Urorectodynamics in patients with colonic inertia

Outcome of colectomy for slow transit constipation

OBJECTIVE

To review the outcome data for colectomy performed for patients with slow transit constipation (STC).

BACKGROUND

The outcome of surgical intervention in patients with STC is unpredictable. This may be a consequence of the lack of effectiveness of such interventions or may reflect heterogeneity within this group of patients.

METHODS

The authors reviewed the data of all series in the English language that document the outcome of colectomy in > or = 10 patients in the treatment of STC.

RESULTS

Thirty-two series fulfilled the entry criteria. There was widespread variability in patient satisfaction rates after colectomy (39% to 100%), reflecting large differences in the incidence of postoperative complications and in long-term functional results. Outcome was dependent on several clinical and pathophysiologic findings and on the type of study, the population studied, and the surgical procedure used.

CONCLUSIONS

It may be possible to predict outcome on the basis of preoperative clinical and pathophysiologic findings. This review suggests a rationale for the selection of patients for colectomy.

Urodynamic and rectomanometric findings in urinary incontinence

To investigate the correlation of urinary and fecal incontinence, 52 patients with urinary incontinence underwent cystometry and rectomanometry. Twenty-five patients suffered from stress, 20 from urge and 7 from overflow urinary incontinence. The rectomanometry showed normal results in 29 patients, 5 presented with a compensated and 18 with a partially compensated sphincter incompetence. Whereas 18 of 20 urge incontinent patients had a normal rectal sphincter function, in contrast 16 of 25 stress incontinent patients suffered from rectal sphincter incompetence. In conclusion, there is a marked correlation between stress urinary incontinence and rectal sphincter incompetence. This supports the general thesis that a weakness of the entire pelvic floor is one of the characteristic features of urinary incontinence.

Idiopathic slow-transit constipation

Until recently, the surgical management of idiopathic slow-transit constipation had remained unchanged since the condition was first described by Arbuthnot Lane in 1908. Although colectomy and ileorectal anastomosis is a successful treatment for the majority of patients, symptoms persist or are worse in some cases following such surgery. The previously inaccessible colon is now an area of interest in both health and disease; recent observations on aetiology, clinical investigation, neuropathology and surgical outcome lead us to question the rationale of colectomy for all patients with severe constipation.

Simultaneous dynamic electromyographic proctography and cystometrography

The rectum and bladder share a common origin and work in harmony; disturbance in one may lead to a similar problem in the other. The two have, however, not previously been investigated dynamically and simultaneously. A new system has been devised allowing dynamic integrated electromyographic proctography to be performed simultaneously with cystometrography in 41 patients (28 women and 13 men). Of 16 women with chronic constipation who underwent the combined study, ten were shown to have obstructed micturition. Eight of these ten women exhibited an inappropriate contraction of the puborectalis muscle during micturition, compared with one of the six with normal micturition (P = 0.02). Of the patients with obstructed micturition, seven of eight women with a rectocele also had anismus, compared with none of four women with a rectocele among those who were able to micturate normally (P = 0.02). Eight of the ten women with obstructed micturition thus had a proctological abnormality that explained the urological symptoms. Of 12 women with idiopathic faecal incontinence who underwent the combined study, eight were shown to have genuine stress incontinence of urine. In seven of these the severity was shown to be of type 2a or greater, indicating that pelvic floor dysfunction may be the causal factor of both rectal and urinary symptoms. The combined study shows abnormalities in one system that could explain similar symptoms in the other.

Autonomic influences on colorectal motility and pelvic surgery

The nervous control of the motility of the human distal bowel was investigated by two physiological studies of electrical stimulation of sacral parasympathetic outflow in patients with high spinal injuries and in patients with intractable constipation following pelvic surgery. Identical and reproducible motility responses of the left colon, rectum, and anal sphincters were obtained by sequential electrical stimulation of anterior sacral roots S2, S3, and S4 in patients with spinal injury. S2 stimulation provoked isolated low-pressure colorectal contractions. S3 stimulation initiated frequency-dependent high-pressure colorectal motor activity which appeared peristaltic and was enhanced with repetitive stimuli. S4 stimulation increased colonic and rectal tone. Quantitative responses were maximal at the splenic flexure and rectum. Pelvic floor activity was stimulated in increasing magnitude from S2 to S4. These results of distal bowel motility were achieved by an implanted Brindley stimulator. A newer generation of externally active stimulators are envisaged for the control of lower bowel in fecal incontinence. Women with intractable constipation following hysterectomy had significantly increased rectal volume and compliance together with deficits of rectal sensory function. Following stimulation with Prostigmine (neostigmine) a colorectal motility gradient was paradoxically reversed in the patients following hysterectomy, thus constituting a functional obstruction. Denervation supersensitivity was demonstrable in 2 patients tested with carbachol provocation. These findings suggest dysfunction in the autonomic innervation of the hindgut in some patients following hysterectomy.

Association of constipation with neurologic diseases

To investigate possible etiologic influences on the development of constipation, the present study examines the concordant occurrence of constipation with other diseases. Using 8.8 million Medicare patients hospitalized in the United States during 1987, the frequency distribution of all three-digit International Classification of Diseases (ICD) codes was compared in constipated patients and patients without constipation. Most associations and the closest associations were observed between constipation and neurologic diseases, the majority of which resulted from damage to the central nervous system. Associations between constipation and disorders of the spine also involved neuronal damage. The influence of potential confounding factors such as immobility or pain on the development of constipation was assessed and found to be minimal. The frequent association of constipation with disorders involving neuronal malfunction suggests that disruption of the neural modulation of colonic motility may play an important role in the development of constipation.

Relationship between outlet obstruction constipation and obstructed urinary flow

Ten women with symptoms and radiological features of outlet obstruction constipation underwent urodynamic bladder studies. The results were compared with ten age- and sex-matched controls. The mean (s.e.m.) peak flow rate for patients was 19.4 (6.4) ml/s compared with 32.1 (7.2) ml/s for controls (P less than 0.05). The mean (s.e.m.) voiding time for patients was 62.9 (23.7) s against a corresponding value of 15.6 (6) for controls (P less than 0.05). The mean (s.e.m.) bladder volume in patients was 482 (80) ml compared with a control value of 254 (112) ml (P less than 0.03). The mean (s.e.m.) detrusor pressure during the voiding phase was 53.3 (12) cmH2O. These results demonstrate that patients with outlet obstruction constipation have a generalized pelvic floor disorder resulting in obstructed urinary flow.

Disordered colorectal motility in intractable constipation following hysterectomy

Colorectal and anal sphincter motility and electrophysiology were investigated in 14 women with profound constipation following hysterectomy and compared with an asymptomatic group of control subjects. Twelve patients complained of significant urinary symptoms. No differences in the motor function of the anal sphincters were detectable. The latency of the pudendoanal reflex was unchanged after hysterectomy. Proctometrograms demonstrated significantly increased rectal volumes and compliance in the hysterectomy group together with deficits of rectal sensory function. In the basal state a significant proximal-to-distal sigmoid colon motility gradient existed only in the control group. Following stimulation with Prostigmin, this gradient was enhanced in the control group but paradoxically reversed in the hysterectomized patients, thus constituting a functional obstruction. Denervation supersensitivity was demonstrable in two patients tested with carbachol provocation but not in control subjects. These findings suggest dysfunction in the autonomic innervation of the hindgut in some patients who had undergone hysterectomy, resulting in severe constipation.

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.

Constipation in the elderly. A physiologic study

Colorectal motility was studied in 25 elderly patients with chronic constipation and compared with an asymptomatic control group (N = 17). Proctometrograms were performed to measure rectal volumes at sensory threshold and maximal tolerance, and rectal compliance. Anal sphincter pressures and reflexes were measured by conventional techniques. Indices of colonic motility were also assessed. Significant impairment of rectal sensory threshold was apparent in constipation. Six patients presenting with impaction demonstrated functional megarectums. The remaining 19 showed a significant reduction in maximal rectal volume and rectal compliance and 14 extruded the balloon. There were no differences in sphincter length or presence of the rectosphincteric reflex. Four patients had an absent pudendoanal reflex and the remainder significant prolongation. Total gastrointestinal transit times were prolonged in the constipation group, mainly distally due to rectal stasis. In two patients bisacodyl failed to elicit a sigmoid motor response. Constipation in the elderly is not merely due to delayed transit. Neurogenic deficits of sacral spinal cord function may be responsible for abnormalities in rectal motor and sensory function.

Urological abnormalities in young women with severe constipation

Anorectal and urodynamic studies were carried out in 10 young women with severe constipation and the results compared with those obtained in controls. The lowest volumes that provoked a desire to defecate (constipated 200 +/- 50 v controls 110 +/- 10 [mean +/- SEM] ml: p less than 0.05), and a desire to micturate (constipated 560 +/- 40 v controls 295 +/- 15 [mean +/- SEM] ml: p less than 0.001), were significantly greater in constipated patients compared with controls. The maximum tolerable rectal volume (380 +/- 30 v 290 +/- 20 [mean +/- SEM] ml: p less than 0.05) and the bladder capacity (720 +/- 50 v 540 +/- 10 [mean +/- SEM] ml: p less than 0.001) were also increased in the constipated subjects compared with controls. Electromyographic studies show failure of relaxation of the external anal sphincter (EAS) on attempted defecation in all 10 patients; and eight of these patients actually contracted their EAS when they strained to defecate, causing a functional outlet obstruction. Urodynamic studies showed normal urinary flow rates, normal detrusor pressures and normal radiology during voiding. Thus, these studies suggest that constipated patients have an increase in capacity and a reduction in sensitivity in the urinary bladder as well as in the rectum, but showed no evidence of obstruction to urine flow.

Hindgut dysgenesis as a cause of constipation with delayed colonic transit

In a patient complaining of constipation since birth, delayed transit time in the ascending colon was related to a congenital malformation of the hindgut, different from Hirschsprung's disease. This was associated with absence of the left lobe of the liver. There was no propagating electrical muscular activity in the distal bowel.

Urorectodynamic evaluation of healthy volunteers

Twelve female and 8 male healthy volunteers underwent urorectodynamic evaluation. Mean bladder capacity was 594 ml. and mean maximal vesical pressure 12.5 cm. water (H2O). Maximal bladder pressure correlated significantly with maximal mural tension (r = 0.96) but did not correlate well with bladder capacity (r = 0.20). Mean bladder volume at first desire to void was 32 per cent of mean bladder capacity. The bladder volume at the first desire did not correlate significantly with the capacity. Mean bladder pressure at 100 ml. volume was 2.9 +/- 0.4 cm. H2O (X +/- SEM). After bethanechol injection, the bladder pressure at 100 ml. volume increased by 8.8 +/- 1.2 cm. H2O (X +/- SEM) at twenty minutes. In only 1 subject did bladder pressure rise higher than 15 cm. H2O (5 per cent). Rectal pressure increased from 1.4 +/- 0.3 to 14.1 +/- 2 cm. H2O (X +/- SEM) at sixteen minutes. Electromyogram (EMG) of the external and sphincter did not follow regular pattern with vesical filling or attempt of voiding. The data obtained in these normal subjects may serve as a basis for comparison in the interpretation of data obtained in patients.