Rectal Sensorimotor Research Articles

Associations among neurophysiology measures in irritable bowel syndrome (IBS) and their relevance for IBS symptoms

Abnormal gut-brain interactions are common in irritable bowel syndrome (IBS), but the associations between neurophysiological measures and their relation to gastrointestinal (GI) symptoms are poorly understood. Our aim was to explore these relationships and define the most relevant neurophysiology measures for GI symptom severity in IBS. IBS patients underwent small intestinal motility (manometry; fasted and fed contraction frequency, phase III time) and secretion (transmural potential difference), rectal sensorimotor (barostat; sensory thresholds, tone response, compliance), autonomic nervous system (baroreceptor sensitivity and effectiveness), and colonic motor function (transit time) examinations. GI symptom severity (GSRS-IBS), and anxiety and depression (HAD) as a proxy measure of central nervous system (CNS) dysfunction, were assessed. In total 281 IBS patients (Rome II criteria) were included (74% females, median age 36 [interquartile range 28–50] years). Significant correlations between neurophysiology measures were stronger within, rather than between, different neurophysiological examinations. The strongest neurophysiology-symptom correlations occurred between a combination of CNS and visceral sensitivity parameters, and GSRS-IBS total score and pain domain (ρ = 0.40, p < 0.001, and ρ = 0.38, p < 0.001). Associations between GI symptoms in IBS and individual and combinations of neurophysiological factors occurred, primarily in CNS and visceral sensitivity measures, providing new insights into the clinical presentation of IBS.

Association between opioid usage and rectal dysfunction in constipation: A cross-sectional study of 2754 patients.

Opioid use has reached epidemic proportions. In contrast to the known effect of opioids on gut transit, the effect on rectal sensorimotor function has not been comprehensively investigated. Cross-sectional (hypothesis-generating) study of anorectal physiology studies in 2754 adult patients referred to a tertiary unit (2004-2016) for investigation of functional constipation (defined by "derived" Rome IV core criteria). Statistical associations between opioid usage, symptoms, and anorectal physiological variables were investigated. Opioids were sub-classified as prescriptions for mild-moderate or moderate-severe pain. A total of 2354 patients (85.5%) were classified as non-opioid users, 162 (5.9%) as opioid users for mild-moderate pain, and 238 (8.6%) for moderate-severe pain. Opioids for moderate-severe pain were associated with increased symptomatic severity (Cleveland Clinic constipation score 18.5 vs 15.1; mean difference 2.9 [95%-CI 2.3-3.6]; P<.001), rectal hyposensitivity (odds ratio 1.74 [95%-CI 1.23-2.46]; P=.002), functional evacuation disorders (odds ratio 1.73 [95%-CI 1.28-2.34]; P<.001), and delayed whole-gut transit (odds ratio 1.68 [95%-CI 1.19-2.37]; P=.003). Differences in anorectal variables between opioid users for mild-moderate pain and non-opioid users were not statistically significant. Hierarchical opioid use (non vs mild-moderate vs moderate-severe) was associated with decreasing proportions of patients with no physiological abnormality on testing (40.2% vs 38.1% vs 29.2%) and increasing proportions with both delayed whole-gut transit and rectal sensorimotor dysfunction (16.6% vs 17.5% vs 28.5%). Opioid use is over-represented in patients referred for investigation of constipation. Opioids for moderate-severe pain are associated with rectal sensorimotor abnormalities. Further studies are required to determine whether this association indicates causation.

A pharmacological challenge predicts reversible rectal sensorimotor dysfunctions in women with fecal incontinence.

In order to understand the pathophysiology of rectal sensorimotor dysfunctions in women with fecal incontinence (FI) and rectal urgency, we evaluated the effects of a muscarinic antagonist and an adrenergic α2 agonist on these parameters. Firstly, rectal distensibility and sensation were evaluated with a barostat and sinusoidal oscillation at baseline and after randomization to intravenous saline or atropine in 16 healthy controls and 44 FI patients. Thereafter, FI patients were randomized to placebo or clonidine for 4wk; rectal compliance and sensation were revaluated thereafter. The effect of atropine and clonidine on rectal functions and the relationship between them were evaluated. At baseline, compared to controls, rectal capacity was lower (P=.03) while the mean pressure (P=.02) and elastance (P=.01) during sinusoidal oscillation were greater, signifying reduced distensibility, in FI. Compared to placebo, atropine increased (P≤.02) the heart rate in controls and FI and reduced (P=.03) the variability in rectal pressures during sinusoidal oscillation in controls. Clonidine increased rectal compliance (P=.04) and reduced rectal capacity (P=.03) in FI. The effects of atropine and clonidine on compliance (r=.44, P=.003), capacity (r=.34, P=.02), pressures during sinusoidal oscillation (r=.3, P=.057), pressure (r=.6, P<.0001), and volume sensory thresholds (r=.48, P=.003) were correlated. The effects of atropine and clonidine on rectal distensibility and sensation were significantly correlated. A preserved response to atropine suggests that reduced rectal distensibility is partly reversible, mediated by cholinergic mechanisms, and may predict the response to clonidine, providing a pharmacological challenge.

Interaction between preprandial and postprandial rectal sensory and motor abnormalities in IBS

Background and aimsRectal sensory and motor interactions in patients with IBS have not been studied in detail. The aim of this study was to evaluate fasting and postprandial rectal sensorimotor...

Tu1425 Relationship of HLA-DQ Genotype With Small Bowel and Colonic Transit and Permeability, and Small Bowel Inflammation in Patients With Irritable Bowel Syndrome With Diarrhea (IBS-D)

Background: Colorectal hypersensitivity is considered an important pathophysiological mechanism in irritable bowel syndrome (IBS). Meal intake exaggerates colorectal sensitivity in IBS and patients often report a meal-related symptom aggravation. Aim: To evaluate the additive information of a test meal during rectal sensitivity testing in IBS regarding the association with other rectal sensorimotor function parameters and gastrointestinal (GI) and psychological symptoms.Methods:We included 221 patients with IBS (age 39±13 (mean±SD) years; 160 females). All subjects underwent a rectal barostat study with two isobaric phasic distension sequences, one before and one 60 min after a liquid meal (800 kcal; 60% lipids). Sensory thresholds were determined during the distensions. Cut-off levels for rectal hypersensitivity (<31 mmHg before, and <26 mmHg after a test meal) were based on data from healthy controls. We also assessed static (V/P) and dynamic compliance (ΔV/ΔP) during the distensions. Patients were characterized regarding GI symptoms (GSRS-IBS), anxiety and depression (HAD) and GI specific anxiety (VSI). Results: In the fasting state, 42% were hypersensitive without gender difference and after the test meal 34% were hypersensitive with a female predominance (p=0.03). Of those with hypersensitivity after meal intake, 20% had normal sensitivity in the fasting state. Hypersensitive patients were younger (p=0.04 before, p<0.001 after meal) and had higher dynamic compliance compared to normosensitive patients both before and after the test meal. Patients with fasting hypersensitivity reported more severe abdominal pain, diarrhea and satiety, as well as higher levels of GI-specific and general anxiety. Patients with hypersensitivity after the test meal reported more severe pain, diarrhea, satiety, bloating and GI specific anxiety (Table 1). Meal hypersensitive patients had more severe bloating (p<0.05) and lower dynamic compliance (p<0.05) than patients with fasting hypersensitivity only. Factors bivariately associated with rectal sensitivity were entered into multiple linear regression analyses, and only GSRS scores for pain were found to be independently associated with rectal sensitivity both in the fasting state (β=-0.19, p= 0.04) and after the test meal (β=-0.19, p=0.04), while diarrhea was independently associated with fasting rectal sensitivity only (β=-0.20, p=0.01). Conclusion: Rectal sensitivity seems to contribute to GI symptom severity in IBS, independently of anxiety and depression levels. Adding a test meal during the procedure provides some additional information to rectal sensitivity testing, even though the majority of relevant information regarding pathophysiology and relevance for symptom generation can be obtained with rectal sensitivity testing in the fasting state only. Table 1. Between group differences (mean (SD))

Tu1399 The Effect of Peppermint Oil on Rectal Sensorimotor Function in Health

Tu1399 The Effect of Peppermint Oil on Rectal Sensorimotor Function in Health

Effects of vaginal hysterectomy on anorectal sensorimotor functions--a prospective study.

While bowel and bladder dysfunction are recognized consequences of a radical hysterectomy, the effects of a simple hysterectomy on anorectal sensorimotor functions, particularly rectal sensation, vary among studies and the effects on rectal compliance remain unknown. Our aims were to prospectively evaluate anorectal sensorimotor functions before and after a hysterectomy. Anal pressures, rectal compliance, capacity, sensation, and bowel symptoms were assessed before, at 2 months, and at 1 year after a simple vaginal hysterectomy for benign indications in 19 patients. Rectal staircase (0-44 mmHg, 4-mmHg steps), ramp (0-200 mL at 50, 200 and 600 mL min(-1)) and phasic distentions (8, 16, and 24 mmHg above operating pressure) were performed. Anal resting (63 ± 4 before, 56 ± 4 mmHg after) and squeeze pressures (124 ± 12 before, 124 ± 12 mmHg after), rectal compliance and capacity (285 ± 12 before, 290 ± 11 mL 1 year after), and perception of phasic distentions were not different before vs after a hysterectomy. Sensory thresholds for first sensation and the desire to defecate were also not different, but pressure and volume thresholds for urgency were somewhat greater (Hazard ratio = 0.7, 95% CI [0.5, 1.0]) 1 year after (vs before) a hysterectomy. Rectal pressures were higher (P < 0.0001) during fast compared with slow ramp distention; this rate effect was greater at 1 year after a hysterectomy, particularly at 100 mL (P = 0.04). A simple vaginal hysterectomy has relatively modest effects (i.e., somewhat reduced rectal urgency and increased stiffness during rapid distention) on rectal sensorimotor functions.

Gender Differences in Motility of the Large and Small Intestine in Patients With IBS

Background: Visceral hypersensitivity, and altered gastrointestinal motility and secretion, are considered to be key pathophysiological factors in irritable bowel syndrome (IBS), and of great importance for symptom generation. The symptom pattern differs between female and male IBS patients , with more severe abdominal pain, bloating and constipation in females (Khatai et al. DDW 2010). Whether this can be explained by gender differences in pathophysiological alterations is incompletely understood. Aim: To evaluate potential gender differences in small intestinal motility and secretion, colonic motility and rectal sensorimotor function in patients with IBS. Methods: We included 36 male and 36 female IBS patients, matched for age (mean age 39 (20-64) years), who fulfilled the ROME II criteria. All patients underwent investigations to assess colonic motility (colonic transit time using radiopaque markers), small intestinal motility and secretion (antroduodenojejunal manometry with jejunal transmural potential difference (PD) measurement in the fasting state (3h) and after meal intake (1h)) and rectal sensorimotor function (rectal balloon distensions before and after meal intake; 800kcal; 60% fat). Results: Colonic transit time differed between female and male IBS patients, with slower transit in females (2.1±1.3 (mean±SD) vs. 1.2±0.8 days; p<0.0001). Differences were also found in the small intestinal motility with slower propagation velocity of phase III in females (8.7±4.5 vs. 15±9.4 cm/min; p<0.01), and a tendency towards shorter duration of phase III in females (p<0.1). The motility indices in the jejunum also tended to be lower in female versus male IBS patients, but this only reached statistical significance in the fasting state (last 30 min of phase II) (3310±1040 vs. 4510±2730 mmHg x sec; p<0.05). No gender differences were seen in PD measurements in the small intestine, reflecting chloride secretion, or in rectal compliance, tone or sensitivity. Conclusion: We have demonstrated gender differences in small and large intestinal motility in IBS patients, but not in small intestinal secretion or rectal sensorimotor function. These findings are of potential importance for observed differences in the symptom pattern between male and female IBS patients.

Rectal sensorimotor dysfunction in constipation

The pathophysiological mechanisms underlying chronic constipation in both adults and children remain to be unravelled. This is a not inconsiderable challenge, but is fundamental to improving management of such patients. Rectal sensorimotor function, which encompasses both sensation and motility, as well as biomechanical components (compliance, capacity), is now strongly implicated in the pathogenesis of constipation. Rectal hyposensitivity, rectal hypercompliance, increased rectal capacity, rectal motor dysfunction (phasic contractility and tone), and altered rectoanal reflex activity are all found in constipated patients, particularly in association with 'functional' disorders of defaecation (i.e. pelvic floor dyssynergia). This review covers contemporary understanding of how components of rectal sensorimotor function may contribute to symptom development in both adult and paediatric populations. The complex interaction between sensory/motor/biomechanical domains, and how best to measure these functions are addressed, and where data exist, the impact of sensorimotor dysfunction on therapeutic outcomes is highlighted.

Corrigendum

Neurogastroenterology & MotilityVolume 22, Issue 3 p. 360-360 Free Access Corrigendum This article corrects the following: Influence of naloxone on rectal sensorimotor function in health B. Geeraerts, L. V. Oudenhove, R. Vos, G. Karamanolis, J. Tack, Volume 21Issue 6Neurogastroenterology & Motility pages: 639-e26 First Published online: February 16, 2009 First published: 05 February 2010 https://doi.org/10.1111/j.1365-2982.2010.01481.xAboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat In [1], the following author’s name was wrongly rendered on page 639. L. V. OUDENHOVE The correct rendering of his name is L. VAN OUDENHOVE. We apologize for this error. Reference 1 Geeraerts B, Oudenhove LV, Vos R, Karamanolis G, Tack J. Influence of naloxone on rectal sensorimotor function in health. Neurogastroenterol Motil 2009; 21: 639– 643. Wiley Online LibraryCASPubMedWeb of Science®Google Scholar Volume22, Issue3March 2010Pages 360-360 ReferencesRelatedInformation

Influence of naloxone on rectal sensorimotor function in health

Abnormal rectal motor physiology and visceral hypersensitivity are implicated in the pathogenesis of irritable bowel syndrome. Endogenous opioids are involved in both the regulation of gut motility and the processing of sensory information. Our aim was to study the effect of suppression of endogenous opioid function by naloxone on rectal sensorimotor function in health. Eighteen healthy subjects participated in a rectal barostat study. Sensorimotor function was evaluated during two consecutive stepwise distensions separated by 30 min of basal tone recording, and with perception scoring on a 0-6 graded scale. Naloxone was administered, after 15 min of basal tone measurements, as an intravenous bolus (0.4 mg), followed by continuous infusion (20 microg kg(-1) h(-1)) in a placebo-controlled, single-blinded and randomized fashion. Naloxone did not alter rectal sensitivity. Comparison of visual analogue scale scores between naloxone and saline did not reveal altered intensities of pain or discomfort. Compared to the baseline distension, a significant adaptive increase in compliance occurred during the second distension after saline (7.8 +/- 0.7 vs 11.0 +/- 0.6 mL mmHg(-1), P = 0.0016). This dynamic change in rectal compliance did not occur after naloxone administration (8.8 +/- 0.7 vs 10.1 +/- 0.8 mL mmHg(-1), ns). Low intensity tonic distension induced a rectal adaptive relaxation, which was absent after naloxone. Naloxone does not alter rectal sensitivity but abolishes rectal adaptation in response to repeated balloon distention. These observations suggest that the endogenous opioid system is involved in control of rectal tone rather than rectal sensitivity.

W1722 Rectal Sensorimotor Dysfunction in the Fasting State and After Meal Intake in Irritable Bowel Syndrome

W1722 Rectal Sensorimotor Dysfunction in the Fasting State and After Meal Intake in Irritable Bowel Syndrome

S1245 ROME III Subtyping Is Associated with Alterations in Intestinal Motility and Secretion, But Not with Sensitivity or Psychosocial Factors

Background: Visceral hypersensitivity, altered gastrointestinal motility and secretion, and psychosocial factors are considered to be of great importance for the symptom pattern in irritable bowel syndrome (IBS). The Rome III criteria propose subtyping of IBS patients based on stool form alone (Longstreth et al Gastroenterology 2006), but the association with the underlying pathophysiology is unknown. Aim: To evaluate the link between pathophysiological factors and Rome III subtyping. Methods: We included 129 IBS patients (96 females, 33 males; mean age 37 (19-67) years). The patients were subtyped according to the Rome III criteria based on one-week diaries, where the stool form (Bristol Stool Form scale) was reported. All patients underwent investigations to assess colonic motility (colonic transit time), small intestinal motility and secretion (antroduodenojejunal manometry with jejunal transmural potential difference (PD) measurement) and rectal sensorimotor function (rectal balloon distensions before and after meal intake). The patients also completed questionnaires to assess the severity of psychological, gastrointestinal and extraintestinal symptoms. Results: Fifty-five patients had IBS-D (diarrhea), 29 IBS-C (constipation), 11 IBS-M (mixed) and 34 IBS-U (unsubtyped). For the analyses M+U was combined into one group (“NonCNonD”). Colonic transit time differed between the subgroups (p<0.0001), with slower transit in IBS-C (1.8±2.9 (mean±SD) days), faster in IBS-D (1.0±1.4 days), and intermediate in the NonCNonD-group (1.4±2.0 days). There were also group differences in small intestinal motility, with higher contraction frequency in the fasted state (p<0.05), longer phase III duration (p<0.01) and faster propagation velocity of phase III (p<0.01) in IBS-D. The small intestinal secretion during phase III (mean PD × length of the secreting segment, calculated from duration and propagation velocity) also differed between the subtypes, with enhanced secretion in IBS-D (p<0.001). Also the mean fasted PD tended to be higher in IBS-D (p<0.05). Rectal sensitivity, compliance and the rectal tone response, as well as psychological or extraintestinal symptom severity was similar in the subtypes. The perceived severity of constipation (p<0.01) and diarrhea (p<0.01), but not other GI symptoms, also differed between the subtypes. Conclusion: Subtyping of IBS patients based on the stool form is associated with alterations small intestinal and colonic motility, as well as small intestinal secretion. However, other pathophysiological factors, as well as symptoms other than constipation and diarrhea, seem unrelated to the different Rome III-based IBS subtypes.

W1723 The Synthetic Cannabinoid Agonist, WIN55,212-2, Inhibits Jejunal Afferent Responses to LPS in a Cannabinoid-Receptor Independent Manner

or a pressure of 70mmHg was reached. Sensory thresholds, the perceived intensity of unpleasantness and pain, and the viscerosomatic referral area were determined during the distensions. Besides sensitivity variables, we also assessed static (V/P) and dynamic compliance (ΔV/ΔP) during the distensions, as well as the initial response contraction and the following receptive relaxation. After meal intake changes in balloon volumes were measured to evaluate the rectal tone response. Results: In the fasting state patients with IBS had lower pressure and volume thresholds for defecatory urge, discomfort and pain, higher unpleasantness and pain ratings and larger viscerosomatic referral areas compared with controls (p<0.0001 for all comparisons). After meal intake IBS patients had lower discomfort (27.8±10.4 vs. 29.3±10.7 mmHg; p<0.0001) and pain thresholds (37.8±13.3 vs. 40.6±13.4 mmHg; p<0.0001) and larger referral area for pain (p<0.01) compared with fasting, which was not seen in control subjects. A larger proportion of patients than controls reduced their pain threshold≥5mmHg after meal intake vs. fasting (50% vs. 21% of subjects; p<0.001). Static compliance and receptive relaxation in the fasting state was lower in IBS patients than in controls (p<0.05), but these differences were not significant after meal intake. No differences between patients and controls were seen in dynamic compliance, rectal tone response or response contraction. IBS subtype had no or minor effect on the results, irrespective of using Rome II or III criteria. Conclusion: Patients with IBS demonstrate rectal sensorimotor dysfunction and this is affected by meal intake. Future studies should focus on the relative importance of these abnormalities for the symptom pattern in IBS.

Influence of abuse history on gastric sensorimotor function in functional dyspepsia

Patients with functional gastrointestinal disorders have elevated rates of sexual or physical abuse, which may be associated with altered rectal sensorimotor function in irritable bowel syndrome. The aim was to study the association between abuse history and gastric sensorimotor function in functional dyspepsia (FD). We studied gastric sensorimotor function with barostat (sensitivity, compliance and accommodation) and gastric emptying test in 233 consecutive FD patients from a tertiary care centre (162 women, mean age 41.6 +/- 0.9). Patients filled out self-report questionnaires on history of sexual and physical abuse during childhood or adulthood. Eighty-four patients (out of 198, 42.4%) reported an overall history of abuse [sexual and physical in respectively 30.0% (60/200) and 20.3% (42/207)]. FD patients reporting general as well as severe childhood sexual abuse have significantly lower discomfort thresholds during gastric distension [respectively 10.5 +/- 0.4 vs 7.5 +/- 1.0 mmHg above minimal distending pressure (MDP), P = 0.014 and 10.5 +/- 0.4 vs 6.6 +/- 1.2 mmHg above MDP, P = 0.007]. The corresponding intra-balloon volume was also significantly lower (respectively 579 +/- 21 vs 422 +/- 59 mL, P = 0.013 and 579 +/- 19 vs 423 +/- 79 mL, P = 0.033). Gastric accommodation was significantly more pronounced in patients reporting rape during adulthood (91 +/- 12 vs 130 +/- 40 mL, P = 0.016). Abuse history was not associated with differences in gastric emptying. A history of abuse is associated with alterations in gastric sensorimotor function in FD. Particularly sexual abuse, rather than physical abuse, may influence gastric sensitivity and motor function.

Influence of experimentally induced anxiety on rectal sensorimotor function in healthy humans

Psychological processes, especially anxiety, may have an influence on visceral perception and gastrointestinal (GI) motor function, thereby eliciting or aggravating GI symptoms. Anxiety has been shown to affect gastric sensorimotor function but it is conceivable that anxiety affects not only the stomach but also other parts of the GI tract, such as the rectum. The aim of this study was to investigate whether experimentally induced anxiety would alter rectal sensorimotor function in health. Eighteen healthy subjects (mean age 26.97 +/- 1.75 years) underwent a rectal barostat study. To assess sensitivity to rectal distension and rectal compliance, stepwise isobaric distension was performed during anxious and neutral emotional state. Two methods of emotion induction were used simultaneously: audiotape assisted recall of a neutral or anxious autobiographical experience and viewing of a set of validated neutral or fearful facial expressions. Anxiety levels were assessed by means of the Spielberger State-Trait Anxiety Inventory (STAI) and anxiety scores on a Likert scale. Anxiety scores (AUC: 2.11 +/- 1.45 vs 42.78 +/- 6.17 mm mmHg, P < 0.0001) and STAI scores (36.06 +/- 2.09 vs 45.56 +/- 2.52, P = 0.005) confirmed the efficacy of anxiety induction. Rectal compliance was not different during anxious compared with neutral emotional state (11.62 +/- 0.93 vs 10.61 +/- 0.96 mL mmHg(-1), P = NS). Pressure and volume thresholds inducing discomfort during rectal distension were not significantly different during anxious and neutral emotional state (29.33 +/- 1.41 vs 29.78 +/- 1.49 mmHg, P = NS and 249.26 +/- 16.22 vs 231.38 +/- 21.19 mL, P = NS respectively). Contrary to its influence on gastric sensorimotor function, experimentally induced anxiety does not affect rectal sensitivity or rectal compliance in healthy subjects.

Rectal sensorimotor dysfunction in women with fecal incontinence

The rate and pattern of rectal distension affect rectal distensibility, perception, and anal relaxation in health. Because rectal urgency is a prominent symptom in fecal incontinence (FI), we assessed rectal distensibility, contractions, perception, and anal pressures during rectal distention in 21 healthy, asymptomatic women (age 61 +/- 2 yr, mean +/- SE) and 51 women with FI (60 +/- 2 yr). Rectal staircases (0-32 mmHg, 4-mm steps) and ramp distensions [0-200 ml at 25, 50, and 100 ml/min with a phase of sustained distension (SD), lasting 1 min, between inflation and deflation]. The rectum was stiffer during rapid than slow ramp distention. This effect was more prominent at a lower volume (50 ml) and was also more pronounced in older subjects and in FI. A rectal contractile response was observed not only during inflation but also during SD and during deflation. During inflation, this contractile response was rate dependent in controls but not in FI. During staircase but not ramp distentions, the threshold for the desire to defecate was lower in FI. During ramp distentions, the duration of perception was significantly longer in FI. The rate of distention did not affect rectal perception (i.e., sensory thresholds or duration of perception) during ramp distentions. Baseline anal pressures and the magnitude of anal relaxation during rectal distention were also reduced in FI. In addition to reduced rectal capacity and compliance, women with FI had an exaggerated rate-dependent reduction in rectal distensibility, lower sensory thresholds, and more prolonged perception, indicative of rectoanal dysfunctions.

Low rectal volumes in patients suffering from fecal incontinence: what does it mean?

Sirs, This study explores rectal sensorimotor function in faecal incontinence (FI),1 reporting a relationship between rectal compliance, sensitivity and perception in those with reduced maximal tolerable volume to isobaric distension. However, the authors have failed to acknowledge significant contributions already published in this field. Traditionally, the focus of attention in FI has been abnormal anal sphincter function, but a multifactorial basis is emerging.2, 3 For example, Bharucha et al., have recently shown that FI is associated with puborectalis atrophy and rectal hypersensitivity (lowered rectal sensory volumes).4 Studies from our institution have also shown rectal sensory mechanisms to be important in FI.5 We examined the relationship between sensation and symptoms in patients with urge FI, and confirmed6 that up to half have rectal hypersensitivity, which is associated with increased stool frequency and urgency, compared to those patients with normal rectal sensation.5 In addition, the influence of rectal hyposensitivity (increased rectal sensory volumes) on FI has been studied, with two pathophysiologies identified: increased rectal compliance and truly disordered afferent function.7, 8 We have also reported the relationship between rectal sensation and motor function in patients with urge FI using prolonged rectosigmoid manometry,9 and shown that in the group with rectal hypersensitivity, symptoms were more prevalent and were more often temporally associated with contractile events. Furthermore, in patients with rectal hypersensitivity, an increase in frequency of high-amplitude contractions, and alteration in variables of the rectal motor complex were demonstrated, in comparison to control subjects and patients with normal rectal sensation. For individual patients, rectal hypocompliance and exaggerated rectal motor complex activity were only found in those with rectal hypersensitivity.9 With regard to the authors’ concluding statement: ‘…a better recognition of physiological impairment may enlarge the fields of rectal surgery in selected patients, suffering from incontinence with low compliant rectum, thus bringing it into a similar perspective than bladder surgery’, it is disappointing that the rectal augmentation procedure, developed in our institution for these reasons, has not been discussed.10 In patients with urge FI, secondary to a deficient sphincter mechanism and rectal hypocompliance/hypersensitivity, standard management is problematic, as correction of the sphincter defect may not abolish faecal urgency, which may be incapacitating. This has been achieved by rectal augmentation with a distal ileal segment, and is associated with normalization of rectal sensory thresholds and frequency of high-amplitude rectal contractions.10 We accept with time a greater understanding of the pathophysiological mechanisms associated with incontinence may unveil further targets for symptomatic relief, but feel that recently published work has already revealed exciting avenues for investigation.

Rectal sensorimotor characteristics in female patients with idiopathic constipation with or without paradoxical sphincter contraction.

Patients with chronic constipation fulfilling the Thompson criteria can show paradoxical sphincter contraction. Aim of this study was to evaluate rectal sensorimotor characteristics in patients with constipation with or without paradoxical sphincter contraction. Thirty female patients with chronic constipation and 22 female controls were investigated with anal manometry and rectal barostat. Paradoxical sphincter contraction was shown with manometry as a paradoxical increase of anal pressure during straining. Visceral sensitivity and compliance were tested by intermittent and continuous pressure-controlled distension. Patients were classified according to their sensations and compliance into normal, hypersensitive, reduced compliant, insensitive or excessive compliant rectum. Postprandial rectal response (PRR) and phasic volume events (PVEs) were registered for 1 h after a 600-kCal meal. Paradoxical sphincter contraction was found in 13 (43%) patients. In these patients, rectal sensitivity scores were higher (P = 0.045) than in patients without paradoxical contractions, but rectal compliance was not different. In 90% of patients an abnormal rectal sensitivity or compliance was found: excessively compliant in 35%, reduced compliant in 10%, hypersensitive in 27% and hyposensitive in 17%. Both patients with constipation (11%; P = 0.042) and controls (25%; P = 0.002) exhibited the presence of a postprandial rectal response. This response was not significantly different between idiopathic constipation, paradoxical sphincter contraction and controls. Patients with rectal hypersensitivity had lower response than other patients (P = 0.04). Patients with constipation had fewer basal PVEs compared controls (P = 0.03). Postprandial PVEs increased in both patients (P = 0.014) and controls (P < 0.001). Postprandial rectal response and PVE were not different in patients with or without paradoxical sphincter contraction. A total of 90% of female patients with idiopathic constipation show an abnormality in rectal sensation or compliance. The postprandial rectal response was comparable between patients with constipation and controls, however, PVEs were diminished. Patients with paradoxical sphincter contraction had higher rectal sensitivity but an unaltered compliance and postprandial rectal response. Future trials should investigate whether the classification of rectal abnormalities in patients with constipation has clinical importance.

Regional specificity in Th2 cytokine-induced alterations in murine small intestinal and colonic smooth muscle function

3 / 16, and velocity: 2 / 16). Both groups contained patients in whom patterns of motor abnormalities were comparable, and suggestive of a neuropathological process: ASTC: 4 normal, 3 (43%) abnormal; ISTC: 6 normal,3 (33%) abnormal. A generalised pattern of colonic transit delay and coexistent abnormalities of rectal sensorimotor function were frequent. Conclusions: Upper gastrointestinal and pan-colonic motility disturbances do exist in patients whose symptoms of intractable constipation were acquired following pelvic surgery or childbirth. Whether this effect is reflex mediated (e.g. recto-intestinal) cannot be answered by this study.