SEARCH · PubMed Health

Results for “DEFECATION”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

PubMed2004

Midline rectovaginal fascial plication for repair of rectocele and obstructed defecation.

OBJECTIVE: To estimate the efficacy of midline fascial plication of the posterior vaginal wall in women with rectoceles and obstructed defecation. METHODS: Prospective evaluation of 38 consecutive women with symptomatic rectoceles (stage II or greater) and obstructed defecation included pre- and postoperative standardized pelvic floor questions, pelvic organ prolapse quantification measurements, validated bowel function questionnaires, defecating proctogram, and patient satisfaction. Reviews were conducted by nonsurgical coauthors. RESULTS: The median follow-up was 12.5 months (range 2.5-26 months). The subjective success rates were 97% (95% confidence interval [CI] 0.83-1.00%) at 12 months and 89% (95% CI 0.55-0.98%) at 24 months. The objective success rates were 87% (95% CI 0.64-0.96%) at 12 months and 79% (95% CI 0.51-0.92%) at 24 months. The average points, Ap and Bp, were significantly reduced from -0.1 (range -2 to 3) and 1.1 (range -1 to 8), preoperatively, to -2.6 (range -3 to -1) and -2.5 (range -3 to 0), postoperatively, respectively (P <.001). Depth of rectocele also reduced postoperatively on defecating fluoroscopy (P <.001). The correction of the anatomical defect was associated with improved functional outcome, with 33 women (87%) no longer experiencing obstructed defecation, and there was a significant reduction in postoperative straining to defecate, hard stools, and dyspareunia (P =.001). The improved anatomical and functional outcomes were reflected in the fact that 97% of the women reported very high patient satisfaction. CONCLUSION: Midline fascial plication is effective in correcting anatomical and functional outcomes associated with symptomatic rectoceles and obstructed defecation. LEVEL OF EVIDENCE: III

Adult↗

PubMed1989

Neuroleptic-induced emotional defecation: effects of scopolamine and haloperidol.

Most investigators have found a decrease in emotional defecation in rats given neuroleptics in novel environments, supporting their action as a major tranquilizer. We have found, however, that in rats a profound increase in emotional defecation can result from neuroleptic administration in well habituated environments, such as the homecage. Anticholinergics are known to be effective in treating the side effects associated with neuroleptic administration in humans. Therefore the present study determined the effects of anticholinergic treatment in this animal model. In male rats, defecation was measured for a 1-h test period in their homecage following various doses of the central and peripheral anticholinergics, scopolamine, and n-methylscopolamine, respectively. A decrease in fecal excretions and an attenuation of haloperidol-induced defecation was found following administration of scopolamine. n-Methylscopolamine reduced defecation at all doses. When n-methylscopolamine was combined with haloperidol, both fecal mass and number decreased significantly. Since both anticholinergic agents reduced haloperidol-induced defecation it is suggested that their effectiveness is mediated through peripheral mechanisms.

Animals↗

PubMed2001

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 defecation, the compliance of the rectal wall is normal.

Adolescent↗

PubMed2002

Parasympathetic extrinsic reflex: role in defecation mechanism.

The rectum has an intrinsic nervous mechanism represented by the enteric nervous plexus (ENP) and an extrinsic one mediated by the parasympathetic nerves. Rectal distension evokes the rectoanal inhibitory reflex, which acts through the ENP and is considered the main mechanism responsible for defecation. However, the role of the parasympathetic innervation compared to the role of the intrinsic mechanism of the defecation act has so far not been sufficiently addressed in the literature. The current study investigated this point. Twelve dogs were anesthetized. The anal and rectal pressures were recorded during rectal balloon distension with normal saline in 10 ml increments until the balloon was expelled to the exterior. The test was repeated after ENP block with a (phentolamine) and b (propranolol) adrenoceptor blocking agents and then after rectal denervation by bilateral pelvic ganglionectomy. The rectal balloon was expelled to the exterior at rectal balloon distension with 30 to 40 ml. After separate administration of phentolamine and propranolol, it was dispelled at a distending volume of 50 to 60 ml, and after rectal denervation at a volume of 80 to 90 ml. The results were reproducible. The balloon expulsion test suggests that the intrinsic defecation reflex is weaker than the extrinsic one for inducing defecation, although the two reflexes appear to be complementary. The difference between them in inducing defecation might be significant to our understanding the defecation act in the neurogenic rectum, a point that needs further study.

Adrenergic alpha-Antagonists↗

PubMed2003

Defecation mechanisms after proctocolectomy and ileal pouch--anal anastomosis in dogs.

BACKGROUND AND AIMS: The role of intrinsic pouch motility after ileal pouch-anal anastomosis (IPAA) during defecation is still speculative. MATERIALS AND METHODS: IPAA was performed in 12 dogs. Defecation mechanisms were evaluated by motility recordings during spontaneous defecation and during expulsion of an endoluminal balloon and by radiography with sequential sector-related gray scale analysis. RESULTS: Spontaneous defecations appeared without significant changes in electrical or mechanical activity of the pouch. Sequential filling of the pouch led to defecation in only seven dogs while the others did not succeed in emptying their pouch even with maximal balloon inflation. Neither strain gauge measurements nor electromyography demonstrated peristaltic contractions of the pouch during defecation while sector-related gray scale analysis revealed strong contractions of the abdominal wall during pouch emptying. CONCLUSION: Pouch emptying is independent of intrinsic pouch motility. The ileoanal pouch acts as a functionally passive reservoir, and its evacuation is initiated by a rise of the intra-abdominal pressure.

Anal Canal↗

PubMed2000

Rectal tone in response to bisacodyl in women with obstructed defecation.

This study investigated the tonic response of the rectum to topical application of bisacodyl in women with obstructed defecation. Forty-five women with obstructed defecation, and 15 female controls were studied. Total colonic transit time was normal in 35 patients, and prolonged in 10. For the purpose of this study an "infinitely compliant" polyethylene bag was inserted into the rectum. Rectal tone was assessed by measuring variations in bag volume with a computerized electromechanical "barostat" system. After an adaptation period of 30 min, a suppository containing 10 mg bisacodyl was inserted into the rectum. Recording was continued for 90 min. In a second recording session rectal tone in response to an evoked urge to defecate was assessed. In a third session we investigated rectal sensory perception. After a mean time interval of 30 +/- 15 min following intrarectal application of bisacodyl, all controls showed a significant increase in rectal tone (mean value: 68.2 +/- 12%). In patients with a normal transit time, a similar increase was observed. In patients with prolonged transit time, the tonic response of the rectum to bisacodyl was significantly lower (mean 21.1 +/- 11%; P < 0.001). Five of these patients showed no response at all. In the second recording session, all controls showed an increase in rectal tone during an evoked urge to defecate (mean 36.3 +/- 7%). In both patient groups this tonic response was absent or significantly blunted (mean 19.2 +/- 6%) (P < 0.001). In both patient groups rectal sensory perception was impaired significantly. In conclusion, rectal tone increases significantly after topical application of bisacodyl in controls as well as in patients with obstructed defecation in whom transit time is normal. This tonic response is absent or significantly blunted in patients with a prolonged transit time. Both the tonic response of the rectum to an evoked urge to defecate and rectal sensory perception are significantly impaired in patients with a normal and those with a prolonged transit time.

Adolescent↗

PubMed1980

Effects of 5-hydroxytryptamine on defecation in open-field behavior in rats.

An attempt was made to elucidate the role of the serotonergic nervous sytem in defecation resulting from environmental stimulation in rats. The open-field (OF) test and shuttle box method were used to study the defecation. 5-Hydroxytryptophan (5-HTP) significantly decreased the number of fecal boluses excreted in both emotional situations, namely, in both OF and shuttle box. The fecal excretion was significantly reduced compared with the controls after intraventricular injection of 5-hydroxytryptamine (5-HT). Animals pretreated with p-chlorophenylalanine (pCPA) and 5,6-dihydroxytryptamine (5,6-DHT) tended to show a slight increase in the OF defecation. 5-HTP was equally effective in diminishing the OF performance of pCPA-treated rats. The inhibitory effects of 5-HTP on the defecation were also observed after depletion of biogenic amines by reserpine treatment. Home cage defecation was increased after 5-HTP administration, decreased under pretreatment with pCPA and not influenced by intraventricular injection of 5-HTP. These results suggested that the defecation after environmental stimuli was due to a change in 5-HT levels in the brain.

5,6-Dihydroxytryptamine↗

PubMed1987

Studies of thyrotropin-releasing hormone (TRH)-induced defecation in cats.

In unanesthetized cats, defecation produced by thyrotropin-releasing hormone (TRH) was investigated after its injection into the cerebral ventricle (ICV) through chronically implanted cannulae. TRH injected in doses from 0.1 to 1.0 mg into the cerebral ventricle evoked defecation which was not dose-dependent. The antimuscarinic drug, atropine, the ganglionic blocker, mecamylamine, the alpha and beta adrenergic blocking agents, yohimbine and propranolol, the dopamine antagonist, chlorpromazine, the 5-hydroxytryptamine antagonist, methysergide, and the antihistamine, antazoline, all injected into the cerebral ventricle had virtually no effect on the defecation evoked by TRH injected similarly. In cats pretreated with ICV reserpine, 5,6-dihydroxytryptamine and hemicholinium-3, the defecation induced by ICV TRH was not significantly changed. On the other hand, in cats pretreated with ICV 6-hydroxydopamine, the defecation caused by ICV TRH was potentiated. Therefore, it is concluded that TRH-induced defecation could not be related to central catecholaminergic, 5-hydroxytryptaminergic and cholinergic receptors, but rather to central TRH sites in the cat.

Animals↗

PubMed1988

Neural pathways and pharmacological modulation of defecation reflex in rats.

1. A new method was developed for quantitative studies on defecation reflex in urethane-anesthetized rats which involves the continuous infusion of saline (0.1 ml/min) to distend a balloon placed in the rectum. At threshold values, the balloon was expelled during an active rectal contraction. 2. Balloon expulsion was greatly delayed or even abolished by i.v. hexamethonium. Cord transection at the upper cervical level increased defecation threshold but a functional, hexamethonium-sensitive response was still elicited in spinal rats. 3. Various parameters of the defecation response were modulated by drugs (phentolamine, picrotoxin, naloxone) expected to interfere (either centrally or peripherally), with neural pathways controlling the autonomic outflow for the reflex response. 4. In capsaicin-pretreated rats (50 mg/kg s.c. on 2nd day of life, experiments performed at 2 months), daily fecal production was unchanged as compared to vehicle-treated, age-matched controls. However, under urethane-anesthesia, defecation threshold was increased at higher-than-normal values by capsaicin-pretreatment. 5. In in vitro experiments, capsaicin (1 microM) induced a transient inhibition of field stimulation-induced contractions of the rat isolated rectum. This effect was mimicked by application of calcitonin gene-related peptide (CGRP) (0.1 microM) while Substance P (0.1 microM) had an opposite effect. In preparations desensitized to exogenous CGRP, the inhibitory effect of capsaicin was almost abolished. 6. These findings indicate that in rats, reflex defecation is mainly organized at spinal level, although the participation of supraspinal centers may modify the functional response. Capsaicin-sensitive afferents may be involved in the initiation of certain forms of reflex defecation, although capsaicin-resistant mechanisms are capable of activating the normal excretory function.

Animals↗

PubMed2000

Increased defecation during stress or after 5-hydroxytryptophan: selective inhibition by the 5-HT(4) receptor antagonist, SB-207266.

5-HT(4) receptor antagonism prevents the ability of exogenous 5-HT or 5-HTP to sensitize the intestinal peristaltic reflex and increase the rate of defecation, generally without affecting non-stimulated intestinal function. In this study we confirmed the ability of the selective 5-HT(4) receptor antagonist SB-207266 1 - 1000 microg kg(-1) p.o., to prevent the increase in defecation evoked over a 60 min period by 5-HTP 10 mg kg(-1) s.c. in conscious mice, in the absence of an apparent constipating action. The role of endogenous 5-HT in the mechanisms of increased defecation and/or diarrhoea was then investigated in conscious, fed rats. This was evoked by 180 min exposure to restraint stress, which increased both the number and mean weight of formed, faecal pellets excreted over the entire time period. SB-207266 1 - 1000 microg kg(-1) p.o. (dosed 30 min before restraint) did not affect the increase in defecation evoked during the first 60 min of restraint stress, but significantly and dose-dependently reduced or prevented the increased defecation during the remaining 120 min of the experiment; this action occurred in the absence of an apparent constipating action of SB-207266. In fasted rats exposed to restraint stress, watery diarrhoea developed and although there was a tendency for SB-207266 1 - 1000 microg kg(-1) p.o. (dosed 30 min before restraint) to reduce the incidence of diarrhoea, this inhibition was not complete. We conclude that selective 5-HT(4) receptor antagonism prevents disruptions in defecation behaviours caused by exogenous or endogenous enteric 5-HT and that this activity is not accompanied by a concomitant suppression of activity (constipation-like) within the intestine itself.

5-Hydroxytryptophan↗

PubMed1990

Genetic analysis of defecation in Caenorhabditis elegans.

Defecation in the nematode Caenorhabditis elegans is achieved by a cyclical stereotyped motor program. The first step in each cycle is contraction of a set of posterior body muscles (pBoc), followed by contraction of a set of anterior body muscles (aBoc), and finally contraction of specialized anal muscles that open the anus and expel intestinal contents (Exp). By testing existing behavioral mutants and screening for new mutants that become constipated due to defects in defecation, I have identified 18 genes that are involved in defecation. Mutations in 16 of these genes affect specific parts of the motor program: mutations in two genes specifically affect the pBoc step; mutations in four genes affect the aBoc step; mutations in four genes affect the Exp step; and mutations in six genes affect both aBoc and Exp. Mutations in two other genes affect the defecation cycle period but have a normal motor program. Sensory inputs that regulate the cycle timing in the wild type are also described. On the basis of the phenotypes of the defecation mutants and of double mutants, I suggest a formal genetic pathway for the control of the defecation motor program.

Animals↗

PubMed2000

Mono- and biphasic plasma concentration-time curves of mesalazine from a 500 mg suppository in healthy male volunteers controlled by the time of defecation before dosing.

This study was based on data from a bioequivalence study (n=24) of two different formulations of suppositories containing 500 mg mesalazine (formulation I and II), with a similar dissolution profile in phosphate buffer pH 6.8. There was a large intra- and intersubject variability in the plasma concentration-time curves of mesalazine from both suppositories. The aim of the investigation was to identify the parameters that caused the observed large variations in release and absorption of mesalazine in the rectum. Plasma mesalazine and acetylmesalazine, and urine acetylmesalazine concentrations were determined according to validated methods involving HPLC analysis with coulometric detection. Lower limit of quantitation values were respectively 10.4 and 19.4 ng mL(-1) in plasma and 0.96 microg mL(-1) in urine. The time of defecation before and after insertion was recorded. There was a clear distinction between subjects who showed monophasic mesalazine release/absorption and those who showed biphasic and more extended release/absorption. With formulation I there was a correlation between time of defecation before dosing and the type of absorption, monophasic and biphasic absorbers showed a significant difference in the time of defecation, e.g. 9.7+/-5.6 h vs 18.8+/-11.9 h (P = 0.0218). The impact of time of defecation before dosing was non-significant with formulation II, 16.7+/-7.2 h vs 15.1+/-4.2 h (P = 0.67). The impact of the time elapsed between administration and time of defecation after the insertion of the suppository was not significant for the type of release/absorption. The plasma concentration-time curves of the metabolite ran parallel to that of the parent drug, the more parent drug was released/absorbed, the more was acetylated (P = 0.0013) and excreted into the urine (P = 0.0004). After absorption the compound was metabolized into acetylmesalazine, and renally excreted (12-13% of the dose). Monophasic release/ absorption resulted in 7.1% metabolite with I and 10.3% with II (P = 0.0004), while biphasic release/absorption gave 16.8% metabolite with I and 15.5% with II. The renal clearance of the metabolite acetylmesalazine was independent of the observed defecation patterns (300 mL min(-1), P > 0.8), stool composition, and type of absorption.

Absorption↗

PubMed1991

Acute pulmonary embolism triggered by the act of defecation.

Pulmonary embolism associated with the act of defecation has not been previously well described. Recently, we reported our experience with four patients who presented to us over a 12-month period with syncope, near syncope, or sudden death following the act of defecation. In all four cases, acute pulmonary embolism was shown to be the etiology of the defecation-associated events. A retrospective chart review of all patients with the diagnosis of pulmonary embolism at our institution over a three-year period yielded five additional patients with the diagnosis of defecation-associated pulmonary embolism. These nine patients accounted for 6.8 percent of all patients with a discharge diagnosis of pulmonary embolism seen at our institution during the three-year study period. Six of the nine patients died from their defecation-associated pulmonary embolism. These six deaths accounted for 25 percent of all deaths from pulmonary embolism seen at our institution during the study period. Based on our experience, we suggest that the act of defecation may trigger the development of acute pulmonary embolism in some patients with deep vein thrombosis.

Acute Disease↗

PubMed1995

[Effects of low anterior resection on colonic motor activity and defecation. An experimental study].

The functional disorder of defecation after low anterior resection (LAR) was studied from the aspect of colonic motility in an experiment with dogs using a strain gage transducer, and the following results were obtained: 1) In early phase after LAR, the frequency of the colonic contractile waves increased at the proximal and distal sites of the anastomosis in both subgroups of dogs denervated and innervated of hypogastric and pelvic nerves. The increase was more remarkable at the distal site of the anastomosis. Also, the contractile waves were not propagated across the anastomosis. 2) After LAR, strong colonic contractions occurred during defecation only at the distal anastomosis. Various patterns of contraction time required for defecation were demonstrated as compared to a single pattern in control dogs. 3) The frequency of the occurrence of colonic contractile waves and the propagation of the contraction tended to be normalized with time after LAR both in denervated and innervated groups, though the recovery was faster in the latter subgroup. 4) The frequency of defecation increased after LAR both in denervated and innervated groups compared to be in the control dogs, though more remarkable in the denervated groups. Although tended to be gradually normalized with time after LAR, the colectomized dogs required a long time for normalization of the frequency of defecation. These results suggested the significant effect of reduction in reservoir space and disturbed continuity of intramural plexus caused by colectomy. Less severity, however, of functional disorder of defecation and earlier recovery from colonic motility disorder in the subgroup of the dogs innervated of autonomic nerves indicated usefulness of retaining autonomic nerves in colectomy.

Animals↗

PubMed1989

[Studies on colonic motor correlates of spontaneous defecation in conscious dogs].

The colonic motilities during defecation were studied by means of extraluminal strain gauge force transducers in six conscious dogs. A set of eight transducers was implanted in each dog: one was on the terminal ileum and the remaining seven were on the whole length of the colon equidistantly. As Karaus & Sarna had already described in 1987, giant migrating contractions (GMC) that were initiated in the proximal colon and rapidly migrated caudad before defecation were reconfirmed also in this study to be motor equivalent of mass movements. Several new findings in addition were obtained. At spontaneous defecation, a reflex relaxation was always observed at the distal end of the colon. This colonic outlet relaxation (COR) usually occurred synchronously with the initiation of GMC at the proximal colon and lasted until GMC had arrived at the distal end. Evacuation of feces occurred during this COR. COR was not observed at defecation induced by neostigmine or prostaglandin F2 alpha. After bilateral pelvic nerve section, both GMC and COR were completely abolished. Instead, group of low amplitude caudad migrating contractions occurred at the proximal or middle colon and were followed by frequent evacuation of small amount of loose stools. COR was not observed at this type of defecation. It is suggested from this study that not only GMC but also COR are the essential motor correlates of spontaneous defecation. Both GMC and COR are under control of pelvic nerves.

Animals↗

PubMed1982

Schedule-induced defecation.

Excessive defecation, typically considered to be a concomitant of stress, was experimentally induced or eliminated under specific schedules of positive reinforcement of lever pressing by rats. The schedules were, by and large, those under which polydipsia is typically induced. In the first of three experiments, rats under fixed-interval 32-second schedules and variable interval 32-second schedules for food and water reinforcers defecated profusely, but not under fixed-interval one-second schedules or other small interval schedules. Somewhat higher rates of defecation were observed on variable interval 32-second schedules than on fixed-interval 32-second schedules. In a second experiment, fixed-ratio schedules were used, some of which resulted in responding such that reinforcement densities were similar to those on the interval schedules that induced defecation. Defecation was not systematically induced by these ratio schedules. In a third experiment, fixed-time schedules of food presentations were utilized. High rates of defecation were induced comparable to those induced by interval schedules of the same time parameter. No other behavior commonly termed "emotional" was observed in any of these experiments.

Animals↗

PubMed1993

Schedule-induced defecation by rats during ratio and interval schedules of food reinforcement.

Lever pressing in rats was maintained by continuous and intermittent schedules of food while defecation was monitored. In Experiment 1, reinforcement densities were matched across variable-ratio and variable-interval schedules for three pairs of rats. Defecation occurred in all 3 rats on the variable-ratio schedule and in all 3 rats on the yoked variable-interval schedule. In Experiment 2, fixed-ratio and fixed-interval schedules with similar reinforcement densities maintained lever pressing. Defecation occurred in 3 of 4 rats on the fixed-ratio schedule and in 4 of 4 rats on the fixed-interval schedule. Almost no defecation occurred during continuous reinforcement in either experiment. These results demonstrate that defecation may occur during both ratio and interval schedules and that the inter-reinforcement interval is more important than the behavioral requirements of the schedule in generating schedule-induced defecation.

Animals↗

PubMed2006

Biofeedback therapy for dyssynergic defecation.

Dyssynergic defecation is one of the most common forms of functional constipation both in children and adults; it is defined by incomplete evacuation of fecal material from the rectum due to paradoxical contraction or failure to relax pelvic floor muscles when straining to defecate. This is believed to be a behavioral disorder because there are no associated morphological or neurological abnormalities, and consequently biofeedback training has been recommended for treatment. Biofeedback involves the use of pressure measurements or averaged electromyographic activity within the anal canal to teach patients how to relax pelvic floor muscles when straining to defecate. This is often combined with teaching the patient more appropriate techniques for straining (increasing intra-abdominal pressure) and having the patient practice defecating a water filled balloon. In adults, randomized controlled trials show that this form of biofeedback is more effective than laxatives, general muscle relaxation exercises (described as sham biofeedback), and drugs to relax skeletal muscles. Moreover, its effectiveness is specific to patients who have dyssynergic defecation and not slow transit constipation. However, in children, no clear superiority for biofeedback compared to laxatives has been demonstrated. Based on three randomized controlled studies in the last two years, biofeedback appears to be the preferred treatment for dyssynergic defecation in adults.

Adult↗