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Background: Irritable bowel syndrome (IBS) is more common in female subjects, and IBS patients generally exhibit reduced pain thresholds to rectal distension. The aim of the present paper was to determine gender-related differences in rectal perception in both healthy controls and IBS patients. Methods: Fifty-nine IBS patients (age 20–65 years; mean, 39.2 years; 31 women, 28 men) with symptoms that fulfilled Rome-II criteria and 21 healthy controls (age 25–58 years; mean, 37.8 years; 11 women, 10 men) were recruited. Participants completed a questionnaire regarding bowel symptoms and psychological distress, and maximal tolerable pressures were evaluated via barostat tests. Results: Although healthy women appear to have lower perception thresholds than men, significant gender differences in pain sensitivity were not detected (P > 0.05). In addition, female patients with IBS also exhibited no enhanced colorectal perception, as compared with male IBS patients (P > 0.05). Conclusions: No gender differences in visceral perception were determined to exist between the healthy controls and the IBS patients. Therefore, the increased prevalence of IBS in women may be related to another set of pathophysiological factors, and not to gender-related differences in visceroperception.

Background and purpose The retrospective planning study for intensity-modulated radiotherapy (IMRT) of prostate cancer evaluated whether proximal rectum and supra-anal rectum/anal canal should be delineated as separated organs-at-risk (OARs) to achieve optimal dose distributions to the anorectal region. Patients and methods For 10 patients with localized prostate cancer IMRT plans were generated with the rectum and anal canal as separated OARs (Rec-sep) and as one single OAR (Rec-tot). Two different treatment planning systems (TPS) were utilized. Influence on dose distributions to target and OARs was analyzed. Results Results from both TPS showed significantly increased doses to the distal rectum/anal canal for plans Rec-tot compared with Rec-sep in case of a distended rectum in the planning CT study: doses were increased by up to mean 31% ( P =0.02) and 18% ( P =0.03), respectively, in both TPS. For the patient with the largest rectum, the maximum dose increase was 61%. No significant differences in doses to target, bladder, femoral head and proximal rectum were seen. Conclusions For patients with a distended rectum in the planning CT, delineation of separated OARs for proximal rectum and distal rectum/anal canal resulted in superior dose distributions to the anorectal region and therefore, we recommend this as standard procedure for IMRT planning of prostate cancer.

Earlier studies have documented activation of the cingulate cortex during gut related sensory-motor function. However, topography of the cingulate cortex in relationship to various levels of visceromotor sensory stimuli and gender is not completely elucidated. The aim was to characterize and compare the activation topography of the cingulate cortex in response to 1) subliminal, 2) perceived rectal distensions, and 3) external anal sphincter contraction (EASC) in males and females. We studied 18 healthy volunteers (ages 18–35 yr; 10 women, 8 men) using functional MRI blood-oxygenation-level-dependent technique. We obtained 11 axial slices (voxel vol. 2.5–6.0 × 2.5 × 2.5 mm3) through the cingulate cortex during barostat-controlled subliminal, liminal, and supraliminal nonpainful rectal distensions as well as EASC. Overall, for viscerosensation, the anterior cingulate cortex exhibited significantly more numbers of activated cortical voxels for all levels of stimulations compared with the posterior cingulate cortex ( P < 0.05). In contrast, during EASC, activity in the posterior cingulate was larger than in the anterior cingulate cortex ( P < 0.05). Cingulate activation was similar during EASC in males and females ( P = 0.58), whereas there was a gender difference in anterior cingulate activation during liminal and supraliminal stimulations ( P < 0.05). In females, viscerosensory cortical activity response was stimulus-intensity dependent. Intestinal viscerosensation and EASC induce different patterns of cingulate cortical activation. There may be gender differences in cingulate cortical activation during viscerosensation. In contrast to male subjects, females exhibit increased activity in response to liminal nonpainful stimulation compared with subliminal stimulation suggesting differences in cognition-related recruitment.

It has been postulated that a viscerosomatic reflex activated by gut distension and inhibiting abdominal wall muscle tone may be one of the mechanisms underlying functional abdominal distension. Any demonstration of such a reflex has to take into account the fact that gut distension may increase abdominal girth as a result of volume displacement. As biomechanical and sensory rectal responses vary at different rates of rectal distension, we hypothesized that different rates of rectal distension might reveal different changes in abdominal girth. Abdominal girth was continuously recorded in 14 healthy subjects using a previously validated extensometer. The rectal distensions were made in a randomized order at rates of 100 mL min(-1) or 10 mL min(-1) up to 150 mL, and sham distensions were used as controls. An increase in abdominal girth was observed at the end of both distensions (P

The success of laparoscopic cholecystectomy has stimulated interest in other general surgical procedures, namely Nissen fundoplication, inguinal hernia repair, splenectomy, adrenalectomy, and colon resection. Indeed, there has been an explosion of clinical and basic science research in this regard. The surgery is labeled minimally invasive surgery , but this term is actually a misnomer because surgery by any means is invasive and the techniques used are generally extensions of their open counterparts. Instead, these procedures should be looked upon as being "minimal-access operations" owing to the fact that they are performed through smaller, much more limited portals of entry. Transanal endoscopic microsurgery (TEM) is also a minimal-access procedure, and it follows the same principles and indications as conventional transanal surgery, but the similarity ends there. TEM extends the boundaries of transanal surgery by providing access to lesions that were previously inaccessible by pre-existing means and does so with improved instrumentation and visibility. The net result is an operative approach to rectal pathology that might have otherwise required a transsacral dissection or laparotomy and low anterior resection; morbidity, length of stay, and discomfort are therefore potentially lessened. TEM distinguishes itself from other endoscopic and minimal-access procedures in several ways. First, the visual image is obtained through a binocular stereoscopic eyepiece, which provides a depth of field quite different from that obtained with monocular instruments or video cameras. Second, the instruments are inserted and manipulated in parallel planes, in contrast to laparoscopic surgery, where opposing portals are used to achieve the traction and countertraction needed to expose the plane of dissection. As a result, exposure can be difficult to obtain, and for the novice, this can be a frustrating endeavor. Lastly, the conditions treated with TEM—adenomas, selected cancers, and prolapse— are encountered far less frequently than those treated laparoscopically. Consequently, as a result of this infrequency, combined with the considerable skill required and the high cost of the equipment, TEM will become the domain of only a few surgeons.

Patients with slow transit constipation frequently have delayed gastric emptying. In animals rectal distensions inhibit gastrointestinal motility. In healthy volunteers isovolumetric rectal distensions delay upper gut transit. The purpose of this study was to determine the effect of continuous isobaric rectal distension on gastric emptying and oro-cecal transit in young females. Using validated 13C octanoic and lactose-[13C] ureide breath tests gastric half-emptying time and oro-cecal transit time for a meal were measured in 12 volunteers. The tests were repeated in randomized order: during isobaric balloon distension and during sham distension. Isobaric rectal distension was applied using a polyethylene bag connected to a barostat. Intraballoon pressure was kept just below the threshold for the urge sensation. Mean gastric half-emptying time during rectal distension (92.3 ±5.1 min) was significantly higher than during sham distension (78.8 ± 4 min; P = 0.015). Mean oro-cecal transit time during rectal distension (391.3 ±29.1 min) and sham distension (328.8 ± 38.4 min) were not significantly different. In conclusion, these findings indicate that isobaric rectal distension inhibits gastric emptying, but not small bowel transit in young healthy women. Studies in patients with constipation are indicated.

Cerebral cortical processing of information relayed via visceral afferents is poorly understood. We determined and compared cortical activity caused by various levels of rectal distension in healthy male and female subjects. Twenty-eight healthy, young (20–44 yr) volunteer subjects (13 male, 15 female) were studied with a paradigm-driven functional magnetic resonance imaging (fMRI) technique during barostat-controlled rectal distension at perception threshold and 10 mmHg below and above perception threshold. Male subjects showed localized clusters of fMRI activity primarily in the sensory and parietooccipital regions, whereas female subjects also showed activity in the anterior cingulate and insular regions. A progressive increase in maximum percent fMRI signal change and total volume of cortical activity was associated with the intensity of rectal distension pressure in both genders. Regions of cortical activity for below-threshold stimuli showed less substantial signal intensity and volume than responses for threshold and above-threshold stimuli. Volume of cortical activity during rectal distension in women was significantly higher than that for men for all distensions. We conclude that 1) there are substantial differences in female cortical activation topography during rectal distension compared with males; 2) intensity and volume of registered cortical activity due to rectal stimulation are directly related to stimulus strength; and 3) rectal stimulation below perception level is registered in the cerebral cortex.

Irritable bowel syndrome (IBS) is a complex, multidetermined syndrome involving altered gut reactivity, altered pain perception, and brain-gut dysregulation that is modulated by psychosocial and biological factors (Palsson & Drossman, 2005). The symptomatology of IBS is a combination of abdominal pain or discomfort, rectal distension, and altered bowel habit (i.e., diarrhea or constipation). Keywords: medically unexplained illness; gut reactivity; stress

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 urge); and those who experience a constant sensation of incomplete evacuation (urge).Aims—To determine whether the two groups differ in symptoms, colonic transit, and perceptual responses to controlled rectal distension.Methods—Forty four patients with constipation were evaluated with a bowel symptom questionnaire, colonic transit (radiopaque markers), and rectal balloon distension. Stool (S) and discomfort (D) thresholds to slow ramp (40 ml/min) and rapid phasic distension (870 ml/min) were determined with an electronic distension device. Fifteen healthy controls were also studied.Results—All patients had Rome positive irritable bowel syndrome (IBS); 17 were no urge and 27 urge. Mean D threshold to phasic rectal distensions was 28 (3) mm Hg in no urge, 27 (3) mm Hg in urge (NS), but higher in the control group (46 (2) mm Hg; pConclusions—Hyposensitivity to slow rectal distension is found in patients with IBS who complain of constipation and have lost the call to stool even though their sensitivity to phasic distension is increased.

The study investigated the relationship be-tween anal canal size and anal canal pressure measured simultaneously by anal endosonography and an electronic pressure probe. Twelve normal subjects were studied. Anal endosonography was performed using a 7.5-Mhz rotating transducer of 2 – 5 cm focal length covered with a sylastic balloon filled with degassed water (25 ml). During anal endosonography an electronic manometric probe was passed along the side of the probe and positioned in the anal canal. The ultrasonic image was frozen when maximal anal pressure was seen at basal, squeeze, and minimal pressure during straining. An image was also obtained at maximal anal relaxation after rectal distension with a balloon filled with 150 ml air. The results showed that anal canal pressure was significantly and linearly correlated with anal canal diameter (P

BACKGROUND Psychological factors have long been implicated in the aetiology of irritable bowel syndrome often associated with abdominal pain. This work was designed to study, in rats, the influence of partial restraint stress on the abdominal cramps induced by rectal distension and to determine the role of corticotropin releasing factor (CRF) and mast cells degranulation in this response. METHODS Abdominal contractions were electromyographically recorded. Thirty minutes after stress or intracerebroventricular CRF, rectal distension was performed by inflation of a balloon (0.4-1.2 mL). alpha-helical CRF9-41 or doxantrazole were administered centrally (15 min) and intraperitoneally (30 min), respectively, before stress. Histamine release and the number of mast cells were determined in colonic pieces from stressed and control rats. RESULTS Stress and CRF enhanced the number of abdominal cramps evoked by rectal distension without affecting rectal compliance. alpha-helical CRF9-41 and doxantrazole antagonized the stress and CRF-induced enhancement of abdominal cramps. Stress increased the colonic histamine content whereas the number of colonic mast cells was unchanged. CONCLUSIONS Stress enhances abdominal contractions in response to rectal distension in rats via pathways involving central CRF and intestinal mast cells.

Background Patients and healthy subjects show large inter-individual differences in visceral pain sensitivity, which may have pathophysiological relevance. However, the factors contributing to differences in pain sensitivity remain poorly understood. Thus, this study aimed to investigate psychological and biological predictors of visceral pain sensitivity in healthy subjects. Methods: In N = 59 healthy young females, psychological (i.e., state and trait anxiety, depression) and biological (i.e., gastrointestinal (GI) symptoms in daily life, serum cortisol, and serum levels of interleukin (IL)-6) were collected, followed by assessment of rectal distension pain sensitivity. To do so, rectal distension sensory and pain thresholds, and pain ratings for discrete rectal distension stimuli at pain threshold level were assessed. Results: Regression analyses revealed that lower pain thresholds were predicted by higher state anxiety and more GI symptoms in daily life (both p

Whereas psychological, immunological and HPA-axis related factors have been implicated in pain sensitivity in several pain models, insight into the mechanisms of visceral pain sensitivity is still limited. The current study aimed to investigate psychological and biological predictors of visceral pain sensitivity in healthy subjects. In N = 59 healthy females, measures of gastrointestinal (GI) symptoms in daily life, trait and state anxiety, depression, serum cortisol, and serum levels of interleukin (IL)-6 were obtained, followed by assessment of rectal distension pain sensitivity measures (i.e. rectal distension sensory threshold, pain threshold, and pain ratings for discrete rectal distension stimuli at pain threshold level). Regression analyses revealed that more GI symptoms in daily life predicted lower sensory thresholds. Further, lower pain thresholds were predicted by increased GI symptoms, higher state anxiety and cortisol concentrations, whereas increased cortisol was also associated with lower pain ratings. IL-6 was positively related to GI symptoms and negatively to the pain threshold, but was a non-significant predictor of pain thresholds in the multiple regression analysis. Similar to findings in patients with functional GI symptoms, we showed that subclinical GI symptoms predict visceral pain sensitivity. In line with somatic pain findings, state but not trait anxiety was found to predict visceral pain sensitivity. Our findings on serum cortisol as predictor point to a differential effect of cortisol on the different aspects of pain sensitivity. Our finding on the role of IL-6 in GI symptoms and pain sensitivity is promising for understanding gastrointestinal complaints in patients and needs further investigation.

overactive bladder, the urodynamic finding of detrusor overactivity and the condition of allodynia with respect to bladder sensation. If its exact role could be characterized and measurement used as a guide to a specific subset of patients who might benefit from a specific type of treatment, this would seem to be a more fruitful path of investigation than pursuing it as a general marker for conditions in which the levels are neither specific nor sensitive.

SPM 8 was applied to test anatomical regions of interest in the pINS, aINS and the aMCC while maintaining a family-wise error rate at p

SUMMARY Anorectal function was assessed with anorectal manometry in 45 children with spina bifida (21 girls and 24 boys, incan age 11 1/2 years). 24 enuretic children served as conirols. The pressure in the first and second centimetres of the anal canal was lower among index children than controls and also lower among those with high spinal lesions compared with those with low lesions. Rectal activity (rectal sensation and trace appearance) during rectal distension appeared to be reduced among index children; sensation was particularly poor among those with high spinal lesions. Manometry may be useful in children with spina bifida as i t provides a clcarer understanding of sphincter function and leadr {cs a more rational approach to the management of howel problems. RESUME Fonction anorectale chez lex enfants a proglemes neurologiques; I: spina bifida La fonction anorcctale a i t e appricibe par manomCirie anorectale chez 45 enfanis spina bifida (21 filles et 24 garqons, d'age moyn de 11 ans et dcnii). 24 enfanis Cneuritiques servaient de contrbles. Le pression dans le premier et Ic deusierne centimetre du canal anal etait plus basse chez les enfants index que chez les contrdes, et aussi plus basse dans les spina hauts par rapport aus sina bas. L'activit; rectale (sensation rectale et apparence de traces) durant la distension rectale est apparue reduite chez les enfants index; la sensation etait particuliPrement faible pour les spina hauts. La manonmetric peut etre utile chez les enfanis spina bifida en fournissant une comprehension plus Claire de la fonction sphinctCrienne et en cotiduisant i une approche plus rationnelle dans Ic traitemcnt des prohlemes intestinaus. ZUSAMMENFASSUNG Anorektale Funktion bei Kindern mit neurologischen Problemen. 1: Spina bifida Bei 45 Kindern rnit Spina bifida (21 Madchen und 24 Jungen, mittleres Alter 11 1/2 Jahre) wurde die anorektale Funktion durch anorekiale holanometrie untersucht. 23 enuretische Kinder dienten als Kontrollzn. Der Druck im ersten und zweitcn Zentimeter des Analkanals war bei den Index-Kindern niedriger als bei den Kontrollen und auch bei den Kindern mit hochsitzenden Lasionen niedriger als bei denen mit tiefsitzenden Lasionen. Die Rektumaktivitat (Rektuminnervation und Austritt von Stuhlspuren) bei Dehnung des Rektums schien bei den Index-Kindern reduziert; bei denen mit hochsitzenden Lasionen war die Innervation besonders gering. Die Manometrie kann bci Kindern mit Spina bifida einc hilfreiche Methode sein, da sie zu einem besseren Verstandnis der Sphincter Funktion fuhrt und da dadurch bei der Behandlung von Stuhlproblemen rationaler vorgegangen werden kann. RESUMEN Foncriron anorcctal err ni˜nos Con problemas neurolopicos. I: EsDina bifida La funcion anorectal fue evaluada con rnanornetria˜anorecral hn 45 ni˜nos con espina bifida (21 niAas y 24 nirjos, con una edad media de 11 1/2 arios), como controles sirvieron 24 niilos enureticos. La presion en el primer y segundo centimetros del canal anal era mas baja entre los niiros indice quc en los controles y tambien era menor en los que tenian una lesion espinal aka, en relacion con los que la tenian baja. La actividad rectal (sensacion rectal y aparicion de trazos) durante la distension rectal estaba reducida en los niilos indice; la sensacion era particularrnente pobre en los casos de lesiones altas. La manometria puede ser util en ni˜nlos con espina bifida ya que proporciona una comprension mas clara de la funcion csfinteriana y conduce a una aproximacion mas racional al manejo de los problemas intestinales.

The involvement of mucosal mast cells (MMC) in the pathophysiology of irritable bowel syndrome (IBS) is still controversial. We aimed to re-evaluate the role of MMC in visceral hypersensitivity associated with IBS using a rat IBS model that develops the IBS symptom after a subsidence of acetic acid-induced colitis. No significant difference in the number of MMC was observed between normal rat colon and IBS rat colon. (61.7 +/- 2.9/mm(2) in normal vs. 88.7 +/- 13.3/mm(2) in IBS, p > 0.29). However, the degranulation rate of MMC was significantly higher in IBS rat colon (49.5 +/- 2.4% in normal vs. 68.8 +/- 3.4% in IBS, p < 0.05). Pretreatment of a mast cell stabilizer, doxantrazole (5 mg/kg, i.p.), reduced the degranulation rate of MMC and significantly attenuated visceral hypersensitivity to rectal distension in IBS rat, whereas it had no effect on the visceral sensory responses in normal rat. These results suggest that, although the number of MMC is not significantly changed in IBS rat colon, the higher degranulation rate of MMC is responsible for visceral hypersensitivity in this model IBS.