Anorectal pressure gradient and rectal compliance in fecal incontinence

To study whether anorectal pressure gradients discriminated better than standard anal manometry between patients with fecal incontinence and subjects with normal anal function, anorectal pressure gradients were measured during rectal compliance measurements in 36 patients with fecal incontinence and in 22 control subjects. Anal and rectal pressures were measured simultaneously during the rectal compliance measurements. With standard anal manometry, 75% of patients with fecal incontinence had maximal resting pressure within the normal range, and 39% had maximum squeeze pressure within the normal range. Anorectal pressure gradients did not discriminate better between fecal incontinence and normal anal function, since, depending on the parameters used, 61%–100% of the incontinent patients had anorectal pressure gradients within the normal range. Patients with fecal incontinence had lower rectal volumes than controls at constant defecation urge (median 138 ml and 181 ml, P<0.05) and at maximal tolerable volume (median 185 ml and 217 ml, P<0.05). We conclude that measurements of anorectal pressure gradients offer no advantage over standard anal manometry when comparing patients with fecal incontinence to controls. Patients with fecal incontinence have a lower rectal volume tolerability than control subjects with normal anal function. Accepted: 5 June 1998     

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.     

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.     

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.     

Filling is believing...?

Sensation is an essential aspect of fecal continence. We aimed to correlate manovolumetric and radiologic changes at successive levels of rectal filling sensation. Combined anorectal manometry and proctography were performed in nine volunteers. Images, volumes, and pressures were analyzed at the start of the test, at 20 s before first sensation, and at first, constant, urge, and maximum tolerable sensation. 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 mm Hg). 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 mm Hg) and sharpening of the angle between the anal axis and the horizontal reference line. The proximal anal canal or its surrounding structures plays 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.     

Rectal compliance, capacity, and rectoanal sensation in fecal incontinence

OBJECTIVE: Assessments of the pathophysiology of fecal incontinence are skewed toward anal sphincter function; however, rectal compliance, rectoanal sensation and capacity may also be relevant. The aim of this study was to evaluate the usual and some novel diagnostic approaches in fecal incontinence. METHODS: In 22 unselected patients with fecal incontinence (21 F, 33-75 yr), we quantified: 1) symptoms, anorectal manometry, and anal ultrasound; 2) anal perception of temperature and light touch; 3) rectal sensitivity and compliance to distension; and 4) rectal reservoir function. Control values were obtained from two groups of 11 (seven F, 32-53 yr), and 32 (18 F, 19-44 yr) volunteers. RESULTS: Patients had urge (14), passive (four), or combined (four) fecal incontinence; symptoms were mild in three, moderate in nine, and severe in 10 patients. Most had low sphincteric pressures and ultrasonic abnormalities. Temperature perception was impaired (p < 0.05) in incontinent patients, to a greater extent in the proximal anal canal and in patients with passive, as opposed to urge, incontinence. Intraluminal pressures for sensations of rectal distension were lower in incontinent patients (p = 0.02). Artificial stools elicited sensations of rectal filling at lower volumes than did a barostat bag, and in patients with urge, as opposed to passive, incontinence. In patients and controls, the sensation of urgency was associated (r2 = 0.2, p < 0.01) with rectal compliance. CONCLUSIONS: We confirm that temperature sensation is impaired, and perception of rectal distension is not always reduced in fecal incontinence. Artificial stool tended to induce sensations at lower volumes than did balloon inflation. Altered sensory mechanisms may contribute to the pathophysiology of fecal incontinence.     

Functional activity of the rectum： A conduit organ or a storage organ or both？

AIM: To investigate whether the degree of rectal distension could define the rectum functions as a conduit or reservoir. METHODS: Response of the rectal and anal pressure to 2 types of rectal balloon distension, rapid voluminous and slow gradual distention, was recorded in 21 healthy volunteers (12 men, 9 women, age 41.7±10.6 years). The test was repeated with sphincteric squeeze on urgent sensation. RESULTS: Rapid voluminous rectal distension resulted in a significant rectal pressure increase (P < 0.001), an anal pressure decline (P < 0.05) and balloon expulsion. The subjects felt urgent sensation but did not feel the 1st rectal sensation. On urgent sensation, anal squeeze caused a significant rectal pressure decrease (P < 0.001) and urgency disappearance. Slow incremental rectal filling drew a rectometrogram with a "tone" limb representing a gradual rectal pressure increase during rectal filling, and an "evacuation limb" representing a sharp pressure increase during balloon expulsion. The curve recorded both the 1st rectal sensation and the urgent sensation. CONCLUSION: The rectum has apparently two functions: transportation (conduit) and storage, both depending on the degree of rectal filling. If the fecal material received by the rectum is small, it is stored in the rectum until a big volume is reached that can affect a degree of rectal distension sufficient to initiate the defecation reflex. Large volume rectal distension evokes directly the rectoanal inhibitory reflex with a resulting defecation.     

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.     

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.     

Sonographic Characteristics of Rectal Sensations in Healthy Females

Purpose This study was designed to characterize rectal sensations by visualizing the internal and external anal sphincter and intra-anal transport of bolus during elicited rectal sensations. Methods The anal canal was visualized with real-time transperineal ultrasonography in 13 healthy female volunteers. Rectal sensations were elicited by injecting water into the rectum. The ultrasound images were recorded on a videotape and analyzed offline. Results The median time between an injection of water and the events studied was calculated in 105 rectal sensations. A relaxation in the internal anal sphincter (4 seconds after the injection of water), an antegrade transport of bolus (4 seconds) into the anal canal, and a contraction in the external anal sphincter (5 seconds) were observed before a sensation (6 seconds) was reported. The antegrade flow continued until the distal internal anal sphincter contracted (18 seconds) and the bolus moved in a retrograde transport direction (17 seconds) thereafter the sensation disappeared (18 seconds) and the external anal sphincter relaxed (22 seconds). A significant correlation in time between the end of the sensation, contraction in the internal anal sphincter, reversed flow of anal contents, and relaxation of the external anal sphincter was found (Pearson, P<0.01). Conclusions The results verified that the internal anal sphincter contributes to the perception of rectal sensations by a relaxation allowing intra-anal bolus to increase the pressure on the anoderm during rectal contraction. A new observation is presented on the time relation between contraction in the distal internal anal sphincter, reversed flow in the anal canal, and the end of rectal sensations. Presented at the meeting of the International Continence Society, Christchurch, New Zealand, November 27 to December 1, 2006. Supported by Hitachi Ultrasound, Supfstrasse 24, 6300 Zug Switzerland provided the sonography system. Reprints are not available.     

Anal inspection and digital rectal examination compared to anorectal physiology tests and endoanal ultrasonography in evaluating fecal incontinence

Background Anal inspection and digital rectal examination are routinely performed in fecal incontinent patients but it is not clear to what extent they contribute to the diagnostic work-up. We examined if and how findings of anal inspection and rectal examination are associated with anorectal function tests and endoanal ultrasonography. Methods A cohort of fecal incontinent patients (n=312, 90% females; mean age 59) prospectively underwent anal inspection and rectal examination. Findings were compared with results of anorectal function tests and endoanal ultrasonography. Results Absent, decreased and normal resting and squeeze pressures at rectal examination correlated to some extent with mean (±SD) manometric findings: mean resting pressure 41.3 (±20), 43.8 (±20) and 61.6 (±23) Hg (p<0.001); incremental squeeze pressure 20.6 (±20), 38.4 (±31) and 62.4 (±34) Hg (p<0.001). External anal sphincter defects at rectal examination were confirmed with endoanal ultrasonography for defects <90 degrees in 36% (37/103); for defects between 90-150 degrees in 61% (20/33); for defects between 150-270 degrees in 100% (6/6). Patients with anal scar tissue at anal inspection had lower incremental squeeze pressures (p=0.04); patients with a gaping anus had lower resting pressures (p=0.013) at anorectal manometry. All other findings were not related to any anorectal function test or endoanal ultrasonography. Conclusions Anal inspection and digital rectal examination can give accurate information about internal and external anal sphincter function but are inaccurate for determining external anal sphincter defects <90 degrees. Therefore, a sufficient diagnostic work-up should comprise at least rectal examination, anal inspection and endoanal ultrasonography.     

Effects of age and sex on anorectal manometry

We studied rectal and anal function in 18 healthy elderly and 18 healthy young adults using intraluminal pressure transducers and a rectal balloon. Both age groups consisted of nine females and nine males. Age did not affect anal length, highest anal resting tone, anal pullthrough pressures obtained during rest and voluntary squeeze, threshold of the rectosphincteric reflex (RSR), amplitude of RSR with 60 ml rectal distension, threshold of sensation, critical volume, and rectal wall elasticity. Sex did not affect anal length, threshold of RSR, amplitude of RSR with 60 ml rectal distension, the critical volume and rectal wall elasticity. But the highest anal resting tone, anal pullthrough pressures obtained during rest and voluntary squeeze, and threshold of rectal sensation were significantly higher in the males than in the females. While aging did not affect anal and rectal function, sex did. Males achieved higher anal canal pressures. Therefore, statistical comparison between different groups of subjects is valid only if the groups are matched for sex.     

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 thedistension volumes required to elicit sensation of rectal filling and an urge to defaecate were within normal limits in all patients thedistension 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.     

Anorectal function investigations in incontinent and continent patients. Differences and discriminatory value

Anal manometry, rectal capacity measurement, and the saline-infusion test were performed in 350 patients, 178 of whom had fecal incontinence and 172 of whom were continent. Anal manometry was also performed in 80 control subjects, whose results were compared with the patients. Women and older patients exhibited lower pressures. Compared with continent patients, incontinent patients had lower anal sphincter pressures at rest and during squeeze, a smaller rectal capacity, and leaked earlier and more with the saline infusion test. Differentiation between incontinent and continent patients was not possible with a single test because there was complete overlap. The maximum squeeze pressure showed the best discrimination. Combining the three tests did not show better discrimination than any individual test. Anal pressure and rectal capacity below the normal range only were found in very few incontinent patients. The authors' study demonstrates that no prediction can be made about continence with anorectal function tests. Therefore, in the individual patient, an abnormal result in one test must be interpreted with caution and only in relationship with other tests, especially when therapeutic surgery is considered.     

Anorectal function investigations in incontinent and continent patients

Anal manometry, rectal capacity measurement, and the saline-infusion test were performed in 350 patients, 178 of whom had fecal incontinence and 172 of whom were continent. Anal manometry was also performed in 80 control subjects, whose results were compared with the patients. Women and older patients exhibited lower pressures. Compared with continent patients, incontinent patients had lower anal sphincter pressures at rest and during squeeze, a smaller rectal capacity, and leaked earlier and more with the saline infusion test. Differentiation between incontinent and continent patients was not possible with a single test because there was complete overlap. The maximum squeeze pressure showed the best discrimination. Combining the three tests did not show better discrimination than any individual test. Anal pressure and rectal capacity below the normal range only were found in very few incontinent patients. The authors' study demonstrates that no prediction can be made about continence with anorectal function tests. Therefore, in the individual patient, an abnormal result in one test must be interpreted with caution and only in relationship with other tests, especially when therapeutic surgery is considered.     

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 H₂O; range, 22–130) than in controls (median, 68 cm H₂O; range, 35–100) (p<0.05). Squeeze pressure tended to be lower in patients (median, 147 cm H₂O; range, 53–382) than in controls (median, 177 cm H₂O; 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 H₂O (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 H₂O (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.     

Prospective evaluation of anorectal function after total mesorectal excision for rectal carcinoma with or without preoperative radiotherapy

OBJECTIVE: Anorectal function is greatly disturbed after rectal surgery with or without radiotherapy (RT). To clarify the underlying mechanisms, we designed a prospective study to evaluate the effect of RT and surgery on anorectal function and clinical outcome of patients with a rectal carcinoma. METHODS: Thirty-four patients with a rectal carcinoma participated in this study. They filled out a symptom questionnaire and underwent anal manometry, anal and rectal mucosal electrosensitivity testing, and a rectal barostat, before surgery, 4 and 12 months postoperatively. Thirteen patients were lost to follow-up, 14 underwent surgery alone (total mesorectal excision [TME]), and seven also received RT (RT + TME). RESULTS: Functional outcome was disappointing in both groups, with at 4 months a significantly higher defecation frequency after RT + TME as compared with TME. Anal sphincter function and rectal sensitivity to pressure-controlled distention were not affected by either treatment. Rectal compliance, however, was significantly reduced after RT + TME at 4 and 1 2 months, resulting in lower rectal volumes at the thresholds for first sensation and desire to defecate. Rectal but not anal mucosal electrosensitivity was higher after TME + RT. CONCLUSIONS: Anorectal function after rectal surgery with or without RT is greatly hampered because of a decreased rectal compliance. After 12 months, partial improvement is shown, especially in the absence of RT.     

Combined sensory and motor deficit in primary neuropathic faecal incontinence.

Eleven patients with idiopathic faecal incontinence (IFI) and nine normal controls were studied with techniques of mucosal electrosensitivity and rectal distention for the quantitative assessment of anal and rectal sensation and with manometric and electromyographic tests for the assessment of anorectal motor function. The tests of motor function showed pelvic floor motor neuropathy in the patients with IFI, compared with controls, anal canal resting and voluntary contraction pressures were significantly (p less than 0.05, p less than 0.002) lower, pudendal nerve terminal motor latency and external anal sphincter fibre density were significantly (p less than 0.05, p less than 0.05) raised. The results of mucosal electrosensitivity (MES) disclosed a sensory deficit in the anal canal in patients with IFI, compared with controls, MES threshold was significantly (p less than 0.002) higher. Sensory thresholds to rectal distension were similar in the two groups. This study shows that sensory deficit of the anal canal occurs in combination with the motor neuropathy of the anal canal musculature in primary neuropathic faecal incontinence.     

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.     

Clinical and manometric effects of combined external beam irradiation and brachytherapy for anal cancer

This study evaluates anorectal function after combined tele- and brachytherapy for anal cancer using manometric measurements and a standardized questionnaire. Eight patients received 44±3 Gy external beam radiation followed by 20±4 Gy interstitial brachytherapy with iridium-192. Patients were examined 43 months (range 25–83) after therapy. Maximum anal basal pressure, squeeze pressure, and squeeze increment were significantly lower in patients (50, 163, 115 mmHg, respectively) than in control subjects (75, 285, 180 mmHg, respectively). Decreased anal elasticity was not observed. Anal prestretch “normalized” the contractility of the internal and external sphincter. Thus damage to the anal epithelium and hemorrhoidal cushions seems to be the most important mechanism explaining reduced anal closing pressure values. The rectoanal inhibitory reflex was observed in all but one patient. Rectal compliance was significantly reduced. Whereas all patients could retain a water filled rectal balloon until the maximum tolerable sensation level was reached, the rectal saline infusion test was strongly abnormal. Four patients were perfectly continent. Four patients were incontinent for gas and presented urgency in case of liquid stools with limited soiling occurring once weekly or less; three of them also had urgency for solids. Defecation frequency was increased but regular in most patients. Reduced anal closure together with reduced rectal compliance are at the basis of stool frequency, urgency and partial incontinence with occasional soiling. However, enough reserve sphincter function was maintained to preserve a clinically acceptable degree of anal continence in our patients. Accepted: 21 November 1997