Impaired anal sensation and early diabetic faecal incontinence.

Faecal incontinence develops in up to 20% of diabetic patients. To try to determine the relative contributions of sensory and motor neuropathy in this troublesome complication, anorectal function was examined in 10 male diabetic patients with early faecal incontinence (mucus leakage or faecal staining without the need to wear a pad), 10 asymptomatic male diabetic patients, and 10 normal control subjects. Motor function was tested using anal manometry to determine the resting and maximum squeeze pressure, and the functional anal canal length. No significant differences were found between the groups. Sensory function was tested by measuring the mucosal sensitivity to electrical stimulation, and the response to inflation of a balloon in the rectum. In the mid-anal canal position the symptomatic patients had a significantly higher sensory threshold at 6.6 +/- 2.8 mA compared with 3.0 +/- 1.2 mA in the normal control subjects (p less than 0.002), and in the high anal zone symptomatic patients had a significantly elevated sensory threshold at 9.1 +/- 2.0 mA compared with 4.6 +/- 1.6 mA in asymptomatic patients and 3.6 +/- 1.3 mA in the normal control subjects (both p less than 0.001). There were no significant differences in the first sensation of fullness, maximum tolerated volume or percentage fall from resting pressure between the groups on inflation of the balloon. Elevation of the sensory threshold in the upper anal canal is an early abnormality in the development of diabetic faecal incontinence.     

Relation between rectal sensation and anal function in normal subjects and patients with faecal incontinence.

The relation between sensory perception of rapid balloon distension of the rectum and the motor responses of the rectum and external and internal anal sphincters in 27 normal subjects and 16 patients with faecal incontinence who had impaired rectal sensation but normal sphincter pressures was studied. In both patients and normal subjects, the onset and duration of rectal sensation correlated closely with the external anal sphincter electrical activity (r = 0.8, p less than 0.0001) and with rectal contraction (r = 0.51, p less than 0.001), but not with internal sphincter relaxation. All normal subjects perceived a rectal sensation within one second of rapid inflation of a rectal balloon with volumes of 20 ml or less air. Six patients did not perceive any rectal sensation until 60 ml had been introduced, while in the remaining nine patients the sensation was delayed by at least two seconds. Internal sphincter relaxation occurred before the sensation was perceived in three of 27 normal subjects and 11 of 16 patients (p less than 0.001), and could be associated with anal leakage, which stopped as soon as sensation was perceived. The lowest rectal volumes required to induce anal relaxation, to cause sustained relaxation, or to elicit sensations of a desire to defecate or pain were similar in patients and normal subjects. In conclusion, these results show the close association between rectal sensation and external anal sphincter contraction, and show that faecal incontinence may occur as a result of delayed or absent external anal sphincter contraction when the internal anal sphincter is relaxed.     

Manometric evaluation of rectal prolapse and faecal incontinence.

Sixty-three patients with complete rectal prolapse and/or faecal incontinence have undergone anal manometry and the results have been compared with an equal number of age- and sex-matched controls. Maximal basal pressure (MBP) and maximum squeeze pressure (MSP) were measured before and at four months and a year after treatment. The anal pressures of normal subjects are presented. Patients with rectal prolapse alone had normal anal pressures, whereas patients with incontinence with or without prolapse had significantly lower basal and squeeze pressures than controls. Successful surgical treatment of prolapse or incontinence did not produce significant change in anal canal pressures, whereas the combination of pelvic floor exercises and a continence aid was associated with a significant rise in MSP.     

Relation between perineal descent and pudendal nerve damage in idiopathic faecal incontinence

In 60 patients with idiopathic anorectal incontinence, without neurological disease, there was a significant relationship, shown by regression analysis, between the pudendal nerve terminal motor latency and the extent of perineal descent during straining (r0.59;p<0.001), and the plane of the perineum on straining (r–0.61;p<0.001). These data are consistent with the suggestion that perineal descent can lead to stretch-induced damage to the perineal nerves in this condition.     

Is rectal intussusception a cause of idiopathic incontinence?

PURPOSE: The cause of rectal intussusception in patients primarily dominated by symptoms of anal incontinence has not been fully elucidated, especially for patients with idiopathic incontinence. METHODS: Between 1991 and 1996, 51 patients referred with a diagnosis of idiopathic incontinence were prospectively evaluated by standard questionnaire, clinical examination, defecography, and anal manometry. Fourteen female patients were identified with rectal intussusception and were treated by transabdominal rectopexy. Postoperatively, clinical assessment and anal manometry were performed at regular intervals. RESULTS: Continence was improved after rectopexy (P<0.01). The postoperative increases in the anal resting pressure, maximum squeeze pressure, and maximum tolerated volume were not statistically significant. CONCLUSIONS: Rectopexy improved anal incontinence in patients with rectal intussusception. The cause of rectal intussusception in anal incontinence could not be explained by functional improvement of the internal anal sphincter tone or an increase in the maximum tolerated volume. Rectal intussusception may be a cause of idiopathic incontinence in patients; however, larger prospective studies are required to support this concept.     

Delayed rectal sensation with fecal incontinence. Successful treatment using anorectal manometry

Retraining of the external sphincter response to rectal distention and improving the sensory threshold to balloon distention is documented as effective treatment for fecal incontinence in selected patients. Using anorectal manometric techniques, delayed conscious rectal sensation was demonstrated in 28% of 46 consecutive patients referred for fecal incontinence. In patients with delayed recognition of balloon distention, conscious rectal sensation seemed to correlate with a consistent level of internal sphincter relaxation rather than the primary stimulus of balloon distention of the rectum. Anorectal retraining techniques resulted in correction of sensory delay of 2-22 s, elimination of fecal incontinence, and improved sensory threshold in 10 of 13 patients. This previously unreported sensory abnormality represents a treatable manometric abnormality identified by anorectal motility in patients with fecal incontinence.     

Perception of and adaptation to rectal isobaric distension in patients with faecal incontinence

BACKGROUND: Perception of, and adaptation of the rectum to, distension probably play an important role in the maintenance of continence, but perception studies in faecal incontinence provide controversial conclusions possibly related to methodological biases. In order to better understand perception disorders, the aim of this study was to analyse anorectal adaptation to rectal isobaric distension in subjects with incontinence. PATIENTS/METHODS: Between June 95 and December 97, 97 consecutive patients (nine men and 88 women, mean (SEM) age 55 (1) years) suffering from incontinence were evaluated and compared with 15 healthy volunteers (four men and 11 women, mean age 48 (3) years). The patients were classified into three groups according to their perception status to rectal isobaric distensions (impaired, 22; normal, 61; enhanced, 14). Anal and rectal adaptations to increasing rectal pressure were analysed using a model of rectal isobaric distension. RESULTS: The four groups did not differ with respect to age, parity, or sex ratio. Magnitude of incontinence, prevalence of pelvic disorders, and sphincter defects were similar in the incontinent groups. When compared with healthy controls, anal pressure and rectal adaptation to distension were decreased in incontinent patients. When compared with incontinent patients with normal perception, patients with enhanced perception experienced similar rectal adaptation but had reduced anal pressure. In contrast, patients with impaired perception showed considerably decreased rectal adaptation but had similar anal pressure. CONCLUSION: Abnormal sensations during rectal distension are observed in one third of subjects suffering from incontinence. These abnormalities may reflect hyperreactivity or neuropathological damage of the rectal wall.     

Relationship between symptoms and disordered continence mechanisms in women with idiopathic faecal incontinence

BACKGROUND AND AIMS: Anal sphincter weakness and rectal sensory disturbances contribute to faecal incontinence (FI). Our aims were to investigate the relationship between symptoms, risk factors, and disordered anorectal and pelvic floor functions in FI. METHODS: In 52 women with "idiopathic" FI and 21 age matched asymptomatic women, we assessed symptoms by standardised questionnaire, anal pressures by manometry, anal sphincter appearance by endoanal ultrasound and magnetic resonance imaging (MRI), pelvic floor motion by dynamic MRI, and rectal compliance and sensation by a barostat. RESULTS: The prevalence of anal sphincter injury (by imaging), reduced anal resting pressure (35% of FI), and reduced squeeze pressures (73% of FI) was higher in FI compared with controls. Puborectalis atrophy (by MRI) was associated (p<0.05) with FI and with impaired anorectal motion during pelvic floor contraction. Volume and pressure thresholds for the desire to defecate were lower, indicating rectal hypersensitivity, in FI. The rectal volume at maximum tolerated pressure (that is, rectal capacity) was reduced in 25% of FI; this volume was associated with the symptom of urge FI (p<0.01) and rectal hypersensitivity (p = 0.02). A combination of predictors (age, body mass index, symptoms, obstetric history, and anal sphincter appearance) explained a substantial proportion of the interindividual variation in anal squeeze pressure (45%) and rectal capacity (35%). CONCLUSIONS: Idiopathic FI in women is a multifactorial disorder resulting from one or more of the following: a disordered pelvic barrier (anal sphincters and puborectalis), or rectal capacity or sensation.     

Percutaneous tibial nerve stimulation (PTNS) in females with faecal incontinence: the impact of sphincter morphology and rectal sensation on the clinical outcome

Background

Percutaneous tibial nerve stimulation (PTNS) is an acceptable second line treatment for patients with faecal incontinence (FI) unresponsive to conservative measures. There is however a paucity of data in the literature regarding its efficacy. The aim of this prospective study was to evaluate the efficacy of PTNS in an exclusively female cohort of patients and to identify factors that may predict treatment response.

Method

A prospective cohort of female patients with FI underwent evaluation of sphincter morphology, anorectal pressures and rectal sensation as part of their physiologic assessment prior to treatment. PTNS was performed according to a specific departmental protocol. The clinical outcomes measured were: (1) Cleveland Clinic incontinence scores, (2) deferment time and (3) weekly incontinence episodes. Outcomes were compared at baseline and following treatment using appropriate statistical tests. Clinical outcomes were correlated with the results of the anorectal physiology testing (i.e. sphincter morphology, rectal sensation).

Results

Eighty-eight female patients with a mean age of 58.0?±?13.6?years were included in the analysis. FI was predominantly a late consequence of obstetric injury. The mean incontinence score improved from 12.2?±?4.0 at baseline to 9.1?±?4.6 following treatment (p?<?0.0001). Statistically significant improvements were also seen in the median deferment time and median number of weekly incontinence episodes. Sphincter damage and altered rectal sensation did not appear to influence the outcomes.

Conclusions

PTNS is an effective treatment in female patients with FI. Improvements in clinical outcomes were independent of damage to the anal sphincter complex in patients with normal rectal sensation.     

Impaired internal anal sphincter in a subgroup of patients with idiopathic fecal incontinence

During multiport manometric recordings of the anorectum, 35 of 140 patients with idiopathic fecal incontinence had abnormally weak sphincters that did not relax during rectal distention, suggesting impaired function of the internal anal sphincter. This study documents this finding and compares anorectal function in these 35 patients with 25 matched normal subjects and the remaining 105 incontinent patients. Basal and squeeze pressures were significantly lower in the incontinent study group than in the other two groups. During rectal distention, 25 of 35 patients showed no anal relaxation at any volume, whereas 10 patients showed some relaxation after 60-ml distention because of the postinflation rebound in internal anal sphincter tone. The electrical responses of the external anal sphincter to rectal distention and to increases in intraabdominal pressure were greater in patients than in normal subjects, but the anal pressures were lower and anal leakage was common. Rectal sensations were not significantly different from normal subjects. These results indicate that 25% of patients with idiopathic fecal incontinence have markedly impaired function of the internal anal sphincter, but these patients also have extremely weak external sphincters.     

Second-line treatment for faecal incontinence

BACKGROUND: In the treatment of faecal incontinence, more than 30% of patients experience continuation of their problem. We discuss new therapeutic procedures for dealing with faecal incontinence. METHODS: Discussion of authors' own work in relation to the literature. RESULTS: First-line care includes diets, constipating drugs, biofeedback therapy, anal repair and operations for prolapse and fistulas. For the failures of these first-line treatments there is hope with second-line therapies. Creation of a neosphincter is possible with a dynamic graciloplasty (DGP) or an artificial bowel sphincter (ABS). A DGP is a conventional graciloplasty with the addition of implanted electrodes and a stimulator that transforms the muscle into an automatic contracting sphincter. ABS comprises an inflatable cuff around the anus that is filled from a pressure-regulating balloon. The cuff can be emptied with an implanted pump. CONCLUSIONS: DGP and ABS give good results in 56%-88% of cases. For patients with an anatomical intact but nonfunctioning sphincter there is a new treatment: sacral nerve stimulation. This gives continence in a high percentage of cases, but experience is rather limited. Second-line treatment for faecal incontinence is successful and should be considered in cases where initial therapies fail.     

Pelvic floor neuropathy: a comparative study of diabetes mellitus and idiopathic faecal incontinence.

Twenty one patients with diabetic peripheral neuropathy, 18 with idiopathic faecal incontinence and 11 normal controls were studied with techniques of mucosal electrosensitivity, rectal distension for the quantitative assessment of anorectal sensation, and manometric and electromyographic tests for the assessment of anorectal motor function. An asymptomatic sensorimotor deficit was found in the anal canal of patients with diabetic peripheral neuropathy. Mucosal electrosensitivity thresholds in the anal canal were significantly higher (p less than 0.01 v controls) and fibre density of the external anal sphincter significantly raised (p less than 0.0001 v controls). Anal manometry and pudendal nerve terminal motor latencies were similar to controls. In patients with idiopathic faecal incontinence the tests of sensory and motor function also showed a sensorimotor neuropathy; compared with controls, mucosal electrosensitivity thresholds were significantly higher (p less than 0.002), anal canal resting and maximum squeeze pressures were significantly lower (p less than 0.05 and p less than 0.002 respectively), and pudendal nerve terminal motor latencies and fibre density of the external anal sphincter were significantly raised (both p less than 0.05). Sensory thresholds to rectal distension were similar in all groups. Pelvic floor sensorimotor neuropathy in diabetic patients has several features in common with that of patients with idiopathic faecal incontinence but its functional significance remains uncertain.     

Why do patients with faecal impaction have faecal incontinence.

To elucidate the phenomenon of faecal incontinence in impacted patients, manometric, radiological and other investigations were carried out in 55 elderly patients, who had impacted masses of faeces in the rectum and were incontinent of faeces and 36 elderly control subjects with no anorectal problems. Maximum basal pressure and the maximum squeeze pressure in impacted patients were not significantly different from elderly controls. Sphincter pressures were no different after disimpaction than they were with faecal masses in situ, suggesting that leakage and soiling were not caused by stretching of the anal ring or prolonged reflex inhibition of anal tone by the faecal mass. The anorectal angle was more obtuse in impacted patients than in elderly controls though there was no greater degree of perineal descent. Anal and perianal sensation was impaired in impacted patients compared with controls. Rectal sensation was also impaired in the impacted patients in that the volume in a rectal balloon that could be perceived by the subject and the volume that gave rise to a desire to defecate were much higher in impacted patients than in controls. The rectal volume required to cause anal relaxation was lower in impacted patients compared with controls though there was no reduction in the volume at which anal relaxation failed to recover its resting tone. Rectal distension elicited external sphincter contractions in 53% impacted patients compared with 80% of controls. In conclusion, faecal soiling in patients with faecal impaction is probably related to the combination of an obtuse anorectal angle and the low anal pressures, normally found in the elderly and to impaired anorectal sensation which prevents conscious contraction of the external sphincter when the internal sphincter is relaxed.