Rectal compliance in females with obstructed defecation

PURPOSE: This study was designed to investigate whether rectal compliance is altered in females with obstructed defecation. METHODS: Eighty female patients with obstructed defecation and 60 control subjects were studied. Rectal compliance was measured with an infinitely compliant polyethylene bag. This bag was inserted in the rectum and inflated with air to selected pressure plateaus (range, 0–60 mmHg; cumulative steps of 2 mmHg with a duration of ten seconds) using a computer-controlled electromechanical barostat system. Volume changes at the levels of distending pressures were recorded. The distending pressures, needed to evoke first sensation of content in the rectum, earliest urge to defecate, and the maximum tolerable volume were noted. RESULTS: In all cases, the compliance curve had a characteristic triphasic (S-shaped) form. The mean compliance curve obtained from the patients was identical to that of the controls. However, the course of the compliance curve fell above the normal range (mean + 2 SD) in 14 patients. In ten (71 percent) of these patients, a large rectocele was seen at evacuation proctography. Such a rectocele was observed in only five patients (7.6 percent) with a normal compliance curve (P<0.001). Eighty percent of the controls experienced earliest urge to defecate during the second phase of the curve. In 75 percent of the patients, this occurred in the third phase. The mean pressure threshold for first sensation, earliest urge to defecate, and maximum tolerable volume were significantly higher in patients compared with control subjects. Ten of the patients experienced no sensation at all in the pressure range between 0 and 60 mmHg. CONCLUSION: In females with obstructed defection, the compliance of the rectal wall is normal.     

Treatment strategies in obstructed defecation and fecal incontinence

Obstructed defecation (OD) and fecal incontinence (FI) are challenging clinical problems, which are commonly encountered in the practice of colorectal surgeons and gastroenterologists. These disorders socially and psychologically distress patients and greatly impair their quality of life. The underlying anatomical and pathophysiological changes are complex, often incompletely understood and cannot always be determined. As a consequence, many medical, surgical, and behavioral approaches have been described, with no panacea. Over the past decade, advances in an understanding of these disorders together with rational and similar methods of evaluation in anorectal physiology laboratories (ARP), radiology studies, and new surgical techniques have led to promising results. In this brief review, we discuss treatment strategies and recent updates on clinical and therapeutic aspects of obstructed defecation and fecal incontinence.     

Management of obstructed defecation

The management of obstructed defecation syndrome(ODS) is mainly conservative and mainly consists of fiber diet, bulking laxatives, rectal irrigation or hydrocolontherapy, biofeedback, transanal electrostimulation, yoga and psychotherapy. According to our experience, nearly 20% of the patients need surgical treatment. If we consider ODS an "iceberg syndrome", with "emerging rocks", rectocele and rectal internal mucosal prolapse, that may benefit from surgery, at least two out of ten patients also has "underwater rocks" or occult disorders, such as anismus, rectal hyposensation and anxiety/depression, which mostly require conservative treatment. Rectal prolapse excision or obliterative suture, rectoceleand/or enterocele repair, retrograde Malone’s enema and partial myotomy of the puborectalis muscle are effective in selected cases. Laparoscopic ventral sacral colporectopexy may be an effective surgical option. Stapled transanal rectal resection may lead to severe complications. The Transtar procedure seems to be safer, when dealing with recto-rectal intussusception. A multidisciplinary approach to ODS provides the best results.     

Complications and reinterventions after surgery for obstructed defecation

Purpose  Functional results following surgery for obstructed defecation (OD) have been widely investigated, but there are few reports aimed to analyze postoperative complications and re-interventions. This study investigates the adverse events requiring retreatment for obstructed defecation. Methods  We retrospectively analyzed the records of 203 patients operated on by a single surgeon, 20 transabdominally and 183 transperineally (159 manual and 24 stapled). Postoperative complications requiring retreatment and outcome of reinterventions were analyzed. Results  Adverse events requiring retreatment occurred in 14.3% more frequently after abdominal than after perineal procedures (20% vs. 13.7%), but the sample size of the two arms is different. Rectal bleeding and strictures were the most common adverse events (6.9%). Major complications, i.e., ischemic colitis requiring hemicolectomy and pelvic sepsis requiring colostomy also occurred (1%). The overall reintervention rate was 7.5%, (5% after abdominal and 7.6% after perineal surgery). Overall, 59% of the reoperated patients were still constipated at a median follow up of 2 years. Conclusions  Complications requiring retreatment are not uncommon after surgery for OD and reinterventions are often unsuccessful. A careful preoperative evaluation and selection of patients should be undertaken in order to minimize adverse events.     

Rectal sensory perception in females with obstructed defecation

PURPOSE: Parasympathetic afferent nerves are thought to mediate rectal filling sensations. The role of sympathetic afferent nerves in the mediation of these sensations is unclear. Sympathetic nerves have been reported to mediate nonspecific sensations in the pelvis or lower abdomen in patients with blocked parasympathetic afferent supply. It has been reported that the parasympathetic afferent nerves are stimulated by both slow ramp (cumulative) and fast phasic (intermittent) distention of the rectum, whereas the sympathetic afferent nerves are only stimulated by fast phasic distention. Therefore, it might be useful to use the two distention protocols to differentiate between a parasympathetic and sympathetic afferent deficit. METHODS: Sixty control subjects (9 males; median age, 48 (range, 20–70) years) and 100 female patients (median age, 50 (range, 18–75) years) with obstructed defecation entered the study. Rectal sensory perception was assessed with an infinitely compliant polyethylene bag and a computer-controlled air-injection system. This bag was inserted into the rectum and inflated with air to selected pressure levels according to two different distention protocols (fast phasic and slow ramp). The distending pressures needed to evoke rectal filling sensations, first sensation of content in the rectum, and earliest urge to defecate were noted, as was the maximum tolerable volume. RESULTS: In all control subjects, rectal filling sensations could be evoked. Twenty-one patients (21 percent) experienced no sensation at all in the pressure range between 0 and 65 mmHg during either slow ramp or fast phasic distention. The pressure thresholds for first sensation, earliest urge to defecate, and maximum tolerable volume were significantly higher in patients with obstructed defecation (P<0.001). In each subject, the pressure thresholds for first sensation, earliest urge to defecate, and maximum tolerable volume were always the same, regardless of the type of distention. CONCLUSION: Rectal sensory perception is blunted or absent in the majority of patients with obstructed defecation. The observation that this abnormality can be detected by both distention protocols suggests that the parasympathetic afferent nerves are deficient. Because none of the patients experienced a nonspecific sensation in the pelvis or lower abdomen during fast phasic distention, it might be suggested that the sympathetic afferents are also deficient. This finding implies that it is not worthwhile to use different distention protocols in patients with obstructed defecation.     

Transanal repair of rectocele corrects obstructed defecation if it is not associated with anismus

PURPOSE: Rectocele is often associated with anorectal symptoms. Various surgical techniques have been described to repair the rectocele. The surgical results are variable. This study evaluated the results of transanal repair of rectocele, with particular emphasis on the impact of concomitant anismus on postoperative functional outcome. METHODS: Fifty-nine consecutive females who underwent transanal repair of rectocele for obstructed defecation were prospectively reviewed. All 59 patients were parous with a median parity of 2 (range, 1–6) and a median age of 58 (range, 46–68) years. The median length of follow-up was 19 (range, 6–40) months. Anismus was detected by anorectal physiology and defecography. The functional outcome was assessed by a standard questionnaire, physical examination, anorectal manometry, neurophysiology, and defecography. The quality-of-life index was obtained using a visual analog scale (from 1–10, with 10 being the best). RESULTS: The functional outcome of transanal repair of rectocele was superior in patients without anismus. Forty (93 percent) of the 43 patients without anismus showed improved evacuation after repair compared with 6 (38 percent) of the 16 patients with anismus (P<0.05). The quality-of-life index improved (9vs. 4) if anismus was not present (P<0.05). There were minimal complications. Hemorrhage requiring blood transfusion (2 units) occurred in one patient and urinary retention in another. CONCLUSION: Transanal repair of rectocele is safe and, in the absence of anismus, effectively corrects obstructed defecation.Supported in part by the Stewardson Charitable Trusts.Presented at the Royal Australasian College of Surgeons Annual Scientific Congress, Sydney, Australia, May 3 to 8, 1998.     

Electromyography of the pelvic floor musculature in the assessment of obstructed defecation symptoms

PURPOSE: The purpose of this study was to use electromyography to examine the behavior of the external sphincter, puborectalis muscle, and pubococcygeus muscle during attempted defecation in patients with symptoms of obstructed defecation and in normal subjects to highlight differences of clinical significance. METHODS: A total of 35 patients (31 females) aged 20 to 80 (mean, 53.7±13.3) years with unprepared bowel who had normal colon transit time and obstructed defecation symptoms and 12 voluntary control subjects (7 females) aged 23 to 68 (mean, 48±11.5) years underwent an electromyography evaluation of the activity of the external sphincter, puborectalis muscle, and pubococcygeus muscle during attempted defecation. The patients were also examined in separate sessions with defecography and anal manometry. RESULTS: During attempted defecation, puborectalis muscle and external sphincter always reacted in the same manner. When evaluated with pubococcygeus muscle, three main patterns of activity were observed either in patients or in controls: 1) coordinated activation pattern; 2) coordinated inhibition pattern; and 3) uncoordinated or equivocal pattern: activation of pubococcygeus muscle with inhibition of puborectalis muscle/external sphincter, activation followed by inhibition of the three muscles, and activation followed by inhibition of pubococcygeus muscle and no change in the others. We never observed activation of puborectalis muscle/external sphincter concomitant with inhibition of pubococcygeus muscle. The inhibitory coordinated pattern occurred significantly (P = 0.01) more frequently in controls than in patients. These subjects also presented a significantly (P = 0.01) lower frequency of pubococcygeus muscle inhibition. CONCLUSIONS: Either activation or inhibition appears as a physiological behavior, possibly adopted in different circumstances, of the pelvic floor muscles during attempted defecation. The higher prevalence of coordinated inhibitory patterns in normal subjects and the lower frequency of pubococcygeus muscle inhibition in patients with symptoms of obstructed defecation, however, suggests that a loss of inhibition capacity progressing from pubococcygeus muscle to puborectalis muscle/external sphincter muscles could determine the insurgence of obstructed defecation symptoms in some subjects, who should therefore benefit from biofeedback retraining aimed at reacquisition of the inhibition capacity of all muscles of the pelvic floor during defecation.Deceased.Supported by a grant (60%) from the Ministry of Scientific and Technological Research, Italy.Presented at the Joint Meeting of the Israel Society of Colon and Rectal Surgery and the Mediterranean Society of Coloproctology, Nazareth, Israel, September 24 to 27, 2000.     

Stapled transanal rectal resection for obstructed defecation syndrome associated with rectocele and rectal intussusception

AIM:To evaluate the safety and efficacy of stapled transanal rectal resection(STARR),and to analyze the outcome of the patients 12-mo after the operation.METHODS:From May 2007 to October 2008,50 female patients with rectocele and/or rectal intussusception underwent STARR.The preoperative status,perioperative and postoperative complications at baseline,3,6 and 12-mo were assessed.Data were collected prospectively from standardized questionnaires for the assessment of constipation[constipation scoring system,...     

Rectal wall contractility in response to an evoked urge to defecate in patients with obstructed defecation

PURPOSE: The aim of this study was to examine rectal sensory perception and rectal wall contractility in response to an evoked urge to defecate and to identify differences between control subjects and patients with obstructed defecation. METHODS: Twenty control patients (10 men; median age, 47 (range, 17–78) years) and 29 female patients with disabling obstructed defecation (median age, 48 (range, 18–70) years) entered the study. Under radiologic control, an infinitely compliant barostat balloon was inserted over a guide wire into the proximal part of the rectum. Additionally, a latex balloon was introduced into the distal part of the rectum. This latex balloon was inflated until an urge to defecate was experienced. Simultaneously, rectal wall contractility was assessed by measuring the variations in barostat balloon volume. These variations were expressed as percentage changes from baseline volume. RESULTS: By comparing controls and patients with obstructed defecation, a significant difference was found regarding mean distending volume required to elicit an urge to defecate (135±38vs. 214±87 ml of air;P<0.001, Mann-WhitneyU-test). In all controls, the evocation of an urge to defecate induced a pronounced increase in rectal tone, proximal to the distal stimulating balloon. By comparing controls and patients, the increase in rectal tone was found to be significantly higher in control subjects (35±10vs. 9±10 percent;P<0.001). Twenty-five patients (86 percent) showed no or only minimum (<20 percent) increase in rectal tone during the perception of an urge to defecate. In 14 of these patients, the threshold for this perception was increased. Only four patients (14 percent) showed a relatively normal increase (>20 percent) in rectal tone. However, their threshold for perception was greatly increased. CONCLUSION: The assembly used in this study provides a useful tool for investigation of rectal evacuation. In all of our patients, obstructed defecation was associated with abnormal rectal sensory perception and/or altered rectal wall contractility.Read at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, June 22 to 26, 1997.     

The gastrorectal reflex in women with obstructed defecation

This study evaluated the tonic response of the rectum to a meal in women with obstructed defecation. Fifteen control subjects and 60 women with obstructed defecation were studied. Total colonic transit time was normal in 30 patients (group I) and prolonged in the other 30 (group II). After over-night fasting an "infinitely compliant" polyethylene bag was inserted into the rectum. Rectal tone was assessed by measuring variations in bag volume with a computerized electromechanical air injection system. After an adaptation period of 30 min all subjects consumed a 450-kcal liquid meal. Postprandial recordings were continued for 3 h. In a second recording session we investigated the tonic response of the rectum to an evoked urge to defecate. In a third session rectal sensory perception was assessed. Following the meal all controls showed an increase in rectal tone (mean 74.8 +/- 17%). Patients in whom colonic transit time was normal showed a similar tonic response. In group II the increase in rectal tone was significantly lower (mean 27.8 +/- 10%; P < 0.001). Three patients of this group showed no response to a meal at all. All controls showed an increase in rectal tone during an evoked urge to defecate (mean 39.2 +/- 9%). In both groups this tonic response was absent or significantly blunted (mean 15.3 +/- 6% and 16.4 +/- 5%, respectively; P < 0.001). In both groups rectal sensory perception was significantly impaired. In conclusion, patients with obstructed defecation in whom colonic transit time is normal have an intact gastrorectal reflex. The increase in rectal tone after a meal is absent or blunted in patients with obstructed defecation in whom transit time is prolonged. The tonic response of the rectum to an evoked urge to defecate as well as rectal sensory perception are significantly impaired both in patients with a normal and in those with a prolonged transit time.     

Consensus statement AIGO/SICCR: diagnosis and treatment of chronic constipation and obstructed defecation (part I: diagnosis)

Chronic constipation is a common and extremely troublesome disorder that significantly reduces the quality of life, and this fact is consistent with the high rate at which health care is sought for this condition. The aim of this project was to develop a consensus for the diagnosis and treatment of chronic constipation and obstructed defecation. The commission presents its results in a "Question-Answer" format, including a set of graded recommendations based on a systematic review of the literature and evidence-based medicine. This section represents the consensus for the diagnosis. The history includes information relating to the onset and duration of symptoms and may reveal secondary causes of constipation. The presence of alarm symptoms and risk factors requires investigation. The physical examination should assess the presence of lesions in the anal and perianal region. The evidence does not support the routine use of blood testing and colonoscopy or barium enema for constipation. Various scoring systems are available to quantify the severity of constipation; the Constipation Severity Instrument for constipation and the obstructed defecation syndrome score for obstructed defecation are the most reliable. The Constipation-Related Quality of Life is an excellent tool for evaluating the patient's quality of life. No single test provides a pathophysiological basis for constipation. Colonic transit and anorectal manometry define the pathophysiologic subtypes. Balloon expulsion is a simple screening test for defecatory disorders, but it does not define the mechanisms. Defecography detects structural abnormalities and assesses functional parameters. Magnetic resonance imaging and/or pelvic floor sonography can further complement defecography by providing information on the movement of the pelvic floor and the organs that it supports. All these investigations are indicated to differentiate between slow transit constipation and obstructed defecation because the treatments differ between these conditions.     

梗阻性排便综合征的外科治疗

梗阻性排便综合征(obstructed defecation syndrome,ODS)的外科治疗首先必须进行充分、全面地评估,根据检查结果排除手术禁忌症,进而制定手术方案。目前,治疗ODS的手术方式主要有PPH-STARR、Contour Transtar和TSTstarr＋等手术方式,其治疗效果相似,但需根据患者的临床表现不同而进行个体化治疗。     

Surgery for obstructed defecation syndrome-is there an ideal technique

Obstructive defecation syndrome(ODS) is a common disorder with a considerable impact on the quality of life of affected patients.Surgery for ODS remains a challenging topic.There exists a great variety of operative techniques to treat patients with ODS.According to the surgeon’s preference the approach can be transanal,transvaginal,transperineal or transabdominal.All techniques have its advantages and disadvantages.Notably,high evidence based studies are significantly lacking in literature,thus making accurate assessments difficult.Careful patient’s selection is crucial to achieveoptimal functional results.It is mandatory to assess not only defecation disorders but also evaluate overall pelvic floor symptoms,such as fecal incontinence and urinary disorders for choosing an appropriate and tailored strategy.Radiological investigation is essential but may not explain complaints of every patient.     

Rectopexy is an ineffective treatment for obstructed defecation

The symptoms of obstructed defecation have been attributed to rectal intussusception, and thus rectopexy has been advocated in the surgical management. In this study, patients with obstructed defecation underwent manometry and proctography before and after rectopexy. Seventeen patients (16 females and one male, mean age 51.6 years) were studied. Eleven underwent anterior and posterior fixation of the rectum and six had posterior fixation only. Preoperatively five patients demonstrated rectoanal intussusceptions. Fifteen had significant pelvic descent. No significant change in maximum resting pressure, maximum voluntary contraction, pelvic descent, or anorectal angle was seen postoperatively. In the initial follow-up, many patients had significant amelioration of symptoms. However, on longer follow-up (mean 30.8 months) only two had long-term improvement. The remainder had a poor clinical result in spite of complete resolution of rectal intussusception. Many reported a worsening of symptoms as reflected by an increase in tenesmus and stool frequency. In the two cases with a satisfactory result, both could empty the rectum completely and demonstrated rectoanal intussusception on preoperative evacuation proctography. In those with poor results, four had complete emptying and three had rectoanal intussusception. In conclusion rectopexy is an ineffective treatment for obstructive defecation in most patients.Read at the Tripartite Meeting, Birmingham, United Kingdom, June 19 to 22, 1989.Work is attributed to the Bristol Royal Infirmary, Bristol, United Kingdom.     

Obstructed defecation after undiverted ileoanal pouch reconstruction for ulcerative colitis: Pharmacologic approach

PURPOSE: Obstructed defecation after ileal pouch construction has been reported only after closure of the diverting loop ileostomy, and biofeedback was an effective treatment modality. METHOD: This is a case report of a patient with immediate obstructed defecation after ileal pouch-anal anastomosis without a covering loop ileostomy and its successful pharmacologic management. RESULTS: A 38-year-old female underwent restorative proctectomy and stapled ileal J-pouch-anal anastomosis without a covering loop ileostomy. On the seventh postoperative day, her pouch catheter (in lieu of a covering loop ileostomy) was removed and she failed to evacuate. After ruling out any technical complications, diltiazem was commenced with successful spontaneous pouch emptying. Obstructed defecation reoccurred after cessation of diltiazem one week later, but the symptoms resolved once the diltiazem was recommenced. CONCLUSIONS: Obstructed defecation has been reported in patients after pelvic pouch reconstruction. However, in all those patients a diverting loop ileostomy had been raised and their obstructive symptoms were only apparent after closure of the ileostomy and when the pouch had healed. The concern regarding our patient was the complete outlet obstruction so soon after surgery, with undue strain on the anastomosis and the potential risk of disruption. Our only two options were either to create a diverting loop ileostomy or to try a fast-acting pharmacologic agent (diltiazem) to treat the presumed levator spasm. The latter option spared the patient a further operation.     

Comparative outcome of stapled trans-anal rectal resection and macrogol in the treatment of defecation disorders

AIM:To prospectively assess the eff icacy and safety of stapled trans-anal rectal resection(STARR) compared to standard conservative treatment,and whether preoperative symptoms and findings at defecography and anorectal manometry can predict the outcome of STARR.METHODS:Thirty patients(Female,28;age:51 ± 9 years) with rectocele or rectal intussusception,a defecation disorder,and functional constipation were submitted for STARR.Thirty comparable patients(Female,30;age 53 ± 13 years),who presented with sympto...     

Ultrasonographic patterns in patients with obstructed defaecation

Background Anal ultrasound is helpful in assessing organic anorectal lesions, but its role in functional disease is still questionable. The purpose of the present study is to assess anal–vaginal–dynamic perineal ultrasonographic findings in patients with obstructed defecation (OD) and healthy controls. Materials and methods Ninety-two consecutive patients (77 women; mean age 51 years; range 21–71) with symptoms of OD were retrospectively evaluated. All patients underwent digital exploration, endoanal and endovaginal ultrasound (US) with rotating probe. Forty-one patients underwent dynamic perineal US with linear probe. Anal manometry and defaecography were performed in 73 and 43 patients, respectively. Ultrasonographic findings of 92 patients with symptoms of OD were compared to 22 healthy controls. Anismus was defined on US when the difference in millimetres between the distance of the inner edge of the puborectalis muscle posteriorly and the probe at rest and on straining was less then 5 mm. Sensitivity and specificity were calculated by assuming defaecography as the gold standard for intussusception and rectocele and proctoscopy for rectal internal mucosal prolapse. Since no gold standard for the diagnosis of anismus was available in the literature, the agreement between anal US and all other diagnostic procedures was evaluated. Results The incidence of anismus resulted significantly higher (P < 0.05) in OD patients than healthy controls on anal (48 vs 22%), vaginal (44 vs 21%), and dynamic perineal US (53 vs 22%). A significantly higher incidence of rectal internal mucosal prolapse was observed in OD patients when compared to healthy controls on both anal (61.9 vs 13.6%, P < 0.0001) and dynamic perineal US (51.2 vs.9% P = 0.001). For the diagnosis of rectal internal mucosal prolapse, anal US had a 100% sensitivity and specificity. For diagnosis of rectal intussusception, anal US had an 83.3% sensitivity and 100% specificity and perineal US had a 66.6% sensitivity and 100% specificity. In the diagnosis of anismus, anal ultrasonography resulted in agreement with perineal and vaginal US, manometry, defaecography, and digital exam (P < 0.05). Other lesions detected by US in patients with OD include solitary rectal ulcer, rectocele and enterocele. Damage of internal and/or external sphincter was diagnosed at anal US in 19/92 (20%) patients, all continent and with normal manometric values. Conclusion Anal, vaginal and dynamic perineal ultrasonography can diagnose or confirm many of the abnormalities seen in patients with OD. The value of the information obtained by this non-invasive test and its role in the diagnostic algorithm of OD is yet to be defined.     

Transanal surgery for obstructed defecation syndrome: Literature review and a single-center experience

Obstructed defecation syndrome (ODS) is a functional disorder commonly encountered by colorectal surgeons and gastroenterologists, and greatly affects the quality of life of patients from both societal and psychological aspects. The underlying anatomical and pathophysiological changes of ODS are complex. However, intra-rectal intussusception and rectocele are frequently found in patients with ODS and both are thought to play an important role in the pathogenesis of ODS. With the development of evaluation methods in anorectal physiology laboratories and radiology studies, a great variety of new operative procedures, especially transanal procedures, have been invented to treat ODS. However, no procedure has been proved to be superior to others at present. Each operation has its own merits and defects. Thus, choosing appropriate transanal surgical procedures for the treatment of ODS remains a challenge for all surgeons. This review provides an introduction of the current problems and options for treatment of ODS and a detailed summary of the essential assessments needed for patient evaluation before carrying out transanal surgery. Besides, an overview of the benefits and problems of current transanal surgical procedures for treatment of ODS is summarized in this review. A report of clinical experience of some transanal surgical techniques used in the authors’ center is also presented.     

Comparison of straining during defecation in three positions: results and implications for human health

The aim of the study was to compare the straining forces applied when sitting or squatting during defecation. Twenty-eight apparently healthy volunteers (ages 17–66 years) with normal bowel function were asked to use a digital timer to record the net time needed for sensation of satisfactory emptying while defecating in three alternative positions: sitting on a standard-sized toilet seat (41–42 cm high), sitting on a lower toilet seat (31–32 cm high), and squatting. They were also asked to note their subjective impression of the intensity of the defecation effort. Six consecutive bowel movements were recorded in each position. Both the time needed for sensation of satisfactory bowel emptying and the degree of subjectively assessed straining in the squatting position were reduced sharply in all volunteers compared with both sitting positions (P < 0.0001). In conclusion, the present study confirmed that sensation of satisfactory bowel emptying in sitting defecation posture necessitates excessive expulsive effort compared to the squatting posture.     

Dynamic anal manometry in the assessment of patients with obstructed defecation

Patients with obstructed defecation show no consistent abnormalities when assessed by standard anorectal physiologic methods. With a recently developed technique for dynamic anal manometry, we studied 13 female patients with obstructed defecation and 20 healthy volunteers. Seven parameters of anal function were measured. There were no differences between the median values for the two groups. Seven patients (54 percent; 95 percent confidence limits, 25–81 percent) had anal compliance below the normal range, either during opening or closing of the sphincter at rest (five patients), during squeeze (one patient), or both (one patient). Opening and closing pressures of the sphincer at rest, maximal closing pressure during squeeze, and anal hysteresis were normal. Standard anal manometry did not show any differences between patients and controls. Rectal compliance was lower in patients with obstructed defecation, median difference 5 ml/cm H ₂ O (95 percent confidence limits, 1–9 ml/cm H ₂ O). In conclusion, the more detailed method of dynamic anal manometry shows that some patients with obstructed defecation have a less compliant anal sphincter and a less compliant rectum, but in many patients no abnormal findings can be made.