Anorectal manometry in children with chronic functional constipation

BACKGROUND: The anorectal manometry is a very utilized and well recognized examination in children with chronic functional constipation. The major manometric findings in these children are: anal hypotonia, anal hypertonia, paradoxal contraction of the external anal sphincter, decreased ability of internal anal sphincter to relax during rectal distension and alterations in rectal contractility, sensibility and compliance. AIMS: To evaluate the anal basal pressure and the relaxation reflex before and after standard treatment for a better understanding of the physiopathologic mechanisms involved in pediatric chronic functional constipation. METHODS: Anorectal manometry was performed before treatment on 20 children with chronic functional constipation aged 4 to 12 years and the results were compared to those obtained after standard treatment, with a good outcome. RESULTS: There was a reduction in anal basal pressure after treatment, but no differences were detected between the anorectal manometries performed before and after treatment in terms of amplitude and duration of relaxation, residual pressure, latency time, or descent and ascent angle. CONCLUSIONS: We conclude that the anal basal pressure decreased in children recovering from chronic functional constipation, but the standard treatment did not provide all the conditions necessary for the relaxation reflex of constipated children to return to the values described in normal children.     

Neurophysiological dysfunction in young women with intractable constipation.

Fifteen women with intractable chronic idiopathic constipation dating from adolescence were investigated by anorectal manometry, neurophysiological evaluation of the conus medullaris and external anal sphincter. Comparison was made with 25 asymptomatic female control subjects. Urological disturbances were common amongst the constipated, in five of whom incidental lumbosacral spinal dysraphism was found. No differences in sphincter pressures or the rectosphincteric reflex were demonstrable between the two groups. Rectal defecatory sensation was blunted and the compliance was increased in the constipated group. The latency of the pudendo-anal reflex was significantly prolonged in idiopathic constipation, two women having an absent reflex (greater than 100 ms). Mean motor unit potential duration of the external anal sphincter was not significantly prolonged in the eight constipated women tested. A central neurogenic deficit is postulated in some women with this disorder.     

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.     

Impairment of defecation in young women with severe constipation

Anorectal manometry, radiology, and tests of simulated defecation were carried out in 14 severely constipated young women and 29 age-matched controls. The resting anal sphincter pressures were reduced in the patients, but the squeeze pressures, rectoanal inhibitory reflex, and rectal pressures upon balloon distention were all normal. At rest, the anorectal angle was more obtuse in the constipated group, but there was no overall increase in perineal descent in constipated patients compared with controls. The presence of a balloon in the rectum and the onset of pain were perceived in constipated patients at volumes that were not significantly different from those in normal volunteers. Constipated patients, however, required higher rectal volumes to induce the desire to defecate and to stimulate regular rectal contractions. Constipated patients also found it more difficult to pass simulated stools from the rectum than the normal controls and, unlike most normal controls, failed to inhibit their external anal sphincter on attempted defecation. These findings suggest that young women with severe constipation have great difficulty initiating the coordinated set of events that constitute a normal defecation response.     

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.     

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.     

Anorectal manometric abnormalities and colonic propulsive impairment in patients with severe chronic idiopathic constipation

Idiopathic chronic constipation is a frequent and disabling symptom, but its pathophysiological grounds are still poorly understood. In particular, there is little knowledge about the relationships between distal (anorectal area) and proximal (colonic area) motor abnormalities in this condition, especially concerning high-amplitude propagated colonic activity. For this purpose, we studied 25 patients complaining of severe idiopathic constipation and categorized them as normal- or slow-transit constipation according to colonic transit time. Twenty-five age-matched controls were also studied. Investigations included standard anorectal motility testing and prolonged (24-hr) colonic motility studies. Analysis of results showed that both groups of constipated patients displayed significantly different (P<0.05) minimum relaxation volumes of the internal anal sphincter, defecatory sensation thresholds, and maximum rectal tolerable volumes with respect to controls. Patients with normal-transit constipation also showed lower internal anal sphincter pressure with respect to slow-transit constipation and controls (P<0.001 andP<0.02, respectively). The daily number of high-amplitude propagated contractions (mass movements) as well as their amplitude and duration, was significantly reduced in both subgroups of constipated patients (P<0.02 vs controls). We conclude that (1) in normal-transit constipation, motor abnormalities are not limited to the anorectal area; (2) patients with slow-transit constipation probably have a severe neuropathic rectal defect; (3) prolonged colonic motility studies may highlight further the functional abnormalities in constipated subjects; and (4) an approach taking into account proximal and distal colon motor abnormalities might be useful to understand pathophysiological grounds of chronic constipation and lead to better therapeutic approaches.     

慢性功能性便秘肛门直肠敏感性和排便动力学研究

目的探讨慢性功能性便秘患者肛门直肠感觉功能的改变及排便时肛门直肠动力学特征。方法采用PC Polygraf HR高分辨多道胃肠功能测定仪检测46例功能性便秘患者的肛门直肠压力、直肠容量感知、疼痛阈值、耐受阈值及排便功能等指标，并与16例健康人做对照。结果功能性便秘组直肠静息压、肛管括约肌静息压、最大缩窄压及静态肛管长度与对照组比较差异无显著性，但功能性便秘患者的初始感觉阈值、疼痛阈值、排便阈值、引起肛门直肠抑制反射的最低充气量、排便状态下肛管功能长度和肛管内括约肌松弛压均高于对照组。模拟排便时，功能性便秘组34．78％的患者在直肠收缩时伴有肛管括约肌的矛盾收缩。结论功能性便秘患者直肠黏膜对容量刺激的反应性降低和排便时肛管括约肌的反向矛盾收缩可能是形成便秘的原因之一。     

Persistence of chronic constipation in children after biofeedback treatment

We investigated the efficacy of biofeedback treatment and evaluated anorectal factors that might be responsible for persistence of chronic constipation with or without encopresis in a group of 38 children with abnormal contraction of the pelvic floor during straining and persistence of chronic constipation with encopresis after conventional treatment. Nine children were unsuccessful in learning to relax the pelvic floor during straining with biofeedback treatment, and one patient had contraction of the pelvic floor on follow-up despite successful biofeedback treatment; none recovered. Twenty-eight children were able to relax the pelvic floor on follow-up; 14 recovered and 14 did not recover from chronic constipation. Nonrecovered patients who learned to relax the pelvic floor had significantly decreased rectal and anal responsiveness to rectal distension as compared to recovered patients during the initial and follow-up anorectal manometric study. Psychological factors such as social competence and behavior problems did not appear to be responsible for recovery or nonrecovery from chronic constipation and encopresis.This work was supported by grant M01-RR-00069 from the General Clinical Research Center Program, Division of Research Resources, National Institutes of Health.Results of this study were published in part as an abstract inJournal of Gastrointestinal Motility 1:69, 1989; and presented at the 12th International Symposium on Gastrointestinal Motility, Gmunden, Austria, September 13, 1989.     

Physiologic status of the anorectum following sphincter-saving resection for carcinoma of the rectum

The physiologic status of the anorectum after low anterior resections or pull-through operations of the rectum was evaluated clinically and by manometric studies. It was demonstrated that the presence of a normal anal resting pressure and an anorectal reflex were important to achieve postoperative continence after sphincter-saving operations. In patients with anastomotic leaks and poor function, a marked high-pressure zone in the anal canal and an anorectal reflex were not found, but as local inflammation resulting from the anastomotic leak disappeared, these parameters returned to normal. A normal anorectal reflex was found in one of three patients after Bacon-type pull-through operations, but the remaining two showed an increase of anal canal pressure during colonic distention. These results indicate that an elevation of anal-canal pressure in response to colonic distention plays a significant role in fecal continence at the time of “a sense of urgency” if internal sphincter function is impaired. Presented at the 8th Biennial Congress of the International Society of University Colon and Rectal Surgeons, Melbourne, Australia, September 7 to 11, 1980.     

Anorectal Manometry: A New Simplified Technique

Several noninvasive techniques using anal balloons or catheter systems to measure anal sphincter function associated with rectal balloon distention have been used in differentiating functional constipation from aganglionic megacolon. We have developed a simplified method for anorectal manometry that uses a microtip pressure transducer to record anal sphincter responses. Seventy-three patients (51 children and 22 adults) with constipation have been studied with this technique. Normal responses of internal anal sphincter relaxation to rectal distentions were obtained in 60 patients (40 children and 20 adults), consistent with the diagnosis of functional constipation. Abnormal responses-no internal anal sphincter relaxation-were recorded in 13 patients (11 children and two adults), consistent with the diagnosis of Hirschsprung's disease. The manometric diagnosis was confirmed in all 21 patients biopsied. There were no false-positive or false-negative results. The technique is a simple, well tolerated, and rapid method for assessing anal sphincter function.     

Rectoanal pressures and rectal sensitivity studies in chronic childhood constipation.

Rectoanal pressures and rectal sensitivity studies were performed in 32 control children and 144 chronically constipated children. The rectoanal inhibitory reflex threshold, the maximal anal resting closure pressure, and the conscious rectal sensitivity threshold were studied in these children. The rectoanal inhibitory reflex threshold was increased in 6.2% of the constipated patients. Anal hypertony (increased maximal anal resting pressure) was found in 46% of the constipated children. Decreased rectal sensitivity (increased conscious sensitivity threshold) was found in 68% of the constipated children. The three parameters were found to be normal in only 13% of the constipated subjects. Thus, it appears that children with chronic constipation who do not have Hirschsprung's disease do have abnormalities at manometry in most cases.     

External anal sphincter function in spinal patients

Six patients with complete transection of the spinal cord and six healthy volunteers were examined by using anorectal manometry together with electromyographic (EMG) recording of the external anal sphincter composed of striated muscle. Anal pressure and EMG activity of the external anal sphincter were continuously recorded at rest and during gradual rectal distention (10, 20, 30, 40, and 50 ml) by means of an air-filled balloon eliciting a rectoanal inhibitory reflex (RAIR) at the upper part, and an inflation reflex (IR) at the lower part of the anal canal. All patients and controls had a RAIR for each rectal distention volume. A relationship between the duration of the RAIR and the rectal distention volume was present in controls only. In controls the IR was present for each rectal distention volume, whereas it was present in only one patient for a 40-ml volume. During the resting period, all controls showed continuous tonic EMG activity of the external anal sphincter, but after 30 minutes all the patients showed a decrease and ultimately in five cases a disappearance of the tonic EMG activity of the external anal sphincter. In spinal patients, the presence or absence of EMG activity of the external anal sphincter did not modify the anal canal pressure. These results indicate that: 1) the tonic EMG activity of the external anal sphincter seems to be under the control of supraspinal structures, because in spinal patients it disappears in the absence of sensitive inputs toward the spinal cord; 2) the absence of EMG activity at rest indicates that the external anal sphincter is not implicated in the RAIR disturbances observed in spinal patients; 3) the IR is not a spinal reflex but is under voluntary control, because it is not present in spinal humans; 4) in spinal humans the tonic EMG activity of the external anal sphincter does not play a role in the maintenance of the anal pressure at rest.     

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.     

Paradoxical sphincter contraction is rarely indicative of anismus

Background—Anismus is thought to be a cause ofchronic constipation by producing outlet obstruction. The underlyingmechanism is paradoxical contraction of the anal sphincter orpuborectalis muscle. However, paradoxical sphincter contraction (PSC)also occurs in healthy controls, so anismus may be diagnosed too often because it may be based on a non-specific finding related to untoward conditions during the anorectal examination.
Aims—To investigate the pathophysiologicalimportance of PSC found at anorectal manometry in constipated patientsand in patients with stool incontinence.
Methods—Digital rectal examination and anorectalmanometry were performed in 102 chronically constipated patients, 102 patients with stool incontinence, and in 18 controls without anorectal disease. In 120 of the 222 subjects defaecography was also performed. Paradoxical sphincter contraction was defined as a sustained increase in sphincter pressure during straining. Anismus was assumed when PSCwas present on anorectal manometry and digital rectal examination andthe anorectal angle did not widen on defaecography.
Results—Manometric PSC occurred about twice asoften in constipated patients as in incontinent patients (41.2% versus25.5%, p<0.017) and its prevalence was similar in incontinentpatients and controls (25.5% versus 22.2%). Oroanal or rectosigmoidtransit times in constipated patients with and without PSC did notdiffer significantly (total 64.6 (8.9) hours versus 54.2 (8.1) hours; rectosigmoid 14.9 (2.4) hours versus 13.8 (2.5) hours).
Conclusions—Paradoxical sphincter contraction is acommon finding in healthy controls as well as in patients with chronic constipation and stool incontinence. Hence, PSC is primarily a laboratory artefact and true anismus is rare.

Keywords:anismus; paradoxical sphincter contraction; constipation; stool incontinence; anorectal manometry

     

Function of the anal sphincters after chronic radiation injury.

Anorectal manometry was done in 10 men with chronic radiation proctitis and symptoms of urgency, frequency, and occasional incontinence of faeces. They were compared with 10 asymptomatic age and sex-matched controls. The maximum resting anal canal pressure and the physiological sphincter length were significantly lower (p less than 0.01) in the irradiated group. The rectosphincteric reflex was absent in one patient and showed abnormalities of recovery in four others, who had received radiotherapy. The squeeze pressure of the external sphincter was not significantly different. These results indicate that dysfunction of the internal anal sphincter may contribute to patients' anorectal symptoms after pelvic radiotherapy. Histological evidence suggests that damage to the myenteric plexus is mainly responsible. The manometric function of the external sphincter remains relatively unaffected.     

Studies of Manometric Abnormalities of the Rectoanal Region during Defecation in Constipated and Soiling Children: Modification through Biofeedback Therapy

Anorectal manometry was performed on 12 normal children and 18 patients suffering from constipation and soiling. In both groups, the results of the rectoanal inhibitory reflex and the squeezing anal pressure were similar. The pressure recording in all the normal children showed that the anal canal relaxed during defecation. Fourteen (78%) constipated children closed the anal canal while straining by contracting the anal sphincter. This paradoxical contraction appears to be the cause of chronic constipation. Twelve children with paradoxical anal closure were treated by biofeedback therapy. The results show that all these children were successfully conditioned to relax their anal sphincter during defecation. This therapy improved their bowel habits and relieved them from constipation and soiling. It is proposed that the paradoxical anal closure itself is the result of a self-conditioning process. In this process, the patient learns to paradoxically contract the external anal sphincter in response to the urge and the act of defecation. Biofeedback therapy seems to be the appropriate treatment in such cases.     

Impaired internal anal sphincter in a subgroup of patients with idiopathic fecal incontinence

During multiport manometric recordings of the anorectum, 35 of 140 patients with idiopathic fecal incontinence had abnormally weak sphincters that did not relax during rectal distention, suggesting impaired function of the internal anal sphincter. This study documents this finding and compares anorectal function in these 35 patients with 25 matched normal subjects and the remaining 105 incontinent patients. Basal and squeeze pressures were significantly lower in the incontinent study group than in the other two groups. During rectal distention, 25 of 35 patients showed no anal relaxation at any volume, whereas 10 patients showed some relaxation after 60-ml distention because of the postinflation rebound in internal anal sphincter tone. The electrical responses of the external anal sphincter to rectal distention and to increases in intraabdominal pressure were greater in patients than in normal subjects, but the anal pressures were lower and anal leakage was common. Rectal sensations were not significantly different from normal subjects. These results indicate that 25% of patients with idiopathic fecal incontinence have markedly impaired function of the internal anal sphincter, but these patients also have extremely weak external sphincters.     

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。     

Physiological studies in young women with chronic constipation

Manometric, radiological and neurophysiological investigations were performed on 34 women, aged between 14 and 53, who suffered with chronic constipation refractory to treatment, and on 27 agematched normal female control subjects. The constipated patients had more difficulty in evacuating simulated stools than control subjects and 13 out of 19 patients tested obstructed defaecation by contracting the external sphincter during straining. The constipated group required a greater degree of rectal distension than control subjects to induce rectal contractions, anal relaxation and a desire to defaecate. Other modalities of rectal sensation were normal in the constipated subjects. Compared with controls, constipated patients had significantly lower anal pressures, an abnormal degree of perineal descent on straining and an obtuse anorectal angulation at rest. These results were compatible with weakness of the pelvic floor and neuropathic damage to the external sphincter. Mouth to anus transit time was abnormally prolonged in 60% of constipated patients, but was within the normal range in the remainder. Anorectal function in patients with slow transit was not significantly different from that in patients with a normal transit time. The mouth to caecum transit time of a standard meal was prolonged in constipated patients irrespective of the duration of the whole gut transit. Gastric emptying was not significantly prolonged.