Phenotypic variation in functional disorders of defecation

BACKGROUND & AIMS: Although obstructed defecation is generally attributed to pelvic floor dyssynergia, clinical observations suggest a wider spectrum of anorectal disturbances. Our aim was to characterize phenotypic variability in constipated patients by anorectal assessments. METHODS: Anal pressures, rectal balloon expulsion, rectal sensation, and pelvic floor structure (by endoanal magnetic resonance imaging) and motion (by dynamic magnetic resonance imaging) were assessed in 52 constipated women and 41 age-matched asymptomatic women. Phenotypes were characterized in patients by principal components analysis of these measurements. RESULTS: Among patients, 16 had a hypertensive anal sphincter, 41 had an abnormal rectal balloon expulsion test, and 20 had abnormal rectal sensation. Forty-nine patients (94%) had abnormal pelvic floor motion during evacuation and/or squeeze. After correcting for age and body mass index, 3 principal components explained 71% of variance between patients. These factors were weighted most strongly by perineal descent during evacuation (factor 1), anorectal location at rest (factor 2), and anal resting pressure (factor 3). Factors 1 and 3 discriminated between controls and patients. Compared with patients with normal (n = 23) or reduced (n = 18) perineal descent, patients with increased (n = 11) descent were more likely (P < or = .01) to be obese, have an anal resting pressure >90 mm Hg, and have a normal rectal balloon expulsion test result. CONCLUSIONS: These observations demonstrate that functional defecation disorders comprise a heterogeneous entity that can be subcharacterized by perineal descent during defecation, perineal location at rest, and anal resting pressure. Further studies are needed to ascertain if the phenotypes reflect differences in the natural history of these disorders.     

Utility of a combined test of anorectal manometry, electromyography, and sensation in determining the mechanism of ''idiopathic'' faecal incontinence.

Combined tests of anorectal manometry, sphincter electromyography and rectal sensation were carried out in 302 patients with faecal incontinence (235 women, 67 men). The results obtained were compared with 65 normal subjects (35 women, 30 men). A mechanism for incontinence was identified in all and the majority of patients had more than one abnormality. Two hundred and seventy eight patients (92%) had a weak external anal sphincter, 185 of these (67%, mostly women) also showed abnormal perineal descent, and 14 women showed clinical evidence of sphincter damage as a result of obstetric trauma. Ten per cent of patients with impaired external anal sphincter contraction showed associated evidence of spinal disease (impaired rectal sensation plus attenuated or enhanced reflex external anal sphincter activity). Unlike the other groups, the 'spinal' group contained equal numbers of men and women. Ninety seven patients (32%) had evidence of a weak internal anal sphincter. The external sphincter was also very weak and 92% of these patients also had perineal descent. Eighty two patients (27%) showed an unstable internal sphincter, characterised by prolonged 'spontaneous' anal relaxation under resting conditions and an abnormal reduction in anal pressure after conscious contraction of the sphincter or an increase in intraabdominal pressure. One hundred and forty two patients (47%) had a hypersensitive rectum associated with enhanced anorectal responses to rectal distension. All these patients had an abnormally weak external sphincter, suggesting that the hypersensitive or 'irritable' rectum should not be regarded as a cause of faecal incontinence unless accompanied by external sphincter weakness. Twenty four patients (8%) showed a normal basal and squeeze pressures and impaired rectal sensation; six showed giant rectal contractions during rectal distension. The results show that idiopathic faecal incontinence is not caused by a single abnormality, and it is suggested that combined anorectal manometry, electromyography, and sensory testing is a useful technique to identify the causes of faecal incontinence and provide a basis for appropriate treatment.     

Comparison of Anorectal Manometry to Endoanal Ultrasound in the Evaluation of Fecal Incontinence

BackgroundFecal incontinence (FI) is a common clinical condition with a negative impact on the quality of life. Commonly performed tests to evaluate FI include anorectal manometry (ARM) and endoanal ultrasonography (EAU). Objective of our study was to compare the results of these 2 tests in a cohort of patients with FI.MethodsRetrospective study of 27 patients (20 women) referred to the gastrointestinal motility clinic for FI. EAU and ARM were performed in all patients. Demographic data and information regarding etiology of FI was also recorded.ResultsMean age of the patients was 56 years (range 26-87 years). Etiology of FI was obstetric trauma in 4, pelvic surgery in 9, pelvic trauma in 3, pelvic radiation in 1, and idiopathic in 8. Based on the ARM data, 14 of 27 had a weak external sphincter squeeze pressure and 3 had impaired rectal sensation, whereas with the EAU there was thinning of the external anal sphincter in 3 and complete disruption in 1, and abnormalities of the internal anal sphincter (IAS) in 7 of 27 with thinning, and defects. Overall, only 2 of 27 had normal findings by combined ARM and EAU.ConclusionsAlthough the yield of finding major sphincter defects was low, only a small percentage of patients had a normal ARM or EAU. When there are degrees of external anal sphincter thinning or partial or complete disruption of the sphincters, a good correlation with ARM is achieved. EAU and ARM are complimentary investigations for the thorough assessment of the anal sphincter apparatus.     

Update of tests of colon and rectal structure and function

This review deals with the indications, methods, strengths, and limitations of anorectal testing in clinical practice. In chronic constipation, anal manometry and a rectal balloon expulsion test, occasionally supplemented by defecography, are useful to identify a functional defecatory disorder, because symptoms may respond to pelvic floor retraining. In patients with fecal incontinence, diagnostic testing complements the clinical assessment for evaluating the pathophysiology and guiding management. Manometry measures anal resting and squeeze pressures, which predominantly reflect internal and external anal sphincter function, respectively. Defecation may be indirectly assessed by measuring the recto-anal pressure gradient during straining and by the rectal balloon expulsion test. Endoanal ultrasound and magnetic resonance imaging (MRI) can identify anal sphincter structural pathology, which may be clinically occult, and/or amenable to surgical repair. Only MRI can identify external sphincter atrophy, whereas ultrasound is more sensitive for internal sphincter imaging. By characterizing rectal evacuation and puborectalis contraction, barium defecography may demonstrate an evacuation disorder, excessive perineal descent or a rectocele. Dynamic MRI can provide similar information and also image the bladder and genital organs without radiation exposure. Because the measurement of pudendal nerve latencies suffers from several limitations, anal sphincter electromyography is recommended when neurogenic sphincter weakness is suspected.     

Functional changes after physiotherapy in fecal incontinence

Background Physiotherapy is a common treatment option in patients with fecal incontinence. Although physiotherapy may result in relief of symptoms, to what extent improvement is associated with changes in anorectal function is still unclear.Aim The aim of the present study was to investigate prospectively how anorectal function changes with physiotherapy and whether these changes are related to changes in fecal incontinence score.Methods Consenting consecutive patients (n=266) with fecal incontinence (91% women; mean age, 59 years) underwent anorectal manometry, anal and rectal mucosal sensitivity measurements, and rectal capacity measurement at baseline and after nine sessions of standardized pelvic floor physiotherapy. These findings were compared with changes in Vaizey incontinence score.Results On follow-up 3 months after physiotherapy, squeeze pressure (p=0.028), as well as urge sensation threshold (p=0.046) and maximum tolerable volume (p=0.018), had increased significantly. The extent of improvement was not related to age, duration of fecal incontinence, menopause, and endosonography findings. All other anorectal functions did not change. An improvement in the Vaizey score was moderately correlated with an increase in incremental squeeze pressure (r=0.14, p=0.04) and a decrease in anal mucosal sensitivity threshold (r=0.20, p=0.01).Conclusions Physiotherapy improves squeeze pressure, urge sensation, and maximum tolerable volume. However, improved anorectal function does not always result in a decrease in fecal incontinence complaints.     

Impaired rectal sensation in idiopathic faecal incontinence

In 15 patients suffering from idiopathic faecal incontinence and in 15 matched controls, manometric studies of anorectal pressure and studies of the rectoanal reflex and rectal sensitivity were carried out. Patients with idiopathic faecal incontinence had normal resting pressure but reduced squeeze and stress pressures; the anal sphincter relaxed before a sensation of rectal distension occurred. The conclusion is that both reduced voluntary muscle contraction and impairment of rectal sensation are conducive to soiling in idiopathic faecal incontinence.     

Role of anorectal sensation in preserving continence.

The role of anal sensation in preserving continence was studied in nine healthy volunteers. Objective assessment of sphincter function by manometry and rectal saline infusion was carried out during topical anaesthesia of the anal canal using 5% lignocaine gel and during lubrication with the same amount of inert gel. Anaesthesia successfully abolished anal sensation and reduced both the amplitude and duration of the voluntary squeeze. Basal pressure was unaffected, but the rectal volume required to produce a sustained internal sphincter relaxation was increased. Saline continence was not impaired. Indeed, two subjects, who were previously unable to retain the full 1500 ml of rectally infused saline, did so when the anal canal was anaesthetised. Our findings suggest that anal sensation is not a critical factor in preserving continence. This implies that the incontinence experienced after anorectal surgery or neuropathy cannot be explained by lack of anal sensation alone.     

Effects of biofeedback on obstructive defecation--reconditioning of the defecation reflex?

Twenty two patients with obstructive defecation were recruited for relaxation training by domiciliary self regulatory biofeedback. Each patient served as his or her own control for anorectal and proctographic assessments. Biofeedback training improved the obstructive symptoms of the patients and showed significant change in various parameters related to the obstructive defecation syndrome. As examined by isotope dynamic proctography: the defecation rate (% of evacuation/defecation time) was significantly increased (p < 0.05), the anorectal angles at rest and during attempted defecation were made more obtuse (p < 0.05), and the pelvic floor movements were made more dynamic on voluntary contraction of the anal sphincter (p < 0.03). The external anal sphincter electromyographic voltage recorded during defecation was significantly reduced (p < 0.0005) as was the surface anal plug electromyographic electrode voltage (p < 0.0001), which was associated with a greatly reduced anismus index (p < 0.0001). The rectal sensation was improved (p < 0.05), concomitantly. Biofeedback thus improves the defecation act in patients suffering from inappropriate contraction of the pelvic floor and sphincter musculature. Furthermore, this study has shown that biofeedback objectively influences the defecation reflex leading to an improved quality of higher control of bowel function.     

Critical reappraisal of anorectal function tests in patients with faecal incontinence who have failed conservative treatment

Objective

Anorectal function tests are often performed in patients with faecal incontinence who have failed conservative treatment. This study was aimed to establish the additive value of performing anorectal function tests in these patients in selecting them for surgery.

Patients and methods

Between 2003 and 2009, all referred patients with faecal incontinence were assessed by a questionnaire, anorectal manometry and anal endosonography. Patients with diarrhea, inflammatory bowel disease, pouches or rectal carcinoma were excluded.

Results

In total, 218 patients were evaluated. Of these, 107 (49%) patients had no sphincter defects, 71 (33%) had small defects and 40 (18%) had large defects. Anorectal manometry could not differentiate between patients with and without sphincter defects. Patients with sphincter defects were only found to have a significantly shorter sphincter length and reduced rectal capacity compared to patients without sphincter defects. Forty-three patients (20%) had a normal anal pressures ≥40?mmHg. Seventeen patients (8%) had also a dyssynergic pelvic floor both on clinical examination and anorectal manometry. Fifteen patients (7%) had a reduced rectal capacity between 65 and 100?ml. There was no difference in anal pressures or the presence of sphincter defects in these patients compared to patients with a rectal capacity >150?ml. There was no correlation between anorectal manometry, endosonography and faecal incontinence severity scores.

Conclusion

In patients with faecal incontinence who have failed conservative treatment, only anal endosonography can reveal sphincter defects. Anorectal manometry should be reserved for patients eligible for surgery to exclude those with suspected dyssynergic floor or reduced rectal capacity.     

Manometric tests of anorectal function in healthy adults

OBJECTIVE: Although tests of anorectal function are useful in the assessment of defecation disorders, there is inadequate and inconsistent information regarding normative data. Also, there are discrepancies in manometric techniques and data interpretation. Our aim was to perform a comprehensive evaluation of anorectal function in healthy adults. METHODS: We used a 6-mm diameter probe containing six radially arrayed microtransducers, and a 4-cm-long latex balloon for performing anorectal manometry in 45 healthy subjects who were controlled for gender and age. Sequentially, subjects were asked to squeeze, bear down, or blow up a party balloon. Subsequently, rectal sensation, rectal compliance, and rectoanal reflexes were assessed simultaneously by performing intermittent phasic balloon distentions. Additionally, balloon defecation, pudendal nerve latency, and saline continence tests were performed. RESULTS: In men, the anal sphincter was longer (p < 0.05) and squeeze sphincter pressure and squeeze duration were higher (p < 0.01), but resting sphincter pressure was similar to that in women. When bearing down, although not significant, the defecation index was higher in men. Distinct thresholds for rectal sensation were identified but there was no gender difference. Likewise, rectal compliance and balloon expulsion time were similar. However, during saline infusion, the onset of first leak and total volume retained were higher (p < 0.001) and pudendal nerve latency was shorter (p < 0.05) in men. Overall, parity or age did not influence anorectal function. CONCLUSIONS: This study represents the most comprehensive age- and gender-controlled assessment of anorectal function using solid state technology. Gender influences some parameters of anorectal function. Our results could serve as a valuable resource of normative data.     

Rectal sensorimotor dysfunction in patients with urge faecal incontinence: evidence from prolonged manometric studies

BACKGROUND AND AIMS: Although external anal sphincter dysfunction is the major cause of urge faecal incontinence, approximately 50% of such patients have evidence of rectal hypersensitivity and report exaggerated stool frequency and urgency. The contribution of rectosigmoid contractile activity to the pathophysiology of this condition is unclear, and thus the relations between symptoms, rectal sensation, and rectosigmoid motor function were investigated. METHODS: Fifty two consecutive patients with urge faecal incontinence, referred to a tertiary surgical centre, and 24 volunteers, underwent comprehensive anorectal physiological investigation, including prolonged rectosigmoid manometry. Patients were classified on the basis of balloon distension thresholds into those with rectal hypersensitivity (n = 27) and those with normal rectal sensation (n = 25). Automated quantitative analysis of overall rectosigmoid contractile activities and, specifically, high amplitude contractions and rectal motor complex activity was performed. RESULTS: External anal sphincter dysfunction was similar in both patient groups. Overall, phasic activity and high amplitude contraction frequency were greater, and rectal motor complex variables significantly altered, in those with rectal hypersensitivity. Symptoms, more prevalent in the rectal hypersensitivity group, were also more often associated with rectosigmoid contractile events. For individuals, reduced compliance and increased rectal motor complex frequency were only observed in patients with rectal hypersensitivity. CONCLUSIONS: We have identified a subset of patients with urge faecal incontinence-namely, those with rectal hypersensitivity-who demonstrated increased symptoms, enhanced perception, reduced compliance, and exaggerated rectosigmoid motor activity. Comprehensive assessment of rectosigmoid sensorimotor function, in addition to evaluation of anal function, should be considered in the investigation of patients with urge faecal incontinence.     

Anorectal sphincter function and rectal barostat study in patients following transanal endoscopic microsurgery

BACKGROUND AND AIMS: This study evaluated the effect of transanal endoscopic microsurgery (TEM) on anorectal sphincter functions and determined the risk factors for anorectal dysfunctions (including incontinence). PATIENTS AND METHODS: A study group of 33 patients with small, mobile rectal tumors (adenoma and carcinoma) located up to 12 cm from the anal verge underwent anorectal motility studies (using pull-through anorectal manometry and rectal barostat) and endoanal ultrasound prior to surgery and 3 weeks and 6 months after TEM; controls were 20 healthy volunteers. RESULTS: Resting and squeeze anal pressures were reduced 3 weeks after TEM. Resting anal pressure remained reduced 6 months after surgery; the changes were related to low preoperative levels and to the internal anal sphincter defects rather than to the procedure duration or the type of surgery. High-pressure zone length and vector volume were decreased 3 weeks after TEM and restored 6 months later. Rectoanal inhibitory reflex, reflex sphincter contraction, rectoanal pressure gradients, threshold and maximal tolerable volume of rectal sensitivity, and compliance were significantly changed 3 weeks after TEM; only rectal wall compliance remained low at 6 months. The rectoanal inhibitory reflex, reflex sphincter contraction, rectal sensitivity, and compliance were related to the extent and type of excision (partial or full thickness). Anal ultrasound revealed internal anal sphincter defects in 29% of patients studied 3 weeks after TEM. Only 76% of patients were fully continent. Disturbed anorectal function (including partial fecal incontinence) was observed in up to 50% of patients at 3 weeks. Partial and moderate anorectal dysfunction was found in 21% patients 6 months after surgery. The main risk factors of anorectal dysfunctions following TEM included: postoperative internal anal sphincter defects, low preoperative resting anal pressure, disturbed rectoanal coordination, extent (>50% of wall circumference) and the depth (full thickness) of tumor excision. CONCLUSION: TEM has a relevant but temporary effect on anorectal motility. As a result of TEM procedures 21% of the patients had disturbed anorectal functions, mostly due to the extent or depth of tumor excision (influencing rectal compliance and rectoanal coordination), and to the sphincter defects lowering resting anal pressure. Preoperative anorectal motility studies and anal ultrasound allow the identification of patients with the risk of postoperative anorectal dysfunctions.     

Effect of Aging on Anorectal and Pelvic Floor Functions in Females

Purpose In females, fecal incontinence often is attributed to birth trauma; however, symptoms sometimes begin decades after delivery, suggesting that anorectal sensorimotor functions decline with aging. Methods In 61 asymptomatic females (age, 44 ± 2 years, mean ± standard error of the mean) without risk factors for anorectal trauma, anal pressures, rectal compliance, and sensation were assessed by manometry, staircase balloon distention, and a visual analog scale during phasic distentions respectively. Anal sphincter appearance and pelvic floor motion also were assessed by static and dynamic magnetic resonance imaging respectively in 38 of 61 females. Results Aging was associated with lower anal resting (r = −0.44, P < 0.001) and squeeze pressures (r = −0.32, P = 0.01), reduced rectal compliance (i.e., r for pressure at half-maximum volume vs. age = 0.4, P = 0.001), and lower (P ≤ 0.002) visual analog scale scores during phasic distentions at 16 (r = −0.5) and 24 mmHg (r = −0.4). Magnetic resonance imaging revealed normal anal sphincters in 29 females and significant sphincter injury, not associated with aging, in 9 females. The location of the anorectal junction at rest (r = 0.52, P < 0.001), squeeze (r = 0.62, P < 0.001), and Valsalva maneuver (r = 0.35, P = 0.03), but not anorectal motion (e.g., from resting to squeeze) was associated with age. Conclusions In asymptomatic females, aging is associated with reduced anal resting and squeeze pressures, reduced rectal compliance, reduced rectal sensation, and perineal laxity. Together, these changes may predispose to fecal incontinence in elderly females. Supported in part by Grants R01 HD38666, R01 HD41129, and R01 EB00212 (SJR) and General Clinical Research Center grant M01 RR00585 from the National Institutes of Health, U.S. Public Health Service. Presented at the meeting of the American Gastroenterological Association, Atlanta, Georgia, May 20 to 23, 2001. An erratum to this article is available at .     

The relationship of pudendal nerve terminal motor latency to squeeze pressure in patients with idiopathic fecal incontinence

PURPOSE: With the advent of transanal ultrasonography it has been possible to identify those incontinent patients without sphincter defects. The majority of these patients are now thought to have neurogenic fecal incontinence secondary to pudendal neuropathy. They have been found to have reduced anal sphincter pressures and increased pudendal nerve terminal motor latencies. The aim of this study was to determine whether in those incontinent patients who do not have a sphincter defect, prolonged pudendal nerve terminal motor latency correlates with anal manometry, in particular maximum squeeze pressure. METHODS: Sixty-six incontinent patients were studied with transanal ultrasonography, anorectal manometry, and pudendal nerve terminal motor latency. Twenty-seven continent controls had anorectal manometry and pudendal nerve terminal motor latency measured. RESULTS: Maximum resting pressure and maximum squeeze pressure were significantly lower in the group of incontinent patients with bilateral prolonged pudendal nerve terminal motor latency (median maximum resting pressure = 26.5 mmHg; median maximum squeeze pressure = 60 mmHg) when compared with incontinent patients with normal bilateral pudendal nerve terminal motor latencies (median maximum resting pressure = 46 mmHg; median maximum squeeze pressure = 79 mmHg; maximum resting pressure P = 0.004; and maximum squeeze pressure P = 0.04). In incontinent patients with no sphincter defects no correlation between pudendal nerve terminal motor latency and maximum squeeze pressure was found (r = -0.109, P = 0.48) and maximum squeeze pressure did not correlate with bilateral or unilateral prolonged pudendal nerve terminal motor latency (r = -0.148, P = 0.56 and r = 0.355, P = 0.19 respectively). CONCLUSIONS: In patients with idiopathic fecal incontinence damage to the pelvic floor is more complex than damage to the pudendal nerve alone. Although increased pudendal nerve terminal motor latency may indicate that neuropathy is present, in patients with neuropathic fecal incontinence, pudendal nerve terminal motor latency does not correlate with maximum squeeze pressure. Normal pudendal nerve terminal motor latency does not exclude weakness of the pelvic floor.     

Anorectal manometry in patients with chronic constipation: a single-center experience

BACKGROUND/AIMS: Constipation is a common complaint, but its clinical presentation varies with each individual. The aim of this study was to evaluate anorectal physiology in a prospective group of patients with chronic constipation. METHODOLOGY: A total of 24 consecutive patients with constipation underwent solid-state anorectal manometry. Fifteen healthy controls were also studied. The anorectal parameters included resting and squeeze sphincter pressure, sensory thresholds in response to balloon distension, compliance of rectum, and rectoanal inhibitory reflex (RAIR). RESULTS: The rectal sensitivity for urge and pain did not differ between the groups, but the threshold volume for first sensation was higher in patients with constipation (p < 0.05). There was no group difference in the volume threshold for RAIR. However, the prevalence of impaired RAIR was higher in constipated patients. Anal pressure was lower in patients for maximal squeeze (p < 0.05). There was a positive correlation between the anal sphincter length and resting pressure in patients (r = 0.51, p = 0.03) and healthy controls (r = 0.72, p = 0.01). CONCLUSIONS: Constipated patients are characterized by impaired rectal sensitivity and decreased anal sphincter contractile pressure. Anorectal manometry is helpful for diagnosing anorectal dysfunction in patients with chronic constipation.     

Risk factors for fecal incontinence: a population-based study in women

BACKGROUND: In women with "idiopathic" fecal incontinence (FI), consensus guidelines recommend anal sphincter imaging and surgical repair, when feasible, of anal sphincter defects believed to cause FI. However, the relative contributions of obstetric trauma and bowel symptoms to FI in the community are unknown. METHODS: To assess risk factors for FI during the past year, a previously validated questionnaire was mailed to an age-stratified random sample of 5,300 women residing in Olmsted County, Minnesota. RESULTS: Altogether, 2,800 women (53%) responded. The risk of fecal incontinence increased with age (odds ratio [OR] per decade 1.3, 95% CI 1.2-1.4). The risk of fecal incontinence was higher among women with rectal urgency (OR 8.3, 95% CI 4.8-14.3) whether or not they also had other bowel disturbances (i.e., constipation, diarrhea, or abdominal pain) or had a vaginal delivery with forceps or stitches (OR 9.0, 95% CI 5.6-14.4). Among women with FI, rectal urgency and age were also risk factors for symptom severity. In contrast, obstetric risk factors for anorectal trauma did not increase the risk for FI. The risk for FI was not significantly different among women with cesarean section, vaginal delivery with or without forceps or stitches, or anorectal surgery, compared with nulliparous women without any of these risk factors. CONCLUSIONS: Rectal urgency rather than obstetric injury is the main risk factor for FI in women. These observations reinforce the importance of behavioral, dietary, and pharmacological measures to ameliorate bowel disturbances before anal imaging in women with "idiopathic" FI.     

便秘型和腹泻型肠易激综合征患者肛门直肠运动及直肠感觉功能的检测分析

目的研究便秘型和腹泻型肠易激综合征(IBS)患者肛门直肠运动及直肠感觉改变。方法对2000-01~2004-01广州医学院第二附属医院根据罗马Ⅱ标准入选的便秘型IBS30例,腹泻型IBS20例,正常对照组26例,进行肛门直肠运动功能及直肠感觉测定。结果(1)便秘型和腹泻型IBS肛门括约肌压力、肛门括约肌最大缩窄压和正常对照组相比差异无显著性(P>0.05);增加腹压时,肛门括约肌净增压腹泻型低于正常对照组(P<0.05);模拟大便时直肠和肛门括约肌出现同步收缩发生率便秘型IBS高于正常对照组(P<0.01)。(2)便秘型IBS直肠对容量刺激的最低敏感量、最大耐受性、顺应性明显高于正常对照组(P<0.01)。(3)腹泻型IBS直肠对容量刺激的最低敏感量、最大耐受性、顺应性明显低于正常对照组(P<0.01)。结论(1)IBS存在肛门直肠运动异常。(2)便秘型IBS直肠对容量刺激低敏感、高耐受、高顺应性,可能是引起便秘原因之一。(3)腹泻型IBS直肠对容量刺激存在高敏感、低耐受、低顺应性和肛门自控能力减弱,可能与腹泻有关。     

Electrical Stimulation and Pelvic Floor Muscle Training With Biofeedback in Patients With Fecal Incontinence: A Cohort Study of 281 Patients

Purpose Pelvic floor rehabilitation is an appealing treatment for patients with fecal incontinence but reported results vary. This study was designed to assess the outcome of pelvic floor rehabilitation in a large series of consecutive patients with fecal incontinence caused by different etiologies. Methods A total of 281 patients (252 females) were included. Data about medical history, anal manometry, rectal capacity measurement, and endoanal sonography were collected. Subgroups of patients were defined by anal sphincter complex integrity, and nature and possible underlying causes of fecal incontinence. Subsequently patients were referred for pelvic floor rehabilitation, comprising nine sessions of electric stimulation and pelvic floor muscle training with biofeedback. Pelvic floor rehabilitation outcome was documented with Vaizey score, anal manometry, and rectal capacity measurement findings. Results Vaizey score improved from baseline in 143 of 239 patients (60 percent), remained unchanged in 56 patients (23 percent), and deteriorated in 40 patients (17 percent). Mean Vaizey score reduced with 3.2 points (P < 0.001). A Vaizey score reduction of ≥ 50 percent was observed in 32 patients (13 percent). Mean squeeze pressure (+5.1 mmHg; P = 0.04) and maximal tolerated volume (+11 ml; P = 0.01) improved from baseline. Resting pressure (P = 0.22), sensory threshold (P = 0.52), and urge sensation (P = 0.06) remained unchanged. Subgroup analyses did not show substantial differences in effects of pelvic floor rehabilitation between subgroups. Conclusions Pelvic floor rehabilitation leads overall to a modest improvement in severity of fecal incontinence, squeeze pressure, and maximal tolerated volume. Only in a few patients, a substantial improvement of the baseline Vaizey score was observed. Further studies are needed to identify patients who most likely will benefit from pelvic floor rehabilitation. Supported by grant 945-01-013 of the Netherlands Organization for Health Research and Development. Presented at the United European Gastroenterology Week, Copenhagen, Denmark, October 15 to October 19, 2005. Reprints are not available.     

Defecation disorders: An important subgroup of functional constipation, its pathophysiology, evaluation and treatment with biofeedback.

Functional defecation disorders are common and affect approximately 50% of patients with chronic constipation. The etiology of functional defecation disorders is not well known, but several pathophysiologic mechanisms have been described, including failure of rectoanal coordination, paradoxical anal contraction or insufficient relaxation of anal sphincter during defecation and impairment of rectal sensation as well as secondary slowing of colonic transit. Symptoms alone are inadequate to distinguish patients with defecation disorders from those with other types of constipation. Detailed clinical evaluation and anorectal physiologic tests are required for definitive diagnosis. There is also a pathophysiological association between functional defecation disorders and other anorectal conditions such as solitary rectal ulcer syndrome. Among the various treatment modalities, biofeedback therapy has emerged as an effective and specific treatment method for functional defecation disorders. The main goals of biofeedback therapy are to relax the pelvic floor and anal sphincter muscles during defecation and to improve rectoanal coordination and sensory perception. Today, it is possible to diagnose most functional disorders of defecation and either effectively treat or ameliorate symptoms in a majority of these patients.     

Why do patients with faecal impaction have faecal incontinence.

To elucidate the phenomenon of faecal incontinence in impacted patients, manometric, radiological and other investigations were carried out in 55 elderly patients, who had impacted masses of faeces in the rectum and were incontinent of faeces and 36 elderly control subjects with no anorectal problems. Maximum basal pressure and the maximum squeeze pressure in impacted patients were not significantly different from elderly controls. Sphincter pressures were no different after disimpaction than they were with faecal masses in situ, suggesting that leakage and soiling were not caused by stretching of the anal ring or prolonged reflex inhibition of anal tone by the faecal mass. The anorectal angle was more obtuse in impacted patients than in elderly controls though there was no greater degree of perineal descent. Anal and perianal sensation was impaired in impacted patients compared with controls. Rectal sensation was also impaired in the impacted patients in that the volume in a rectal balloon that could be perceived by the subject and the volume that gave rise to a desire to defecate were much higher in impacted patients than in controls. The rectal volume required to cause anal relaxation was lower in impacted patients compared with controls though there was no reduction in the volume at which anal relaxation failed to recover its resting tone. Rectal distension elicited external sphincter contractions in 53% impacted patients compared with 80% of controls. In conclusion, faecal soiling in patients with faecal impaction is probably related to the combination of an obtuse anorectal angle and the low anal pressures, normally found in the elderly and to impaired anorectal sensation which prevents conscious contraction of the external sphincter when the internal sphincter is relaxed.