conditions.

Diagnostic approach to faecal incontinence: What test and when to perform?

Faecal incontinence (FI) is a debilitating common end result of several diseases affecting the quality of life and leading to patient disability, morbidity, and increased societal burden. Given the various causes of FI, it is important to assess and identify the underlying pathomechanisms. Several investigatory tools are available including high-resolution anorectal manometry, transrectal ultrasound, magnetic resonance imaging, and electromyography. This review article provides an overview on the causes and pathophysiology of FI and the author’s perspective of the stepwise investigation of patients with FI based on the available literature. Overall, high-resolution anorectal manometry should be the first investigatory tool for FI, followed by either transrectal ultrasound or magnetic resonance imaging for anal internal sphincter and external anal sphincter injury, respectively.

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 Is a Promising Option for Fecal Incontinence

ABSTRACT

Fecal incontinence is a common symptom that can significantly impair quality of life. The treatment options range from conservative measures (e.g., Kegel exercises, pelvic floor biofeedback therapy, fiber supplementation, or medications) to noninvasive nerve stimulation (e.g., posterior tibial nerve stimulation and transcutaneous tibial nerve stimulation), implanted neurostimulation (i.e., sacral nerve stimulation), perianal injection of dextranomer, and anal sphincteroplasty. In this issue of the journal, a promising, uncontrolled study suggests that noninvasive, repetitive magnetic stimulation of the lumbosacral nerves significantly improved symptoms, increased anal squeeze pressure, and increased rectal compliance in patients with fecal continence. Sham-controlled studies are necessary to confirm these findings.

Management of Fecal Incontinence

Nine percent of adult women experience episodes of fecal incontinence at least monthly. Fecal incontinence is more common in older women and those with chronic bowel disturbance, diabetes, obesity, prior anal sphincter injury, or urinary incontinence. Fecal incontinence negatively affects quality of life and mental health and is associated with increased risk of nursing home placement. Fewer than 30% of women with fecal incontinence seek care, and lack of information about effective solutions is an important barrier for both patients and health care professionals. Even among women with both urinary and fecal incontinence presenting for urogynecologic care, the rate of verbal disclosure of fecal incontinence symptoms remains low. This article provides an overview of the evaluation and management of fecal incontinence for the busy obstetrician-gynecologist, incorporating existing guidance from the American College of Obstetricians and Gynecologists, the American College of Gastroenterology, and the American Society of Colon and Rectal Surgeons. The initial clinical evaluation of fecal incontinence requires a focused history and physical examination. Recording patient symptoms using a standard diary or questionnaire can help document symptoms and response to treatment. Invasive diagnostic testing and imaging generally are not needed to initiate treatment but may be considered in complex cases. Most women have mild symptoms that will improve with optimized stool consistency and medications. Additional treatment options include pelvic floor muscle strengthening with or without biofeedback, devices placed anally or vaginally, and surgery, including sacral neurostimulation, anal sphincteroplasty, and, for severely affected individuals for whom other interventions fail, colonic diversion.

Constipation and Fecal Incontinence in the Elderly

PURPOSE OF REVIEW

To review the epidemiology, pathogenesis, clinical features, and management of primary constipation and fecal incontinence in the elderly.

RECENT FINDINGS

Among elderly people, 6.5%, 1.7%, and 1.1% have functional constipation, constipation-predominant IBS, and opioid-induced constipation. In elderly people, the number of colonic enteric neurons and smooth muscle functions is preserved; decreased cholinergic function with unopposed nitrergic relaxation may explain colonic motor dysfunction. Less physical activity or dietary fiber intake and postmenopausal hormonal therapy are risk factors for fecal incontinence in elderly people. Two thirds of patients with fecal incontinence respond to biofeedback therapy. Used in combination, loperamide and biofeedback therapy are more effective than placebo, education, and biofeedback therapy. Vaginal or anal insert devices are another option. In the elderly, constipation and fecal incontinence are common and often distressing symptoms that can often be managed by addressing bowel disturbances. Selected diagnostic tests, prescription medications, and, infrequently, surgical options should be considered when necessary.

Anorectal pressures measured with high-resolution manometry in healthy people-Normal values and asymptomatic pelvic floor dysfunction

BACKGROUND

High-resolution manometry (HRM) is used to measure rectoanal pressures in defecatory disorders and fecal incontinence. This study sought to define normal values for rectoanal HRM, ascertain the effects of age and BMI on rectoanal pressures, and compare pressures in asymptomatic women with normal and prolonged balloon expulsion time (BET).

METHODS

High-resolution manometry pressures and BET were measured in 163 asymptomatic healthy participants. Women (96) and men (47) with normal BET were used to estimate normal values and the effects of age/BMI on pressures using a Medtronic 4.2-mm-diameter rectoanal catheter.

KEY RESULTS

Age is associated with lower resting pressure, higher rectal pressure during evacuation, and a higher rectoanal gradient during evacuation in women and men. In women, the BET is also inversely correlated with age while the BMI is correlated with a higher threshold volume for discomfort and a longer BET. The anal squeeze pressure increment, squeeze duration, and HPZ length are higher in men than women. The rectoanal gradient during evacuation is also lower (ie, more negative) in asymptomatic women with an abnormal than a normal BET.

CONCLUSIONS & INFERENCES

These findings provide an expanded database of normal values for anorectal HRM in men and women. Age and sex affect anal resting and squeeze pressures, respectively; rectal pressure during evacuation is also higher in older people. Less than 15% of asymptomatic people have BET >60 seconds, which is associated with manometry features of impaired evacuation.

Cortico-anorectal, Spino-anorectal, and Cortico-spinal Nerve Conduction and Locus of Neuronal Injury in Patients With Fecal Incontinence

BACKGROUND & AIMS

The neuropathophysiology of fecal incontinence (FI) is incompletely understood. We examined the efferent brain-anorectal and spino-anorectal motor-evoked potentials (MEP) to characterize the locus of neuronal injury in patients with FI.

METHODS

We performed bilateral transcranial, translumbar, and transsacral magnetic stimulations in 27 patients with FI (19 female) and 31 healthy individuals (controls, 20 female) from 2015 through 2017. MEPs were recorded simultaneously from the rectum and anus using 4 ring electrodes. The difference in MEP latencies between the transcranial (TMS) and translumbar transsacral magnetic stimulations was calculated as cortico-spinal conduction time. MEP data were compared between patients with FI and controls. Patients filled out questionnaires that assessed the severity and effects of FI.

RESULTS

The MEP latencies with TMS were significantly longer in patients with FI than controls at most sites, and on both sides (P < .05). Almost all translumbar and transsacral MEP latencies were significantly prolonged in patients with FI vs controls (P < .01). The cortico-spinal conduction time were similar, on both sides, between patients with FI and controls. Ninety-three percent of patients had 1 or more abnormal translumbar and transsacral latencies, but neuropathy was patchy and variable, and not associated with sex or anal sphincter function or defects.

CONCLUSIONS

Patients with FI have significant neuropathy that affects the cortico-anorectal and spino-anorectal efferent pathways. The primary loci are the lumbo-rectal, lumbo-anal, sacro-rectal, and sacro-anal nerves; the cortico-spinal segment appears intact. Peripheral spino-anal and spino-rectal neuropathy might therefore contribute to the pathogenesis of FI.

Normal values for assessment of anal sphincter morphology, anorectal motion, and pelvic organ prolapse with MRI in healthy women

BACKGROUND

Endoanal MRI and MR defecography are used to identify anal sphincter injury and disordered defecation. However, few studies have evaluated findings in asymptomatic healthy people. The effects of BMI and parity on rectoanal motion and evacuation are unknown.

METHODS

In 113 asymptomatic females (age 50 ± 17 years, Mean ± SD) without risk factors for anorectal trauma, anal sphincter appearance, anorectal motion, and pelvic organ prolapse were evaluated with MRI. The relationship between age, BMI, and parity and structural findings were evaluated with parametric and non-parametric tests.

RESULTS

The anal sphincters and puborectalis appeared normal in over 90% of women. During dynamic MRI, the anorectal angle was 100 ± 1º (Mean ± SEM) at rest, 70 ± 2° at squeeze, and 120 ± 2° during defecation. The change in anorectal angle during squeeze (r = -.25, P < .005), but not during evacuation (r = .13, P = .25) was associated with age. In the multivariable models, BMI (P < .01) and parity (P < .01) were, respectively, independently associated with the intersubject variation in the anorectal angle at rest and the angle change during squeeze. Ten percent or fewer women had had descent of the bladder base or uterus 4 cm or more below the pubococcygeal line or a rectocele measuring 4 cm or larger. Only 5% had a patulous anal canal.

CONCLUSIONS

In addition to age, BMI and parity also affect anorectal motion in asymptomatic women. These findings provide age-adjusted normal values for rectoanal anatomy and pelvic floor motion.

High-resolution anorectal manometry: An expensive hobby or worth every penny?

Introduced approximately 10 years ago, high-resolution manometry catheters have fostered interest in anorectal manometry. This review, which accompanies two articles in this issue of Neurogastroenterology and Motility, reviews the methods, clinical indications, utility, and pitfalls of anorectal manometry and revisits the American Gastroenterological Association (AGA) Medical Position Statement on Anorectal Testing Techniques, which was last published in 1999. High-resolution manometry provides a refined assessment of the anorectal pressure profile, obviates the need for station pull-through maneuvers, and minimizes movement artifacts. In selected cases, this refined assessment may be useful for identifying structural abnormalities or anal weakness. However, many manometry patterns that were previously regarded as abnormal are also observed in a majority of healthy patients, which substantially limits the utility of manometry for identifying defecatory disorders. It is our impression that most conclusions of the AGA medical position statement from 1999 remain valid today. High-resolution techniques have not substantially affected the number of publications on or management of anorectal disorders. The ongoing efforts of an international working group to standardize techniques for anorectal manometry are welcome. Although high-resolution manometry is more than an expensive hobby, improvements in catheter design and further research to rigorously define and evaluate these techniques are necessary to determine if they are worth every penny.

Pathophysiology and Therapeutic Options for Fecal Incontinence

Fecal incontinence (FI), defined as the involuntary loss of solid or liquid feces through the anus is a prevalent condition with significant effects on quality of life. FI can affect individuals of all ages and in many cases greatly impairs quality of life but, incontinent patients should not accept their debility as either inevitable or untreatable. The severity of incontinence can range from unintentional elimination of flatus to the complete evacuation of bowel contents. It is reported to affect up to 18% of the population, with a prevalence reaching as high as 50% in nursing home residents. However, FI is often underreported, thus obscuring its true prevalence in the general population. The options for treatment vary according to the degree and severity of the FI. Treatment can include dietary and lifestyle modification, certain medications, biofeedback therapy, bulking agent injections, sacral nerve stimulation as well as various types of surgery. In this article, we aim to provide a comprehensive review on the diagnosis and management of FI.

Management of opioid-induced constipation for people in palliative care

Constipation is common in the palliative population. Opioid medications, which are frequently prescribed to this cohort, represent a significant risk factor for this condition. Opioid-induced constipation may be of such severity that opioid doses are reduced or missed, and analgesia and quality of life are therefore reduced. However, underlying chronic constipation, local and systemic disease effects, and other medications may also precipitate constipation in this population. The assessment and treatment of constipation in a palliative individual should be undertaken in a fashion similar to that used in non-palliative patients. Initial management should include minimising exposure to predisposing factors and general measures such as encouraging hydration, fibre intake and mobility. Pharmacological treatment should commence with a stool softener and a stimulant laxative. Recently published literature demonstrates that newer laxatives, including lubiprostone (a chloride channel activator) and prucalopride (a 5-HT4 receptor agonist) can effectively treat opioid-induced constipation. For patients not responding to laxatives, opioid antagonists (non-specific or peripherally acting μ-opioid receptor antagonists) can be co-prescribed with laxatives. These agents have also proven efficacy in treating opioid-induced constipation. This review discusses the recent literature regarding the management of opioid-induced constipation and provides a rational approach to assessing and managing constipation in the palliative population.

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.

Relationship Among Anal Sphincter Injury, Patulous Anal Canal, and Anal Pressures in Patients With Anorectal Disorders

BACKGROUND & AIMS

The anal sphincters and puborectalis are imaged routinely with an endoanal magnetic resonance imaging (MRI) coil, which does not assess co-aptation of the anal canal at rest. By using a MRI torso coil, we identified a patulous anal canal in some patients with anorectal disorders. We aimed to evaluate the relationship between anal sphincter and puborectalis injury, a patulous anal canal, and anal pressures.

METHODS

We performed a retrospective analysis of data from 119 patients who underwent MRI and manometry analysis of anal anatomy and pressures, respectively, from February 2011 through March 2013 at the Mayo Clinic. Anal pressures were determined by high-resolution manometry, anal sphincter and puborectalis injury was determined by endoanal MRI, and anal canal integrity was determined by torso MRI. Associations between manometric and anatomic parameters were evaluated with univariate and multivariate analyses.

RESULTS

Fecal incontinence (55 patients; 46%) and constipation (36 patients; 30%) were the main indications for testing; 49 patients (41%) had a patulous anal canal, which was associated with injury to more than 1 muscle (all P ≤ .001), and internal sphincter (P < .01), but not puborectalis (P = .09) or external sphincter (P = .06), injury. Internal (P < .01) and external sphincter injury (P = .02) and a patulous canal (P < .001), but not puborectalis injury, predicted anal resting pressure. A patulous anal canal was the only significant predictor (P < .01) of the anal squeeze pressure increment.

CONCLUSIONS

Patients with anorectal disorders commonly have a patulous anal canal, which is associated with more severe anal injury and independently predicted anal resting pressure and squeeze pressure increment. It therefore is important to identify a patulous anal canal because it appears to be a marker of not only anal sphincter injury but disturbances beyond sphincter injury, such as damage to the anal cushions or anal denervation.

Diagnosis and treatment of faecal incontinence: Consensus statement of the Italian Society of Colorectal Surgery and the Italian Association of Hospital Gastroenterologists

Faecal incontinence is a common and disturbing condition, which leads to impaired quality of life and huge social and economic costs. Although recent studies have identified novel diagnostic modalities and therapeutic options, the best diagnostic and therapeutic approach is not yet completely known and shared among experts in this field. The Italian Society of Colorectal Surgery and the Italian Association of Hospital Gastroenterologists selected a pool of experts to constitute a joint committee on the basis of their experience in treating pelvic floor disorders. The aim was to develop a position paper on the diagnostic and therapeutic aspects of faecal incontinence, to provide practical recommendations for a cost-effective diagnostic work-up and a tailored treatment strategy. The recommendations were defined and graded on the basis of levels of evidence in accordance with the criteria of the Oxford Centre for Evidence-Based Medicine, and were based on currently published scientific evidence. Each statement was drafted through constant communication and evaluation conducted both online and during face-to-face working meetings. A brief recommendation at the end of each paragraph allows clinicians to find concise responses to each diagnostic and therapeutic issue.

Rectal tone and compliance affected in patients with fecal incontinence after fistulotomy

AIM: To investigate the anal sphincter and rectal factors that may be involved in fecal incontinence that develops following fistulotomy (FIAF).

METHODS: Eleven patients with FIAF were compared with 11 patients with idiopathic fecal incontinence and with 11 asymptomatic healthy subjects (HS). All of the study participants underwent anorectal manometry and a barostat study (rectal sensitivity, tone, compliance and capacity). The mean time since surgery was 28 ± 26 mo. The postoperative continence score was 14 ± 2.5 (95%CI: 12.4-15.5, St Mark’s fecal incontinence grading system).

RESULTS: Compared with the HS, the FIAF patients showed increased rectal tone (42.63 ± 27.69 vs 103.5 ± 51.13, P = 0.002) and less rectal compliance (4.95 ± 3.43 vs 11.77 ± 6.9, P = 0.009). No significant differences were found between the FIAF patients and the HS with respect to the rectal capacity; thresholds for the non-noxious stimuli of first sensation, gas sensation and urge-to-defecate sensation or the noxious stimulus of pain; anal resting pressure or squeeze pressure; or the frequency or percentage of relaxation of the rectoanal inhibitory reflex. No significant differences were found between the FIAF patients and the patients with idiopathic fecal incontinence.

CONCLUSION: In patients with FIAF, normal motor anal sphincter function and rectal sensitivity are preserved, but rectal tone and compliance are impaired. The results suggest that FIAF is not due to alterations in rectal sensitivity and that the rectum is more involved than the anal sphincters in the genesis of FIAF.

Epidemiology, pathophysiology, and classification of fecal incontinence: state of the science summary for the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) workshop

In August 2013, the National Institutes of Health sponsored a conference to address major gaps in our understanding of the epidemiology, pathophysiology, and management of fecal incontinence (FI) and to identify topics for future clinical research. This article is the first of a two-part summary of those proceedings. FI is a common symptom, with a prevalence that ranges from 7 to 15% in community-dwelling men and women, but it is often underreported, as providers seldom screen for FI and patients do not volunteer the symptom, even though the symptoms can have a devastating impact on the quality of life. Rough estimates suggest that FI is associated with a substantial economic burden, particularly in patients who require surgical therapy. Bowel disturbances, particularly diarrhea, the symptom of rectal urgency, and burden of chronic illness are the strongest independent risk factors for FI in the community. Smoking, obesity, and inappropriate cholecystectomy are emerging, potentially modifiable risk factors. Other risk factors for FI include advanced age, female gender, disease burden (comorbidity count, diabetes), anal sphincter trauma (obstetrical injury, prior surgery), and decreased physical activity. Neurological disorders, inflammatory bowel disease, and pelvic floor anatomical disturbances (rectal prolapse) are also associated with FI. The pathophysiological mechanisms responsible for FI include diarrhea, anal and pelvic floor weakness, reduced rectal compliance, and reduced or increased rectal sensation; many patients have multifaceted anorectal dysfunctions. The type (urge, passive or combined), etiology (anorectal disturbance, bowel symptoms, or both), and severity of FI provide the basis for classifying FI; these domains can be integrated to comprehensively characterize the symptom. Several validated scales for classifying symptom severity and its impact on the quality of life are available. Symptom severity scales should incorporate the frequency, volume, consistency, and nature (urge or passive) of stool leakage. Despite the basic understanding of FI, there are still major knowledge gaps in disease epidemiology and pathogenesis, necessitating future clinical research in FI.

ACG clinical guideline: management of benign anorectal disorders

These guidelines summarize the definitions, diagnostic criteria, differential diagnoses, and treatments of a group of benign disorders of anorectal function and/or structure. Disorders of function include defecation disorders, fecal incontinence, and proctalgia syndromes, whereas disorders of structure include anal fissure and hemorrhoids. Each section reviews the definitions, epidemiology and/or pathophysiology, diagnostic assessment, and treatment recommendations of each entity. These recommendations reflect a comprehensive search of all relevant topics of pertinent English language articles in PubMed, Ovid Medline, and the National Library of Medicine from 1966 to 2013 using appropriate terms for each subject. Recommendations for anal fissure and hemorrhoids lean heavily on adaptation from the American Society of Colon and Rectal Surgeons Practice Parameters from the most recent published guidelines in 2010 and 2011 and supplemented with subsequent publications through 2013. We used systematic reviews and meta-analyses when available, and this was supplemented by review of published clinical trials.

An update on anorectal disorders for gastroenterologists

Gastroenterologists frequently encounter pelvic floor disorders, which affect 10% to 15% of the population. The anorectum is a complex organ that collaborates with the pelvic floor muscles to preserve fecal continence and enable defecation. A careful clinical assessment is critical for the diagnosis and management of defecatory disorders and fecal incontinence. Newer diagnostic tools (eg, high-resolution manometry and magnetic resonance defecography) provide a refined understanding of anorectal dysfunctions and identify phenotypes in defecatory disorders and fecal incontinence. Conservative approaches, including biofeedback therapy, are the mainstay for managing these disorders; new minimally invasive approaches may benefit a subset of patients with fecal incontinence, but more controlled studies are needed. This mini-review highlights advances, current concepts, and controversies in the area.