Rectal Perception Research Articles

Sensory retraining is key to biofeedback therapy for formed stool fecal incontinence

OBJECTIVES: Biofeedback is a nonsurgical treatment that reportedly produces good results in 65–75% of fecally incontinent patients. However, previous studies have not ruled out nonspecific treatment effects. It is also unknown whether biofeedback works primarily by improving the strength of the striated pelvic floor muscles or by improving the rectal perception. We aimed to 1) evaluate the efficacy of biofeedback in formed-stool fecal incontinence, 2) assess the relative contribution of sensory and strength retraining to biofeedback outcomes, and 3) identify patient characteristics that predict a good response to treatment. METHODS: Twenty-four patients with frequent (at least once a week) solid-stool incontinence were provided with three to four biofeedback sessions. They were taught to squeeze in response to progressively weaker rectal distentions. Patients were re-evaluated by anorectal manometry and symptom diary 3 months after completing training and by diary and interview 6–12 months after training. RESULTS: Seventeen (71%) were classified responders: 13 became continent and four reduced incontinence frequency by at least 75%. Clinical improvements were maintained at 12-month follow-up. At 3-month follow-up, responders had significantly lower thresholds for perception of rectal distention and for sphincter contraction, but squeeze pressures did not significantly differ from those of nonresponders. Baseline measures that predicted a favorable response were sensory threshold (50 ml or less), urge threshold (100 ml or less), lower threshold for sphincter contraction, and lower threshold for the rectoanal inhibitory reflex; neither anal squeeze pressure nor severity of incontinence predicted treatment outcome. CONCLUSIONS: In solid-stool fecal incontinence biofeedback training effects are robust and seem not to be explained by expectancy or nonspecific treatment effect. Sensory retraining appears to be more relevant than strength training to the success of biofeedback.

Rectal sensory perception in females with obstructed defecation.

Parasympathetic afferent nerves are thought to mediate rectal filling sensations. The role of sympathetic afferent nerves in the mediation of these sensations is unclear. Sympathetic nerves have been reported to mediate nonspecific sensations in the pelvis or lower abdomen in patients with blocked parasympathetic afferent supply. It has been reported that the parasympathetic afferent nerves are stimulated by both slow ramp (cumulative) and fast phasic (intermittent) distention of the rectum, whereas the sympathetic afferent nerves are only stimulated by fast phasic distention. Therefore, it might be useful to use the two distention protocols to differentiate between a parasympathetic and sympathetic afferent deficit. Sixty control subjects (9 males; median age, 48 (range, 20-70) years) and 100 female patients (median age, 50 (range, 18-75) years) with obstructed defecation entered the study. Rectal sensory perception was assessed with an "infinitely" compliant polyethylene bag and a computer-controlled air-injection system. This bag was inserted into the rectum and inflated with air to selected pressure levels according to two different distention protocols (fast phasic and slow ramp). The distending pressures needed to evoke rectal filling sensations, first sensation of content in the rectum, and earliest urge to defecate were noted, as was the maximum tolerable volume. In all control subjects, rectal filling sensations could be evoked. Twenty-one patients (21 percent) experienced no sensation at all in the pressure range between 0 and 65 mmHg during either slow ramp or fast phasic distention. The pressure thresholds for first sensation, earliest urge to defecate, and maximum tolerable volume were significantly higher in patients with obstructed defecation (P < 0.001). In each subject, the pressure thresholds for first sensation, earliest urge to defecate, and maximum tolerable volume were always the same, regardless of the type of distention. Rectal sensory perception is blunted or absent in the majority of patients with obstructed defecation. The observation that this abnormality can be detected by both distention protocols suggests that the parasympathetic afferent nerves are deficient. Because none of the patients experienced a nonspecific sensation in the pelvis or lower abdomen during fast phasic distention, it might be suggested that the sympathetic afferents are also deficient. This finding implies that it is not worthwhile to use different distention protocols in patients with obstructed defecation.

Visceral afferent hypersensitivity in irritable bowel syndrome—evaluation by cerebral evoked potential after rectal stimulation

OBJECTIVES: Gut hypersensitivity has been shown to be present in irritable bowel syndrome. The current study sought to determine the involvement or hypersensitivity of the gut afferents, objectively, by recording cerebral evoked potential after rectal stimulation. METHODS: In 13 patients with irritable bowel syndrome and nine healthy controls, rectal perception thresholds to electrical stimulation were measured, and cerebral evoked potentials were recorded from 2 cm behind vertex (Cz′) after rectal stimulation electrically (frequency 1 Hz, duration 0.5 ms) at an intensity 50% above perception threshold and with filter setting 1–250 Hz. RESULTS: Perception thresholds to rectal electrical stimuli in patients with irritable bowel syndrome were lower than controls ( p < 0.05). Rectal stimulation led to recognizable and reproducible cerebral evoked potentials. P1, N1, P2 latencies in patients with irritable bowel syndrome were shorter than that in controls ( p < 0.05). P1/N1 amplitude was greater in patients with irritable bowel syndrome than in controls ( p < 0.05). CONCLUSIONS: The shorter latency and increased amplitude of cerebral evoked potential after rectal stimulation in patients with irritable bowel syndrome compared to controls provide objective evidence supporting visceral afferent hypersensitivity as the underlying mechanism in irritable bowel syndrome.

Intrarectal injection of glycerol induces hypersensitivity to rectal distension in healthy subjects without modifying rectal compliance.

Rectal sensory thresholds are lowered in patients with irritable bowel syndrome (IBS), reflecting visceral hyperlagesia, which might be related to subclinical inflammation. To evaluate the effects of an intraluminal injection of glycerol, a mucosal irritant, on rectal tone and perception of distension in 12 healthy subjects. Rectal tone was evaluated with a barostat. First sensation, need to defecate and pain thresholds were evaluated during isobaric phasic distensions, before and 20 and 120 min after injection of 10 ml glycerol in the rectum. Baseline bag volume (97.9 +/- 56.2 ml) significantly decreased 20 min (49.7 +/- 42.2 ml; P= 0.026) and 120 min (66.5 +/- 38.3 ml; P= 0.050) after injection of glycerol, indicating its hypertonic effect. The pressure defining sensory thresholds was decreased significantly 20 min after glycerol injection: first sensation, 14.6 +/- 2.9 versus 18.3 +/- 7.2 mm Hg (P = 0.01); need to defecate, 19.6 +/- 3.7 versus 26.0 +/- 6.9 mm Hg; pain, 23.8 +/- 4.5 versus 35.6 +/- 9.5 mm Hg (P = 0.001). This effect was maintained for 120 min after injection of glycerol. Slopes of the compliance curves did not differ before and after injection of glycerol. Intraluminal injection of glycerol significantly increases rectal tone and sensitizes healthy volunteers to rectal distension, since they show significantly lower thresholds after glycerol. This could constitute a model of visceral hypersensitivity in healthy volunteers.

Therapie der Stuhlinkontinenz bei älteren Patienten: Untersuchung zur Wirksamkeit eines Biofeedback-Heimtrainingsprogramms

The increased prevalence of urinary and fecal incontinence is one of the most important factors in the loss of independence and mobility in the elderly population. It is also one of the major reasons for elderly people to give up their household and move into a nursing home. Anorectal biofeedback therapy is a very effective treatment for fecal incontinence. However, due to the increased immobility of elderly people, ambulatory biofeedback training programs which require the participants to leave their homes and travel to the next available outpatient clinic on a regular basis, especially when depending on public transportation, may prove particularly difficult for elderly, incontinent subjects. Supervised home biofeedback training programs may offer an alternative for those patients, who are motivated enough and not mentally impaired. Two different age groups of women (between 49 and 63; and between 65 and 78 years old) suffering from fecal incontinence due to external anal sphincter impairment, received a supervised home biofeedback program, after extensive anorectal diagnostics including manometry. The program focused on improving voluntary sphincter contraction. After an average of 9 months, anorectal manometry was repeated, and anal resting and squeeze pressure as well as minimal rectal perception threshold were determined. There was no effect on anal resting pressure and rectal perception. However, anal maximum squeeze pressure as well as squeeze pressure over 10 s was substantially increased with no difference between the age groups. Supervised home biofeedback for sphincter insufficiency was effective in improving the voluntary contraction of the anorectum in both age groups. Therefore, biofeedback home training programs may offer an alternative to ambulatory programs for those individuals, who are not mobile enough to regularly attend an outpatient clinic.

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.

Anorectal manometric abnormalities and effect of cisapride in patients with chronic idiopathic constipation

OBJECTIVES: To investigate abnormalities in anorectal motility, changes in rectal visceral perception of balloon distention and the effect of cisapride on patients with chronic idiopathic constipation (CIC). METHODS: Anorectal manometry was carried out in 30 CIC patients using the Synectics Visceral Stimulator combined with PcPolygraf before and after treatment with cisapride (10 mg three times daily for 4 weeks). Twenty age-matched controls were also studied before cisapride therapy. RESULTS: Patients with CIC had lower anorectal sphincter squeeze pressures (P < 0.05), larger minimum relaxation volumes necessary to elicit the anorectal inhibitory reflux (P < 0.05), higher rectal defecation volume thresholds and higher rectal maximum tolerable volume thresholds (P < 0.01) compared with the controls. All of the abnormalities significantly improved and defecation frequency greatly increased after 4 weeks of cisapride therapy (P < 0.01). Cisapride was effective in 46.67% of patients with CIC. CONCLUSIONS: Patients with CIC have abnormalities of both anorectal motility and rectal visceral perception of balloon distention. Cisapride can improve these abnormalities and is effective in approximately one-half of CIC cases.

Vertical reduction rectoplasty: a new treatment for idiopathic megarectum

The aetiology of idiopathic megarectum is unknown and the results of surgery are often unsatisfactory. Rectal hyposensation is common and poor perception of rectal filling may contribute to the poor evacuatory function. By reducing the capacity of the rectum, it was hypothesized that sensory thresholds to rectal distension and perception of urge to defaecate would be improved. Vertical reduction rectoplasty (VRR) and concomitant sigmoid colectomy was performed on six patients with idiopathic megarectum. Patients were evaluated before and after operation by detailed questionnaire and anorectal physiology. Postoperative rectal compliance was also studied by means of a programmable electronic barostat. Where appropriate, physiological data were compared with those obtained in eight healthy volunteers. Bowel frequency increased from a preoperative median of 2.5 to 16 per month after operation. Four patients reported improved rectal perception of the urge to defaecate. Thresholds for defaecatory urge and maximum tolerated volume were significantly reduced following VRR (P<0.05). Post-VRR rectal compliance was no different from that in healthy volunteers. Colonic transit time decreased significantly after VRR (P<0.05) and evacuation on proctography increased from a median of 30 per cent to 50 per cent. At a median of 57 weeks' follow-up five of the six patients expressed continued satisfaction with the results. VRR is a new approach to the treatment of idiopathic megarectum. Clinical and physiological studies confirm that it can improve sensory feedback and defaecation. The procedure needs further evaluation as the number of patients undergoing the procedure increases.

Fecal continence after rectocele repair: a prospective study.

Combined transvaginal/transanal rectocele repair was performed in series of 89 consecutive women (mean age 55, range 35-81 years) with obstructed defecation due to a rectocele with a depth of more than 3 cm. The impact of this procedure on anal sphincter pressure and continence status was evaluated prospectively. Anorectal manometry was carried out before and after surgery (at 3, 6, 12, and 24 months). The following measurements were performed: maximal anal resting pressure (MARP), maximal anal squeeze pressure (MASP), and rectal sensory perception including first initial sensation, urge to defecate, and maximum tolerable volumes (MTV). The outcome was successful in 71% of patients with respect to symptoms such as the need for straining at defecation, manual assistance, feelings of incomplete evacuation, sense of rectal fullness, constipation, abdominal pain, and the use of laxatives. However, after rectocele repair seven patients experienced deterioration in fecal continence, and dyspareunia developed in 41% of the sexually active patients. Manometric studies revealed a significant decline in mean of 18% of MARP and 16% of MASP. In contrast to MASP, MARP gradually improved during the follow-up period. Distending volumes required for initial sensation and urge to defecate did not change after the procedure. MTV values were significantly lower 3 and 6 months after rectocele repair than those before and 24 months after surgery. MARP and MASP values after surgery did not differ between patients with impaired and those with normal continence. In conclusion, transvaginal/transanal rectocele repair is beneficial for patients with obstructed defecation; however, care should be taken in sexually active patients, and patients at risk of developing fecal incontinence.

On the adequate stimulus for rectal mechanoreception and perception: a study in cat and humans.

The adequate stimulus that is specific for both rectal mechanoreceptor excitation and rectal perception is still undefined. Using a visual analogue scale, healthy male volunteer subjects rated the intensity of the non-noxious 'pressure sensation evoked by slow balloon-induced distensions of the rectum. In a parallel study, the responses of spinal afferents originating from intramural mechanoreceptors of the rectum to the same stimulus were recorded in decerebrate cats. Both receptor activity and sensation intensity were linearly related to the diameter of the rectum, which is in turn a linear function of the tangential length of the rectal wall. In contrast, both saturated when expressed as a function of intrarectal pressure or rectal wall tension. It is concluded that the perception associated with rectal dis tensions in the non-noxious range is mediated by intramural mechanoreceptors that linearly encode tangential wall length, and that the underlying information is linearly transmitted throughout the CNS.

Visceral algesia in irritable bowel syndrome, fibromyalgia, and sphincter of oddi dysfunction, type III.

Visceral hyperalgesia has been demonstrated in patients with irritable bowel syndrome who are seen in tertiary care centers. It has been hypothesized that visceral hyperalgesia may be related to psychological distress associated with health care seeking behavior in these patients. Patients with fibromyalgia and sphincter of Oddi dysfunction, type III, share many demographic and psychosocial characteristics with patients with irritable bowel syndrome and provide an opportunity to test the hypothesis that rectal hyperalgesia is unique to IBS. Fifteen patients with IBS, 10 patients with fibromyalgia, 10 with sphincter of Oddi dysfunction, type III, and 12 controls underwent evaluation of rectal pain perception in response to phasic distensions and psychological testing with a self-report instrument. Patients with irritable bowel syndrome demonstrated significantly lower rectal pain thresholds and increased levels of psychologic distress compared to controls. Although sphincter of Oddi dysfunction patients also exhibited increased psychologic distress, rectal pain perception was similar to controls. Patients with fibromyalgia exhibited rectal algesia that was not significantly different from either controls or IBS. In conclusion, rectal hyperalgesia is not a function of chronic functional pain, health care seeking behavior, or psychological distress. However, it may not be specific for IBS.

Effect of cholecystokinin on rectal compliance and perception in irritable bowel syndrome

Kuyvenhove, J.; van er Schaar, P. J.; Lamers, C. B.H.W.; Masclee, A. A.M. Author Information

Anorectal functions in patients with spinal cord injury.

We wished to establish anorectal functions in patients with spinal cord lesions, related to the level of lesion and its completeness. We also wished to determine the value of neurophysiological tests for completeness of transsections in comparison with manometry and visceral sensory testing. In 32 patients (31.5 +/- 14.1 years, 25 males) with spinal trauma, completeness of transsection was assessed clinically. In 16 of these patients (30 +/- 15.6 years, nine males), a neurological work-up included recording of somatosensory evoked potentials (SEP) and motor evoked potentials (MEP) from the pudendal nerve within the first week after trauma. Also, anal sphincter EMG and pudendal nerve terminal motor latency (PNTML) were assessed. All patients also underwent conventional anorectal manometry and visceral sensory testing. Of all 32 patients, 15 were judged as 'complete' based on their clinical signs. Of those 16 tested neurologically, seven were labelled 'complete' since no MEP or SEP were detectable; one had pudendal SEP and MEP present, while SEP were present but delayed (47.0 +/- 8.8 msec) in the remaining patients. In four of these patients, also MEP were recorded (27.9 +/- 5.2 msec) and normal. PNTML was present in 12/16 patients independent of the completeness of lesion, and was rated normal in nine and delayed in three patients. EMG was normal in five, and pathological in 11 cases. In 5/15 cases of those judged as 'complete' (in 3/7 evaluated neurologically), visceral sensory testing revealed a minimal threshold for rectal perception of distension of 44 mL (range: 10-130), which sometimes was also perceived as urge to defecate. In a further case, manometry showed major voluntary action of the anal sphincter. These patients had lesions at all levels of the spinal column, ranging from cervical (C4,C6,C7) via thoratical (2 x T7,T8,T12) to lumbar segments. Anorectal function testing, and specifically visceral sensory testing may be superior to neurological assessment of 'completeness' of spinal cord lesions. It may be that visceral afferent pathways others than spinothalamic tract are involved in rectal perception that are less accessible to conventional neurophysiological diagnostic work-up.

Subtypes of constipation predominant irritable bowel syndrome based on rectal perception

Background—Patients who complain of constipation can be divided into those who have lost the natural call to stool, but develop abdominal discomfort after several days without a bowel movement (no...

Acute effects of therapeutic irradiation for prostatic carcinoma on anorectal function

Aim—The incidence of anorectal symptoms after radiotherapy (RTH) for localised pelvic malignant disease is unclear. In addition, the effects of pelvic irradiation on both anorectal motility and sensory function are...

Neuroimmunomodulation in inflammatory bowel disease. How far from "bench" to "bedside"?

The chronic inflammatory bowel diseases (BID), Crohn's disease and ulcerative colitis, are characterized by recurrent periods of inflammation and tissue destruction. The clinical course is influenced by genetics, environmental factors, and the immune system. Recent insights (bench trials) benefiting from advances in genetic engineering and molecular biology have contributed to clinical care (bedside) in terms of actual or potential therapies. Does the neuroendocrine system significantly modify disease activity? Although conceptually appealing, evidence remains circumstantial. Compelling anecdotal reports exist that "stress" affects disease activity in terms of the frequency and severity of IBD flares (bedside), but the mechanisms underlying these observations are unknown. Evidence that neuroendocrine factors play a significant role in immunomodulation is progressing (bench). (i) Trinitrobenzene sulfonic acid (TNB)-induced colitis, although similar in unstressed Fisher and Lewis rats, shows marked worsening in stressed Lewis rats. (ii) Early studies of rectal pain perception suggest there are specific differences in neuroimaging studies (PET scans) in IBD patients compared to controls. (iii) Levels of substance P (SP) and its receptor are altered. (iv) Preliminary clinical studies with SP receptor antagonists show a trend toward improvement. (v) Importantly, the placebo response in clinical trials is as high as 45%. Evidence that neuroendocrine systems significantly modulate local inflammation is rapidly accumulating (bench), which will facilitate enhanced coordination of clinically relevant therapies (bedside).

Rectal wall contractility in response to an evoked urge to defecate in patients with obstructed defecation.

The aim of this study was to examine rectal sensory perception and rectal wall contractility in response to an evoked urge to defecate and to identify differences between control subjects and patients with obstructed defecation. Twenty control patients (10 men; median age, 47 (range, 17-78) years) and 29 female patients with disabling obstructed defecation (median age, 48 (range, 18-70) years) entered the study. Under radiologic control, an infinitely compliant barostat balloon was inserted over a guide wire into the proximal part of the rectum. Additionally, a latex balloon was introduced into the distal part of the rectum. This latex balloon was inflated until an urge to defecate was experienced. Simultaneously, rectal wall contractility was assessed by measuring the variations in barostat balloon volume. These variations were expressed as percentage changes from baseline volume. By comparing controls and patients with obstructed defecation, a significant difference was found regarding mean distending volume required to elicit an urge to defecate (135 +/- 38 vs. 214 +/- 87 ml of air; P < 0.001, Mann-Whitney U-test). In all controls, the evocation of an urge to defecate induced a pronounced increase in rectal tone, proximal to the distal stimulating balloon. By comparing controls and patients, the increase in rectal tone was found to be significantly higher in control subjects (35 +/- 10 vs. 9 +/- 10 percent; P < 0.001). Twenty-five patients (86 percent) showed no or only minimum (<20 percent) increase in rectal tone during the perception of an urge to defecate. In 14 of these patients, the threshold for this perception was increased. Only four patients (14 percent) showed a relatively normal increase (>20 percent) in rectal tone. However, their threshold for perception was greatly increased. The assembly used in this study provides a useful tool for investigation of rectal evacuation. In all of our patients, obstructed defecation was associated with abnormal rectal sensory perception and/or altered rectal wall contractility.

Effect of distention rate on rectal accommodation and perception in irritable bowel syndrome (IBS)

Effect of distention rate on rectal accommodation and perception in irritable bowel syndrome (IBS)

Effect of cholecystokinin on rectal compliance and perception in irritable bowel syndrome

Effect of cholecystokinin on rectal compliance and perception in irritable bowel syndrome

The coexistence of fibromyalgia (FM) alters rectal perception before and after sigmoid stimulation in female IBS patients

The coexistence of fibromyalgia (FM) alters rectal perception before and after sigmoid stimulation in female IBS patients