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Combined radiologic and manometric study of rectal filling sensation.

PURPOSE: Sensation is an essential aspect of fecal continence. We aimed to correlate manovolumetric and radiologic changes at successive levels of rectal filling sensation. METHODS: Combined anorectal manometry and proctography were performed in nine volunteers. Images, volumes, and pressures were analyzed at the start of the test, at 20 seconds before first sensation, and at first, constant, urge, and maximum tolerable sensation. RESULTS: Consecutive levels of rectal filling sensation were associated with progressive opening and dilation of the upper anal canal (up to 44 mm) and sliding down of the rectal contents (14 mm), which had already started before the first sensation. This coincided initially with a pressure decrease in the proximal anal canal (from 94 to 42 mmHg). With constant sensation and particularly with urge sensation, rectal pressure increase appeared to be responsible for further proximal anal dilation. This was accompanied by a significant increase of proximal anal pressure (up to 133 mmHg) and sharpening of the angle between the anal axis and the horizontal reference line. CONCLUSION: The proximal anal canal or its surrounding structures play an important role in the desire-to-defecate sensation. They can be activated by a progressive buildup of rectal reservoir pressure in the presence of a competent distal anal sphincter barrier.

Adult↗

Evaluation of preoperative and postoperative radiotherapy on long-term functional results of straight coloanal anastomosis.

PURPOSE: Preoperative radiotherapy for rectal cancer avoids radiation to the reconstructed rectum and may circumvent the detrimental effects on bowel function associated with postoperative radiotherapy. We compared the long-term functional results of patients who received preoperative radiotherapy, postoperative radiotherapy, or no radiotherapy in conjunction with low anterior resection and coloanal anastomosis to assess the impact of pelvic radiation on anorectal function. METHODS: One hundred nine patients treated by low anterior resection and straight coloanal anastomosis for rectal cancer between 1986 and 1997 were assessed with a standardized questionnaire at two to eight years after resection. All radiotherapy was given to a total dose of 4,500 to 5,400 cGy with conventional doses and techniques. Most patients received concurrent 5-fluorouracil-based chemotherapy. RESULTS: There were 39 patients in the preoperative radiotherapy group, 11 patients in the postoperative radiotherapy group, and 59 patients in the no radiotherapy group. The postoperative radiotherapy group reported a significantly greater number of bowel movements per 24-hour period (P < 0.01) and significantly more episodes of clustered bowel movements (P < 0.02) than either the preoperative radiotherapy group or the no radiotherapy group. No significant difference in anal continence or satisfaction with bowel function was found among the three groups. CONCLUSION: In this study of straight (nonreservoir) coloanal anastomoses, postoperative pelvic radiotherapy had significant adverse effects on anorectal function, with higher rates of clustering and frequency of defecation than with preoperative radiotherapy. No differences in continence rates were demonstrated, perhaps because of the sample size of the compared groups. We attribute the adverse effects of postoperative radiotherapy to irradiation of the neorectum, which is spared when treatment is given preoperatively. The deleterious effects of adjuvant radiation on long-term anorectal function can be reduced by preoperative treatment.

Adult↗

Predictors of response to biofeedback treatment in anal incontinence.

PURPOSE: Biofeedback is considered an effective treatment for anal incontinence, but a substantial proportion of patients fails to improve. The purpose of this study was to identify the key predictors of outcome. METHODS: We retrospectively analyzed the clinical and physiologic data of 145 patients consecutively treated in our unit for anal incontinence by biofeedback. Clinical evaluation was performed by means of a structured questionnaire that included previous history, symptoms of incontinence, and bowel habit. Anorectal evaluation measured anal pressure profiles, neural reflexes, defecatory dynamics, rectal compliance, and rectal sensitivity. Biofeedback treatment was performed by a manometric technique with reinforcement sessions scheduled every three months and daily exercising at home. Six months after the onset of biofeedback treatment the clinical response was evaluated as good (improvement of incontinence) or poor (no improvement or worsening). RESULTS: Of 126 patients (104 female; age range, 17-82 years) with at least six-month follow-up, 84 percent had a good response to treatment. By univariate analysis, several factors, such as age, history of constipation, abnormal defecatory maneuver, and rectal compliance, were significantly related to treatment response, but by multivariate logistic regression only age and defecatory maneuver were independent predictors of the response. The association of both factors provided the best sensitivity and specificity; 48 percent of patients younger than age 55 years and with abnormal defecatory maneuver had negative response to treatment, whereas 96 percent of patients age 55 years or older with normal defecatory maneuver had a positive response. CONCLUSION: In patients with anal incontinence scheduled for biofeedback treatment, potential alterations of defecation should be first searched for and corrected, particularly in younger patients.

Adolescent↗

Colostomy closure after Hartmann's procedure with fast-track rehabilitation.

PURPOSE: The aim of this study was to assess the effect of postoperative multimodal rehabilitation after colostomy closure after Hartmann's procedure. METHODS: Twenty-seven consecutive patients scheduled for colostomy closure after Hartmann's procedure received continuous postoperative epidural analgesia, laxative, and enforced oral liquids, protein drinks, and mobilization. RESULTS: Defecation occurred at a median 2 days postoperatively. Mean and median postoperative stay was 3 days, with two readmissions (1 anastomotic dehiscence and 1 social) increasing mean total 1-month hospital stay to 4.3 (median, 3) days. No other complications occurred except three superficial wound infections. CONCLUSION: Postoperative hospital stay and morbidity may be reduced with multimodal rehabilitation after open colostomy closure after Hartmann's resection.

Adult↗

A population-based study on bowel habits in a Korean community: prevalence of functional constipation and self-reported constipation.

Most studies of bowel habits have been conducted in Western countries. This study was conducted to estimate the epidemiology of constipation and the discrepancy between self-reported constipation and bowel habits in Koreans. Telephone interviews regarding bowel habits were conducted with a total of 1029 individuals in Korea, 15 years of age or older. Subjects were given a questionnaire which asked about bowel symptoms, sociodemographic associations, laxative use, and physician visits. Of all subjects 95.6% had a defecation frequency of between three per week and three per day. The prevalence was 16.5% for self-reported constipation, 9.2% for functional constipation (FC), and 3.9% for constipation-predominant irritable bowel syndrome (IBS-C). Of subjects' self-reporting constipation, proportions of FC and IBS-C were 21.8% and 23.5%, respectively. Of subjects excluding self-reported constipation, the proportion of FC was 6.8%. Prevalences of self-reported constipation and IBS-C were higher in females than in males (P < 0.001). Of subjects' self-reporting constipation, 8.2% used laxatives. We conclude that constipation is a common problem in the general Korean population.

Adolescent↗

Changes in bowel function: pregnancy and the puerperium.

Pregnancy is a time when women are susceptible to bowel habit perturbations. The purpose of this study was to provide new baseline data for a range of bowel habit parameters. Prospective 7-day bowel habit diaries were completed during each of the three trimesters of pregnancy and after birth. Sensations of incomplete evacuation and time spent defecating were significantly increased during all three trimesters of pregnancy compared with after birth (P < 0.05). Symptoms of urgency were higher in nonlactating mothers (41% of occasions) compared with lactating women (17% pf occasions) (P=0.07). This study has confirmed the importance of investigating a range of bowel habit parameters during and after pregnancy-investigation of constipation per se may obscure changes in individual bowel habit parameters.

Adult↗

Constipation caused by functional outlet obstruction.

Functional constipation is a very common problem in Western societies. Functional outlet obstruction, part of the spectrum of functional constipation, is suspected when patients present with select symptoms. Diagnosis is commonly made with anorectal manometry, electromyography, and rectal evacuation tests. Abnormal test patterns include poor relaxation and contraction of the anal sphincter in response to attempted defecation and difficult rectal evacuation. Several treatment approaches have been tested in these patients. Biofeedback training is considered the most specific therapeutic modality, and it is particularly attractive because of its safety. This review provides an assessment of the diagnostic tests for functional outlet obstruction and summarizes current options for therapy.

Anal Canal↗

Electrical stimulation of the sacral dermatomes in spinal cord injury: effect on rectal manometry and bowel emptying.

The impairment in defecation function that comes as a result of spinal cord injury may have a significant negative impact upon quality of life. Electrical stimulation (ES) of the somatic nervous system has been used to elicit autonomic reflexes in animals, before and after spinal cord transection. To determine whether ES might be used to promote bowel emptying, seven persons with recent spinal cord injury (SCI) and seven control subjects were studied. Electrical stimulation of the second sacral dermatome was applied during rectal manometry in both groups, and ES was added to the bowel programs of SCI patients. A significant rise in the number of rectal pressure spikes was noted in both groups after application of ES (p < .002, f = 6.34). There was no significant differences between the SCI and control groups when measuring the amplitude of spike waves in the colon. No significant change was noted in the time required for SCI patients to initiate a bowel movement, or in the time required to complete bowel emptying. Electrical stimulation of the sacral dermatomes can result in a change in the bowel activity of the recto-sigmoid colon. To date, no clinical effect on bowel emptying has been demonstrated.

Colon↗

An alternative biofeedback-based behavior modification treatment for a case of chronic constipation.

A 31-year old female with chronic constipation was referred for treatment of a paradoxical contraction of the external anal sphincter (EAS) muscle during straining to defecate. The patient was dependent on laxative use and the digital removal of feces. The present program emphasized biofeedback training of the EAS utilizing the inexpensive, noninvasive procedure of disposable surface electrodes placed on the anal verge. Outcome of treatment resulted in an 89% decrease in laxatives used, complete termination of the digital removal of feces, and a notable decrease in EAS tension. The patient was able to maintain these gains at an 8 month follow-up.

Adult↗

Identification by microinjection of TRH-sensitive sites in the cat's brain stem that mediate respiratory, temperature and other autonomic changes.

Cats were prepared with an array of stereotaxically implanted guide tubes, the tips of which rested just above selected structures in the brain stem. Thyrotropin-releasing hormone (TRH) was microinjected in a volume of 0.5 micronl at 347 individual sites scattered throughout the hypothalamus and mesencephalon Polypnea, hypothermia, vocalization, salivation, defecation and vasodilation were evoked by 10-20 ng of TRH injected only at loci in the mesencephalon, principally in the reticular substance. TRH failed to lower body temperature when it was infused at the same sites in the anterior hypothalamus at which norepinephrine produced its characteristic hypothermia. These results suggest that the TRH-induced hypothermia is a secondary effect of tachypnea which results from the action of the tripeptide on the mesencephalic respiratory-autonomic mechanism.

Animals↗

Regulatory changes following kainic acid-induced striatal lesions.

Kainic acid-induced lesions (KAL) of the striatum produce body weight and regulatory deficits in the rat. Unlike lateral hypothalamic rats. KAL rats drink more during food deprivation and eat more afterwards as compared to both baseline conditions and control rats. The present study investigated these effects further. As in previous studies, food deprivation was found to cause polydipsia and increased postdeprivational food intake in the KAL animal. Urination and defecation, often used as an index of emotionality, were also found to increase under these conditions. When the antidiuretic hormone vasopressin was injected, all of these differences remained with the exception of postdeprivational feeding--KAL rats no longer ate more than controls. These findings suggest that psychogenic factors--but not hormonal influences--may play a primary role in the regulatory peculiarities seen in the KAL rat.

Animals↗

Studies on the mechanism of bowel disturbance in ulcerative colitis.

The transit of a radiolabeled meal through the gastrointestinal tract and stool output were measured in 62 patients with ulcerative colitis, subdivided according to the activity and extent of their disease. The results were compared with those from 20 sex-matched normal subjects. Mouth-to-cecum transit was significantly slower than normal in all patient groups although gastric emptying was normal. Whole gut transit was not accelerated in any group of patients. An abdominal x-ray taken 48 h after ingesting the meal showed that patients with active colitis had proximal colonic stasis, whereas transit through the rectosigmoid region was rapid. Stool weights and frequencies were higher in patients with active colitis than in patients with quiescent disease. Patients with active colitis also passed smaller amounts of stool during each bowel movement, suggesting that they experienced a desire to defecate at lower rectal volumes. These results indicate that (a) diarrhea in ulcerative colitis is associated with rectosigmoid irritability rather than rapid transit and (b) caution should be used when treating active colitis with antidiarrheal drugs that could further retard proximal colonic transit.

Colitis, Ulcerative↗

Prolonged ambulant recordings of small bowel motility demonstrate abnormalities in the irritable bowel syndrome.

Continuous 72-h recordings of duodenojejunal contractile activity were obtained from 20 freely ambulant subjects; pressure was detected by two strain-gauge sensors incorporated in a transnasal catheter attached to an encoder and a miniature tape recorder. The subjects were 12 patients with irritable bowel syndrome, 6 of whom were constipation predominant and 6 of whom were diarrhea predominant, and 8 healthy controls. The procedure was well tolerated by all subjects and did not interfere with sleep or normal activity. In all subjects, the diurnal migrating motor complex cycle was characterized by a brief phase 1 and a prolonged phase 2; this was reversed during sleep when phase 2 was virtually absent. All subjects showed a circadian variation in migrating motor complex propagation velocity, and there was no difference in the patterns of motor activity during sleep between any of the groups. During the day, the duration of postprandial motor activity was shorter in irritable bowel syndrome patients than in controls, and diurnal migrating motor complex intervals were shorter in diarrhea-predominant than in constipation-predominant irritable bowel syndrome. In 11 of 12 inflammatory bowel syndrome patients, episodes of clustered contractions recurring at 0.9-min intervals were noted; these episodes had a mean duration of 46 min and were often associated with transient abdominal pain and discomfort. In both groups of irritable bowel syndrome patients, defecation was significantly (p less than 0.01) prolonged with a greater number of voluntary abdominal contractions (p less than 0.01) than in controls. Prolonged ambulant monitoring of proximal bowel motor activity in subjects who are free to move, eat, and sleep as they choose has, for the first time, clearly defined the striking difference in motility between the sleeping and waking state and shown that abnormalities associated with irritable bowel syndrome are confined to the latter.

Adult↗

Sensory and motor responses to rectal distention vary according to rate and pattern of balloon inflation.

Anorectal motor activity and rectal sensation were recorded in 12 normal male subjects during ramp distention of the rectum with water and air at randomized rates of 10, 20, 50, and 100 mL/min and during intermittent rapid distention with air. There were no significant differences between the results of ramp inflation with water or with air, and the repeated infusion of the same medium yielded reproducible results. Ramp distention induced sigmoid pressure-volume profiles. Different sensations occurred at specific points on the pressure-volume curve and were maintained until succeeded by the next sensation. Initial perception of the distention occurred during the initial steep pressure increase, the sensation of wind occurred during the plateau phase, and the desire to defecate occurred at the onset of the final rapid ascent. Rectal sensations were induced at lower volumes at low infusion rates when the slope of the pressure-volume relationship was shallower than at high infusion rates. This suggests that the receptor triggering rectal sensation is not a simple volume or pressure receptor, but is more likely to be a slowly adapting mechanoreceptor lying parallel to the circular muscle of the rectal wall. During rapid intermittent distention, the rectal volumes required to elicit rectal sensations were lower than during ramp distention, although the pressure-volume curve was steeper. Moreover, sensations often only lasted a short period of time but recurred on deflation. These data suggest activation of an additional population of rapidly adapting or high threshold mechanoreceptors. Anal relaxation was always evoked by intermittent rectal distention and was almost always associated with a rectal sensation and an increase in external anal sphincter activity. In contrast, anal relaxation could be absent or delayed during ramp inflation, especially at lower infusion rates, suggesting that internal sphincter can maintain continence for a long period of time while the rectum is slowly filling. Rectal sensation and concomitant external anal sphincter activity was not associated with anal relaxation during ramp inflation; most subjects felt the sensation long after the pressure reached its lowest level. However, under all circumstances the onset of rectal sensation was associated with an increase of external anal sphincter electrical activity. In conclusion, the rectal sensory and anorectal motor responses to distention depend on the rate and pattern of distention, which may activate a different population of receptors. Results from different laboratories cannot be compared directly unless the pattern and rate of distension are the same.

Adult↗

Comparison of triplicated (S) and quadruplicated (W) pelvic ileal reservoirs. Studies on manovolumetry, fecal bacteriology, fecal volatile fatty acids, mucosal morphology, and functional results.

Capacity and compliance, efficiency of evacuation, fecal bacteriology, fecal volatile fatty acids, mucosal morphology, and functional outcome were studied in 20 patients with triplicated (S) and 20 patients with quadruplicated (W) reservoirs after ileal pouch-anal anastomosis. Compared with patients with S reservoirs, patients with W reservoirs were found to have greater efficiency of evacuation of radiolabeled synthetic stool [97% (91%-98%) vs. 74% (62%-89%); P less than 0.05], and their reservoirs were more capacious [350 mL (320-400 mL) vs. 228 mL (175-290 mL); P less than 0.01] and compliant [16.0 mL/cm H2O (13.8-19.0 mL/cm H2O) vs. 12.3 mL/cm H2O (7.4-14.6 mL/cm H2O); P less than 0.01]. Effluent from S reservoirs contained significantly greater numbers of bacteroides (P less than 0.05) and concentrations of acetic and propionic acids (P less than 0.05) than effluent from W reservoirs. The degree of mucosal inflammation and villous atrophy in each design of reservoir was not significantly different. The ratio of anaerobes to aerobes in pouch effluent was significantly correlated with the degree of mucosal inflammation (rs = 0.433; P = 0.035). Fecal volatile fatty acids were significantly correlated with the percentage of stool retained after defecation and degree of mucosal inflammation. The frequency of bowel action was significantly less in patients with W reservoirs than in patients with S reservoirs [3.5/day (3-4/day) vs. 6.0/day (4-7/day); P less than 0.01]. The results indicate marked differences between these two ileal reservoir designs.

Adolescent↗

Continence after posterior sagittal anorectoplasty.

Posterior sagittal anorectoplasty (PSARP) was introduced in 1982 by Peña and De Vries as a new operation for patients with a high anorectal malformation. The degree of postoperative continence is reported to be high. During the past decade, too, new insights have been gained into the embryology of anorectal malformations. Evaluation of PSARP in relation to current understanding of the development and anatomy of the anorectum and the pelvic floor has led us to conclude that optimal continence cannot be expected. Fifty patients with a high anorectal malformation underwent PSARP between June 1983 and May 1990. Postoperative follow-up consisted of anamnesis (subjective) and electrostimulation, defecography, and anorectal manometry (objective). All patients are alive, and all but one are being evaluated regularly. Subjectively, the majority of patients were more or less incontinent, with soiling of pants at least once a day. On the basis of objective criteria, virtually all patients appeared to be incontinent, and in only one patient was the mechanism of defecation almost unimpaired after PSARP. From this study, we conclude that although PSARP provides a good aesthetic result, patients will never acquire normal continence.

Adolescent↗

Transposition of the antropylorus for anal incontinence--an experimental model in the pig.

An experimental model in the pig rendered incontinent of feces was developed to assess the sphincteric activity of the transposed antropylorus. In the control group, normal defecation was studied clinically, radiologically, and manometrically. Nineteen 7- to 10-week-old pigs were rendered incontinent by resection of 20 cm of colon and rectum to below the dentate line. The antropylorus was prepared on its own blood supply and transposed to the anus, initially with a colostomy, which was closed 15 to 21 days later. Clinically these pigs passed semisolid stool in a piecemeal fashion. Contrast defecography showed hold-up at the pylorus, reflux of contrast into the colon, with pyloric contraction independent of antral stimulation. Manometry showed pyloric contraction with rise in antral pressure and independence. The authors conclude that transposition of an antropyloric segment to the anus provides a sphincter-like mechanism and could have application in fecal incontinence.

Animals↗

Neuroendocrine and behavioral effects of m-chlorophenylpiperazine administration in rhesus monkeys.

The effects of m-chlorophenylpiperazine (mCPP), a serotonin receptor agonist, on the release of plasma prolactin (PRL), growth hormone (GH), and cortisol in the rhesus monkey were studied. mCPP was administered intravenously at doses of 0.5, 1.5, and 3.0 mg/kg. GH and cortisol were increased significantly at all doses while PRL was significantly increased only following administration of 3.0 mg/kg mCPP. mCPP administration also produced behavioral alterations in each monkey, including sedation, penile erection, and defecation. PRL, GH and behavioral responses to mCPP were completely blocked by pretreatment with the serotonin antagonist metergoline (MTG). However, pretreatment treatment with MTG failed to entirely anagonize the cortisol response to mCPP. These data suggest that mCPP has prominent neuroendocrine and behavioral effects which are mediated, in part, by serotonergic mechanisms.

Animals↗