The Clinical Impact of Obesity in Patients With Disorders of Defecation: A Cross-Sectional Study of 1,155 Patients.

INTRODUCTION: Obesity is a global epidemic. Its clinical impact on symptoms of fecal incontinence (FI) and/or constipation and underlying anorectal pathophysiology remains uncertain. METHODS: This is a cross-sectional study of consecutive patients meeting Rome IV criteria for FI and/or functional constipation, with data on body mass index (BMI), attending a tertiary center for investigation between 2017 and 2021. Clinical history, symptoms, and anorectal physiologic test results were analyzed according to BMI categories. RESULTS: A total of 1,155 patients (84% female) were included in the analysis (33.5% normal BMI; 34.8% overweight; and 31.7% obese). Obese patients had higher odds of FI to liquid stools (69.9 vs 47.8%, odds ratio [OR] 1.96 [confidence interval: 1.43-2.70]), use of containment products (54.6% vs 32.6%, OR 1.81 [1.31-2.51]), fecal urgency (74.6% vs 60.7%, OR 1.54 [1.11-2.14]), urge FI (63.4% vs 47.3%, OR 1.68 [1.23-2.29]), and vaginal digitation (18.0% vs 9.7%, OR 2.18 [1.26-3.86]). A higher proportion of obese patients had Rome criteria-based FI or coexistent FI and functional constipation (37.3%, 50.3%) compared with overweight patients (33.8%, 44.8%) and patients with normal BMI (28.9%, 41.1%). There was a positive linear association between BMI and anal resting pressure (ß 0.45, R 2 0.25, P = 0.0003), although the odds of anal hypertension were not significantly higher after Benjamini-Hochberg correction. Obese patients more often had a large clinically significant rectocele (34.4% vs 20.6%, OR 2.62 [1.51-4.55]) compared with patients with normal BMI. DISCUSSION: Obesity affects specific defecatory (mainly FI) and prolapse symptoms and pathophysiologic findings (higher anal resting pressure and significant rectocele). Prospective studies are required to determine whether obesity is a modifiable risk factor of FI and constipation.

Habit training versus habit training with direct visual biofeedback in adults with chronic constipation: A randomized controlled trial.

AIM: The aim was to determine whether specialist-led habit training using Habit Training with Biofeedback (HTBF) is more effective than specialist-led habit training alone (HT) for chronic constipation and whether outcomes of interventions are improved by stratification to HTBF or HT based on diagnosis (functional defaecation disorder vs. no functional defaecation disorder) by radio-physiological investigations (INVEST). METHOD: This was a parallel three-arm randomized single-blinded controlled trial, permitting two randomized comparisons: HTBF versus HT alone; INVEST- versus no-INVEST-guided intervention. The inclusion criteria were age 18-70 years; attending specialist hospitals in England; self-reported constipation for >6 months; refractory to basic treatment. The main exclusions were secondary constipation and previous experience of the trial interventions. The primary outcome was the mean change in Patient Assessment of Constipation Quality of Life score at 6 months on intention to treat. The secondary outcomes were validated disease-specific and psychological questionnaires and cost-effectiveness (based on EQ-5D-5L). RESULTS: In all, 182 patients were randomized 3:3:2 (target 384): HT n = 68; HTBF n = 68; INVEST-guided treatment n = 46. All interventions had similar reductions (improvement) in the primary outcome at 6 months (approximately -0.8 points of a 4-point scale) with no statistically significant difference between HT and HTBF (-0.03 points; 95% CI -0.33 to 0.27; P = 0.85) or INVEST versus no-INVEST (0.22; -0.11 to 0.55; P = 0.19). Secondary outcomes showed a benefit for all interventions with no evidence of greater cost-effectiveness of HTBF or INVEST compared with HT. CONCLUSION: The results of the study at 6 months were inconclusive. However, with the caveat of under-recruitment and further attrition at 6 months, a simple, cheaper approach to intervention may be as clinically effective and more cost-effective than more complex and invasive approaches.

Abnormal Perception of Urge to Defecate: An Important Pathophysiological Mechanism in Women With Chronic Constipation.

INTRODUCTION: Although the association of absent or attenuated "call to stool" with constipation is well-recognized, no studies have systematically evaluated the perception of urge to defecate in a well-defined cohort of patients with chronic constipation (CC). METHODS: A prospective study of 43 healthy adult women and 140 consecutive adult women attending a tertiary center for investigation of CC. All participants completed a 5-day viscerosensory questionnaire, and all women with CC also underwent anorectal physiologic investigations. Normal urge perception and abnormal urge perception were defined using a Naive Bayes model trained in healthy women (95% having normal urge). RESULTS: In total, 181 toilet visits in healthy women and 595 in women with CC were analyzed. Abnormal urge perception occurred in 70 (50.0%) women with CC. In this group, the urge to defecate was more often experienced as abdominal sensation (69.3% vs 41.4%; P < 0.0001), and the viscerosensory referral area was 81% larger (median pixels anterior: 1,849 vs 1,022; P < 0.0001) compared to women with CC and normal urge perception. Abnormal (vs normal) urge in women with CC was associated with more severe constipation (Cleveland Clinic constipation score: 19 vs 15 P < 0.0001), irritable bowel syndrome (45.7% vs 22.9% P < 0.0001), and a functional evacuation disorder on defecography (31.3% vs 14.3% P = 0.023). A distinct pattern of abnormal urge was found in women with CC and rectal hyposensitivity. DISCUSSION: Abnormal urge perception was observed in 50% of women with CC and was frequently described as abdominal sensation, supporting the concept that sensory dysfunction makes an important contribution to the pathophysiology of constipation.

Redundancy in the International Anorectal Physiology Working Group Manometry Protocol: A Diagnostic Accuracy Study in Fecal Incontinence.

BACKGROUND: Anorectal manometry (ARM) is essential for identifying sphincteric dysfunction. The International Anorectal Physiology Working Group (IAPWG) protocol and London Classification provide a standardized format for performing and interpreting ARM. However, there is scant evidence to support timing and number of constituent maneuvers. AIMS: To assess the impact of protocol modification on diagnostic accuracy in patients with fecal incontinence. METHODS: Retrospective analysis of high-resolution ARM recordings from consecutive patients based on the current IAPWG protocol and modifications thereof: (1) baseline rest period (60 vs. 30 vs. 10 s); (2) number of abnormal short squeezes (SS) out of 3 (SS1/SS2/SS3) based on maximal incremental squeeze pressures over 5 s; (3) resting anal pressures (reflecting recovery) at 25-30 versus 15-20 s after SS1. RESULTS: One hundred patients (86 F, median age 55 [IQR: 39-65]; median St. Mark's incontinence score 14 [10-17]) were studied. 26% and 8% had anal hypotonia and hypertonia, respectively. Compared with 60-s resting pressure, measurements had perfect correlation (κ = 1.0) over 30 s, and substantial correlation (κ = 0.85) over 10 s. After SS1, SS2, and SS3, 43%, 49%, and 46% had anal hypocontractility, respectively. Correlation was substantial between SS1 and SS2 (κ = 0.799) and almost perfect between SS2 and SS3 (κ = 0.9). Compared to resting pressure of 5 s before SS1, pressure recordings at 25-30 and 15-20 s after SS1 were significantly correlated. CONCLUSIONS: A 30-s resting anal pressure, analysis of 2 short-squeezes with a 20-s between-maneuver recovery optimizes study duration without compromising diagnostic accuracy. These findings indicate the IAPWG protocol has redundancy.

Clinical Impact of Rectal Hyposensitivity: A Cross-Sectional Study of 2,876 Patients With Refractory Functional Constipation.

INTRODUCTION: Normal bowel function requires intact sensory pathways. Diminished rectal sensation (rectal hyposensitivity [RH]) is associated with constipation, although its clinical importance remains unclear. METHODS: Consecutive patients (aged 18-80) attending a tertiary center (2004-2016) for investigation of refractory functional constipation (Rome IV core criteria defined, applied post hoc) were included. Patients completed a clinical symptom questionnaire and underwent anorectal physiologic investigations, including rectal sensory testing (balloon distension) to determine 3 well-established sensory thresholds. Multivariate regression analyses were performed to evaluate associations between RH, symptomology, and allied physiologic investigations. RESULTS: Of 2,876 patients meeting inclusion criteria, 722 (25%) had RH based on ≥1 elevated sensory thresholds (0: n = 2,154 [74.9%]; 1: n = 327 [11.4%]; 2: n = 209 [7.3%]; and 3: n = 186 [6.5%]). A linear relationship existed between increasing number of elevated sensory thresholds and constipation severity (Cleveland Clinic constipation score: mean difference per threshold [95% confidence interval] 0.69 [0.48-0.90]; P < 0.001). Several symptoms were significantly (P < 0.05) associated with RH including: infrequent defecation (odds ratio 1.29 [1.17-1.42]), painful evacuation (1.15 [1.05-1.27]), prolonged toileting (1.14 [1.05-1.24]), and digitation or enema use (1.18 [1.08-1.30]). On defecography, a "functional" evacuation disorder was also associated with RH (1.37 [1.25-1.50], P < 0.001), as was megarectum (2.52 [2.08-3.05], P < 0.001). DISCUSSION: RH occurs in 25% of patients with refractory functional constipation. Increased number of elevated sensory thresholds is associated with more severe constipation phenotype. These data, in the largest study to date, provide for the first time evidence to show that RH is a major pathophysiologic mechanism in constipation, with recognized clinical impact (http://links.lww.com/AJG/B765).(Equation is included in full-text article.).

Systematic Characterization of Defecographic Abnormalities in a Consecutive Series of 827 Patients With Chronic Constipation.

BACKGROUND: Barium defecography can assess structural and functional abnormalities in patients with chronic constipation. OBJECTIVE: The purpose of this study was to determine the prevalence of individual and overlapping defecographic findings in this setting. DESIGN: This was a cross-sectional study. SETTINGS: The study was conducted at a university hospital tertiary GI physiology department. PATIENTS: Consecutive examinations of 827 consecutive patients presenting over a 30-month period with well-defined symptom severity (≥12 points on the Cleveland Clinic Constipation score) were included. Systematic evaluation of images with results stratified by sex is described. MAIN OUTCOME MEASURES: Six individual functional or anatomic (intussusception, rectocele, enterocele, megarectum, excessive dynamic perineal descent) defecographic observations were defined a priori, thus permitting 26 possible combinations of findings (ie, 63 abnormal types + 1 normal). RESULTS: Patients with constipation (mean symptom score = 19) were predominantly female (88%), with median age of 49 years (range, 17-98 y) . All 6 individual radiologic findings were identified with a total of 43 combinations found in the cohort; the 14 most prevalent of these accounted for >85% of patients. Only 136 patients (16.4%) had a normal defecography (34.3% males vs 13.9% females; p < 0.0001). Overall, 612 patients (74.0%) had structural (n = 508 (61.4%)) or functional (n=104 (12.6%)) abnormalities in isolation, with 79 (9.6%) others exhibiting combinations of both. Functional abnormalities in isolation were more common in males compared with females (22.5% vs11.2%; p = 0.025) as opposed to structural abnormalities (57.8% vs 85.7%; p < 0.0001). Expulsion time was longer in females compared with males (110 s (60-120 s) vs 90 s (60-120 s); p = 0.049). LIMITATIONS: The study was limited by its lack of multiorgan opacification. CONCLUSIONS: These results provide a contemporary atlas of defecographic findings in constipation. Several individual structural and functional features have been systematically classified, with overlap greater than previously acknowledged and profound differences among sexes that carry implications for tailoring management. See Video Abstract at http://links.lww.com/DCR/B552. CARACTERIZACIN SISTEMTICA DE ANOMALAS DEFECOGRFICAS EN UNA SERIE CONSECUTIVA DE PACIENTES CON ESTREIMIENTO CRNICO: ANTECEDENTES:La defecografía con bario puede evaluar anomalías estructurales y funcionales en pacientes con estreñimiento crónico.OBJETIVO:Determinar la prevalencia de hallazgos defecográficos individuales y superpuestos en este entorno.DISEÑO:Transversal.ENTORNO CLINICO:Hospital Universitario de tercer nivel, departamento de fisiología gastrointestinal.PACIENTES:Exploraciones consecutivas de 827 pacientes consecutivos que se presentaron durante un período de 30 meses con una gravedad de los síntomas bien definida (≥12 puntos en la escala de estreñimiento de la Cleveland Clinic): evaluación sistemática de imágenes con resultados estratificados por sexo.PRINCIPALES MEDIDAS DE VALORACION:Se definieron a priori seis observaciones defecográficas individuales, funcionales o anatómicas (intususcepción, rectocele, enterocele, megarecto, descenso perineal dinámico excesivo), lo que permitió 26 combinaciones posibles de hallazgos (es decir, 63 tipos anormales + 1 normal).RESULTADOS:Los pacientes con estreñimiento (puntuación media de síntomas, 19) eran predominantemente mujeres (88%) con una edad mediana de 49 (17-98) años. Se identificaron 6 hallazgos radiológicos individuales con un total de 43 combinaciones encontradas en la cohorte; los 14 más predominantes de éstos representaron >85% de los pacientes.Solo 136 (16,4%) pacientes tuvieron una defecografía normal (34,3% hombres vs. 13,9% mujeres; P < 0,0001). En general, 612 (74,0%) pacientes tenían anomalías estructurales (n = 508 [61,4%]) o funcionales (n = 104 [12,6%]) de forma aislada, y otros 79 (9,6%) presentaban combinaciones de ambas. Las anomalías funcionales aisladas fueron más comunes en los hombres en comparación con las mujeres (22,5% vs. 11,2%, P = 0,025) en comparación con las anomalías estructurales (57,8 vs. 85,7%, P < 0,0001). El tiempo de expulsión fue mayor en las mujeres en comparación con los hombres (110 [60-120] vs. 90 [60-120] segundos; P = 0,049).LIMITACIONES:Falta de opacificación multiorgánica.CONCLUSIONES:Estos resultados proporcionan un atlas contemporáneo de hallazgos defecográficos en estreñimiento. Varias características individuales, estructurales y funcionales; se han clasificado sistemáticamente, con una superposición mayor que la reconocida anteriormente y con grandes diferencias entre los sexos que tienen implicaciones para adaptar su tratamiento. Consulte Video Resumen en http://links.lww.com/DCR/B552.

Altered anal slow-wave pressure activity in low anterior resection syndrome: short case series in two independent specialist centres provide new mechanistic insights.

AIM: Conventional parameters (anal resting and squeeze pressures) measured with anorectal manometry (ARM) fail to identify anal sphincter dysfunction in many patients with low anterior resection syndrome (LARS). We aimed to assess whether there are differences in anal canal slow-wave pressure activity in LARS patients and healthy individuals. METHOD: High-resolution ARM (HR-ARM) traces of 21 consecutive male LARS patients referred to the Royal London Hospital, UK (n = 12) and Aarhus University Hospital, Denmark (n = 9) were compared with HR-ARM data from 37 healthy men. RESULTS: Qualitatively (by visual inspection of HR-ARM recordings), the frequency of slow-wave pressure activity was strikingly different in 11/21 (52.4%) LARS patients from that observed in all the healthy individuals. Quantitative analysis showed that peaks of the mean spectrum in these 11 LARS patients occurred at approximately 6-7 cycles per minute (cpm), without activity at higher frequencies. An equivalent pattern was found in only 2/37 (5.4%) healthy individuals (P < 0.0001). Peaks of the mean spectrum in healthy individuals were concentrated at 16 cpm and 3-4 cpm. CONCLUSION: Over half of the male LARS patients studied had altered anal slow-wave pressure activity based on analysis of HR-ARM recordings. Further studies could investigate the relative contributions of sex, human baseline variance and neoadjuvant/surgical therapies on anal slow waves, and correlate the presence of abnormal activity with symptom severity.

The London Classification: Improving Characterization and Classification of Anorectal Function with Anorectal Manometry.

PURPOSE OF REVIEW: Objective measurement of anorectal sensorimotor function is a requisite component in the clinical evaluation of patients with intractable symptoms of anorectal dysfunction. Regrettably, the utility of the most established and widely employed investigations for such measurement (anorectal manometry (ARM), rectal sensory testing and the balloon expulsion test) has been limited by wide variations in clinical practice. RECENT FINDINGS: This article summarizes the recently published International Anorectal Physiology Working Group (IAPWG) consensus and London Classification of anorectal disorders, together with relevant allied literature, to provide guidance on the indications for, equipment, protocol, measurement definitions and results interpretation for ARM, rectal sensory testing and the balloon expulsion test. The London Classification is a standardized method and nomenclature for description of alterations in anorectal motor and sensory function using office-based investigations, adoption of which should bring much needed harmonization of practice.

High-resolution Anorectal Manometry Measures Are More Accurate Than Conventional Measures in Detecting Anal Hypocontractility in Women With Fecal Incontinence.

BACKGROUND & AIMS: Anorectal manometry is a common test of anal tone and contractility. However, existing measures are often criticized for their poor ability to detect functional differences between individuals with presumably normal sphincter function and individuals with fecal incontinence. We investigated whether new measures, derived from high-resolution anal manometry (HR-ARM), more accurately identify incontinent women with abnormal sphincter function than measures from conventional anal manometry (C-ARM). METHODS: We performed a prospective HR-ARM study of 85 healthy female volunteers (median age 41 years; range 18-68 years) and 403 women with fecal incontinence (median age 55; range 18-91 years) from June 2013 through December 2015. We compared the diagnostic accuracy of conventional measurements of contractility (C-ARM squeeze increment) and tone (C-ARM resting pressure) (the reference standards), with HR-ARM measures (HR-ARM squeeze increment, HR-ARM contractile integral, HR-ARM resting average, HR-ARM rest integral). We also investigated associations between symptom severity and structural sphincter integrity. RESULTS: We identified anal hypocontractility in 129 women with fecal incontinence using the C-ARM squeeze increment (32% sensitivity; likelihood ratio, 6.4), in 189 women using the HR-ARM squeeze increment (47% sensitivity; likelihood ratio, 9.4), and in 220 women using the HR-ARM contractile integral (55% sensitivity; likelihood ratio, 11.0). In contrast, HR-ARM measures of anal tone did not particularly outperform conventional measures (31% sensitivity for HR-ARM resting average vs 28% for C-ARM resting pressure). Ninety-eight of the 206 patients with fecal incontinence who were classified as having normal anal function, based on C-ARM measures, were reclassified as having abnormal function based on HR-ARM measures. CONCLUSION: In a prospective study of healthy women and women with fecal incontinence, we demonstrated that the newly developed HR-ARM contractile integral increased the sensitivity of detection of anal hypocontractility, from 32% to 55%, compared with conventional measurements of squeeze.

Perceptions of Constipation Among the General Public and People With Constipation Differ Strikingly From Those of General and Specialist Doctors and the Rome IV Criteria.

OBJECTIVES: To compare the perceptions of constipation among the general population (with and without constipation), general and specialist doctors, and the Rome IV criteria. METHODS: A cross-sectional survey using a self-administered questionnaire where participants were asked to report symptoms perceived to be most important for a diagnosis of constipation. Participants also judged 10 case studies in which constipation was either present or absent according to Rome IV criteria. RESULTS: Two thousand five hundred fifty-seven members of the general population (934 with self-reported constipation and 1,623 without constipation), 411 general practitioners (GPs) and 365 gastroenterology specialists completed the questionnaire. Of the 934 with self-reported constipation, 877 (94%) met Rome IV criteria for functional constipation, whereas of the 1,623 who did not self-report constipation, 473 (29%) actually met Rome IV criteria. Infrequent bowel movements were perceived as important for diagnosing constipation by less than a third of the constipated general population (26%), compared with 41% of GPs and 65% of specialist doctors (P < 0.001). Principal component analysis revealed 7 symptom clusters, with most symptoms not being part of formal diagnostic criteria. Using case studies, correct diagnosis of constipation ranged from 99% down to as low as 39%, depending upon the number and type of symptom present. DISCUSSION: The general population's perceptions of constipation differ strikingly from those of GPs and specialist doctors, and there is limited agreement between public perceptions of constipation and Rome IV criteria. These findings emphasize the need to educate doctors and the general population regarding the symptoms of constipation, and realign diagnostic criteria to address those symptoms patients perceive to be important.

The extracellular matrix glycoprotein tenascin-X regulates peripheral sensory and motor neurones.

KEY POINTS: Tenascin-X (TNX) is an extracellular matrix glycoprotein with anti-adhesive properties in skin and joints. Here we report the novel finding that TNX is expressed in human and mouse gut tissue where it is exclusive to specific subpopulations of neurones. Our studies with TNX-deficient mice show impaired defecation and neural control of distal colonic motility that can be rescued with a 5-HT4 receptor agonist. However, colonic secretion is unchanged. They are also susceptible to internal rectal intussusception. Colonic afferent sensitivity is increased in TNX-deficient mice. Correspondingly, there is increased density of and sensitivity of putative nociceptive fibres in TNX-deficient mucosa. A group of TNX-deficient patients report symptoms highly consistent with those in the mouse model. These findings suggest TNX plays entirely different roles in gut to non-visceral tissues - firstly a role in enteric motor neurones and secondly a role influencing nociceptive sensory neurones Studying further the mechanisms by which TNX influences neuronal function will lead to new targets for future treatment. ABSTRACT: The extracellular matrix (ECM) is not only an integral structural molecule, but is also critical for a wide range of cellular functions. The glycoprotein tenascin-X (TNX) predominates in the ECM of tissues like skin and regulates tissue structure through anti-adhesive interactions with collagen. Monogenic TNX deficiency causes painful joint hypermobility and skin hyperelasticity, symptoms characteristic of hypermobility Ehlers Danlos syndrome (hEDS). hEDS patients also report consistently increased visceral pain and gastrointestinal (GI) dysfunction. We investigated whether there is a direct link between TNX deficiency and GI pain or motor dysfunction. We set out first to learn where TNX is expressed in human and mouse, then determine how GI function, specifically in the colon, is disordered in TNX-deficient mice and humans of either sex. In human and mouse tissue, TNX was predominantly associated with cholinergic colonic enteric neurones, which are involved in motor control. TNX was absent from extrinsic nociceptive peptidergic neurones. TNX-deficient mice had internal rectal prolapse and a loss of distal colonic contractility which could be rescued by prokinetic drug treatment. TNX-deficient patients reported increased sensory and motor GI symptoms including abdominal pain and constipation compared to controls. Despite absence of TNX from nociceptive colonic neurones, neuronal sprouting and hyper-responsiveness to colonic distension was observed in the TNX-deficient mice. We conclude that ECM molecules are not merely support structures but an integral part of the microenvironment particularly for specific populations of colonic motor neurones where TNX exerts functional influences.

Type 1 diabetic patients with peripheral neuropathy have pan-enteric prolongation of gastrointestinal transit times and an altered caecal pH profile.

AIMS/HYPOTHESIS: We hypothesised that type 1 diabetic patients with established diabetic sensorimotor polyneuropathy (DSPN) would have segmental and/or pan-enteric dysmotility in comparison to healthy age-matched controls. We aimed to investigate the co-relationships between gastrointestinal function, degree of DSPN and clinical symptoms. METHODS: An observational comparison was made between 48 patients with DSPN (39 men, mean age 50 years, range 29-71 years), representing the baseline data of an ongoing clinical trial (representing a secondary analysis of baseline data collected from an ongoing double-blind randomised controlled trial investigating the neuroprotective effects of liraglutide) and 41 healthy participants (16 men, mean age 49 years, range 30-78) who underwent a standardised wireless motility capsule test to assess gastrointestinal transit. In patients, vibration thresholds, the Michigan Neuropathy Screening Instrument and Patient Assessment of Upper Gastrointestinal Symptom questionnaires were recorded. RESULTS: Compared with healthy controls, patients showed prolonged gastric emptying (299 ± 289 vs 179 ± 49 min; p = 0.01), small bowel transit (289 ± 107 vs 224 ± 63 min; p = 0.001), colonic transit (2140, interquartile range [IQR] 1149-2799 min vs 1087, IQR 882-1650 min; p = 0.0001) and whole-gut transit time (2721, IQR 1196-3541 min vs 1475 (IQR 1278-2214) min; p < 0.0001). Patients also showed an increased fall in pH across the ileocaecal junction (-1.8 ± 0.4 vs -1.3 ± 0.4 pH; p < 0.0001), which was associated with prolonged colonic transit (r = 0.3, p = 0.001). Multivariable regression, controlling for sex, disease duration and glycaemic control, demonstrated an association between whole-gut transit time and total GCSI (p = 0.02). CONCLUSIONS/INTERPRETATION: Pan-enteric prolongation of gastrointestinal transit times and a more acidic caecal pH, which may represent heightened caecal fermentation, are present in patients with type 1 diabetes. The potential implication of delayed gastrointestinal transit on the bioavailability of nutrition and on pharmacotherapeutic and glycaemic control warrants further investigation. TRIAL REGISTRATION: EUDRA CT: 2013-004375-12.

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.

Colonic and anorectal motility testing in the high-resolution era.

PURPOSE OF REVIEW: The past few years have seen an increase in the number of research and clinical groups around the world using high-resolution manometry (HRM) to record contractile activity in the anorectum and colon. Yet despite the uptake and growing number of publications, the clinical utility and potential advantages over traditional manometry remain undetermined. RECENT FINDINGS: Nearly all of the publications in the field of anorectal and colonic HRM have been published within the last 3 years. These studies have included some data on normal ranges in healthy adults, and abnormalities in patient groups with constipation or fecal incontinence, anal fissure, perineal descent, rectal cancer, and Hirschsprung's disease. Most of the studies have been conducted on adults, with only three published studies in pediatric populations. Very few studies have attempted to show advantages of HRM over traditional manometry SUMMARY: High-resolution anorectal and colonic manometry provide a more comprehensive characterization of motility patterns and coordinated activity; this may help to improve our understanding of the normal physiology and pathophysiology in these regions. To date, however, no published study has conclusively demonstrated a clinical, diagnostic, or interventional advantage over conventional manometry.

Gastrointestinal Transit Times in Health as Determined Using Ingestible Capsule Systems: A Systematic Review.

BACKGROUND: Ingestible capsule (IC) systems can assess gastrointestinal (GI) transit times as a surrogate for gut motility for extended periods of time within a minimally invasive, radiation-free and ambulatory setting. METHODS: A literature review of IC systems and a systematic review of studies utilizing IC systems to measure GI transit times in healthy volunteers was performed. Screening for eligible studies, data extraction and bias assessments was performed by two reviewers. A narrative synthesis of the results was performed. RESULTS: The literature review identified 23 different IC systems. The systematic review found 6892 records, of which 22 studies were eligible. GI transit time data were available from a total of 1885 healthy volunteers. Overall, seventeen included studies reported gastric emptying time (GET) and small intestinal transit time (SITT). Colonic transit time (CTT) was reported in nine studies and whole gut transit time (WGTT) was reported in eleven studies. GI transit times in the included studies ranged between 0.4 and 15.3 h for GET, 3.3-7 h for SITT, 15.9-28.9 h for CTT and 23.0-37.4 h for WGTT. GI transit times, notably GET, were influenced by the study protocol. CONCLUSIONS: This review provides an up-to-date overview of IC systems and reference ranges for GI transit times. It also highlights the need to standardise protocols to differentiate between normal and pathological function.

Simultaneous Colonic Pressure Waves in Children and Young Adults with Gastrointestinal Motility Disorders: Artefact or Colonic Physiology?

BACKGROUND: Simultaneous pressure waves (SPW) spanning all recording sites in colonic manometry studies have been described as a potential biomarker of normal gas transit and extrinsic neural reflexes. In pediatric studies utilizing combined antroduodenal and colonic manometry, it was noted that most colonic SPWs appeared to also span all sensors in the gastric and small bowel regions. This suggests that a proportion of colonic SPWs may represent an artefact caused by forces extrinsic to the colon. Our aim was to characterize colonic SPWs and determine how many of these spanned most of the digestive tract. METHODS: In 39 combined high-resolution antroduodenal and colonic manometry traces from 27 pediatric patients, we used our purpose-built software to identify all SPWs that spanned either (i) all recording sites in the digestive tract or (ii) those restricted to the colon. RESULTS: A total of 14,565 SPWs were identified (364 ± 316 SPWs/study), with 14,550 (99.9%) spanning the entire antroduodenal and colonic recording sites. Only 15 SPWs (0.1% of the total) were restricted to the colon (all in one recording). CONCLUSIONS: Based on these findings, we suggest that, in pediatric studies, SPWs should not form part of any diagnostic criteria, as these events appear to be an artefact caused by factors outside the colon (abdominal strain, body motion).

Prospective randomized double-blind study of temporary sacral nerve stimulation in patients with rectal evacuatory dysfunction and rectal hyposensitivity.

OBJECTIVE: Prospective randomized double-blind placebo-controlled crossover trial of 14 female patients (median age 52 [30-69] years) with proctographically defined evacuatory dysfunction (ED) and demonstrable rectal hyposensitivity (elevated thresholds to balloon distension in comparison with age- and sex-matched controls). BACKGROUND: Sacral nerve stimulation (SNS) is an evolving treatment for constipation. However, variable outcomes might be improved by better patient selection. Evidence that the effect of SNS may be mediated by modulation of afferent signaling promotes a role in patients with ED associated with rectal hyposensation. METHODS: SNS was performed by the standard 2-stage technique (temporary then permanent implantation). During a 4-week period of temporary stimulation, patients were randomized ON-OFF/OFF-ON for two 2-week periods. Before insertion (PRE), and during each crossover period, primary (rectal sensory thresholds) and secondary (bowel diaries, constipation, and GIQoL [gastrointestinal quality of life] scores) outcome variables were blindly assessed. RESULTS: Thirteen patients completed the trial. Following stimulation, defecatory desire volumes to rectal balloon distension were normalized in 10 of 13 patients (PRE: mean 277 mL [234-320] vs ON: 163 mL [133-193] vs OFF: 220 mL [183-257 mL]; P = 0.006) and maximum tolerable volume in 9 of 13 (PRE: mean 350 mL [323-377] vs ON: 262 mL [219-305] vs OFF: 298 mL [256-340 mL]; P = 0.012). There was a significant increase in the percentage of successful bowel movements (PRE: median 43% [0-100] vs ON: 89% [11-100] vs OFF: 83% [11-100]; P = 0.007) and Wexner constipation scores improved (PRE: median 19 [9-26] vs ON: 10 [6-27] vs OFF: 13 [5-29]; P = 0.01). There were no significant changes in disease-specific or generic quality of life measures. Eleven patients progressed to permanent stimulation (9/11 success at 19 months). CONCLUSIONS: Most patients with chronic constipation secondary to ED with rectal hyposensitivity responded to temporary SNS. The physiological results presented support a mechanistic role for rectal afferent modulation.

Fecal incontinence in men: coexistent constipation and impact of rectal hyposensitivity.

BACKGROUND: The pathophysiology of fecal incontinence in men is poorly established. OBJECTIVE: The aim of this study was to assess the coexistence of constipation and determine the impact of rectal sensorimotor dysfunction in males with fecal incontinence. SETTING: This study was conducted at a tertiary referral center. PATIENTS: Included were adult male patients referred for the investigation of fecal incontinence over a 5-year period who underwent full anorectal physiology testing and completed a standardized symptom questionnaire. INTERVENTION: Standardized symptom questionnaires were fully completed, and anorectal physiologic test results (including evacuation proctography) were evaluated. MAIN OUTCOME MEASURES: : The primary outcomes measured were the frequency of symptoms of associated constipation, the association of blunted rectal sensation (rectal hyposensitivity) with symptoms, and other physiologic measures. RESULTS: One hundred sixty patients met the inclusion criteria, and 47% of these patients described concurrent constipation. Fifty-four patients (34%) had sphincter dysfunction on manometry, only 19 of whom had structural abnormalities on ultrasound. Overall, 28 patients (18%) had rectal sensory dysfunction, 26 (93%) of whom had rectal hyposensitivity. Patients with rectal hyposensitivity were more likely to subjectively report constipation (77%) in comparison with patients with normal rectal sensation (44%; p = 0.001), allied with decreased bowel frequency (19% vs 2%; p = 0.003) and a sense of difficulty evacuating stool (27% vs 8%; p = 0.008). Cleveland Clinic constipation scores were higher in patients with rectal hyposensitivity (median score, 13 (interquartile range: 8-17) vs normosensate, 9 (5-13); p = 0.004). On proctography, a higher proportion of patients with rectal hyposensitivity had protracted defecation (>180 s; 35% vs 10%; p = 0.024) and incomplete rectal evacuation (<55% of barium neostool expelled, 50% vs 20%; p = 0.02). LIMITATIONS: : This study was limited by the retrospective analysis of prospectively collected data. CONCLUSIONS: Only one-third of incontinent men had sphincteric dysfunction. Other pathophysiologies must therefore be considered. Nearly half of patients reported concurrent constipation, and one-sixth had rectal hyposensitivity, which was associated with higher frequencies of both symptomatic and objective measures of rectal evacuatory dysfunction. In the majority of adult males, fecal incontinence may represent a secondary phenomenon.