Anorectal biofeedback for neurogenic bowel dysfunction in incomplete spinal cord injury.

STUDY DESIGN: A case-control study of prospectively collected data was performed. OBJECTIVES: To compare anorectal biofeedback (BF) outcomes in patients with incomplete motor spinal cord injury (SCI) and neurogenic bowel dysfunction (NBD) with a group of functional anorectal disorder-matched control patients. SETTING: Neurogastroenterology Unit affiliated with a Spinal Injury Unit in a tertiary referral centre in Sydney, Australia. METHODS: All consecutive patients with SCI and NBD referred for anorectal manometry and BF were matched in a 1:2 ratio with age, gender, parity and functional anorectal disorder-matched control patients. Instrumented BF was performed in six nurse-guided weekly visits. Outcomes included changes in anorectal physiology measures, symptom scores and quality-of-life measures. RESULTS: Twenty-one patients were included. These were matched with 42 patient controls. Following BF, symptom scores improved significantly in both groups, as did effect of bowel disorder on quality of life. Improvement in these measures did not differ between the groups. Patients with SCI and NBD showed improvement in their sensory and motor anorectal function, including lowering of first sensation threshold and more effective balloon expulsion. CONCLUSIONS: Patients with incomplete motor SCI responded as well to anorectal BF as functional anorectal disorder-matched controls. Spinal cord-injured patients also showed improvement in anorectal sensorimotor dysfunction and balloon expulsion. These novel findings indicate that clinicians should not be dissuaded from considering behaviour-based therapeutic interventions such as anorectal BF in selected spinal cord-injured patients.

Altered temporal characteristics of the rectoanal inhibitory reflex in patients with abdominal distension.

The rectoanal inhibitory reflex (RAIR) is important in gas and stool evacuation. We examined RAIR features in patients with chronic constipation who exhibited bloating with and without abdominal distension, to determine whether alterations in RAIR may be a factor in the pathogenesis of abdominal distension. Seventy-five female patients with chronic constipation with or without abdominal distension were included in the study. The presence or absence of abdominal distension was assessed according to the Rome II questionnaire. All patients underwent both RAIR and rectal sensitivity testing, and specific RAIR parameters were analyzed. Patients were divided into two groups: abdominal bloating with distension (D, n = 55) and abdominal bloating without distension (ND, n = 20). D had a longer time to the onset of anal sphincter inhibition (latency of inhibition) (P = 0.03) compared with ND. In logistic regression analysis, a combination of age, latency of inhibition and the time measured from onset of inhibition to the point of maximum inhibition predicted abdominal distension (P = 0.002). There were no differences between groups for the time from point of maximum inhibition to recovery and for the percentage of internal anal sphincter relaxation. This is the first study to examine the role of RAIR in patients with abdominal distension. Female patients with constipation and abdominal distension exhibited differences in the temporal characteristics of, but not in the degree of, anal sphincter relaxation compared with patients without distension. Since this study was uncontrolled, further studies are necessary to determine the contribution of altered anorectal reflexes to abdominal distension.

Predictors of outcome of anorectal biofeedback therapy in patients with constipation.

BACKGROUND: Anorectal biofeedback therapy (BFT) is a safe and effective treatment in patients with constipation. Given the high prevalence of constipation and therefore high demand for BFT, there is a need to prioritise patients. AIMS: To explore clinical features and anorectal physiology which predict success or failure of BFT and to derive a statistical model which helps to predict the success of BFT. METHODS: A total of 102 patients with constipation referred for BFT were evaluated. All patients underwent comprehensive clinical and anorectal function assessment, including balloon expulsion testing. The BFT protocol consisted of a comprehensive 6-weekly visit programme comprising instruction on toilet behaviour and abdominal breathing, achieving adequate rectal pressure and anal relaxation, and balloon expulsion and rectal sensory retraining. Success of BFT was based on an improvement in global bowel satisfaction. RESULTS: Harder stool consistency (P=0.009), greater willingness to participate (P<0.001), higher resting anal sphincter pressure (P=0.04) and prolonged balloon expulsion time (P=0.02) correlated with an improvement in bowel satisfaction score. A longer duration of laxative use (P=0.049) correlated with no improvement in bowel satisfaction score. Harder stools, shorter duration of laxative use, higher straining rectal pressure and prolonged balloon expulsion independently predicted successful BFT. A model (S(i) = (p)∑ ß(j)X(ij), where ß represents a regression coefficient, X is a given predictive variable and S(i) is the weighted index score for each individual) incorporating these four variables enabled prediction of successful BFT, with sensitivity and specificity of 0.79 and 0.81, respectively. CONCLUSIONS: Important clinical and anorectal physiological features were found to be associated with outcome of anorectal biofeedback therapy in patients with constipation. This information and the predictive model will assist clinicians to prioritise patients for anorectal biofeedback therapy.

Prolonged balloon expulsion is predictive of abdominal distension in bloating.

OBJECTIVES: Abdominal bloating and distension are common in patients with constipation. The precise mechanism of abdominal distension remains uncertain. We hypothesized that constipated patients with bloating plus distension exhibit a greater degree of anorectal dysfunction, potentially affecting gas evacuation, than those without distension. Therefore, our aim was to evaluate anorectal function and other clinical features in patients with constipation who exhibit bloating with and without distension. METHODS: In all, 88 female patients with abdominal bloating and either non-diarrhea irritable bowel syndrome (IBS) or functional constipation were included in the study. The presence or absence of abdominal distension was assessed according to the Rome II questionnaire, and all patients underwent comprehensive clinical assessment and anorectal function studies. RESULTS: Patients were divided into two groups: abdominal bloating with distension (D; n=53) and abdominal bloating without distension (ND; n=35). D featured a prolonged balloon expulsion time (P=0.005), a higher resting anal sphincter pressure (P=0.002), and a higher maximum anal sphincter squeeze pressure (P=0.015) than ND. They also experienced more bloating (P<0.001), more abdominal pain (P=0.004), harder stools (P=0.01), and more incomplete emptying (P=0.005). In logistic regression modeling, prolonged balloon expulsion time was a significant predictor of abdominal distension (P=0.018). CONCLUSIONS: This is the first study to show that prolonged balloon expulsion time predicts abdominal distension in patients with bloating and constipation. Hence, ineffective evacuation of gas and stool associated with prolonged balloon expulsion may be an important mechanism underlying abdominal distension.

Evidence for pelvic floor dyssynergia in patients with irritable bowel syndrome.

PURPOSE: Although functional constipation is known to often manifest concomitant features of pelvic floor dyssynergia, the nature of pelvic floor symptoms and anorectal dysfunction in non-diarrhea predominant irritable bowel syndrome is less clear. This study aims to compare anorectal sensorimotor function and symptoms of patients who have non-diarrhea predominant irritable bowel syndrome with those who have functional constipation. METHODS: We studied 50 consecutive female patients referred with constipation and 2 or more symptoms of pelvic floor dyssynergia, who also satisfied Rome II criteria for either non-diarrhea predominant irritable bowel syndrome (n = 25; mean age, 47 +/- 3 y) or functional constipation (n = 25; 49 +/- 3 y). Assessments included the Rome II Integrative Questionnaire, a validated constipation questionnaire, Hospital Anxiety and Depression scale, visual analog scores for satisfaction with bowel habit and for impact on quality of life, and a comprehensive anorectal physiology study. RESULTS: Both groups displayed physiological evidence of pelvic floor dyssynergia; but patients with non-diarrhea predominant irritable bowel syndrome exhibited a higher prevalence of abnormal balloon expulsion (P < .01) and less paradoxical anal contraction with strain (P = .045) than patients with functional constipation. These patients with irritable bowel syndrome also reported more straining to defecate (P = .04), a higher total constipation score (P = .02), lower stool frequency (P = .02), a trend toward harder stools (P = .06), and less satisfaction with bowel habit (P = .03) than patients with functional constipation. CONCLUSION: Patients with non-diarrhea predominant irritable bowel syndrome with symptoms of pelvic floor dyssynergia exhibit overall pelvic floor dyssynergia physiology similar to that of patients with functional constipation. Certain features, however, such as abnormal balloon expulsion, may be more prominent in the patients with irritable bowel syndrome. Therapeutic modalities, such as biofeedback, that are effective in patients with functional constipation with pelvic floor dyssynergia should therefore be considered in selected patients with irritable bowel syndrome with pelvic floor dyssynergia.

Colorectal responses to distension and feeding in patients with spinal cord injury.

The role of the central nervous system in enteroenteric motor reflexes remains controversial. Our aims were as follows: 1) to evaluate colorectal, rectocolic, gastrocolonic, and gastrorectal reflex responses in patients with cervical spinal cord injury (SCI) and 2) to compare these responses with those in healthy subjects. In six patients with SCI (5 male, 42 +/- 4 yr) and six healthy control subjects (5 male, 36 +/- 5 yr), 2-min phasic distensions were performed randomly via dual-barostat balloons in the colon and rectum. Continuous colonic and rectal balloon volumes were recorded during distensions and after a 1,000-kcal liquid meal. Mean balloon volumes were recorded before, during, and after phasic distensions and over 60 min postprandially. The colorectal response was similar in control subjects and SCI patients (rectal volume reduction = 28 +/- 11% and 15 +/- 5% in SCI patients and healthy subjects, respectively); the rectocolic response was variable. The gastrocolonic response was present in all subjects (colonic volume reduction = 49 +/- 4% and 44 +/- 3% in SCI patients and healthy subjects, respectively), with a time effect in the first 30 min (P < 0.0001) and a group effect in the second 30 min (P < 0.004). The gastrorectal response was present in four SCI patients and five healthy subjects (rectal volume reduction = 38 +/- 4% and 41 +/- 3% in SCI patients and healthy subjects, respectively), with a time effect in the first 30 min (P < 0.0001) but no group effect in the second 30 min. Intact neural transmission between the spinal cord and higher centers is not essential for normal colorectal motor responses to feeding and distension; however, a degree of central nervous system and neurohormonal modulation of these responses is likely.

Distension technique influences the relationship between colonic and rectal hypersensitivity in irritable bowel syndrome.

In irritable bowel syndrome (IBS), it remains unclear whether rectal hypersensitivity is a 'marker' of colonic hypersensitivity. Our aim was to examine the relation between colonic and rectal sensitivity in IBS patients, comprising phasic and ramp distension techniques. Twenty IBS patients and 12 healthy subjects (N) underwent stepwise ramp and random phasic barostat distensions in the colon and rectum in random order. The sensory threshold pressure (ramp distension) and the visual analogue scale score (VAS, phasic distension), for pain and non-pain, were recorded. Colonic thresholds were lower, and VAS scores were generally higher, for pain and non-pain sensitivities in IBS compared to N. Rectal thresholds were lower, and VAS scores were higher, for pain but not for non-pain, in IBS compared to N. In IBS, for phasic distension, there was good correlation between the colon and rectum for non-pain (e.g. at 16 mmHg, r=0.59, P=0.006) and pain (r=0.60, P=0.006) sensitivities. In contrast, there was no significant correlation between the colon and rectum for ramp distension. In conclusion, colonic and rectal sensitivity in IBS are correlated in response to phasic but not ramp barostat distensions. The rectum serves as a legitimate 'window' for evaluating colonic hypersensitivity in IBS, provided that phasic distensions are employed.

Esophageal dysmotility and acid sensitivity in patients with mitral valve prolapse and chest pain.

Mitral valve prolapse (MVP) patients often experience non-cardiac chest pain. The aims of this study were to determine, in patients with non-cardiac chest pain: (i) whether esophageal dysmotility is more common in patients with MVP than in patients without MVP; and (ii) if acid sensitivity is an important cause of the chest pain in MVP patients. Esophageal manometry and acid perfusion testing were performed in 277 consecutive patients with non-cardiac chest pain. Patients with MVP (13 female, one male; mean age 49 years) were more likely (P = 0.01) to have esophageal dysmotility, while acid perfusion was less likely (P < 0.05) to provoke their chest pain, than in patients without MVP. The most common esophageal motor abnormalities detected in patients with and without MVP were diffuse esophageal spasm (prevalence, 57%) and non-specific motor disorder (prevalence, 9%), respectively. This study, the first large prospective series examining possible esophageal sensorimotor correlates of chest pain in MVP patients, demonstrates that in the absence of a cardiac cause for chest pain, a specific esophageal motility disorder should be excluded, rather than assuming the chest pain is likely to be due to acid sensitivity.

Treatment goals in irritable bowel syndrome.

Irritable bowel syndrome (IBS) carries a considerable economic and social impact which may, in part, be due to inefficient diagnosis and inappropriate treatment choice leading to continued patient ill health and absenteeism. Even assuming that IBS can be diagnosed positively, using well-established symptom-based criteria, management difficulties remain. Thus, pharmacological treatment choice is still based on the single predominant symptom, and many currently available treatments are ineffective in the long term. A greater understanding of the pathophysiology of IBS may lead to the development of more effective treatments that can target the multiple symptoms present in IBS. A new understanding of the role of serotonin (5-HT) and specific receptors (5-HT3 and 5-HT4) found in the gastrointestinal (GI) tract has led to the development of serotonergic agents which have potential clinical benefits. Recent clinical trials suggest that 5-HT4 receptor partial agonists, in particular, may have the ability to offer multiple symptom relief, without the risk of significant adverse reactions.

Alterations in cerebral potentials evoked by rectal distension in irritable bowel syndrome.

OBJECTIVE: Central nervous system correlates of the visceral hyperalgesia documented in patients with irritable bowel syndrome are limited. Reproducible cerebral evoked potentials can be recorded in response to rhythmic balloon distension of the rectum in healthy adults. Irritable bowel syndrome patients and healthy subjects were studied to compare the characteristics of mechanically-evoked rectal cerebral potentials obtained during fasting and after the ingestion of a standard meal. METHODS: Twenty-two pairs of age-matched healthy female subjects and female irritable bowel syndrome patients were studied. Cerebral evoked potentials were recorded in response to rhythmic rectal distension (two distension series each of 100 repetitions at 0.8 hertz); cerebral evoked potential recordings were repeated after a 1000 kcal (46% fat) liquid meal. Trait and state anxiety questionnaires were also completed. RESULTS: Compared to healthy subjects, irritable bowel syndrome patients demonstrated higher prevalence of cerebral evoked potential early peaks (latency < 100 ms) postprandially, and uniformly shorter cerebral evoked potential latencies both before and after feeding. CONCLUSION: These findings provide further objective evidence for defective visceral afferent transmission in irritable bowel syndrome patients.

Direct clinical evidence for spinal hyperalgesia in a patient with irritable bowel syndrome.

OBJECTIVE: Our objective was to evaluate GI motor and sensory function and spinal cord testing in a patient with severe irritable bowel syndrome. METHODS: A patient is described who underwent an extensive assessment of GI motor and sensory function including transit studies, colonic and rectal barostat studies, sensory and manometric studies of the small bowel, and colon and anorectal physiology testing. The patient also underwent testing with spinal cord stimulation and spinal drug delivery as part of a pain management assessment. RESULTS: The viscerosomatic referral pain pattern resulting from rectal distention was consistent with spinal hyperalgesia. The patient underwent testing for spinal cord stimulation and spinal drug delivery. CONCLUSION: This novel finding provides direct clinical evidence for the presence of spinal hyperalgesia in a patient with irritable bowel syndrome, consistent with the existing indirect clinical evidence and animal data.

Small intestine motility.

During the period of review, work has been ongoing to refine existing techniques and to better define normal patterns of small intestinal motility. Researchers continue to learn more about the established neurohumoral control mechanisms of motility, as well as the effects and potential importance of newly discovered neuropeptides and receptors. There has also been continued interest in alterations in motility in various disease states and in the effects on motility of a number of pharmacologic agents.

Psychological and sex features of delayed gut transit in functional gastrointestinal disorders.

BACKGROUND: The relation of demographic and psychological factors to the presence and extent of gut transit impairment in the functional gastrointestinal disorders has received little attention. AIMS: To compare the psychosocial and demographic features of patients with functional gastrointestinal disorders and delayed transit in one region of the gastrointestinal tract with those displaying more widespread delayed transit (that is, delay in two or three regions), and those with normal transit in all three regions. PATIENTS: Of 110 outpatient participants who satisfied standardised criteria for functional gastrointestinal disorders, 46 had delayed transit in one region, 32 had delay in two or three regions, and 17 exhibited normal transit in all regions. METHODS: Transit in the stomach, the small intestine, and the large intestine was assessed concurrently using a wholly scintigraphic technique; psychological status was assessed using established psychometric measures. RESULTS: Patients with delayed transit displayed demographic and psychological features that contrasted with patients with normal transit in all regions. In particular, widespread delayed transit featured female sex, a highly depressed mood state, increased age, frequent control of anger, and more severe gastric stasis, while the features distinguishing normal transit were male sex and high levels of hypochondriasis. CONCLUSION: These data suggest the existence of a distinct psychophysiological subgroup, defined by the presence of delayed transit, in patients with functional gastrointestinal disorders.

Principles of applied neurogastroenterology: physiology/motility-sensation.

Many of the symptoms characteristic of the functional gastrointestinal disorders (FGID) are consistent with dysfunction of the motor and/or sensory apparatus of the digestive tract. Those aspects of sensorimotor dysfunction most relevant to the FGID include alterations in: gut contractile activity; myoelectrical activity; tone and compliance; and transit, as well as an enhanced sensitivity to distension, in each region of the gastrointestinal tract. Assessment of these phenomena involves a number of techniques, some well established and others requiring further validation. Using such techniques, researchers have reported a wide range of alterations in sensory and in motor function in the FGID. Importantly, however, relationships between such dysfunction and symptoms have been relatively weak, and so the clinical relevance of the former remains unclear. Moreover, the proportions of patients in the various symptom subgroups who display dysfunction, and the extent and severity of their symptoms, require better characterization. On a positive note, progress is occurring on several fronts, especially in relation to functional dyspepsia and irritable bowel syndrome, and based on the data gathered to date, a number of areas where further advances are required can be highlighted.

Fructose-sorbitol malabsorption and symptom provocation in irritable bowel syndrome: relationship to enteric hypersensitivity and dysmotility.

BACKGROUND: Fructose-sorbitol (F-S) mixtures can provoke symptoms in irritable bowel syndrome (IBS) patients, and a proportion of IBS patients also have enteric hypersensitivity to distension. We hypothesized, therefore, that sugar malabsorption and fermentation to produce hydrogen gas may provoke symptoms to a greater extent in IBS patients hypersensitive to distension than in those patients without such hypersensitivity. Our aims were therefore to compare, in IBS patients, symptoms and breath hydrogen responses after F-S, on the basis of jejunal sensitivity and jejunal motor function. METHODS: Fifteen female IBS patients (44 +/- 15 years) underwent, on separate occasions, 3-h breath hydrogen analyses after ingesting 10 g lactulose and 25 g fructose with 5 g sorbitol. Jejunal sensitivity and motor function were determined by balloon distension and 24-h manometry studies, respectively. Cumulative symptom scores and breath hydrogen production were analysed on the basis of the presence or absence of jejunal hypersensitivity and dysmotility. RESULTS: Four and seven patients had jejunal hypersensitivity for initial perception and pain, respectively. Eleven, nine, and nine patients had jejunal dysmotility for fasting phase 3, phase 2, and fed motor activity, respectively. Of the patients with symptom provocation after F-S (n = 8 within 3 h, n = 12 within 12 h) or with F-S malabsorption (n = 10), the relative proportion did not differ on the basis of the presence or absence of jejunal hypersensitivity or of motor dysfunction. Symptom scores and hydrogen production also were not different in these subgroups. CONCLUSIONS: Although carbohydrate malabsorption can provoke symptoms in some IBS patients, there is no consistent association between such a phenomenon and the presence of either jejunal hypersensitivity or dysmotility.

Physiological modulation of jejunal sensitivity in health and in irritable bowel syndrome.

OBJECTIVES: In irritable bowel syndrome (IBS), enhanced sensitivity to distention of the small bowel has been demonstrated. We sought to compare, in healthy subjects and in IBS patients, the effects on jejunal sensitivity and compliance of feeding, nonperceived rectal mechanoreceptor stimulation, and the above two stimuli in combination. METHODS: Eleven female IBS patients (49 +/- 13 yr)--six with predominant constipation (IBS-C), and five with predominant diarrhea (IBS-D)--and seven healthy female controls (39 +/- 13 yr) participated. Jejunal distention was applied during fasting, 30 min after a 400-kcal meal, and also during simultaneous nonperceived rectal stimulation. RESULTS: Jejunal sensitivity was increased after feeding in IBS patients (p = 0.004), specifically in IBS-C patients (p = 0.0001) and in controls (p = 0.02), and was reduced during rectal stimulation in IBS patients (p = 0.0001)--both in IBS-D (p = 0.0001) and in IBS-C (p = 0.03) patients--but not significantly so in controls (p = 0.06). Jejunal sensitivity remained unaltered in both IBS patients and controls during concurrent feeding and rectal stimulation. CONCLUSIONS: Physiological stimuli in different parts of the gut modify the intensity of jejunal perception, and the interaction of such stimuli further modifies enteric sensitivity. Nonperceived rectal stimulation appears to modify the intensity of jejunal perception to a greater extent in IBS than in health.