Manometric and clinical evaluation of patients after low anterior resection for rectal cancer

The aim of this study was to examine the anorectal physiological and clinical changes that occur after low anterior resection for rectal cancer. Since 1998, 30 patients underwent laboratory tests of anorectal function, preoperatively and 1 month and 6 months after low anterior resection. Postoperatively all patients presented with increased bowel frequency, 60% of the patients with mild soiling and 30% with urgency for defecation. Six months after surgery there was a significant improvement of these symptoms. The anal resting pressure was significantly decreased postoperatively, while maximum squeezing pressure remained unchanged. The rectoanal inhibitory reflex was absent in 80% of the patients and at 6 months after surgery it tended to recover. Rectal capacity and compliance were reduced in all patients. In the current study, the majority of patients demonstrated manometric anorectal changes and clinical anorectal function disorders during the first year after surgery. We observed that these disorders correlated with the low level of the anastomosis.     

Rectoanal reflex parameters in incontinence and constipation

PURPOSE: The transient relaxation of the internal anal sphincter in response to rectal distention is believed to play an important role in the continence mechanism. Most anorectal physiology laboratories merely report the rectoanal inhibitory reflex as being either present or absent. This study aimed to assess the parameters of the rectoanal inhibitory reflex in incontinent and constipated patients and healthy control subjects, in an attempt to analyze differences in internal anal sphincter function in these groups. We analyzed each response of the internal anal sphincter to rectal distention with progressively increasing volumes of air at a single site (proximal anal canal). METHODS: Fifty-five constipated and 99 incontinent patients and healthy control subjects underwent manometry. Various parameters of the rectoanal inhibitory reflex were analyzed, and percentage sphincter relaxation was calculated at each volume at which rectoanal inhibitory reflex occurred. RESULTS: There was no difference in the volume of rectal distention required to elicit sensation (P = 0.626) or the rectoanal inhibitory reflex (P = 0.371) in the three groups. There was a significant correlation between the volume required to elicit the rectoanal inhibitory reflex and that at which sensation was first felt only in the incontinent (P = 0.0001) group. Significantly greater sphincter relaxation was seen at each volume (P = 0.001) in the incontinent as compared with the constipated patients. With progressive rectoanal inhibitory reflex, consistently progressive increases in internal anal sphincter relaxation were found only in the incontinent group. This consistent relationship was not seen in the constipated patients or in healthy control subjects. CONCLUSIONS: Assessment of various parameters of the rectoanal inhibitory reflex yielded important information regarding the continence mechanism. Altered responses of the internal anal sphincter in anorectal disorders plays a role in the associated physiologic impairment. This may have significant clinical implications with regard to sphincter-saving resections.     

Serial evaluation of anorectal function following low anterior resection of the rectum

Purpose: This prospective study was performed to serially assess the changes in anorectal function after low anterior resection of the rectum, and to elucidate the mechanisms of functional impairment and the recovery process. Materials and methods: Thirty-two patients undergoing low anterior resection for rectal cancer were evaluated prospectively. Standardized interviews concerning anorectal function and physiologic studies consisting of manometry and balloon proctometry were performed preoperatively, then at 1, 3, and 6 months, and 1 year after the operation. Depending on the length of the residual rectum, patients were divided into two groups: (1) shorter than 4 cm (the short group, n = 18), and (2) longer than or equal to 4 cm (the long group, n = 14). Results: Postoperatively, stool frequency increased and urgency to defecate occurred, which continued until 3–6 months had passed and was more remarkable in the short group. Overall incontinence score increased, which was more remarkable in the short group. Anal resting pressure showed a moderate reduction after 3 months, whereas squeeze pressure did not decrease significantly. Rectoanal inhibitory reflex was postoperatively abolished in almost all patients in the short group, which showed nearly no recovery for 1 year. In the long group, it persisted postoperatively in half the cases, and the reflex returned in a few cases within 1 year. Balloon proctometry revealed overall reduction in rectal capacity and compliance. Although the values tended to recover steadily, they did not reach the preoperative level for 1 year. Urgent volume and maximal tolerable volume remarkably declined, which continued for 1 year and for 6 months, respectively. Rectal compliance also decreased considerably, which continued for 6 months. Most values of rectal capacity tended to be smaller in the short group. Conclusion: Impairment of continence after low anterior resection seemed multifactorial, including diminished rectal capacity and compliance, impaired internal anal sphincter tone, and loss of rectoanal inhibitory reflex. Clinical outcome was better and reduction in rectal capacity was less in patients whose rectum remained more than 4 cm. Most of the functional impairments clinically recovered by 6 months postoperation. In the process of clinical recovery of continence, restoration of rectal capacity and compliance and internal anal sphincter tone seemed to contribute a significant degree, while the rectoanal inhibitory reflex did not contribute as much. Accepted: 14 September 1998     

Chronic effects of pelvic radiation therapy on anorectal function

PURPOSE: The long-term effect of 4,500 cGy of preoperative radiation on anorectal function has not been prospectively evaluated. METHODS: Anal manometry was performed on 20 patients with rectal carcinoma before and four weeks after receiving 4,500 cGy of external radiotherapy. Four patients underwent proctectomies, three died, and three refused follow-up. Ten patients were available for long-term follow-up and underwent anal manometry at 14 to 42 (average, 35.5) months after initial radiotherapy. RESULTS: No significant difference in mean maximum squeeze or resting pressures was found after radiation therapy. The sphincter profile and minimum sensory threshold were unchanged. The rectoanal inhibitory reflex was present in all patients. Nine patients reported normal anal function. One patient who was incontinent before treatment remained incontinent. CONCLUSION: Preoperative radiation therapy has a minimal chronic effect on anorectal function. Incontinence after sphincter-saving operations for rectal cancer should not be attributed to preoperative radiation therapy.     

功能性便秘患者直肠肛门压力变化

目的研究功能性便秘患者直肠肛门运动功能,探讨该疾病发生的可能机制。方法测定了35例慢性功能性便秘患者和11例正常对照者的直肠肛门压力及排便功能。结果①直肠静息压、肛门括约肌静息压及其最大缩窄压等在功能性便秘患者和正常人之间无显著差异(P>0.05);②肛管高压带长度在功能性便秘患者显著高于正常人(P<0.0005);③功能性便秘患者直肠壶腹部的感觉阈值和最大耐受量显著高于正常对照组(P<0.05),直肠最大顺应性显著低于正常对照组(P<0.0005),引起直肠肛门抑制反射的直肠扩张容量在便秘组显著高于正常对照组(P<0.05),肛门松弛率在便秘组显著低于正常对照组(P<0.05);④功能性便秘患者排便时肛门内外括约肌松弛反射均障碍,尤以外括约肌明显。结论功能性便秘患者存在直肠肛门运动功能障碍,这在其发病机制中起重要作用。     

“Rectal dissatisfaction” in the irritable bowel syndrome

Conventional radiographic and manometric criteria failed to distinguish 9 irritable bowel syndrome patients with the symptom of rectal dissatisfaction from 6 without it. Manometric values (including sphincter length, resting and squeeze pressures, and the rectoanal inhibitory reflex, as well as rectal compliance and maximum tolerable volume), radiographic indices (anorectal angle and level of pelvic floor at rest and on straining), and tests of anal and rectal sensitivity were all statistically indistinguishable. Conceivably, the symptom results from incomplete rectal emptying; it may also be an early warning of abnormal perineal descent. Only 4 of the 15 patients with irritable bowel syndrome in this study were able to expel a 50-ml balloon from the rectum in the left lateral position.     

Internal anal sphincter

The internal anal sphincter, the smooth muscle component of the anal sphincter complex, has an ambiguous role in maintaining anal continence. Despite its significant contribution to resting anal canal pressures, even total division of the internal anal sphincter in surgery for anal fistulas may fail to compromise continence in otherwise healthy subjects. However, recently reported abnormalities of the innervation and reflex response of the internal anal sphincter in patients with fecal incontinence indicate its significance in maintaining continence. The advent of sphincter-saving surgery and restorative proctocolectomy has re-emphasized the major contribution of the internal anal sphincter to resting pressure and its significance in preventing fecal leakage. The variable effect of rectal excision on rectoanal inhibitory reflex has led to a reappraisal of the significance of this reflex in discrimination of rectal contents and its impact on anal continence. Electromyographic, manometric, and ultrasonographic evaluation of the internal anal sphincter has provided new insights into its pathophysiology. This article reviews advances in our understanding of internal anal sphincter physiology in health and disease.     

Progressive systemic sclerosis of the internal anal sphincter leading to passive faecal incontinence.

Two female patients aged 62 and 44 years with progressive systemic sclerosis and passive faecal incontinence are described. Both had the typical gut motility disorders of dysphagia, heartburn, and constipation. Anorectal physiology tests showed a low resting pressure in both and an absent rectoanal inhibitory reflex in one. In both patients anal endosonography showed a thin internal anal sphincter with changed reflectivity suggestive of fibrosis. In both patients anorectal sensation and pudendal nerve function were normal. Histological examination of the rectum in one patient showed collagenous replacement of the rectal muscularis propria with prominent atrophy of the musculature. This study suggests that the internal sphincter may be selectively affected by progressive systemic sclerosis, which may lead to passive faecal incontinence.     

Functional abnormalities of the anal sphincters in patients with myotonic dystrophy

Motility of the anorectal area was studied in 19 patients with myotonic dystrophy and in 20 control subjects, before and after pudendal block. In patients with myotonic dystrophy, before anesthesia, resting pressure in the upper anal canal ( p less than 0.001) and duration and amplitude of relaxation of the rectoanal inhibitory reflex (p less than 0.01) were decreased. A myotonic contraction of high amplitude followed relaxation in all patients, but in control subjects this was not the case. In the lower anal canal, the duration of the rectoanal contractile reflex was prolonged as compared with control subjects (p less than 0.001). The pudendal block had no effect in the upper anal canal either on resting pressure or on amplitude and duration of the rectoanal inhibitory reflex, neither in patients nor in controls. After blockade, however, the myotonic contraction subsequent to the reflex in patients was significantly reduced in amplitude (p less than 0.01). In lower anal canal, the resting pressure was reduced to similar levels, both in patients and in control subjects, after pudendal block (p less than 0.01), and the rectoanal contractile reflex was abolished in both groups. This study demonstrates a number of functional abnormalities in the anorectal structures of patients with myotonic dystrophy. These abnormalities produce a decrease in resting pressure in the anal canal, and a reflex myotonic contraction subsequent to rectal distention due to both external and internal sphincter dysfunction.     

Clinical and manometric effects of combined external beam irradiation and brachytherapy for anal cancer

This study evaluates anorectal function after combined tele- and brachytherapy for anal cancer using manometric measurements and a standardized questionnaire. Eight patients received 44±3 Gy external beam radiation followed by 20±4 Gy interstitial brachytherapy with iridium-192. Patients were examined 43 months (range 25–83) after therapy. Maximum anal basal pressure, squeeze pressure, and squeeze increment were significantly lower in patients (50, 163, 115 mmHg, respectively) than in control subjects (75, 285, 180 mmHg, respectively). Decreased anal elasticity was not observed. Anal prestretch “normalized” the contractility of the internal and external sphincter. Thus damage to the anal epithelium and hemorrhoidal cushions seems to be the most important mechanism explaining reduced anal closing pressure values. The rectoanal inhibitory reflex was observed in all but one patient. Rectal compliance was significantly reduced. Whereas all patients could retain a water filled rectal balloon until the maximum tolerable sensation level was reached, the rectal saline infusion test was strongly abnormal. Four patients were perfectly continent. Four patients were incontinent for gas and presented urgency in case of liquid stools with limited soiling occurring once weekly or less; three of them also had urgency for solids. Defecation frequency was increased but regular in most patients. Reduced anal closure together with reduced rectal compliance are at the basis of stool frequency, urgency and partial incontinence with occasional soiling. However, enough reserve sphincter function was maintained to preserve a clinically acceptable degree of anal continence in our patients. Accepted: 21 November 1997     

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17–47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h interdigestive period. Ten healthy volunteers (mean age 34.5, range 19–50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7±0.1 mm) was correlated neither with its rectal spike amplitude (0.73±0.1 mV) nor with rectal spike frequency (17.06±3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2±0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1±3.2/2 h), duration (14.9±1.5 s), or amplitude (14.1 ±1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r=0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome. Accepted: 21 November 1997     

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.     

Preoperative and postoperative evaluation by manometric study of the anal sphincter after coloanal anastomosis for carcinoma

The purpose of the present study was to pre- and postoperatively evaluate the anal sphincter after coloanal anastomosis in 20 patients with carcinoma of the rectum at 5.5 to 8 cm from the anal verge. The 20 patients matched age and sex with the controlled subjects. Of the 20 patients, 17 with normal preoperative manometric studies when compared with control subjects underwent a coloanal anastomosis as described by Castrini, and three patients with preoperative incontinence underwent abdominoperineal resection. Manometric studies preoperatively, and postoperatively at three and 12 months, indicated a statistically significant decrease in squeezing pressure, and rectal compliance at three months that almost normalized by 12 months. The rectal compliance correlated with the number of bowel movements per day at three months (four to five per day) and at 12 months (two to three per day). The rectoanal reflex and length of pressure zone have remained unchanged. Results seem to indicate that anal continence can be preserved after coloanal anastomosis.     

Prospective evaluation of anorectal function after total mesorectal excision for rectal carcinoma with or without preoperative radiotherapy

OBJECTIVE: Anorectal function is greatly disturbed after rectal surgery with or without radiotherapy (RT). To clarify the underlying mechanisms, we designed a prospective study to evaluate the effect of RT and surgery on anorectal function and clinical outcome of patients with a rectal carcinoma. METHODS: Thirty-four patients with a rectal carcinoma participated in this study. They filled out a symptom questionnaire and underwent anal manometry, anal and rectal mucosal electrosensitivity testing, and a rectal barostat, before surgery, 4 and 12 months postoperatively. Thirteen patients were lost to follow-up, 14 underwent surgery alone (total mesorectal excision [TME]), and seven also received RT (RT + TME). RESULTS: Functional outcome was disappointing in both groups, with at 4 months a significantly higher defecation frequency after RT + TME as compared with TME. Anal sphincter function and rectal sensitivity to pressure-controlled distention were not affected by either treatment. Rectal compliance, however, was significantly reduced after RT + TME at 4 and 1 2 months, resulting in lower rectal volumes at the thresholds for first sensation and desire to defecate. Rectal but not anal mucosal electrosensitivity was higher after TME + RT. CONCLUSIONS: Anorectal function after rectal surgery with or without RT is greatly hampered because of a decreased rectal compliance. After 12 months, partial improvement is shown, especially in the absence of RT.     

Should we care about the internal anal sphincter?

The internal anal sphincter is currently regarded as a significant contributor to continence function. Four physiological and morphological aspects of the internal anal sphincter are presented as part of the current evidence base for its preservation in anal surgery. 1) The incidence of continence disturbance following deliberate internal anal sphincterotomy is underestimated, although there is presently no prospective imaging or physiologic data supporting the selective use of sphincter-sparing surgical alternatives. 2) Given that the resting pressure is a measure of internal anal sphincter function, its physiologic representation (the rectoanal inhibitory reflex) shows inherent differences between incontinent and normal cohorts which suggest that internal anal sphincter properties act as a continence defense mechanism. 3) Anatomical differences in distal external anal sphincter overlap at the point of internal anal sphincter termination may preclude internal anal sphincter division in some patients where the distal anal canal will be unsupported following deliberate internal anal sphincterotomy. 4) internal anal sphincter-preservation techniques in fistula surgery may potentially safeguard postoperative function. Prospective, randomized trials using preoperative sphincter imaging and physiologic parameters of the rectoanal inhibitory reflex are required to shape surgical decision making in minor anorectal surgery in an effort to define whether alternatives to internal anal sphincter division lead to better functional outcomes.     

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

AIM: To investigate the anal sphincter and rectal factors that may be involved in fecal incontinence that develops following fistulotomy(FIAF).METHODS: Eleven patients with FIAF were compared with 11 patients with idiopathic fecal incontinence and with 11 asymptomatic healthy subjects(HS). All of the study participants underwent anorectal manometry and a barostat study(rectal sensitivity, tone, compliance and capacity). The mean time since surgery was 28 ± 26 mo. The postoperative continence score was 14 ± 2.5(95%CI: 12.4-15.5, St Mark's fecal incontinence grading system).RESULTS: Compared with the HS, the FIAF patients showed increased rectal tone(42.63 ± 27.69 vs 103.5 ± 51.13, P = 0.002) and less rectal compliance(4.95 ± 3.43 vs 11.77 ± 6.9, P = 0.009). No significant differences were found between the FIAF patients and the HS with respect to the rectal capacity; thresholds for the non-noxious stimuli of first sensation, gas sensation and urge-to-defecate sensation or the noxious stimulus of pain; anal resting pressure or squeeze pressure; or the frequency or percentage of relaxation of the rectoanal inhibitory reflex. No significant differences were found between the FIAF patients and the patients with idiopathic fecal incontinence.CONCLUSION: In patients with FIAF, normal motor anal sphincter function and rectal sensitivity are preserved, but rectal tone and compliance are impaired. The results suggest that FIAF is not due to alterations in rectal sensitivity and that the rectum is more involved than the anal sphincters in the genesis of FIAF.     

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。     

The effect of loperamide on anorectal function in normal healthy men.

Loperamide improves anorectal functioning in patients with diarrhea and incontinence. Loperamide reduces sensitivity of the recto-anal inhibitory reflex and increases internal anal sphincter tone. Additionally, it has an effect on rectal compliance in incontinent patients with diarrhea. We studied the effect of loperamide versus placebo at different distances from the anal verge in 18 healthy male volunteers, using standard anorectal manometry was a double-blind, two-factorial design. We found that the recto-anal inhibitory reflex is most pronounced when stimulated in regions close to the anal canal and that distention stimuli are also perceived best in that region. Both effects are counteracted by loperamide. We found no effect on internal sphincter tone or rectal compliance. These results imply a gradient of sensitivity for rectal perception and the recto-anal inhibitory reflex in healthy volunteers. Loperamide action on both mechanisms suggests a common mediator for both effects.     

Anorectal function and morphology in patients with sporadic proctalgia fugax

PURPOSE: The pathophysiology of sporadic proctalgia fugax remains unknown. This study investigates whether patients with this syndrome exhibit alterations in anal function and morphology. METHODS: Eighteen patients with sporadic proctalgia fugax and 18 sex-matched and age-matched healthy controls were studied. Manometric studies investigated anal resting and squeeze pressures, the rectoanal inhibitory reflex, rectal compliance, and smooth muscle response to edrophonium chloride administration. External and internal sphincter thickness was measured endosonographically. RESULTS: Patients had slightly higher (P=0.0291) anal resting pressures (65.5±11.4 mmHg) than controls (56±9.9 mmHg). However, anal squeeze pressure, sphincter relaxation during rectal distention, and rectal compliance were similar in both groups, and no alterations were detected in external and internal anal sphincter thickness. Edrophonium chloride administration was followed by sharp postrelaxation contractions in two patients, whereas anal function remained unaltered in controls. Acute episodes of proctalgia, which occurred in two patients while under study, were associated with a rise in anal resting tone and an increase in slow wave amplitude. CONCLUSIONS: In the resting state, patients with proctalgia fugax have normal anorectal function and morphology. However, they may exhibit a motor abnormality of the anal smooth muscle during an acute attack.Supported by Grant Ec 105/1-2 from the Deutsche Forschungsgemeinschaft.     

Permanent sacral nerve modulation for fecal incontinence and associated urinary disturbances

Background and aims Sacral nerve modulation (SNM) using an implantable pulse generator is gaining increasing acceptance in the treatment of several functional disturbances of the urinary and intestinal tract. This new therapeutic approach offers new possibilities in the treatment of fecal incontinence (FI) by means of its possible effects on anorectal physiology.Patients and methods Fourteen patients with FI, six of whom had associated urinary disturbances, underwent permanent SNM after successful peripheral nerve evaluation tests. All had a clinical evaluation including FI grading systems (American Medical systems, AMS; Continence Grading System, CGS) and quality of life questionnaires (Fecal Incontinence Quality of Life, FIQL), and anorectal physiology tests performed before and during electrostimulation. Two patients had a lead displacement which was repositioned. Median follow-up was 14 months (range 6–48 months).Results AMS scores decreased significantly from 101 to 67 after 24 months CGS scores from 15 to 2 after 2 months. The median number of episodes of major incontinence per 2 weeks decreased from 14 to 1 after 24 months. FIQL scores improved significantly in the nine patients tested from an overall score of 1.59 to 3.3, with improvement in all areas of the FIQL. Four of the six patients with associated urinary disturbances had a significant improvement in their symptoms. Anal resting and squeezing tone did not change significantly, nor did rectal volumetry, compliance, rectoanal inhibitory reflex, or length of the anal high-pressure zone, while 24-h rectal manometry showed inhibition of the spontaneous rectal motility complexes after meal and on awakening in the only two patients undergoing this investigation.Conclusion Although the mechanism of action of SMN is still unclear and requires further investigations, clinical results are very encouraging, confirming the role of this new and safe procedure in the treatment of FI and associated urinary disturbances.