Anterior resection syndrome.

Up to 80% of patients with rectal cancer undergo sphincter-preserving surgery. It is widely accepted that up to 90% of such patients will subsequently have a change in bowel habit, ranging from increased bowel frequency to faecal incontinence or evacuatory dysfunction. This wide spectrum of symptoms after resection and reconstruction of the rectum has been termed anterior resection syndrome. Currently, no precise definition or causal mechanisms have been established. This disordered bowel function has a substantial negative effect on quality of life. Previous reviews have mainly focused on different colonic reconstructive configurations and their comparative effects on daily function and quality of life. The present Review explores the potential mechanisms underlying disturbed functions, as well as current, novel, and future treatment options.

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.

The physiology of human defecation.

Human defecation involves integrated and coordinated sensorimotor functions, orchestrated by central, spinal, peripheral (somatic and visceral), and enteric neural activities, acting on a morphologically intact gastrointestinal tract (including the final common path, the pelvic floor, and anal sphincters). The multiple factors that ultimately result in defecation are best appreciated by describing four temporally and physiologically fairly distinct phases. This article details our current understanding of normal defecation, including recent advances, but importantly identifies those areas where knowledge or consensus is still lacking. Appreciation of normal physiology is central to directed treatment of constipation and also of fecal incontinence, which are prevalent in the general population and cause significant morbidity.

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.

Accurate localization of a fall in pH within the ileocecal region: validation using a dual-scintigraphic technique.

Stereotypical changes in pH occur along the gastrointestinal (GI) tract. Classically, there is an abrupt increase in pH on exit from the stomach, followed later by a sharp fall in pH, attributed to passage through the ileocecal region. However, the precise location of this latter pH change has never been conclusively substantiated. We aimed to determine the site of fall in pH using a dual-scintigraphic technique. On day 1, 13 healthy subjects underwent nasal intubation with a 3-m-long catheter, which was allowed to progress to the distal ileum. On day 2, subjects ingested a pH-sensitive wireless motility capsule labeled with 4 MBq (51)Chromium [EDTA]. The course of this, as it travelled through the GI tract, was assessed with a single-headed γ-camera using static and dynamic scans. Capsule progression was plotted relative to a background of 4 MBq ¹¹¹Indium [diethylenetriamine penta-acetic acid] administered through the catheter. Intraluminal pH, as recorded by the capsule, was monitored continuously, and position of the capsule relative to pH was established. A sharp fall in pH was recorded in all subjects; position of the capsule relative to this was accurately determined anatomically in 9/13 subjects. In these nine subjects, a pH drop of 1.5 ± 0.2 U, from 7.6 ± 0.05 to 6.1 ± 0.1 occurred a median of 7.5 min (1-16) after passage through the ileocecal valve; location was either in the cecum (n = 5), ascending colon (n = 2), or coincident with a move from the cecum to ascending colon (n = 2). This study provides conclusive evidence that the fall in pH seen within the ileocolonic region actually occurs in the proximal colon. This phenomenon can be used as a biomarker of transition between the small and large bowel and validates assessment of regional GI motility using capsule technology that incorporates pH measurement.

Efficacy of sacral nerve stimulation for fecal incontinence in patients with anal sphincter defects.

PURPOSE: Sacral nerve stimulation has traditionally been used to treat patients with fecal incontinence with intact anal sphincters. This rationale has been challenged, but it remains unknown if its efficacy is related to the extent of the sphincter injury. METHODS: This was a prospective study of 15 patients with sphincter defects (9 combined, 2 external only, and 4 internal only) undergoing sacral nerve stimulation for fecal incontinence. Endoanal ultrasound scans were reviewed and defects scored (0-16) with use of a system published by two independent observers. These were correlated with the following outcomes: 1) reduction in fecal incontinence episodes, 2) reduction in soiling, 3) improvement in Cleveland Clinic scores, and 4) improvement in ability to defer defecation. All patients were studied after temporary stimulation and again at three to six months after permanent implantation. RESULTS: Thirteen patients (87%) progressed to permanent stimulation. Median fecal incontinence episodes per two weeks decreased from 15 (range, 1-53) to 3 (range, 0-16; P = 0.01). Median soiling episodes were reduced from 10 (range, 1-14) to 6 (range, 0-14; P = 0.009). Median Cleveland Clinic scores decreased from 12 (range, 9-18) to 9 (range, 4-14; P = 0.0005). The ability to defer defecation was improved significantly (P = 0.05). There were no relationships between sphincter defect scores and outcome measures after sacral nerve stimulation (r = 0.001-0.10; P = 0.28-0.94). CONCLUSION: Sacral nerve stimulation is an effective treatment in patients with fecal incontinence who have anal sphincter defects, and outcome is not associated with severity of sphincter disruption.

Risk factors in acquired faecal incontinence.

Acquired faecal incontinence arising in the non-elderly population is a common and often devastating condition. We conducted a retrospective cohort analysis in 629 patients (475 female) referred to a tertiary centre, to determine the relative importance of individual risk factors in the development of faecal incontinence, as demonstrated by abnormal results on physiological testing. Potential risk factors were identified in all but 6% of patients (7 female, 32 male). In women, the principal risk factor was childbirth (91%), and in most cases at least one vaginal delivery had met with complications such as perineal injury or the need for forceps delivery. Of the males, half had undergone anal surgery and this was the only identified risk factor in 59%. In many instances, assignment of cause was hampered by a long interval between the supposed precipitating event and the development of symptoms. Abnormalities of anorectal physiology were identified in 76% of males and 96% of females (in whom they were more commonly multiple). These findings add to evidence that occult damage to the continence mechanism, especially through vaginal delivery and anal surgery, can result in subsequent faecal incontinence, sometimes after an interval of many years.

Rectal augmentation: short- and mid-term evaluation of a novel procedure for severe fecal urgency with associated incontinence.

BACKGROUND: Rectal augmentation (RA) with or without electrically stimulated gracilis neosphincter (ESGN) was developed to address the physiologic and anatomic abnormalities present in a subset of patients with incapacitating fecal urgency and associated urge fecal incontinence (UFI). This study evaluated the short- and medium-term clinical and physiologic results. METHODS: Eleven patients with fecal urgency and UFI underwent RA, 6 with concomitant ESGN formation. Patients were evaluated preoperatively, and at a median of 12.5 and 54 months after surgery. RESULTS: At 4.5 years, 7/11 patients had avoided stoma construction. Symptoms recurred leading to permanent stoma formation in 1 patient, whereas one other developed evacuatory difficulty with overflow incontinence. Median ability to defer defecation improved from seconds preoperatively to 10 minutes at 1 year (P = 0.0002), and 15 minutes at 4.5 years (P = 0.002). Median Wexner incontinence scores improved from 15 preoperatively to 3 at 1 year (P = 0.002), and 4 at 4.5 years (P = 0.02). At 1 year, 2 of the rectal sensory thresholds (DDV: P = 0.008; MTV: P = 0.008) and compliance were normalized (P = 0.008), whereas at 4.5 years, all sensation thresholds improved (FCS: P = 0.002; DDV: P = 0.002; MTV: P = 0.002), but changes in compliance were not significant. CONCLUSION: RA with or without ESGN improved reported symptoms and normalized rectal sensation. Improvements were sustained in the medium term. The procedure had no associated morbidity or mortality, and should be considered in the surgical management of a select group of patients presenting with severe urgency and UFI.

In patients with slow transit constipation, the pattern of colonic transit delay does not differentiate between those with and without impaired rectal evacuation.

BACKGROUND: Severe constipation may be subclassified on the basis of speed of colonic transit and efficacy of rectal evacuation. It is hypothesized that rectal evacuatory disorder (RED) may be associated with a secondary transit delay. OBJECTIVES: To determine whether scintigraphy can discriminate between slow transit constipation (STC) with or without coexistent RED on the basis of progression of isotope throughout the colon and by analyses of specific regions of interest. METHODS: One hundred ninety-six patients with STC (radio-opaque marker study) were subclassified according to results of proctography into those with a RED (STC-RED N = 30) or normal (STC-ONLY N = 41) evacuation. Patients subsequently underwent colonic scintigraphy. Distribution of generalized or left-sided patterns of colonic transit was assessed. Severities of transit delay and regional transit at specific time points were also evaluated. RESULTS: Time-activity curves and severity of global transit delay were similar between groups as were the incidences of generalized and left-sided patterns of delay. Percentage of radioisotope retention in the right colon at 18 h was higher for the STC-ONLY group (P < 0.05), but this was poorly discriminative. No differences were observed for the percentage of radioisotope retained in the left colon at later scans. CONCLUSIONS: Global and regional assessment of colonic transit by scintigraphy failed to discriminate between patients with STC with or without coexistent RED. Thus, RED is not associated with a specific pattern of transit delay and scintigraphy alone cannot predict the presence or absence of RED, knowledge of which is important for management.

Unilateral pudendal neuropathy is common in patients with fecal incontinence.

PURPOSE: Pudendal neuropathy and fecal incontinence frequently coexist; however, the contribution of neuropathy is unknown. The pudendal nerve innervates the external anal sphincter muscle, anal canal skin, and coordinates reflex pathways. Lateral dominance or a dominantly innervating nerve and its subsequent damage may have major implications in the etiology and treatment of fecal incontinence. This study was designed to establish the prevalence of pudendal neuropathy, in particular a unilateral one, and to examine the impact on anorectal function. METHODS: A total of 923 patients (745 females; mean age, 52 (range, 17-92) years) with fecal incontinence were studied using endoanal ultrasonography, anorectal manometry, rectal sensation, and pudendal nerve terminal motor latencies. RESULTS: A total of 520 patients (56 percent) demonstrated a pudendal neuropathy, which was unilateral in 38 percent (351 patients; 169 right-sided, 182 left-sided). Neuropathy, whether it was bilateral (bilateral vs. normal; 56 (range, 7-154) cm H2O) vs. 67 (range, 5-215) cm H2O; P < 0.01) or unilateral (unilateral vs. normal; 61 (range, 0-271) cm H2O vs. 67 (range, 5-215) cm H2O; P = 0.04) was associated with reduced anal resting tone. This also was seen with respect to squeeze increments (bilateral vs. normal; 34 (range, 0-207) cm H2O vs. 52 (range, 0-378) cm H2O; P < 0.001, unilateral vs. normal; 41 (range, 0-214) cm H2O vs. 52 (range, 0-378) cm H2O; P < 0.01). In those with intact sphincters, unilateral neuropathy was associated with reduced squeeze increments (unilateral vs. normal; 60 (range, 10-286) cm H2O vs. 69 (range, 7-323) cm H2O; P = 0.01) but no significant reduction in resting pressures. There was no association between pudendal neuropathy and abnormal rectal sensitivity. CONCLUSIONS: Unilateral pudendal neuropathy is a common abnormality in individuals with fecal incontinence and is significantly associated with both attenuated resting pressures and squeeze increments. Although there are limitations in the interpretation of pudendal nerve terminal motor latencies, this study demonstrates that further exploration of the concept of lateral dominance is needed.

A novel technique to identify patients with megarectum.

PURPOSE: Traditional methods of identifying patients with persistent dilation of the rectum, or megarectum, are associated with inherent methodologic limitations. The purpose of this study was to use a barostat to establish criteria for the diagnosis of megarectum and to assess rectal diameter during isobaric (barostat) and volumetric (barium contrast) distention protocols in constipated patients with megarectum on anorectal manometry. METHODS: During fluoroscopic screening, rectal diameter was measured at minimum distending pressure of the rectum, achieved using a barostat. It was also measured during evacuation proctography (volumetric distention). Having established a normal range in 25 healthy volunteers, 30 constipated patients with evidence of megarectum on anorectal manometry (elevated maximum tolerable volume on latex balloon distention) were studied. A further 10 constipated patients without evidence of megarectum were studied (normal rectum). RESULTS: Megarectum was diagnosed when the rectal diameter was greater than 6.3 cm at minimum distending pressure. Rectal diameter at minimum distending pressure was increased in 20 patients (67 percent) with megarectum on anorectal manometry, but was normal in the remaining 10 patients (33 percent) and all patients with a normal rectum on anorectal manometry. Rectal diameter was increased at evacuation proctography in only 15 patients (50 percent) with evidence of megarectum on anorectal manometry. CONCLUSIONS: The prevalence of megarectum is overestimated and underestimated when rectal diameter is assessed using anorectal manometry and contrast studies, respectively. Controlled (pressure-based) distention combined with fluoroscopic imaging allowed accurate identification of patients with megarectum on the basis of a rectal diameter greater than 6.3 cm at the minimum distention pressure. Measurement of rectal diameter at minimum distention pressure may be useful in those patients with an elevated maximum tolerable volume on anorectal manometry when surgery is being contemplated.

Multimedia article. External pelvic rectal suspension (the express procedure) for internal rectal prolapse, with or without concomitant rectocele repair: a video demonstration.

PURPOSE: Internal rectal prolapse has been proposed as a cause of symptomatic rectal evacuatory dysfunction. Abdominal rectopexy, the standard surgical approach, has significant attendant risk and does not address any concomitant rectocele. This video was designed to demonstrate a novel surgical method that uses porcine collagen implants (Permacol), designed to correct internal rectal prolapse, with or without rectocele. INCLUSION CRITERIA: severe rectal evacuatory dysfunction refractory to maximal conservative therapy and full-thickness internal rectal prolapse impeding rectal emptying on defecography with or without associated functional rectocoele; normal colonic transit. Patients undergo comprehensive preoperative and postoperative symptomatic assessment and anorectal physiologic testing, including defecography. A crescenteric perineal skin incision allows development of the rectovaginal/rectoprostatic plane to Denonvilliers fascia, with rectal mobilization. A curved tunneller inserted via the perineal wound is guided retropubically to emerge through suprapubic wounds created on each side. Permacol T-strips are sutured to the anterolateral rectal wall bilaterally, upward traction exerted, and the stem of each T-strip is sutured to the suprapubic periosteum, suspending the rectum. Concomitant rectocele is repaired using a Permacol patch in the rectovaginal plane. RESULTS: Short-term results for the "Express" are encouraging with improvement in evacuatory and prolapse symptoms and concomitant anatomic improvement at defecography. CONCLUSIONS: This procedure promises to be an effective technique for managing patients with refractory evacuatory dysfunction secondary to internal rectal prolapse, with or without rectocele.

Rectal hyposensitivity.

Rectal hyposensitivity (RH) relates to a diminished perception of rectal distension that is diagnosed during anorectal physiologic investigation. There have been few direct studies of this physiologic abnormality, and its contribution to the development of functional bowel disorders has been relatively neglected. However, it appears to be common in patients with such disorders, being most prevalent in patients with functional constipation with or without fecal incontinence. Indeed, it may be important in the etiology of symptoms in certain patients, given that it is the only "apparent" identifiable abnormality on physiologic testing. Currently, it is usually diagnosed on the basis of elevated sensory threshold volumes during balloon distension in clinical practice, although such a diagnosis may be susceptible to misinterpretation in the presence of altered rectal wall properties, and thus it is uncertain whether a diagnosis of RH reflects true impairment of afferent nerve function. Furthermore, the etiology of RH is unclear, although there is limited evidence to support the role of pelvic nerve injury and abnormal toilet behavior. The optimum treatment of patients with RH is yet to be established. The majority are managed symptomatically, although "sensory-retraining biofeedback" appears to be the most effective treatment, at least in the short term, and is associated with objective improvement in the rectal sensory function. Currently, fundamental questions relating to the contribution of this physiologic abnormality to the development of functional bowel disorders remain unanswered. Acknowledgment of the potential importance of RH is thus required by clinicians and researchers to determine its relevance.

Systematic review of surgical options for idiopathic megarectum and megacolon.

OBJECTIVE: A subgroup of patients with intractable constipation has persistent dilatation of the bowel, which in the absence of an organic cause is termed idiopathic megabowel (IMB). The aim of this systematic review was to evaluate the published outcome data of surgical procedures for IMB in adults. METHODS: Electronic searches of the MEDLINE (PubMed) database, Cochrane Library, EMBase, and Science Citation Index were performed. Only peer-reviewed articles of surgery for IMB published in the English language were evaluated. Studies of all surgical procedures were included, providing they were performed on 3 or more patients, and overall success rates were documented. Studies were critically appraised in terms of design and methodology, inclusion criteria, success, mortality and morbidity rates, and functional outcomes. RESULTS: A total of 27 suitable studies were identified, all evidence was low quality obtained from case series, and there were no comparative studies. The studies involved small numbers of patients (median 12, range 3-50), without long-term follow-up (median 3 years, range 0.5-7). Inclusion of subjects, methods of data acquisition, and reporting of outcomes were extremely variable. Subtotal colectomy was successful in 71.1% (0%-100%) but was associated with significant morbidity related to bowel obstruction (14.5%, range 0%-29%). Segmental resection was successful in 48.4% (12.5%-100%), and recurrent symptoms were common (23.8%). Rectal procedures achieved a successful outcome in 71% to 87% of patients. Proctectomy, the Duhamel, and pull-through procedures were associated with significant mortality (3%-25%) and morbidity (6%-29%). Vertical reduction rectoplasty (VRR) offered promising short-term success (83%). Pelvic-floor procedures were associated with poor outcomes. A stoma provided a safe alternative but was only effective in 65% of cases. CONCLUSIONS: Outcome data of surgery for IMB must be interpreted with extreme caution due to limitations of included studies. Recommendations based on firm evidence cannot be given, although colectomy appears to be the optimum procedure in patients with a nondilated rectum, restorative proctocolectomy the most suitable in those with dilatation of the colon and rectum, and VRR in those patients with dilatation confined to the rectum. Appropriately designed studies are required to make valid comparisons of the different procedures available.

Rectal intussusception: characterization of symptomatology.

PURPOSE: Rectal intussusception is a common finding at evacuation proctography; however, its significance has been debated. This study was designed to characterize clinically and physiologically a large group of patients with rectal intussusception and test the hypothesis that certain symptoms are predictive of this finding on evacuation proctography. METHODS: A total of 896 patients underwent evacuation proctography from which three groups were identified: those with isolated rectal intussusception (n = 125), those with isolated rectocele (n = 100), and those with both abnormalities (n = 152). Multivariate analyses were used to identify symptoms predictive of findings by evacuation proctography. RESULTS: The symptoms of anorectal pain and prolapse were highly predictive of the finding of isolated intussusception over rectocele (odds ratio, 3.6, P = 0.006; odds ratio, 4.9, P < 0.001) or combined intussusception and rectocele (odds ratio, 2.9, P = 0.02; odds ratio, 2.4, P = 0.03). The symptom of "toilet revisiting" was associated with the finding of rectoanal intussusception (odds ratio, 3.55, P = 0.04). Although patients with mechanically obstructing intussuscepta evacuated slower and less completely (P < 0.001) than those with nonobstructing intussuscepta, no symptom was predictive of this finding on evacuation proctography. CONCLUSIONS: Although certain symptoms are predictive of the finding of rectal intussusception, there is a wide overlap with symptoms of rectocele, another common cause of evacuatory dysfunction. Furthermore, the observation that "obstruction to evacuation" made on proctography had no impact on the incidence of evacuatory symptoms suggests that beyond simply demonstrating the presence of an intussusception, analysis of proctography and subclassifying intussusception morphology seems of little clinical significance, and selection for surgical intervention on the basis of proctographic findings may be illogical.

Rectal hypersensitivity worsens stool frequency, urgency, and lifestyle in patients with urge fecal incontinence.

PURPOSE: Rectal sensory mechanisms are important in the maintenance of fecal continence. Approximately 50 percent of patients with urge incontinence have lowered rectal sensory threshold volumes (rectal hypersensitivity) on balloon distention. Rectal hypersensitivity may underlie the heightened perception of rectal filling; however, its impact on fecal urgency and incontinence is unknown. This study was designed to investigate the impact of rectal hypersensitivity in patients with urge fecal incontinence. METHODS: Prospective and retrospective audit review of all patients (n = 258) with an intact native rectum referred to a tertiary colorectal surgical center for physiologic investigation of urge fecal incontinence during a 7.5-year period. Patients with urge fecal incontinence who had undergone pelvic radiotherapy (n = 9) or rectal prolapse (n = 6) were excluded. RESULTS: A total of 108 of 243 patients (44 percent) were found to have rectal hypersensitivity. The incidence of anal sphincter dysfunction was equal (90 percent) among those with or without rectal hypersensitivity. Patients with urge fecal incontinence and rectal hypersensitivity had increased stool frequency (P < 0.0001), reported greater use of pads (P = 0.003), and lifestyle restrictions (P = 0.0007) compared with those with normal rectal sensation, but had similar frequencies of incontinent episodes. CONCLUSIONS: Urge fecal incontinence relates primarily to external anal sphincter dysfunction, but in patients with urge fecal incontinence, rectal hypersensitivity exacerbates fecal urgency, and this should be considered in the management and surgical decision in patients who present with fecal incontinence.