Descending perineum syndrome: audit of clinical and laboratory features and outcome of pelvic floor retraining

Objective: Our aim was to retrospectively analyze the Mayo Clinic experience of descending perineum syndrome from 1987–1997. Methods: Clinical records were abstracted for demographic features, risk factors, results of anorectal and defecation tests, and a mailed questionnaire evaluated outcome and current symptoms. Results: All results are mean ± SD. Clinically, 39 patients (38 women, one man), mean age 53 ± 14 yr, presented with constipation (97%), incomplete rectal evacuation (92%), excessive straining (97%), digital rectal evacuation (38%), and fecal incontinence (15%). Laboratory tests showed anal sphincter resting pressure was 54 ± 26 mm Hg, and squeeze pressure was 96 ± 35 mm Hg; expulsion from the rectum of a 50-ml balloon required > 200 g added weight in 27%; perineal descent was 4.4 ± 1 cm (normal < 4 cm) by scintigraphy. Scintigraphic evacuation, rectoanal angle change during defecation, and perineal descent were abnormal in 23%, 57%, and 78% of the patients, respectively. Associated features included female gender (96%), multiparity with vaginal delivery (55%), hysterectomy or cystocele/rectocele repair (74%). On follow-up, 64% responded; 17 of these 25 responders underwent pelvic floor retraining. At 2-yr median follow-up (range, 1–6 yr), 12 still experienced constipation or excessive straining; their perineal descent was greater than in patients who responded to retraining (   p = 0.005  ). Conclusions: Descending perineum syndrome is identifiable by clinical history and examination, and the most prevalent abnormality on testing is perineal descent > 4 cm; rectal balloon expulsion is an insensitive screening test for descending perineum syndrome. Pelvic floor retraining is a suboptimal treatment for this chronic disorder of rectal evacuation; the extent of perineal descent appears to be a useful predictor of response to retraining.     

Parameters of anorectal and colonic motility in health and in severe constipation

Anorectal function and colonic transit was assessed in 17 severely constipated patients and 15 age-matched controls. The constipated patients were divided into those who had immobile perineum (perineal descent 1.0 cm during attempted defecation) and those who had a normal descent (>1.0 cm) of the perineum. When constipation was accompanied by an immobile perineum, patients had impaired balloon expulsion, impaired and delayed artificial stool expulsion, decreased straightening of the anorectal angle, decreased descent of the pelvic floor with defecation, and prolonged rectosigmoid colon transit compared with the patients with constipation who had a mobile perineum and with normal controls. The mobile-perineum group differed from controls only in colon transit times, having prolonged total colon transit. Anal sphincter resting pressures, immediate artificial stool expulsion, resting anorectal angles, and electromyography of the external anal sphincter and puborectalis did not differentiate the constipated patients from the controls. We concluded that descent of the perineum of <1 cm was associated with impaired expulsion, an adynamic anorectal angle, and slowed distal colon transit. This simple sign of pelvic floor function distinguished constipated patients with disordered expulsion from constipated patients with normal pelvic floor function. These patients may respond poorly to surgery and conventional management and would therefore be candidates instead for pelvic floor retraining. Accurate characterization and appreciation of pelvic floor dysfunction in patients with severe chronic constipation may improve the selection for and results of surgical and nonsurgical intervention.Supported in part by Research Grants DK37990, RR585, and DK34988 from the National Institutes of Health and by the Mayo Foundation, Rochester, Minnesota.     

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.     

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.     

Changes in colorectal function in severe idiopathic chronic constipation

Physiologic studies of colorectal and anal function were performed in 25 adult patients with severe idiopathic long-standing constipation compared with 22 age- and sex-matched normal subjects. Only patients with primary severe idiopathic constipation with no known underlying primary etiology have been studied. No significant changes were observed in the resting or squeeze anal canal pressures. There was indirect evidence that rectal sensation was grossly impaired in 17 of the constipated patients: mean values for constant sensation compared with controls being 269 +/- 21 ml and 136 +/- 10.3 ml, respectively (p less than 0.01). The mean anorectal angles during attempted defecation were significantly less in constipated patients compared with controls (p less than 0.001), and 10 patients were unable to evacuate from the rectum a balloon containing 150 ml of a weak barium suspension. Electromyography of the pelvic floor showed increased puborectalis activity on attempted defecation in 9 subjects. Although there was no significant difference in the basal sigmoid motility index between constipated patients and controls, response to intrarectal bisacodyl (5 mg) was impaired in the constipated group, being 479 +/- 22.1 and 735 +/- 24.7, respectively (p less than 0.01). Transit time was significantly delayed in the constipated patients; the percentage of markers passed by constipated patients after 5 days was 39.0 +/- 6.9 compared with 73.9 +/- 2.8 passed by controls (p less than 0.02). These results imply that there is often a motor abnormality of the pelvic floor and the colon in patients with long-standing chronic constipation.     

Intrarectal pressures and balloon expulsion related to evacuation proctography.

Seventy four patients with constipation were examined by standard evacuation proctography and then attempted to expel a small, non-deformable rectal balloon, connected to a pressure transducer to measure intrarectal pressure. Simultaneous imaging related the intrarectal position of the balloon to rectal deformity. Inability to expel the balloon was associated proctographically with prolonged evacuation, incomplete evacuation, reduced anal canal diameter, and acute anorectal angulation during evacuation. The presence and size of rectocoele or intussusception was unrelated to voiding of paste or balloon. An independent linear combination of pelvic floor descent and evacuation time on proctography correctly predicted maximum intrarectal pressure in 74% of cases. No patient with both prolonged evacuation and reduced pelvic floor descent on proctography could void the balloon, as maximum intrarectal pressure was reduced in this group. A prolonged evacuation time on proctography, in combination with reduced pelvic floor descent, suggests defecatory disorder may be caused by inability to raise intrarectal pressure. A diagnosis of anismus should not be made on proctography solely on the basis of incomplete/prolonged evacuation, as this may simply reflect inadequate straining.     

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.     

Defecometry

The parameters of defecation,i.e., maximum rectal pressure increase during straining, duration of effective evacuation, and the work performed to evacuate a simulated stool, can be quantified by defecometry, a new method to evaluate the defecation act. Simultaneous anal pressure records demonstrate the nature of the sphincter activity during simulated defecation. The test was performed on 19 patients with constipation and on 14 controls. Five patients could not evacuate the simulated stool, while five others could, but more laboriously than the remaining nine patients whose defecation was comparable with the controls. Laborious defecation is characterized by longer duration and more performed work during evacuation. Every patient with difficult or ineffective evacuation had sphincter contraction during defecation, whereas this phenomenon was not observed in patients with normal defecation. Defecometry permits more adequate identification and characterization of the outlet-obstruction-type constipated patients than the simple balloon expulsion test and the analysis of sphincter activity during straining with empty rectum in lateral decubitus. Early diagnosis and treatment of patients with outlet obstruction is important to avoid late neuromuscular damage to the pelvic floor.     

“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.     

Evacuation proctography: an investigation of rectal expulsion in 20 subjects without defecatory disturbance

Evacuation proctography is a dynamic investigation of rectal expulsion that records the voluntary evacuation of thick barium paste on videotape. Evacuation is a passive phenomenon in a defined zone of the rectum, associated with pelvic floor descent of 3 cm from a resting position of the anorectal junction less than 2 cm above the plane of the ischial tuberosities. The anal canal does not open immediately; it takes about 4.5 sec to open to a maximum diameter of 1.5 cm, with rectal emptying in 11 sec. Anterior rectoceles commonly invert over the anal canal as the rectum collapses in at the end of evacuation.     

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.     

肠易激综合征患者肛门直肠感觉阈值和动力学的改变

采用PC Polygraf HR高分辨多道胃肠功能测定仪,检测42例肠易激综合征(IBS)患者的肛门直肠压力、直肠容量感知、疼痛阈值、耐受阈值等指标,并与15例健康人做对照.结果发现IBS的直肠静息压、肛管括约肌静息压、最大缩窄压及肛管长度与对照组无显著性差异(P＞0.05),而初始感觉阈值、疼痛阈值、排便阈值腹泻组低于正常对照组(P＜0.05),便秘组高于正常对照组(P＜0.05).排便时IBS便秘组患者的肛管松弛压高于正常对照组(P＜0.05).提示IBS患者排便功能和直肠感觉功能存在异常.     

Functional disorders of defecation: Evaluation and treatment

Opinion statement Functional disorders of defecation are common and often overlap with slow-transit constipation. They are comprised of functional obstructive conditions such as dyssynergic defecation, as well as structural obstructive conditions such as rectal prolapse, excessive perineal descent, and rectocele. Evaluation includes detailed history and rectal and pelvic exam together with physiologic tests such as anorectal manometry, balloon expulsion test, defecography, and MRI. Treatment involves several medical, behavioral, and surgical approaches. Recently, randomized controlled trials have shown that biofeedback therapy is an effective treatment for dyssynergic defecation. Stapled transanal rectal resection appears to be a promising technique for treating defecation disorders associated with rectocele, excessive perineal descent, and mucosal intussusception, but controlled trials are lacking.     

Manometric assessment of idiopathic megarectum in constipated children

AIM: Chronic constipation is a frequent finding in children. In this age range, the concomitant occurrence of megarectum is not uncommon. However, the definition of megarectum is variable, and a few data exist for Italy. We studied anorectal manometric variables and sensation in a group of constipated children with megarectum defined by radiologic criteria. Data from this group were compared with those obtained in a similar group of children with recurrent abdominal pain. METHODS: Anorectal testing was carried out in both groups by standard manometric technique and rectal balloon expulsion test. RESULTS: Megarectum patients displayed discrete abnormalities of anorectal variables and sensation with respect to controls. In particular, the pelvic floor function appeared to be impaired in most patients. CONCLUSION: Constipated children with megarectum have abnormal anorectal function and sensation. These findings may be helpful for a better understanding of the pathophysiological basis of this condition.     

Rectoanal Intussusception: Presentation of the Disorder and Late Results of Resection Rectopexy

BACKGROUND Rectoanal intussusception may cause symptoms of obstructed defecation, and functional results of prosthesis rectopexy are usually not satisfactory. The aim of this study was to assess several parameters of the disorder and to evaluate the outcome of resection rectopexy.METHODS During a 10-year period, 27 female patients with symptomatic large rectoanal intussusception had resection rectopexy (23 laparoscopy; 4 laparotomy). Conservative treatment, including biofeedback treatment in 22 patients, had failed in all cases. Preoperative and postoperative evaluation included clinical assessment, anorectal manometry, evacuation defecography, and colon transit studies. Follow-up ranged between one and five years.RESULTS Length of intussusception was 2 to 4.9 cm and was significantly related to pelvic floor descent (P = 0.003) and inversely related to resting anal pressures (P < 0.001). Eleven patients had undergone a previous hysterectomy, 9 had enterocele-sigmoidocele, 7 had incontinence of varying severity, and 8 had a solitary rectal ulcer. Colon transit was abnormal in all but five cases. Immediate functional results were bad in two-thirds of the cases; tenesmus, urge to defecate, and frequent stools were the main complaints. By the time these symptoms had subsided, and one year after surgery, all but two patients were satisfied with the outcome. Intussusception was reduced in all cases, anal sphincter tone recovered (P = 0.002), perineal descent decreased (P < 0.001), and colonic transit was accelerated (P < 0.001). Patients available at five-year follow-up had no or only minor defecatory problems.CONCLUSION Resection rectopexy improves symptoms of obstructed defecation attributed to large rectoanal intussusception.     

Anismus in chronic constipation

Among patients complaining of constipation, a group can be defined in which there is slow whole gut transit shown by retention of radiopaque markers but a rectum and colon of normal width judged by measurements of barium enema radiographs compared with control observations. It is not known whether their symptoms are due to an abnormality of colonic motility or to a failure of the defecatory mechanism. Defecation was simulated experimentally in a group of these patients by asking them to expel a water-filled rectal balloon. The constipated patients were not able to expel the balloon, whereas normal subjects could do so. Electromyography of the striated pelvic floor muscles during attempts at expulsion of the balloon in the constipated patients showed failure of the normal inhibition of resting activity. Failure of external anal sphincter relaxation on attempted defecation may contribute to the symptoms of some patients who complain of constipation.D.M.P. was supported by a grant from the St. Mark's Research Foundation.     

Functional activity of the rectum： A conduit organ or a storage organ or both？

AIM: To investigate whether the degree of rectal distension could define the rectum functions as a conduit or reservoir. METHODS: Response of the rectal and anal pressure to 2 types of rectal balloon distension, rapid voluminous and slow gradual distention, was recorded in 21 healthy volunteers (12 men, 9 women, age 41.7±10.6 years). The test was repeated with sphincteric squeeze on urgent sensation. RESULTS: Rapid voluminous rectal distension resulted in a significant rectal pressure increase (P < 0.001), an anal pressure decline (P < 0.05) and balloon expulsion. The subjects felt urgent sensation but did not feel the 1st rectal sensation. On urgent sensation, anal squeeze caused a significant rectal pressure decrease (P < 0.001) and urgency disappearance. Slow incremental rectal filling drew a rectometrogram with a "tone" limb representing a gradual rectal pressure increase during rectal filling, and an "evacuation limb" representing a sharp pressure increase during balloon expulsion. The curve recorded both the 1st rectal sensation and the urgent sensation. CONCLUSION: The rectum has apparently two functions: transportation (conduit) and storage, both depending on the degree of rectal filling. If the fecal material received by the rectum is small, it is stored in the rectum until a big volume is reached that can affect a degree of rectal distension sufficient to initiate the defecation reflex. Large volume rectal distension evokes directly the rectoanal inhibitory reflex with a resulting defecation.     

Constipation of anorectal outlet obstruction: pathophysiology, evaluation and management

Constipation is a subjective symptom of various pathological conditions. Incidence of constipation fluctuates from 2 to 30% in the general population. Approximately 50% of constipated patients referred to tertiary care centers have obstructed defecation constipation. Constipation of obstructed defecation may be due to mechanical causes or functional disorders of the anorectal region. Mechanical causes are related to morphological abnormalities of the anorectum (megarectum, rectal prolapse, rectocele, enterocele, neoplasms, stenosis). Functional disorders are associated with neurological disorders and dysfunction of the pelvic floor muscles or anorectal muscles (anismus, descending perineum syndrome, Hirschsprung's disease). However, this type of constipation should be differentiated by colonic slow transit constipation which, if coexists, should be managed to a second time. Assessment of patients with severe constipation includes a good history, physical examination and specialized investigations (colonic transit time, anorectal manometry, rectal balloon expulsion test, defecography, electromyography), which contribute to the diagnosis and the differential diagnosis of the cause of the obstructed defecation. Thereby, constipated patients can be given appropriate treatment for their problem, which may be conservative (bulk agents, high-fiber diet or laxatives), biofeedback training or surgery.     

Magnetic resonance imaging of anatomic and dynamic defects of the pelvic floor in defecatory disorders

OBJECTIVE: Endoanal ultrasound identifies anal sphincter anatomy, and evacuation proctography visualizes pelvic floor motion during simulated defecation. These complementary techniques can evaluate obstructed defecation and fecal incontinence. Our aim was to develop a single, nonionizing, minimally invasive modality to image global pelvic floor anatomy and motion. METHODS: We studied six patients with fecal incontinence and seven patients with obstructed defecation. The anal sphincters were imaged with an endoanal magnetic resonance imaging (MRI) coil and endoanal ultrasound (five patients). MR fluoroscopy acquired images every 1.4-2 s, using a modified real-time, T2-weighted, single-shot, fast-spin echo sequence, recording motion as patients squeezed pelvic floor muscles and expelled ultrasound gel; no contrast was added to other pelvic organs. Six patients also had scintigraphic defecography. RESULTS: Endoanal ultrasound and MRI were comparable for imaging defects of the internal and external sphincters. Only MRI revealed puborectalis and/or external sphincter atrophy; four of these patients had fecal incontinence. MR fluoroscopy recorded pelvic floor contraction during squeeze and recorded relaxation during simulated defecation. Corresponding comparisons for angle change and perineal descent during defecation were not significant; only MRI, but not scintigraphy, identified excessive perineal descent in two patients. CONCLUSIONS: Pelvic MRI is a promising single, comprehensive, nonradioactive modality to measure structural and functional pelvic floor disturbances in defecatory disorders. This method may provide insights into mechanisms of normal and disordered pelvic floor function in health and disease.     

Effects of Biofeedback Therapy on Anorectal Function in Obstructive Defecation

Biofeedback therapy improves symptoms inpatients with constipation and obstructive defecation.Whether it also improves anorectal function is unclear.Our purpose was to investigate prospectively the effects of biofeedback therapy on subjective andobjective parameters of anorectal function in 25consecutive patients with obstructive defecation.Biofeedback therapy consisted of pelvic floor relaxationexercises (phase I) and neuromuscular conditioning ofrectal sensation and rectoanal coordination, with asolid state manometry system and simulated defecationmaneuvers (phase II). The number of sessions wascustomized for each patient. Clinical improvement wasassessed from the changes in anorectal manometry,balloon (50 cc) expulsion test, and the symptom andstool diaries. The number of therapy sessions varied[mean (range) = 6 (2-10)]. After therapy, whenstraining as if to defecate, the percentage analrelaxation, intrarectal pressure, and defecation indexincreased (P < 0.001). The balloon expulsion time,laxative consumption, and straining effort decreased (P< 0.001). Before therapy, 16/25 (64%) patients hadimpaired rectal sensation, and after therapy thisimproved (P < 0.001). After therapy, 15/25 (60%) patients reported 75% satisfaction with bowelhabit and 8/25 (32%) reported 50% satisfaction (P< 0.001); 15/16 (94%) patients discontinued digitaldisimpaction. Biofeedback therapy not only improves subjective but also objective parameters ofanorectal function in at least 76% of patients byrectifying the underlying pathophysiologicdisturbance(s). Sensory conditioning and customizing thenumber of sessions may offer additionalbenefits.