Diagnosis and surgical management of intractable constipation

Resting anal pressure, not outlet obstruction or transit, predicts healthcare utilization in chronic constipation: a retrospective cohort analysis

BACKGROUND

Chronic constipation is common and exerts a considerable burden on health-related quality of life and healthcare resource utilization. Anorectal manometry (ARM) and colonic transit testing have allowed classification of subtypes of constipation, raising promise of targeted treatments. There has been limited study of the correlation between physiological parameters and healthcare utilization.

METHODS

All patients undergoing ARM and colonic transit testing for chronic constipation at two tertiary care centers from 2000 to 2014 were included in this retrospective study. Our primary outcomes included number of constipation-related and gastroenterology visits per year. Multivariate linear regression adjusting for confounders defined independent effect of measures of colonic and anorectal function on healthcare utilization.

KEY RESULTS

Our study included 612 patients with chronic constipation. More than 50% (n = 333) of patients had outlet obstruction by means of balloon expulsion testing and 43.5% (n = 266) had slow colonic transit. On unadjusted analysis, outlet obstruction (1.98 vs 1.68), slow transit (2.40 vs 2.07) and high resting anal pressure (2.16 vs 1.76) were all associated with greater constipation-related visits/year compared to patients without each of those parameters (p < 0.05 for all). Outlet obstruction and high resting anal pressure were also associated with greater number of gastroenterology visits/year. After multivariate adjustment, high resting anal pressure was the only independent predictor of increased constipation-related visits/year (p = 0.02) and gastroenterology visits/year (p = 0.04).

CONCLUSIONS & INFERENCES

Among patients with chronic constipation, high resting anal pressure, rather than outlet obstruction or slow transit, predicts healthcare resource utilization.

Diagnostic testing for dyssynergic defecation in chronic constipation: meta-analysis

BACKGROUND

Dyssynergic defecation (DD) results from inadequate relaxation of the pelvic floor on attempted defecation. The prevalence of DD in patients with chronic constipation (CC) is not certain. Aims of this study are to estimate the prevalence of abnormal findings associated with DD across testing modalities in patients referred for physiological testing for CC.

METHODS

Systematic search of MEDLINE, EMBASE and PUBMED databases were conducted. We included full manuscripts reporting DD prevalence in CC, and specific findings at pelvic floor diagnostic tests. Random effects models were used to calculate pooled DD prevalences (with 95% CI) according to individual tests and specific findings.

KEY RESULTS

A total of 79 studies on 7581 CC patients were included. The median prevalence of any single abnormal finding associated with DD was 37.2%, ranging from 14.9% (95% CI 7.9-26.3) for absent opening of the anorectal angle (ARA) on defecography to 52.9% (95% CI 44.3-61.3) for a dyssynergic pattern on ultrasound. The prevalence of a dyssynergic pattern on manometry was 47.7% (95% CI 39.5-56.1). The prevalence of DD was similar across specialty and geographic area as well as when restricting to studies using Rome criteria to define constipation.

CONCLUSIONS & INFERENCES

Dyssynergic defecation is highly prevalent in CC and is commonly detected across testing modalities, type of patient referred, and geographical regions. We believe that the lower prevalence of findings associated with DD by defecography supports use of manometry and balloon expulsion testing as an initial evaluation for CC.

Rectal sensorimotor dysfunction in constipation

The pathophysiological mechanisms underlying chronic constipation in both adults and children remain to be unravelled. This is a not inconsiderable challenge, but is fundamental to improving management of such patients. Rectal sensorimotor function, which encompasses both sensation and motility, as well as biomechanical components (compliance, capacity), is now strongly implicated in the pathogenesis of constipation. Rectal hyposensitivity, rectal hypercompliance, increased rectal capacity, rectal motor dysfunction (phasic contractility and tone), and altered rectoanal reflex activity are all found in constipated patients, particularly in association with 'functional' disorders of defaecation (i.e. pelvic floor dyssynergia). This review covers contemporary understanding of how components of rectal sensorimotor function may contribute to symptom development in both adult and paediatric populations. The complex interaction between sensory/motor/biomechanical domains, and how best to measure these functions are addressed, and where data exist, the impact of sensorimotor dysfunction on therapeutic outcomes is highlighted.

Anorectal manovolumetry in the decision making before surgery for slow transit constipation

BACKGROUND

Colectomy with ileorectal anastomosis for slow transit constipation (STC) is being challenged by other operations, such as segmental resections. The importance of preoperative anorectal physiology testing may therefore be increased. The aim of this study was to identify anorectal abnormalities in patients with STC, which may influence the surgical approach.

METHODS

Fifty consecutive patients with STC (43 women; median age, 49 years) and 28 controls (23 women; median age, 50 years) were examined with anorectal manovolumetry. Anal pressures and rectal volumes were recorded, at stepwise rectal distension.

RESULTS

Anal resting pressure was lower in patients (median, 54 cm H(2)O; range, 22-130) than in controls (median, 68 cm H(2)O; range, 35-100) (p<0.05). Squeeze pressure tended to be lower in patients (median, 147 cm H(2)O; range, 53-382) than in controls (median, 177 cm H(2)O; range, 65-423) (p=0.09). Rectal sensory thresholds did not differ significantly between patients and controls, although 10 patients had a threshold for filling above the 95(th) percentile of controls. Rectal compliance was increased in patients in the pressure interval 5-35 cm H(2)O (p<0.05-0.01). The threshold and amplitude of the recto-anal inhibitory reflex did not differ significantly, but the recovery of resting pressure after eliciting the reflex was lower in patients than in controls in the pressure interval 10-50 cm H(2)O (p<0.05-0.001).

CONCLUSIONS

More than half of the patients with STC deviated in some parameter. An impaired internal sphincter function and increased rectal compliance were seen. One fifth of the patients had impaired rectal sensation.

Anorectal physiology in relation to clinical subgroups of patients with severe constipation

OBJECTIVE

The aim of this study was to evaluate anorectal physiology in relation to clinically defined subgroups of patients with idiopathic constipation and to analyse relationships between anorectal physiology and rectal evacuation.

SUBJECTS AND METHODS

One hundred consecutive patients with idiopathic constipation were clinically categorized as slow transit (n=19), outlet obstruction (n=52) and a group with mixed symptoms (n=29). They were examined by recording anal pressures and also rectal volumes in response to stepwise increases in rectal pressure (5-60 cm H2O). The manovolumetric results were compared with 28 sex and aged matched controls. Rectal evacuation was measured by computer-based image analysis of rectal emptying rate in defaecography.

RESULTS

The rectal pressure thresholds for filling, urge and pain did not differ between the groups but there were proportionally more patients in the slow transit and mixed group with thresholds for filling exceeding 25 cm H2O (P=0.04). In total, 18% of patients had impaired sensitivity which was associated with long duration of symptoms (P < 0.05). Patients with grossly impaired rectal sensitivity (filling threshold > 40 cm H2O) had impaired rectal evacuation (P < 0.05). The rectal compliance was increased in the slow transit and mixed group (P < 0.01-0.05) in the pressure interval 5-15 cm H2O. Anal resting and squeeze pressures did not differ between the groups although 7/19 in the slow transit group had values around the lower limit of controls. Slow wave frequency was lower in all patient groups (P < 0.001 vs. controls). Rectal evacuation was not related to sphincter function or to rectal compliance.

CONCLUSIONS

Clinical categorization of constipated patients defines groups where altered anorectal physiology is not uncommon. Constipation with symptoms of infrequent defaecation may be associated with impaired rectal sensitivity and increased rectal compliance whereas outlet obstruction symptoms are not clearly related to changes in anorectal physiology.

Pilot study of subtotal colectomy with antiperistaltic cecoproctostomy for the treatment of chronic slow-transit constipation

PURPOSE

Functional results of total colectomy with ileorectal anastomosis for the treatment of chronic constipation caused by colonic inertia are often considered unsatisfactory because of the frequency of postoperative diarrhea and the high rate of postoperative small-bowel obstruction. Patients affected by severe colonic inertia underwent a subtotal colectomy with a novel antiperistaltic cecorectal anastomosis. The aim of the study was to assess the functional results after preservation of the cecorectal junction.

METHODS

Eight females affected by isolated colonic inertia and two females with both paradoxical puborectalis contraction and colonic inertia, of a median age of 40 years, underwent subtotal colectomy with antiperistaltic cecorectal anastomosis. Before antiperistaltic cecorectal anastomosis all ten patients were laxative-dependant, with a mean bowel frequency of ten days; eight of them (80 percent) had distention, seven (70 percent) bloating, and three (30 percent) abdominal pain.

RESULTS

There was no mortality or major postoperative morbidity. One month after antiperistaltic cecorectal anastomosis, bowel frequency was a mean of 2.2 (range, 1-4) per day, with a semiliquid stool consistency. After one year, bowel frequency was a mean of 1.3 (range, 0.5-3) per day, with a solid stool consistency; the same results were recorded at last follow-up. Although no patients used antidiarrheal medicine, laxatives continued to be used by both patients with paradoxical puborectalis contraction. All ten (100 percent) of the patients reported a good or improved quality of life.

CONCLUSION

This preliminary experience seems to show that antiperistaltic cecorectal anastomosis is safe and effective for patients with colonic inertia. It results in prompt and prolonged relief from constipation for patients with isolated colonic inertia.

Surgical treatment of constipation and fecal incontinence

Fecal incontinence is a disabling and distressing condition. Many patients are reluctant to discuss the condition with a physician. A thorough history, good physical examination, and detailed anorectal physiologic investigations can help in the therapeutic decision-making algorithm. Patients with isolated anterior sphincter defects are candidates for overlapping repair. In the presence of unilateral or bilateral pudendal neuropathy, the patient should be counseled preoperatively regarding a [table: see text] lower anticipation of success. If the injury occurred shortly before the planned surgery and neuropathy is present, it may be prudent to wait because neuropathy sometimes can resolve within 6 to 24 months of the injury. Pudendal nerve study may help determine surgical timing. An anterior sphincter defect combined with a rectovaginal fistula can be approached by overlapping sphincter repair and a concomitant transanal advancement flap. Patients who had undergone multiple such procedures may benefit from concomitant fecal diversion at the time of repeat sphincter repair. Patients with global or multifocal sphincter injury may be candidates for a neosphincter procedure. The stimulated graciloplasty and artificial bowel sphincter are reasonable options. In the absence of the availability of these techniques or because of financial constraints, consideration could be given to bilateral gluteoplasty or unilateral or bilateral nonstimulated graciloplasty. The postanal repair still serves a role in patients with isolated decreased resting pressures with or without neuropathy or external sphincter injury with minimal degrees of incontinence. Biofeedback and the Procon device may play a role in these patients. Lastly, fecal diversion must be considered as a means of improving the quality of life because the patient can participate in the activities of daily living without the fear of fecal incontinence.

Comparison of methods used for measurement of rectal compliance

INTRODUCTION

Compliance is defined as the change in volume or cross-sectional area divided by the change in pressure. Pressure-volume measurement during distention with a compliant balloon is the most commonly used method for computation of rectal compliance. However, intraindividual and interindividual variations are large, restricting the usefulness of the method. Other methods such as rectal distention by a large, noncompliant bag and rectal impedance planimetry for assessment of pressure-cross-sectional-area relations have been proposed as alternatives owing to the reduction of errors from elongation of the balloon within the rectal lumen. However, in vivo reproducibility of pressure-volume measurement during distention with a compliant balloon, pressure-volume measurement during rectal distention by a large, noncompliant bag, and rectal impedance planimetry have never been compared.

PURPOSE

The aim of this study was to compare in vivo reproducibility of the above-mentioned methods and to study their in vitro reproducibility and validity.

METHODS

Ten healthy volunteers (six men) aged 21-59 years were randomized to either rectal pressure-volume measurement with a compliant balloon or rectal impedance planimetry. After a one-hour rest, the other procedure was performed. After two weeks, both procedures were again performed in the same order. During rectal impedance planimetry the volume of the bag used (maximum volume 450 ml; secured at both ends to the probe) was continuously registered, measuring pressure-volume relations during rectal distention by a large, noncompliant bag. Reproducibility was tested by comparing the difference divided by the mean for each method at eight pressure steps in the range from 5 to 40 cm H2O. Furthermore, the in vitro reproducibility and validity of the three methods were studied using polyvinyl chloride tubes with known cross-sectional areas.

RESULTS

In vivo reproducibility for pressure-volume measurement with a large, noncompliant bag and rectal impedance planimetry was significantly better than for pressure-volume measurement with a compliant balloon (P = 0.005 and P = 0.019, respectively). No statistically significant difference was found between pressure-volume measurement with a large, noncompliant bag and rectal impedance planimetry (P = 0.20). In vitro reproducibility of pressure-volume measurement with a large, noncompliant bag and rectal impedance planimetry was good, but some elongation occurred, reducing the validity of pressure-volume measurement with a large, noncompliant bag. Coiling and elongation of the balloon within the lumen were major sources of error for pressure-volume measurement with a compliant balloon.

CONCLUSION

In vivo and in vitro reproducibility of methods used for measurement of rectal compliance can be improved by restricting the effects of elongation within the lumen either by using a large-volume, noncompliant bag or by rectal impedance planimetry. However, pressure-volume measurement will to some degree depend on the properties of the balloons or bags.

Effect of colectomy on gastric emptying in idiopathic slow-transit constipation

INTRODUCTION

Gastric emptying is delayed in patients with idiopathic slow-transit constipation (ISTC). Gastric emptying was measured before and after colectomy and ileorectal anastomosis in patients with ISTC to determine whether the abnormality persists after operation.

METHODS

Twelve patients undergoing colectomy for severe ISTC had solid-phase gastric emptying measured after an overnight fast. All 12 had an uncomplicated subtotal colectomy and ileorectal anastomosis; 11 had an excellent functional outcome. In ten of these patients gastric emptying was repeated within 3 months of operation. Seven patients (including the remaining two) had the study performed at 1 year.

RESULTS

All 12 patients had severely delayed gastric emptying before operation. Gastric emptying remained delayed in the ten patients who underwent an early postoperative gastric emptying study. Six of seven patients assessed at 1 year had improved gastric emptying, of whom four had returned to normal. Functional outcome did not relate to gastric emptying.

CONCLUSION

Patients with ISTC have delayed gastric emptying. In some patients this returns to normal after colectomy, but is persistent in others. This may have implications for our understanding of ISTC.

Long-term results of colorectal resection for slow transit constipation

OBJECTIVE

To determine the long-term outcome for surgery for slow transit constipation.

PATIENTS AND METHODS

A long-term retrospective review of 61 patients who had undergone surgery for slow transit constipation between 1977 and 1996. Patients with megabowel, Hirschsprung's disease or primary anorectal pathology were excluded from the study.

RESULTS

Subtotal colectomy was performed in 48 patients and segmental colectomy in 13. Twenty-four patients (39%) required further surgery. Fourteen patients (23%) eventually had a permanent stoma. Twenty-nine patients (48%) had normal bowel habit and improved symptoms (grade 1) following treatment. The permanent stoma rate was significantly higher in patients with proven psychological disturbance (70% vs 14%, P = 0.0005). Unsatisfactory outcomes (grades 3 and 4) were more common in patients with a psychological disorder (n = 10), 70% vs 18% (P = 0.002), and those with slow transit and impaired rectal evacuation, 39% vs 11% (P = 0.025). Satisfactory outcomes (grades 1 and 2) were achieved in 95% of the psychologically stable patients with slow transit constipation after subtotal colectomy.

CONCLUSION

The long-term results of surgery for slow transit constipation may be poor. However, a good outcome can be predicted in patients with slow transit constipation without impaired evacuation and overt psychological or psychiatric disease.

Quality of life in patients with different types of functional constipation

BACKGROUND

Little information is available about the health-related quality of life (QoL) in patients with different types of chronic constipation.

METHODS

We used two self-administered questionnaires, the Psychological General Well-Being (PGWB) index and the Gastrointestinal Symptom Rating Scale (GSRS) to assess QoL and gastrointestinal symptoms in 102 consecutive patients with chronic constipation. The type of constipation was determined from transit time, electrophysiologic investigation of sphincter function, anorectal manometry, and defecography.

RESULTS

Overall, our patients with constipation reported low scores for general well-being (mean score, 85.5, compared with 102.9 in a healthy population). Patients with normal-transit constipation (n = 49) reported considerably lower scores in the PGWB than those with slow-transit constipation (n = 35). The symptoms increased frequency of defecation, loose stools, and urgent need for defecation were commoner in normal-transit constipation, which indicates that this group may have a relation to the irritable bowel syndrome. The overall PGWB index was strongly correlated with the total GSRS (P < 0.001).

CONCLUSIONS

The general well-being of patients with chronic constipation is lower than that of a comparable normal population. Symptom severity correlates negatively with perceived quality of life.

Long-term results of surgery for chronic constipation

BACKGROUND

Developments in anorectal physiologic testing have facilitated better understanding of the process of defecation and factors that might cause chronic constipation.

AIM

Patients with severe idiopathic chronic constipation were evaluated using colonic transit and pelvic floor function in an attempt to identify those patients suitable for aggressive surgical intervention.

MATERIALS AND RESULTS

Among 1,009 patients studied using either a marker or scintigraphic transit technique and tests of pelvic floor function, 52 with slow-transit constipation (STC) were identified and underwent abdominal colectomy and ileorectostomy (IRA). Twenty-two patients had pelvic floor dysfunction and STC; these patients underwent initial pelvic floor retraining followed by IRA. A total of 249 patients had pelvic floor dysfunction without evidence of slow-transit and were offered pelvic floor retraining alone. The remaining 597 patients had no quantifiable abnormality of colon or pelvic floor dysfunction; these patients had normal transit constipation/irritable bowel syndrome and were treated medically. There were, thus, 74 patients operated on, 68 women, with a mean age of 53 years and a mean follow-up of 56 months. There was no operative mortality, seven patients (9 percent) had small-bowel obstruction, and nine patients (12 percent) had prolonged ileus. All patients were able to pass a stool spontaneously, 97 percent of patients were satisfied with the results of surgery, and 90 percent have a good or improved quality of life. There was no difference in the outcome of surgery in patients with STC alone compared with STC and pelvic floor dysfunction.

CONCLUSION

Physiologic evaluation reliably identified patients with severe chronic constipation who might benefit from surgery. IRA is safe and effective, resulting in prompt and prolonged relief of constipation.

Role of segmental colonic transit time studies to select patients with slow transit constipation for partial left-sided or subtotal colectomy

This prospective study investigated the value of segmental colonic transit time studies in the surgical treatment of slow transit constipation. Overall, 346 patients with chronic constipation were analysed; slow transit constipation was diagnosed in 86 (25 per cent). Based on the results of segmental colonic transit time studies, 18 patients underwent partial left-sided colectomy and 24 subtotal colectomy. Recurrent constipation was seen in three of 18 patients and seven of 24 respectively. Severe abdominal discomfort was noted in six of 18 and 15 of 24 respectively. Disabling diarrhoea and faecal incontinence developed in two of 14 and five of 20 patients with an anastomosis respectively. Although these results indicate that segmental colonic transit time studies are useful in selecting patients with slow transit constipation for partial left-sided or subtotal colectomy, both procedures should be performed with prudence.

Surgery for constipation: a review

PURPOSE

Constipation is related to intestinal motility disorders (colonic inertia (CI)), pelvic floor disturbances (pelvic outlet obstruction), or a combination of both problems. This review summarizes the physiologic and pathophysiologic changes in patients with intractable constipation and gives an overview of surgical treatment options.

RESULTS

Although subtotal colectomy with ileorectal anastomosis is the best surgery for CI, there are still approximately 10 percent of patients who will complain of pain and constipation. A completion proctectomy and an ileoanal pouch procedure may be a viable option in a highly select group of patients. In patients with megabowel, reported results are mixed. Subtotal colectomy, partial colectomy for megacolon, and the Duhamel procedure for megarectum have all been reported with variable results. In patients with an isolated distended sigmoid colon, sigmoid colectomy has achieved good results. Anorectal myectomy has not been proven to be successful in the long term. However, in patients with adult short segment Hirschsprung's disease, myectomy can be successful. Patients with pelvic outlet obstruction can be successfully treated with biofeedback. In a small group of patients with a rectocele or a third degree sigmoidocele, surgical intervention yields a high success rate. Division or resection of the puborectalis muscle is not recommended. In patients with a mixed pattern of CI and pelvic outlet obstruction, surgical intervention alone is often not successful. These patients achieve better results by conservative treatment of pelvic outlet obstruction, followed by a colectomy.

CONCLUSION

Surgical intervention for patients with intractable constipation is rarely necessary. However, thorough preoperative physiologic testing is mandatory for a successful outcome.

Long-term results of total abdominal colectomy for chronic idiopathic constipation. Value of preoperative assessment

PURPOSE

A small proportion of patients with chronic idiopathic constipation are incapacitated by the problem. We have assessed 1) the efficacy of total abdominal colectomy, and 2) the predictive value of preoperative testing.

METHODS

Preoperative testing included complete history and physical examination, appropriate biochemical and hematologic assessment, psychiatric interview, colon transit studies using ingested radiopaque pellets, anorectal manometry, colonic intraluminal manometry, and measurement of colon diameters and length on barium enema examination. All patients were followed for 65 +/- 40 months.

RESULTS

Seventy-one percent had excellent or very good results. Twenty-one percent were satisfied, had improved the quality of their life, and felt the operation was worthwhile despite frequent residual or new symptoms. Two (8 percent) patients did not improve. Patients with a psychiatric history or physiologic evidence of an afferent nerve defect had poorer results (P < 0.05).

CONCLUSIONS

Total abdominal colectomy with ileorectal anastomosis is highly effective in alleviating symptoms in patients with chronic idiopathic constipation.

Treatment of intractable constipation in children: experience with cisapride

To establish whether cisapride is beneficial in children with intractable constipation, an open trial was performed. Chronically constipated children who had failed at least 12 weeks of medical therapy received cisapride at a dose of 0.2 mg/kg/dose TID for 12 weeks. Children with pelvic floor dyssynergia were excluded. Patients were followed prospectively for at least 12 months. Thirty children were initially enrolled, and 27 (14 boys, 13 girls) completed the study. At the end of 12 weeks of cisapride treatment, there was a significant increase in the number of bowel movements per week (1.43 +/- 0.52 to 6.48 +/- 4.16; p < 0.05) and significant decreases in the number of accidents per day (2.86 +/- 2.71 to 0.52 +/- 1.23; p < 0.05) and doses of laxatives used per week (14.33 +/- 5.84 to 3.37 +/- 7.10; p < 0.05). Encopresis disappeared in 65.2% of cases (p < 0.0001) and improved in 26%. Sixty-nine percent of the patients stopped using laxatives (p < 0.001). After 12 weeks 18 patients (66.6%) were asymptomatic, seven (25.9%) showed some improvement in bowel movement frequency and number of accidents, and two (7.4%) showed no improvement. The cisapride was well tolerated. After long-term follow-up (20 +/- 9.8 months), 37% of patients had recovered (asymptomatic and off laxatives and cisapride) and 29.6% were still asymptomatic but were using laxatives or cisapride. There were no differences in baseline characteristics between recovered and nonrecovered patients. We conclude that cisapride is effective in the treatment of some children with intractable constipation without pelvic floor dyssynergia.

Defecography. Results of investigations in 2,816 patients

PURPOSE

This study was designed to analyze the frequency of different findings at defecography in patients with defecation disorders and see in what way the evaluation could be improved.

METHODS

The reports of investigations in 2,816 patients were analyzed.

RESULTS

Twenty-three percent of the investigations were considered normal. Thirty-one percent of the patients had rectal intussusception, 13 percent had rectal prolapse, 27 percent had rectocele, and 19 percent had enterocele. Twenty-one percent of the patients had a combination of two or three of these diagnoses. The combination of rectocele and enterocele was rare. The majority of patients with enterocele had other concomitant findings. Patients with or without abnormal perineal descent had similar frequencies of rectal prolapse, rectal intussusception, and enterocele. Rectocele was more common in patients with abnormal perineal descent.

CONCLUSIONS

Defecography is valuable when investigating patients with defecation disorders. Pathologic findings were found in 77 percent of the patients. A standardized protocol should ensure a complete evaluation of defecography.

Antegrade enemas for the treatment of severe idiopathic constipation

The technique of appendicocaecostomy produces a continent catheterizable channel through which colonic washouts are given. This procedure was performed on six women of mean age 33.5 years with severe idiopathic constipation (mean stool frequency less than 1 per week) resistant to medical therapy. All patients had prolonged colonic transit times, three had evidence of obstructed defaecation and all had reduced or absent voluntary anal squeeze pressure. Patients found the appendicocaecostomy and catheterization acceptable, and symptoms of abdominal distension and pain resolved. All patients were able to initiate defaecation and evacuate the colon within 1 h of irrigation, and no patient had appreciable incontinence. Irrigation was necessary every 48-72 h. Adults with intractable constipation and pelvic floor weakness would be at risk of faecal incontinence after ileorectal anastomosis; it is in these patients that appendicocaecostomy has potential for the greatest benefit.

Abdominal rectopexy for rectal prolapse. Influence of surgical technique on functional outcome

PURPOSE

The aim of this study was to investigate the influence of surgical technique on functional and manovolumetric results in patients treated with Marlex mesh abdominal rectopexy.

METHODS

The lateral ligaments were completely divided (the Wells procedure) in 16 patients and preserved (the Ripstein procedure) in 16 patients. Clinical and physiologic assessment were performed before and at 3, 6, and 12 months after operation.

RESULTS

Improvement of continence was similar. Bowel regulation problems which were unchanged after the Ripstein procedure increased significantly after the Wells procedure (P < 0.01). Rectal volume became reduced in the group who received the Wells procedure (225 ml vs. 115 ml, P < 0.05 at one year), but remained unchanged after receiving the Ripstein procedure. The pressure thresholds required to elicit sensation of rectal filling and defecation urge were increased after the Wells procedure (15 cm of H2O vs. 25 cm of H2O, P < 0.05 and 25 cm of H2O vs. 45 cm of H2O, P < 0.05, respectively). In the Ripstein group there was only a slight increase of the threshold for urge (P < 0.05).

CONCLUSION

The Wells procedure was followed by severe rectal dysfunction accompanied by increased constipation and evacuation problems. The Ripstein procedure, preserving the lateral ligaments, appears not to affect such symptoms adversely. On the other hand, improvement is not likely to occur.

The trigger for rectal filling sensation

In order to evaluate whether rectal volume, weight or pressure is the main trigger for rectal sensation, their respective values were determined at each of the rectal filling sensation thresholds (first, constant, urge, maximum) in 12 adult control subjects. The rectal balloon was filled at 60 ml/min in sitting position using water (twice), air and mercury consecutively. Pressure values were corrected for the elastic properties of the balloon, while the volume of inflated air was recalculated taking into account the prevalent rectal pressure and temperature. The results obtained using water, air and mercury demonstrated a constant relationship between a given rectal sensation level and the pressure recorded in the distending balloon, but not its volume or weight. Pressure values recorded at each sensation level were constant during repeated determinations of rectal sensation, the volume of rectal distension increased, probably because the rectum had already been dilated by previous testing. Balloon distension using air with the patient in the lateral position were found to be most practical for routine evaluation of rectal sensation. It is therefore concluded that any disturbance of rectal sensation will be reflected by changes in pressure and not by changes in the volume needed to produce a given sensation level. The location of the receptors involved has to be elucidated, but it seems that the pelvic floor can be excluded since the weight of the rectal contents was not related to sensation.

Anorectal function

A review in a historic perspective of the present knowledge of anorectal physiology is presented. The techniques used in the anorectal physiology laboratory are discussed. Application of new sophisticated techniques to anorectal physiology research in recent years continue to improve our knowledge of anorectal function. Anal continence and defecation depend on both the anal sphincter and the rectum. The assessment of patients with functional anorectal diseases should include a more complete physiologic evaluation of the anorectum than used previously.

Surgery for severe constipation: the use of radioisotope transit scan and barium evacuation proctography in patient selection

Nineteen women aged 19-64 years (median 38) with intractable constipation were assessed by Indium-111 DTPA colonic transit scan and barium evacuation proctogram. Patients were classified as having an isolated (I) or predominant disorder of colonic transit (II), a mixed disorder of colonic transit and rectal evacuation (III), a predominant disorder of rectal evacuation (IV) or normal colorectal emptying (V). Twelve patients fell into categories I and II and were considered suitable for surgery. Three responded to further vigorous aperient therapy and nine (32-55 years, median 38) underwent subtotal colectomy with ileorectal anastomosis at the level of the sacral promontory. Two patients required re-operation for suspected anastomotic leak. One patient required readmission on two occasions for small bowel obstruction. Follow up has been 2-21 months (median 16). Eight of the nine patients no longer take oral aperients. Eight patients have a satisfactory stool frequency of 2-8 per 24 h; the other patient has an ileostomy and incapacitating postprandial abdominal pain. Abdominal pain is troublesome in two other patients. Two patients require antidiarrhoeal therapy but none experience faecal incontinence. In severely constipated patients with a proven disorder of colonic transit but normal or near normal rectal evacuation subtotal colectomy provides excellent symptomatic relief.

Review article: the management of constipation in adults

The successful management of constipation depends on defining the patient's symptoms, excluding secondary causes, and characterizing the abnormality of defecation. Constipation without gut dilatation is found commonly in pregnancy, the elderly, and those with the irritable bowel syndrome. In addition, there is a group of patients that has intractable, severe idiopathic constipation. Some have 'slow transit' and open their bowels every 1-4 weeks. Others have a defecatory disorder with normal colonic transit. Constipation with gut dilatation is seen in Hirschsprung's disease, idiopathic megarectum and megacolon, chronic intestinal pseudo-obstruction and Chagas' disease. Constipation can also result from disturbance to the autonomic outflow of the gastrointestinal tract, and colonic function may be also affected by psychological factors. This review article discusses the presentation, investigation and management of patients with constipation.

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 sphincter 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 H2O (95 percent confidence limits, 1-9 ml/cm H2O). 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.

Defecographic findings in patients with anal incontinence and constipation and their relation to rectal emptying

PURPOSE

The aim of this study was to examine defecographic findings in patients with anal incontinence and constipation and to compare these findings with rectal emptying.

METHODS

One hundred seventy-five preoperative defecographies documented on videotape in patients with either anal incontinence or constipation were retrospectively reviewed. The examinations were evaluated with respect to anatomic abnormalities of the rectum or anal canal. The results were compared with a semi-quantitative assessment of rectal emptying as it appeared on the video sequence after one minute of strain.

RESULTS

Anatomic abnormalities were found equally in incontinent and constipated patients, except for failure to open the anal canal, which was found only in constipated patients. Rectal intussusception was the most frequent finding. Abnormal defecograms were found in both sexes. Enteroceles, sigmoidoceles, and large rectoceles were found only in women. The presence of intussusception, lacking relaxation of the puborectalis muscle, and rectocele did not correlate with poor rectal emptying. Poor rectal emptying was also found in 19 of 58 patients with normal defecograms.

CONCLUSIONS

Anatomic abnormalities of the rectum may be demonstrated independently of the clinical symptoms and are not always correlated to impaired rectal emptying. Since they may also be found in healthy controls, surgical correction of these abnormalities should be considered only with great caution.

Function of the human colon

Despite the volume of research on human colonic dysfunction, little is known about colonic function in health. This has stemmed partly from the difficulty in obtaining access to the organ. Two approaches have been used: studies on patients with stomas, and intestinal intubation techniques. The colonoscope has also recently been used to gain access. All these methods have limitations and results must be interpreted with caution. The accepted roles of the colon include the conservation of water and electrolytes and the controlled evacuation of faeces. Recent research has demonstrated its importance as a metabolic organ with an influence on overall metabolism, an effect that may in large part be attributed to the activity of colonic microflora. Evidence demonstrating that the defunctioned colon behaves differently from the functioning colon in the same individual has implications for a proper understanding of the organ, as practically all previous in vivo studies have been conducted in cleansed or defunctioned human colon.

Balloon expulsion test facilitates diagnosis of pelvic floor outlet obstruction due to nonrelaxing puborectalis muscle

We compared balloon expulsion, defecography, colonic transit times, anal manometry, and electromyography in 21 patients with severe constipation. Defecography demonstrated nonrelaxation of the sphincter during straining in all patients. Only 12 patients were unable to expel a balloon. Colonic transit was normal (five) or showed rectosigmoid delay (seven). All 12 patients were offered biofeedback. The nine patients able to expel a balloon had normal colonic transit (six) or colonic inertia (two). Rectosigmoid delay was due to severe intussusception in one patient. Anal manometry and pudendal nerve latencies revealed no difference between those who could and those who could not expel a balloon. Balloon expulsion seems to be a more reliable way to diagnose pelvic floor outlet obstruction due to nonrelaxation of the puborectalis muscle. Nonrelaxation of the sphincter on defecography should be correlated with balloon expulsion and colonic transit studies.

Testing for and the role of anal and rectal sensation

The rectum is insensitive to stimuli capable of causing pain and other sensations when applied to a somatic cutaneous surface. It is, however, sensitive to distension by an experimental balloon introduced through the anus, though it is not known whether it is the stretching or reflex contraction of the gut wall, or the distortion of the mesentery and adjacent structures which induces the sensation. No specific sensory receptors are seen on careful histological examination of the rectum in humans. However, myelinated and non-myelinated nerve fibres are seen adjacent to the rectal mucosa, but no intraepithelial fibres arise from these. The sensation of rectal distension travels with the parasympathetic system to S2, S3 and S4. The two main methods for quantifying rectal sensation are rectal balloon distension and mucosal electrosensitivity. The balloon is progressively distended until particular sensations are perceived by the patient. The volumes at which these sensations are perceived are recorded. Three sensory thresholds are usually defined: constant sensation of fullness, urge to defecate, and maximum tolerated volume. The modalities of anal sensation can be precisely defined. Touch, pain and temperature sensation exist in normal subjects. There is profuse innervation of the anal canal with a variety of specialized sensory nerve endings: Meissner's corpuscles which record touch sensation, Krause end-bulbs which respond to thermal stimuli, Golgi-Mazzoni bodies and pacinian corpuscles which respond to changes in tension and pressure, and genital corpuscles which respond to friction. In addition, there are large diameter free nerve endings within the epithelium. The nerve pathway for anal canal sensation is via the inferior haemorrhoidal branches of the pudendal nerve to the sacral roots of S2, S3 and S4. Anal sensation may be quantitatively measured in response to electrical stimulation. The technique involves the use of a specialized constant current generator and bipolar electrode probe inserted in the anal canal. The equipment is generally available and the technique has been shown to be an accurate and repeatable quantitative test of anal sensation.

The surgical management of constipation

The anal physiology laboratory plays a very important role in the selection of patients for surgical treatment for constipation. Any report which does not include reference to these methods of evaluation will not be helpful since there are several causes of constipation. The current recommended treatment for slow transit constipation is still total abdominal colectomy with ileorectal anastomosis. Treatment of pelvic floor outlet obstruction seems to be best accomplished using muscle/sensory retraining techniques since this is a functional disorder rather than an anatomical or physiological disorder. Combinations of colonic inertia, pelvic floor outlet obstruction and internal intussusception should be treated to correct the pelvic floor outlet obstruction initially, followed by correction of the colonic inertia. In this way failure will be avoided at the time of surgical treatment of the constipation.

Outpatient protocol for biofeedback therapy of pelvic floor outlet obstruction

Pelvic floor outlet obstruction is a rare cause of severe constipation. Anal myectomy, subtotal colectomy, and medical therapy have limited success. The purpose of this study was to develop a short outpatient treatment using biofeedback techniques. Nine patients with severe constipation and straining resulting from pelvic floor outlet obstruction underwent complete investigation of the pelvic floor musculature and anal sphincter mechanism. Patients were unable to expel a 60-cc rectal balloon and had nonrelaxing puborectalis on defecography. The treatment protocol utilized anal surface electromyography to document improper straining and retrain pelvic floor muscles to relax during defecation. Sensory retraining with a rectal balloon, behavioral relaxation techniques, and defecation of simulated stool using a 120-cc Metamucil (Procter & Gamble, Cincinnati, OH) slurry in the rectum allowed re-establishment of normal defecation in all nine patients. Repeat training was required in three patients during follow-up. Treatment of pelvic floor outlet obstruction with outpatient retraining techniques is possible.

Colectomy for constipation: physiologic investigation is the key to success

The results of total abdominal colectomy (TAC) with ileorectal anastomosis as a treatment for colonic inertia (CI) were prospectively assessed. One hundred sixty-three patients were evaluated for chronic constipation between July 1988 and November 1990. Patients underwent pancolonic transit times, anorectal manometry, cinedefecography (CD), and electromyography (EMG). CI was defined as diffuse marker delay on transit study without evidence of puborectalis contraction on CD or EMG. Sixteen patients (10 percent; 15 females and 1 male) with a mean age of 45 years (range, 24-75 years) with CI underwent TAC. Preoperative bowel frequency ranged from three per week to one per month; all 16 patients evacuated only with high doses of laxatives, enemas, or both. TAC was performed with no postoperative mortality or major morbidity; three patients were readmitted four times for successful conservative treatment of partial small bowel obstruction. At a mean follow-up of 15 months (range, 2-35 months), these 16 patients reported a mean frequency of spontaneous bowel evacuations of 3.5 per day (range, one to six per day). Patient satisfaction with the operation was "excellent" or "good" in 15 cases (94 percent). Thorough preoperative physiologic evaluation permits the selection of a small group of patients with CI who may benefit tremendously from TAC.

Anismus in patients with normal and slow transit constipation

This study examined differences in anorectal function, with particular reference to anismus, which might explain why some patients with intractable constipation have slow and others have normal whole gut transit times. Twenty-four patients were studied; 13 with slow transit (all female, median age 32 years, range 16-52 years) and 11 with normal transit (eight women, three men, median age 37 years, range 21-60 years). Videoproctography with synchronous sphincteric electromyography and anorectal manometry was performed. There were no differences between the two groups, suggesting that slow transit constipation is not secondary to any abnormality in anorectal function and may therefore be a primary disorder of colonic motility. There was no correlation between electromyographic evidence of anismus (pelvic floor contraction on defaecation) and the ability of the patient to evacute the rectum or symptoms of obstructed defaecation. Electromyography findings alone can be misleading and should be related to proctographic evidence of incomplete rectal evacuation before functional anismus can be said to be present.

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.

Severe, longstanding constipation in adults. Indications for surgical treatment

In recent years new techniques for the investigation of colonic motility and defaecation mechanism have been developed. On the basis of the results of these studies it has been suggested that there might be an indication for a surgical approach to the distressing problem of constipation. Because this approach is still controversial, it seems to be appropriate to review the suggested indications for the use of surgery in the treatment of constipation and to discuss the results as reported in the literature so far.

Streamlining the management of defecation disorders

Obstinate constipation is a frequent but elusive gastrointestinal symptom. Increased understanding of defecation physiology and recent availability of simple, ready-to-use tools have increased specificity of both diagnosis and treatment. This patient series includes over 700 severely constipated patients with over 70 percent overall therapeutic success. Cinedefecography, pelvic floor electromyography, and determination of rectoanal inhibitory reflex were performed with simple and readily available equipment to document outlet anatomy and dynamics. Colonic transit time was examined in patients whose defecography and electromyography results were nondiagnostic and/or whose response to medical management was suboptimal, using a commercially available marker capsule, followed by abdominal x-rays. Retention of markers throughout the colon suggested colonic hypomotility or "inertia"; rectosigmoid retention confirmed functional outlet obstruction. With careful history, physical examination, and exclusion of organic causes, orderly application of readily available techniques can afford rapid, objective, and anatomically specific evidence upon which treatment of disordered defecation may be based.

Chronic constipation in adults. How far should evaluation and treatment go?

In all patients who present with constipation, a history should be taken and physical examination and proctosigmoidoscopy performed. Structural evaluation of the entire colon by barium enema should be considered when constipation is of recent onset, is severe, or does not resolve with simple measures. A colonic transit study should also be considered in the latter two situations. Anorectal manometry, defecography, and electromyography are helpful in patients with diagnosed or suspected outlet delay. Treatment is most often empirical. Simple, helpful measures include education, dietary fiber supplementation, adequate fluid intake, and regular physical activity. When laxatives are necessary, they should be used sparingly. Pelvic floor retraining may be helpful in the management of patients with outlet delay. Select patients with intractable constipation may benefit from surgery, although results are variable.

Rectocele repair. Four years' experience

A retrospective review of 64 rectocele repairs done over a four-year period was performed. The most common indication for repair was constipation. Thirty-five patients were repaired transanally, and 29 were repaired transvaginally. The overall morbidity was 34 percent, and the overall mortality was 0 percent. The most common complication was urinary retention in 12.5 percent. There was no difference in complications between techniques. Of 46 patients contacted for follow-up, 25 (54 percent) still complained of constipation, 17 (34 percent) had partial incontinence, 8 (17 percent) noted persistent rectal pain, 15 (32 percent) mentioned occasional rectal bleeding, and 10 (22 percent) complained of vaginal tightness or sexual dysfunction. Thirty-seven (80 percent) patients stated that they had improved after surgery. Except for persistent rectal pain, there was no difference in results between transanal and transvaginal repairs. Those undergoing transvaginal repair had a much greater problem with pain. Our relatively poor results may be due to an unselective approach to rectocele repair. The presence of both constipation and a rectocele does not imply an association, and a complete anorectal physiologic examination should precede repair. There is no functional difference between transvaginal and transanal rectocele repair.

Improvement of anal sensation with preservation of the anal transition zone after ileoanal anastomosis for ulcerative colitis

One of the most important considerations in restorative proctocolectomy for ulcerative colitis is postoperative continence. Preservation of the anal transition zone has been associated with improved results after this procedure in the pediatric age group. This study was carried out to determine the effect of preservation of the amal transition zone in adult patients undergoing restorative proctocolectomy, comparing a group of patients with the anal transition zone preserved with a group of patients with the anal transition zone removed. Physiologic testing demonstrated improved sensation in those patients with a preserved anal transition zone. Functional results were not significantly improved, although there was a trend toward improved continence and discrimination in those with the anal transition zone preserved. Although the results are early and are not conclusive from the clinical standpoint, they are certainly encouraging and may justify continued use of this technique.

Defecography in patients with anorectal disorders. Which findings are clinically relevant?

To evaluate the results and clinical impact of defecography in patients with anorectal disorders, 100 results of defecographic examinations from 92 patients were reviewed. The defecographic results were screened for the anorectal angle, defined both at rest and during straining, perineal descent, and abnormalities of the rectal configuration during straining. Anal manometry, saline infusion test, rectal capacity measurement, and anal electromyography (EMG) were also performed. There was a significant difference (P less than 0.001) both at rest (22 degrees) and during straining (12 degrees) between the two anorectal angle measurements. Incontinent patients had a larger anorectal angle, both at rest and during straining, than continent patients (P less than 0.04), but with a large overlap. The anorectal angle was not influenced by gender or age. An abnormal rectal configuration was found in 62 defecographic examinations. From the 8 patients with rectopexy performed for a large rectocele or intussusception, incontinent patients with an intussusception had the best results. In four patients, anal EMG showed an increased activity of the external sphincter during straining. Two of these four patients had abnormal defecograhic results. No correlations were found between anorectal angle and the other function tests. In conclusion, the anorectal angle lacks clinical relevance. In patients with defecation problems, defecography may be indicated whenever other investigations (physical examination, anal manometry, anal EMG) have excluded local pathology or a spastic pelvic floor syndrome. In these situations, defecography could detect an intussusception, which could easily be treated with rectopexy.

Rectal compliance: a critical reappraisal

Compliance is a widely measured parameter of rectal function. Its value is determined clinically by recording pressure changes associated with volume infusion into a rectal balloon. This paper examines the inherent assumptions of the rectal balloon technique and discusses several of its shortcomings. A stricter definition of rectal compliance is needed, and in vivo compliance should be correlated with the directly measured mechanical properties of the rectal wall.

Application of the colorectal laboratory in diagnosis and treatment of functional constipation

Defecography, pelvic floor electromyography, and segmental colonic transit times were performed in 74 patients with functional constipation. Signs of functional outlet obstruction occurred in 74 percent. Transit times were normal in 33 percent. Measurement of colonic transit time in patients with disordered evacuation studies is useless from a clinical point of view, because abnormal segmental transit time is the result of outlet obstruction in most cases and will return to normal after adequate treatment. Only when evacuation studies are normal, or have become normal after treatment and constipation persists, are segmental transit studies indicated because they may demonstrate primary slow transit constipation. Primary slow transit constipation probably is caused by impaired motility of the whole gastrointestinal tract. As small-bowel transit time increases, defecation frequency decreases, laxatives are taken again, and abdominal pain persists. Surgery should be performed with restraint.

Clinical indications for anorectal function investigations

Interest in anorectal function investigation tests has increased, and new investigation techniques have been introduced, gaining new insight in the pathogenesis of fecal incontinence and constipation. Normal values in anorectal function tests have shown a large overlap between controls and patients with fecal incontinence or constipation. Therefore, the pure clinical indications for the individual anorectal function tests are small, and the strength comes from combining these test results. When the patient is not eligible for surgery or biofeedback, there is no indication to perform anorectal function tests. Guidelines for selective use of anorectal function tests are given. In patients with fecal incontinence, the clinical consequence of demonstrating severe pudendal neuropathy is not yet clear. Defecography is important to demonstrate an intussusception as a treatable cause of incontinence. In patients with constipation an anal EMG (of defecography) can diagnose the spastic pelvic floor syndrome, which should be treated with relaxation exercises or biofeedback. Patients with other anorectal diseases, patients receiving a stoma, and patients considered for reanastomosis operation after (partial) colectomy may benefit from anorectal function tests.

Rectal reservoir and sensory function studied by graded isobaric distension in normal man

The rectal expansion and concomitant sensory function on graded, isobaric, rectal distension within the interval 5-60 cm H2O was investigated in 36 healthy young volunteers. Anal pressure and electromyography (EMG) from the external anal sphincter were simultaneously recorded. Rectal distension caused an initial rapid expansion followed by transient, often repeated, reflex rectal contractions and a slow gradual increase of rectal volume. The maximal volume displaced by the first reflex rectal contraction was 18 (13) ml, which was less than 10% of the volume at 60 s. The pressure threshold for appreciation of rectal filling was 12 cm H2O (95% CL 5-15 cm H2O) and coincided with the threshold for rectoanal inhibition. Urge to defecate was experienced at 28 cm H2O (15-50 cm H2O) distension pressure, which was close to the threshold for maximal rectal contraction, also coinciding with the appearance of the external anal sphincter reflex. The interindividual variation of rectal volume on distension with defined pressures varied widely, indicating a considerable variation of rectal compliance in normal man. No correlation was found between rectal volume and sex or anthropometric variables. The relative variations in pressure thresholds for eliciting rectal sensation and rectoanal reflexes were less than the corresponding threshold volumes. It was concluded that the dynamic rectal response to distension reflects a well graded reflex adjustment ideal for a reservoir.

Neurophysiological dysfunction in young women with intractable constipation

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

The functional results after colectomy and ileorectal anastomosis for severe constipation (Arbuthnot Lane's disease) as related to rectal sensory function

Rectoanal manovolumetry during graded isobaric rectal distension was carried out in 12 women with severe constipation classified as slow transit constipation (Arbuthnot Lane's disease). The resting anal sphincter pressure, the rectoanal inhibitory reflex and the rectal capacity were all normal. While the distension volumes required to elicit sensation of rectal filling and an urge to defaecate were within normal limits in all patients the distension pressures required to elicit such sensations fell outside the 95% limits of variation of control subjects in 4 patients. All patients were subsequently subjected to colectomy and ileorectal anastomosis. Patients with normal rectal sensory function had a satisfactory functional result after colectomy, whereas the four patients with blunted sensation did not improve. These findings suggest that rectoanal manovolumetry with determination of the distension pressures required to elicit rectal sensation is an important preoperative measure to be used in patients with severe constipation for selection of patients suitable for colectomy and ileorectal anastomosis.