Anismus: a marker of multi-site functional disorders?

PURPOSE: This study was undertaken to assess the clinical significance of anismus in patients who complain of constipation. PATIENTS AND METHODS: Thirty control subjects and 93 consecutive patients complaining of functional constipation took part in the study. Colonic transit time study and anorectal manometry were performed. Questions about depression and urinary and sexual diseases were added to a questionnaire based on the Rome II criteria, and visual analog scales about four items (constipation, diarrhoea, abdominal bloating and abdominal pain). RESULTS: Constipated patients have lower threshold sensation volume, lower constant sensation volume, and lower maximum tolerable volume than controls. Thirty-seven patients (40%) were found to have anismus, based on anorectal manometry. No significant difference was found between constipated patients with anismus and constipated patients without anismus, using anorectal manometry. Constipated patients had longer colorectal transit time than controls, but neither total nor segmental colonic transit time was correlated with the presence or absence of anismus. In patients with anismus, a higher frequency of oesophageal symptoms, dysmotility-like dyspepsia, aerophagia, functional bowel disorders, functional abdominal pain, soiling, and dyschezia was found. In addition, a higher frequency of urinary complaints, sexual complaints, and depression was found. Anismus was associated with increased awareness of constipation, abdominal bloating, and abdominal pain, but not with diarrhoea.     

Function and dysfunction of the colon and anorectum in adults: Working team report of the Swedish Motility Group (SMoG)

Symptoms of fecal incontinence and constipation are common in the general population. These can, however, be unreliably reported and are poorly discriminatory for underlying pathophysiology. Furthermore, both symptoms may coexist. In the elderly, fecal impaction always must be excluded. For patients with constipation, colon transit studies, anorectal manometry and defecography may help to identify patients with slow-transit constipation and/or pelvic floor dysfunction. The best documented medical treatments for constipation are the macrogols, lactulose and isphagula. Evolving drugs include lubiprostone, which enhances colonic secretion by activating chloride channels. Surgery is restricted for a highly selected group of patients with severe slow-transit constipation and for those with large rectoceles that demonstrably cause rectal evacuatory impairment. For patients with fecal incontinence that does not resolve on antidiarrheal treatment, functional and structural evaluation with anorectal manometry and endoanal ultrasound or magnetic resonance (MR) of the anal canal may help to guide management. Sacral nerve stimulation is a rapidly evolving alternative when other treatments such as biofeedback and direct sphincter repair have failed. Advances in understanding the pathophysiology as a guide to treatment of patients with constipation and fecal incontinence is a continuing important goal for translational research. The content of this article is a summary of presentations given by the authors at the Fourth Meeting of the Swedish Motility Group, held in Gothenburg in April 2007.     

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.     

Subtypes of constipation: sorting out the confusion

In patients with chronic constipation, identifying subtypes based on underlying physiology guides subsequent therapeutic choices. Chronic constipation subtypes include slow-transit constipation, pelvic floor dyssynergia, functional constipation, and irritable bowel syndrome with constipation. Chronic constipation subtypes are defined by the result of colonic transit, pelvic floor function, and the presence or absence of significant abdominal pain. Although a variety of tests are available, the most straightforward approach uses the 5-day colonic marker test of transit and anorectal manometry with balloon expulsion testing to evaluate for pelvic floor dysfunction. Patients with normal physiologic tests have either irritable bowel syndrome with constipation or normal-transit constipation. Significant overlap exists between subtypes and a clear distinction is not always possible, with up to a 50% overlap between patients with slow-transit constipation and irritable bowel syndrome, approximately 10% of patients evaluated exhibiting both slow transit and pelvic floor dyssynergia, and 50% of patients with pelvic floor dyssynergia also found to have slow transit. Symptom severity assessment provides the rationale for pursuing further testing and directing the aggressiveness of treatment as patients with greater symptom severity have reduced quality of life and poor physical functioning scores. Few constipation-specific validated measures exist for measuring symptom severity in chronic constipation. In clinical practice severity may be defined as mild symptoms having minimal impact upon daily activities or moderate to severe symptoms that increasingly interfere with daily life.     

Anismus: Fact or fiction?

PURPOSE: Although anismus has been considered to be the principal cause of anorectal outlet obstruction, it is doubtful whether contraction of the puborectalis muscle during straining is paradoxical. The present study was conducted to answer this question. METHODS: During the first part of the study, we retrospectively reviewed 121 patients with constipation and/or obstructed defecation (male:female, 10/111; median age, 51 years). All of these patients underwent electromyography (EMG) of the pelvic floor and the balloon expulsion test (BET) in the left lateral position. Evacuation proctography was performed in all of these patients in the sitting position. Both the posterior anorectal angle and the central anorectal angle were measured. EMG and BET were also performed in ten controls (male:female, 4/6; median age, 47). In 147 patients with fecal incontinence (male:female, 24/123; median age, 58) only EMG activity was recorded. Criteria for anismus during straining were increase or insufficient (<20 percent) decrease of EMG activity, failure to expel an air-filled balloon on BET, and decrease or insufficient (<5 percent) increase of anorectal angle on evacuation proctography. Between June 1994 and March 1995, we conducted a second prospective study in a consecutive series of 49 patients with constipation and/or obstructed defecation and 28 patients with fecal incontinence. Both groups were compared with 19 control subjects. In this study, all three tests were performed. EMG and BET were performed both in the left lateral position and in the sitting position. RESULTS: The retrospective study was undertaken by comparing the constipated patients with the incontinent patients and the controls, and the anismus detected by EMG was found in, respectively, 60, 46, and 60 percent. Failure to expel the air-filled balloon was observed in 80 constipated patients (66 percent) and in 9 control subjects (90 percent). Based on posterior anorectal angle and central anorectal angle measurements, anismus was diagnosed in, respectively, 21 and 35 percent of constipated patients. In the prospective study, none of the tests showed significant differences regarding the prevalence of anismus between the two subgroups of patients and the control subjects. The prevalence of anismus only differed between constipated and incontinent patients when the diagnosis was based on BET in the sitting position (67 vs.32 percent;P <0.005). Our study shows that contraction of the puborectalis muscle during straining is not exclusively found in patients with constipation and/or obstructed defecation. The three tests most commonly used for the diagnosis of anismus showed an extremely poor agreement. CONCLUSION: Based on these findings, we doubt the clinical significance of anismus.     

Constipation: evaluation and treatment

Constipation is a common clinical problem that comprises a constellation of symptoms that include excessive straining, hard stools, feeling of incomplete evacuation, use of digital maneuvers, or infrequent defecation. Although many conditions, such as metabolic problems, fiber deficiency, anorectal problems, and drugs, can cause constipation, when excluded functional constipation consists of two subtypes: slow-transit constipation and dyssynergic defecation. Some patients with irritable bowel syndrome may exhibit features of both types of constipation. The Rome criteria for functional constipation together with modifications proposed here for dyssynergic defecation may serve as useful guidelines for making a diagnosis. Recent advances in technology, together with a better understanding of the underlying mechanisms, have led to real progress in the diagnosis of this condition. Management options are limited, however, and evidence to support these treatments is only modest. The treatment is primarily medical; surgical options should be reserved for refractory disease and after careful diagnostic work-up. Although laxatives remain the mainstay of therapy, prokinetics that are colon-selective are optimal for treating patients with slow-transit constipation, but they are not yet available for clinical use. Recent controlled trials, however, are promising. Biofeedback therapy is the preferred treatment for patients with dyssynergia, but is not widely available. In the near future, user-friendly biofeedback programs including home therapy may facilitate wider use of these methods for patients with dyssynergic defecation.     

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

     

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.     

Botulinum toxin type-a in therapy of patients with anismus

INTRODUCTION: Anismus is a common cause of constipation and outlet obstruction. Standard therapy with laxatives or biofeedback has conflicting results. Surgical treatment gives poor results and has practically been abandoned. PURPOSE: This study was designed to evaluate the efficacy of botulinum toxin type-A (Botox) injection to the puborectalis muscle in patients with anismus. METHODS: Twenty-five patients (15 females; mean age, 23.2) with history of constipation and symptoms of outlet obstruction underwent anorectal perfusion manometry and video-proctography. All patients were found to have a nonrelaxing puborectalis muscle on both modalities. All have been unable to expel a rectal balloon. Each patient who participated in the study was randomly assigned to undergo local injection of Botox--10 units to each side of the puborectalis or 20 units to the posterior aspect of this muscle. Eight patients underwent further injections1-5 every 3 months in accordance with previous results. Follow-up was conducted 1, 4, 12, and 24 weeks after injection. Straining, anorectal pain, and overall satisfaction were assessed on a visual analog scale. Weekly evacuation, fecal incontinence, and complications were recorded. At the weekly meeting, each patient underwent anorectal manometry with a balloon expulsion test. RESULTS: Manometric relaxation was achieved after the first injection in 18 patients (75 percent). Once relaxation was achieved, it lasted throughout the follow-up. Nine patients (37.5 percent) expelled the rectal balloon after the first injection. Seven of 16 patients who failed the first injection had an additional one. In 2 patients it was successful (28.6 percent). Symptom improvement of 29.2 percent in straining index was recorded during follow-up. In 3 patients (12.5 percent) pain developed after injection. No other complications were observed. Overall satisfaction with Botox injection results was observed in 58.3 percent. CONCLUSIONS: Botox injection to the puborectalis muscle has been found to have a limited therapeutic effect on patients suffering from anismus. Our results justify the need for further double-blind placebo-controlled trials to determine the exact role of botulinum toxin type-A in anismus.     

Treatment of severe and intractable constipation

Opinion statement A careful clinical evaluation, exclusion of secondary causes (eg, colonic obstruction, metabolic conditions [hypothyroidism, hypercalcemia], and drug-induced constipation), and assessments of colonic transit and rectal evacuation are necessary to ascertain whether constipation is attributable to normal colonic transit, delayed colonic transit (ie, slow-transit constipation), or a rectal evacuation disorder (with or without delayed colonic transit). Idiopathic slow-transit constipation is a clinical syndrome predominantly affecting women and is characterized by intractable constipation and delayed colonic transit. This syndrome is attributed to disordered colonic motor function and spans a spectrum of variable severity ranging from patients who have relatively mild delays in transit, but are otherwise indistinguishable from irritable bowel syndrome, at one extreme to patients with colonic inertia or chronic megacolon at the other extreme. Most patients are treated with one or more pharmacological agent. A subtotal colectomy is effective and occasionally indicated for patients with medically refractory severe slow-transit constipation, provided that pelvic floor dysfunction has been excluded or treated. Pelvic floor dysfunction can be diagnosed by the clinical features and anorectal testing. Most patients with pelvic floor dysfunction will respond to pelvic floor retraining by biofeedback therapy.     

Long-Term Study on the Effects of Visual Biofeedback and Muscle Training as a Therapeutic Modality in Pelvic Floor Dyssynergia and Slow-Transit Constipation

PURPOSE: Biofeedback training has been shown as an effective therapeutic measure in patients with pelvic floor dyssynergia, at least in the short term. Long-term effects have received less attention. Moreover, its effects in patients with slow-transit constipation have been scarcely investigated. This study was designed to assess in an objective way the medium- and long-term effects of biofeedback and muscle training in patients with pelvic floor dyssynergia and slow-transit constipation. METHODS: Twenty-four patients (14 with pelvic floor dyssynergia and 10 with slow transit) meeting the Rome II criteria for constipation, and unresponsive to conventional treatments, entered the study. Clinical evaluation and anorectal manometry were performed basally and three months after a cycle of electromyographic biofeedback and muscle training; moreover, a clinical interview was obtained one year after biofeedback. Patients with slow-transit constipation also had colonic transit time reassessed at one year. RESULTS: Clinical variables (abdominal pain, straining, number of evacuations/week, use of laxatives) all significantly improved in both groups at three-month assessment; anorectal manometric variables remained unchanged, apart from a significant decrease of sensation threshold in the pelvic floor dyssynergia group and of the maximum rectal tolerable volume in the slow-transit constipation group. At one-year control, 50 percent of patients with pelvic floor dyssynergia still maintained a beneficial effect from biofeedback, whereas only 20 percent of those complaining of slow-transit constipation did so. Moreover, the latter displayed no improvement in colonic transit time. CONCLUSIONS: In our experience, patients with pelvic floor dyssynergia are likely to have continued benefit from biofeedback training in the time course, whereas its effects on slow-transit constipation seems to be maximal in the short-term course.     

Comparative study between biofeedback retraining and botulinum neurotoxin in the treatment of anismus patients

Purpose  Anismus is a significant cause of chronic constipation. This study came to revive the results of BFB training and BTX-A injection in the treatment of anismus patients. Materials and methods  Forty-eight patients with anismus (33 women; mean age 39.6 ± 15.9) were included in this study. All patients fulfilled Rome II criteria for functional constipation. All patients underwent anorectal manometry, balloon expulsion test, defecography, and electromyography (EMG) activity of the EAS. All patients had non-relaxing puborectalis muscle. The patients were randomized into two groups. Group I patients received biofeedback therapy, two times per week for about 1 month. Group II patients were injected with BTX-A. Follow-up was conducted weekly in the first month then monthly for about 1 year. Results  In the BFB training group, three patients quit before the end of sessions with no improvement; initial improvement was recorded in 12 patients (50%) while long-term success was recorded in six patients (25%). In the BTX-A group, clinical improvement was recorded in 17 patients (70.83%), but the improvement persisted only in eight patients (33.3%). There is a significant difference between BTX-A group and BFB group regarding the initial success, but this significant difference disappeared at the end of follow-up. Manometric relaxation was achieved significantly post-BFB and post-BTX-A injection with no significant difference between the two groups. Conclusions  Biofeedback training has a limited therapeutic effect on patients suffering from anismus. BTX-A injection seems to be successful for temporary treatment of anismus.     

Audit of Constipation in a Tertiary Referral Gastroenterology Practice

Objective : Our objective was to assess how often "outlet obstruction" was the cause of constipation in a tertiary referral population. Methods : We retrospectively audited the case records of 70 consecutive patients referred to a single gastroenterologist in a tertiary referral motility clinic. Patients were classified by physiological tests of colonic transit, as well as tests of anorectal and pelvic floor function. A subset of 28 patients also underwent a battery of tests to assess the autonomic nervous system supply. Results : Thirty-six patients had symptoms suggestive of a rectal outlet obstruction syndrome. Thirty seven percent of patients had pelvic floor dysfunction, 27% had slow transit constipation, and 8% had anismus. Fully 55% of those with pelvic floor dysfunction had slow transit in addition. The remaining patients (23%) had at least two of Manning's criteria suggestive of the irritable bowel syndrome. Only four patients had documented abnormalities of autonomic function. Conclusions : Pelvic floor dysfunction is the most common cause of severe constipation in a tertiary referral motility clinic; slow transit constipation and irritable bowel syndrome occur equally. An algorithmic approach to evaluating patients using clinical features, anorectal functions tests, and assessment of colonic transit facilitates selection of management strategies. Autonomic dysfunction occurs rarely.     

Slow-transit constipation

INTRODUCTION: Autonomic neuropathy is thought to play a role in the pathogenesis of slow-transit constipation, but other gastrointestinal organs may also be involved, even if they are symptom-free. We investigated whether motility in gastrointestinal organs other than the colon was impaired in patients with slow-transit constipation and whether the autonomic nervous system was involved. METHODS: Twenty-one consecutive patients (18 females; median age, 46 years) with severe chronic constipation (< or = 2 defecations/week and delayed colonic transit time) were studied. Autonomic neuropathy function was tested with esophageal manometry, gastric and gallbladder emptying (fasting and postprandial motility) by ultrasonography, orocecal transit time (H2-breath test), colonic transit time (radiopaque markers), and anorectal volumetric manometry. The integrity of the autonomic nervous system was assessed by a quantitative sweat-spot test for preganglionic and postganglionic fibers, tilt-table test, and Valsalva electrocardiogram R-R ratio. RESULTS: Esophageal manometry showed gastroesophageal reflux or absence of peristalsis in five of the seven patients examined. Gallbladder dysmotility (i.e., increased fasting, postprandial residual volume, or both) was observed in 6 of 14 (43 percent) patients. Gastric emptying was decreased in 13 of 17 (76 percent) patients. Orocecal transit time was delayed in 18 of 20 (90 percent) patients; median transit time was 160 (range, 90-200) minutes. Median colonic transit time was 97 (range, 64-140) hours. Anorectal function showed abnormal rectoanal inhibitory reflex and decreased rectal sensitivity in 11 of 19 (58 percent) patients. Signs of autonomic neuropathy of the sympathetic cholinergic system were found in 14 of 18 (78 percent) patients. Only one of nine patients had vagal abnormalities detected with the Valsalva test and four of five patients with a history of orthostatic hypotension had a positive tilt-table test. CONCLUSIONS: Slow-transit constipation may be associated with impaired function of other gastrointestinal organs. More than 70 percent of patients with slow-transit constipation present some degree of autonomic neuropathy. Severe constipation may be the main complaint in patients with a systemic disease involving several organs and possibly involving the autonomic nervous system. This should be considered in the management of such cases.     

A Novel Surgical Approach to Slow-Transit Constipation: Report of Two Cases

Introduction Slow-transit constipation after proper diagnosis and extensive medical therapy may have a surgical solution. Total abdominal colectomy and ileorectal anastomosis, at our institution, is the surgical procedure of choice. Nonetheless, patients may reject this alternative because of morbidity. Discussion We report two cases of slow-transit constipation diagnosed after a thorough investigation with two colonic transit tests showing slow-transit constipation, a normal anorectal manometry, balloon expulsion test, small-bowel follow-through, defecography, laboratory and psychologic tests. The patients rejected standard surgical treatment (total colectomy + ileorectal anastomosis). A colonic bypass with an ileorectal anastomosis, leaving the colon in situ, was offered and accepted by the two patients. This was performed laparoscopically liberating the cecum and terminal ileum, transecting the terminal ileum through a small suprapubic incision, and anastomosing the terminal ileum to the rectosigmoid junction intracorporeally. The total surgical time was 50 and 60 minutes, respectively. Summary Both patients made uneventful recoveries and were discharged on the fourth postoperative day. They have completed four and two months of close follow-up and at present have one to four bowel movements per day with mild abdominal distension and pain. To our knowledge this is the first report of colonic bypass for the treatment of slow-transit constipation. Reprints are not available.     

Botulinum toxin type-A injection to treat patients with intractable anismus unresponsive to simple biofeedback training

AIM: To evaluate the efficacy of botulinum toxin type A injection to the puborectalis and external sphincter muscle in the treatment of patients with anismus unresponsive to simple biofeedback training.METHODS: This retrospective study included 31 patients suffering from anismus who were unresponsive to simple biofeedback training. Diagnosis was made by anorectal manometry, balloon expulsion test, surface electromyography of the pelvic floor muscle, and defecography. Patients were given botulinum toxin type A (BTX-A) injection and pelvic floor biofeedback training. Follow-up was conducted before the paper was written. Improvement was evaluated using the chronic constipation scoring system.RESULTS: BTX-A injection combined with pelvic floor biofeedback training achieved success in 24 patients, with 23 maintaining persistent satisfaction during a mean period of 8.4 mo.CONCLUSION: BTX-A injection combined with pelvic floor biofeedback training seems to be successful for intractable anismus.     

Constipation: Initial evaluation and diagnostic approach

Constipation is a common gastrointestinal symptom and affects about 20% of the general population. This symptom can reflect a vast array of problems, from inadequate fiber intake to colonic dismotility function. Identifying chronic constipation subtypes on underlying physiology guides the therapeutic choices. Chronic constipation subtypes includes: slow-transit constipation, functional constipation, irritable bowel syndrome with constipation predominance and pelvic floor dysfunction. The most useful tests for the evaluation of those patients are the colonic transit time with radiopaque markers and anorrectal manometry with balloon expulsion test. Patients with both normal tests have either functional constipation or irritable bowel syndrome with constipation. Subjects with a delayed colonic transit and normal anorectal manometry maybe classified as colonic inertia. Pelvic floor dysfunction maybe suspected if the patient had an abnormal manometry with failure to expulse de balloon. Initial treatments of chronic constipation are dietary fiber and medicinal bulk. Subsequent treatments if fiber is not successful or tolerated would include saline osmotic laxatives such as lactulose and polyethylene glycol, or stimulants like senna or bisacodyl. For patients with pelvic floor dyssynergia biofeedback therapy is the first therapeutic option. In this article we present an overview of current diagnostic tools for patients with chronic constipation.     

功能性便秘的诊断与治疗

功能性便秘根据结肠动力学特点和肛门直肠功能可分为三类：慢传输型便秘、出口梗阻型便秘和混合型便秘。功能性便秘的诊断目前采用罗马Ⅲ诊断标准,须注意排除器质性病变所致。对于功能性便秘,目前尚无确切有效的治疗药物和方案。在治疗上采取个体化综合性的治疗措施,包括生活习惯、饮食结构调整及合理选择药物等,生物反馈治疗是功能性出口梗阻型便秘患者的首选治疗,而外科手术可能对部分严重慢传输型便秘患者有良好效果。     

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.     

Constipation

Chronic constipation is a common disorder manifested by a variety of symptoms. Assessments of colonic transit and anorectal functions are used to categorize constipated patients into three groups, i.e., normal transit or irritable bowel syndrome, pelvic floor dysfunction (i.e., functional defaecatory disorders) and slow transit constipation. 'Slow transit' constipation is a clinical syndrome attributed to ineffective colonic propulsion and/or increased resistance to propagation of colonic contents. Defaecatory disorders are caused by insufficient relaxation of the pelvic floor muscles or a failure to generate adequate propulsive forces during defaecation. Colonic transit is often delayed in patients with functional defaecatory disorders. Normal and slow transit constipation are generally managed with medications; surgery is necessary for a minority of patients with slow transit constipation. Functional defaecatory disorders are primarily treated with pelvic floor retraining using biofeedback therapy.