Rectal Distension Research Articles

Constipation-Induced Spontaneous Rectus Sheath Hematoma

Rectus sheath hematoma (RSH) is a unique condition that is often misdiagnosed by clinicians in patients presenting with abdominal pain. RSH is an accumulation of blood within the abdominal rectus sheath muscle as a result of rupturing of the epigastric arteries supplying the rectus sheath muscle. RSH is difficult to diagnose because it presents with similar symptoms as other intra-abdominal pathologies. In severe cases, patients may also present with confusion, fever, chills, and vomiting. If left untreated RSH can lead to hypovolemic shock. Based on the CT scan results, RSH can also be sub classified further. An 83 year-old-female with a past medical history of HTN, Arthritis, Deep vein thrombosis (DVT), HTLV-1 associated myopathy and paraparesis, CVA with right hemiplegia, Umbilical Hernia since birth, and constipation; presented to the emergency department complaining of left sided abdominal pain for two weeks that has gradually worsened over time. The patient describes the pain as being dull at first and gradually becoming sharp, throbbing, and colicky in character. The pain is located diffusely over the left side of the abdomen. On abdominal examination, the left side of the abdomen was warm to touch relative to the right side. The patient also reports that the abdominal pain intensified while trying to pass stools. The patient denies any recent abdominal trauma or surgery that would increase the patient's risk for bleeding into the rectus sheath. A computed tomography (CT) scan without contrast was performed on the Abdomen/Pelvis to evaluate for the underlying pathology causing the presenting symptoms. The CT scan revealed a Left Rectus Sheath Hematoma, Rectal distention suggesting constipation. We would classify this patient as having a Type I RSH, since the hematoma did not cross midline and the patient was stable. The patient was treated with close observation in the hospital and a follow up CT scan showed no significant change in the hematoma. Rectus Sheath Hematoma is a rare clinical condition resulting in blood accumulation within the rectus sheath, whose presenting symptoms are commonly seen in other abdominal pathologies. This patient's chief complaint was left sided diffuse abdominal pain that intensified while straining to pass bowel movements. In conclusion, we feel clinicians should keep RSH as a differential when considering a case of abdominal pain with a history of chronic constipation in conjunction with anticoagulation therapy.

Dynamics of Vaginal Cuff Displacement Due to Bladder Filling in Adjuvant Pelvic Irradiation for Uterine Cancers

RTOG Consensus contouring guidelines for IMRT recommend combining two separate clinical target volumes (CTV) for vaginal cuff based on full and empty bladders to create an ITV (Internal Target Volume). In this study, we report the magnitude of vaginal cuff position displacement when going from an empty to full bladder in post-operative patients with uterine cancers. We examined 42 patients treated with pelvic irradiation at our institution for post-operative uterine cancers FIGO stage I - IIIC. The median age was 67 years (range 41 to 81). Patients were simulated in the supine position using appropriate immobilization. A urinary catheter was inserted, and the bladder was drained to obtain the initial empty bladder (EB) scan. After this, the bladder was filled with diluted contrast (200-300 cm3), and a second full bladder (FB) CT scan was obtained. The amount of bladder fill was determined depending on the volume tolerable by the individual patient. Average Rectal distension in the AP direction was 28.9 ±7.5 mm. The vaginal cuff was visualized on the CT scans by injecting a mixture of contrast and lubricant. The EB and FB CT scans were co-registered before contouring. Target volumes and normal structures were contoured according to RTOG contouring atlas. For each patient, the vaginal cuff wall position displacement in all directions for FB in reference to EB was measured. Additionally, the vaginal cuff width and thickness at a reference level (1 cm inferior to the apex) for EB and FB were also measured. In representative patients, weekly CBCT images were obtained to assess bladder volume at treatment. The average bladder volume from FB CT scans was 272.9 cm3(range 197.5 to 485.7). The average and maximum values for vaginal cuff wall displacement due to FB relative to its position on the EB scan are summarized in Table 1. The vaginal cuff displacement appears to be more favored in the cranial direction. At the reference level, the vaginal cuff width and thickness values were 59.6 ± 12 mm, 16 ± 4.9 mm for EB and 65.8 ±12.8 mm, 12.6 ± 4.1 mm for FB, respectively. CBCT data revealed that the bladder volumes at treatment did not exceed FB nor were below EB values at simulation. Our study data quantify magnitude of vaginal cuff positional variation with bladder filling from EB to FB state. The use of a urinary catheter in all patients eliminated the need for repeat scans during CT/simulation to obtain true EB and FB scans. As also supported by our study limited CBCT data, the use of a urinary catheter to drain bladder as well as determine FB volume ensures that the intra-treatment bladder volumes never exceed nor fall below the FB and EB bladder volumes at simulation and thereby guarantees that the maximum vaginal cuff position variation has been accounted in the ITV generation.Abstract 2750; Table 1Vaginal Cuff Wall Displacement, mmRight WallLeft WallAnterior WallPosterior WallCranialCaudal(Mean ±SD)7.7 ±5.56.6 ±3.66.7 ±2.67.0 ±2.57.7 ±5.50.8 ±1.2Maximum20.314.718.514.522.52.5 Open table in a new tab

Altered brain and gut responses to corticotropin-releasing hormone (CRH) in patients with irritable bowel syndrome

Stress is a known trigger of irritable bowel syndrome (IBS) and exacerbates its gastrointestinal symptoms. However, underlying the physiological mechanism remains unknown. Here, we investigated hypothalamic–pituitary–adrenal (HPA) axis, colonic motility, and autonomic responses to corticotropin-releasing hormone (CRH) administration as well as brain activity alterations in IBS. The study included 28 IBS patients and 34 age and sex-matched healthy control subjects. IBS patients demonstrated greater adrenocorticotropic hormone (ACTH) responses to CRH than control subjects. Male IBS patients had greater increases in colonic motility than male HCs after CRH. Female IBS patients showed altered sympathovagal balance and lower basal parasympathetic tone relative to female control subjects. Brain responses to rectal distention were measured in the same subjects using functional magnetic resonance imaging, and their associations with individual ACTH responses to CRH were tested. A negative association between ACTH response to CRH and activity in the pregenual anterior cingulate cortex (pACC) during rectal distention was identified in controls but not in IBS patients. Impaired top-down inhibitory input from the pregenual ACC to the HPA axis may lead to altered neuroendocrine and gastrointestinal responses to CRH. Centrally acting treatments may dampen the stress induced physical symptoms in IBS.

MicroRNA-29a increased the intestinal membrane permeability of colonic epithelial cells in irritable bowel syndrome rats.

BackgroundThe whole pathogenesis of diarrhea-predominant irritable bowel syndrome(IBS-D) is poorly understood. Our goal was to evaluate the expression change of microRNA-29a(miR-29a) in colonic epithelial cells in IBS rats and clarify the mechanism of miR-29a increasing the intestinal membrane permeability through aquaporins(AQPs).MethodsThe IBS-D rats models were induced by rectal distention pressure combining with extremities constraint. The colonic epithelial cells were divided into four groups. A: normal group. B: IBS-D control group. C: IBS-D +miR-29a NC. D: IBS-D + miR-29a antagomir. The expression of miR-29a, the concentration of the K+ and Lactate Dehydrogenase(LDH) and the expression of AQPs were detected.ResultsThe miR-29a expression increased in IBS-D control group(2.090±0.022) compared with the control group(1.00±0.031) (P<0.001) while it decreased in IBS-D+miR-29a antagomir group(1.403±0.042) compared with IBS-D control group(P<0.001). The K+ decreased in IBS-D control group(1.305±0.289) compared with the control group(2.171±0.204)(P<0.05) while it increased in IBS-D+miR-29a antagomir group(1.813±0.102)(P<0.05) compared with IBS-D control group. The LDH increased in IBS-D control group(4153.440±177.365) compared with the control group(1434.573±96.111)(P<0.001) while it decreased in IBS-D+miR-29a antagomir group(2700.473±275.414) compared with IBS-D control group (P<0.01). The expression of AQP1, AQP3 and AQP8 decreased in IBS-D control group(0.132±0.010,0.110±0.005,0.108±0.007) compared with the control group (P<0.001) while it increased in IBS-D+miR-29a antagomir group(0.197±0.005,0.182±0.011,0.194±0.003) compared with IBS-D control group(P<0.001). The IBS-D+miR-29a negative control(NC) group, a comparison with IBS-D+miR-29a antagomir group, each date showed the similar trend to the IBS-D control group.ConclusionsMiR-29a increased the intestinal membrane permeability of colonic epithelial cells by reducing the AQPs expression in IBS-D rats.

Vaginal cuff brachytherapy in endometrial cancer - a technically easy treatment?

Endometrial cancer (EC) is one of the most common gynecological cancers among women in the developed countries. Vaginal cuff is the main location of relapses after a curative surgical procedure and postoperative radiation therapy have proven to diminish it. Nevertheless, these results have not translated into better survival results. The preeminent place of vaginal cuff brachytherapy (VCB) in the postoperative treatment of high- to intermediate-risk EC was given by the PORTEC-2 trial, which demonstrated a similar reduction in relapses with VCB than with external beam radiotherapy (EBRT), but VCB induced less late toxicity. As a result of this trial, the use of VCB has increased in clinical practice at the expense of EBRT. A majority of the clinical reviews of VCB usually address the risk categories and patient selection but pay little attention to technical aspects of the VCB procedure. Our review aimed to address both aspects. First of all, we described the risk groups, which guide patient selection for VCB in clinical practice. Then, we depicted several technical aspects that might influence dose deposition and toxicity. Bladder distension and rectal distension as well as applicator position or patient position are some of those variables that we reviewed.

Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology.

Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors impacting bee health.

Targeting fatty acid amide hydrolase and transient receptor potential vanilloid-1 simultaneously to modulate colonic motility and visceral sensation in the mouse: A pharmacological intervention with N-arachidonoyl-serotonin (AA-5-HT).

Endocannabinoid anandamide (AEA) inhibits intestinal motility and visceral pain, but it may also be proalgesic through transient receptor potential vanilloid-1 (TRPV1). AEA is degraded by fatty acid amide hydrolase (FAAH). This study explored whether dual inhibition of FAAH and TRPV1 reduces diarrhea and abdominal pain. Immunostaining was performed on myenteric plexus of the mouse colon. The effects of the dual FAAH/TRPV1 inhibitor AA-5-HT on electrically induced contractility, excitatory junction potential (EJP) and fast (f) and slow (s) inhibitory junction potentials (IJP) in the mouse colon, colonic propulsion and visceromotor response (VMR) to rectal distension were studied. The colonic levels of endocannabinoids and fatty acid amides were measured. CB1-positive neurons exhibited TRPV1; only some TRPV1 positive neurons did not express CB1. CB1 and FAAH did not colocalize. AA-5-HT (100nM-10μM) decreased colonic contractility by ~60%; this effect was abolished by TRPV1 antagonist 5'-IRTX, but not by CB1 antagonist, SR141716. AA-5-HT (1μM-10μM) inhibited EJP by ~30% and IJPs by ~50%. The effects of AA-5-HT on junction potentials were reversed by SR141716 and 5`-IRTX. AA-5-HT (20mg/kg; i.p.) inhibited colonic propulsion by ~30%; SR141716 but not 5`-IRTX reversed this effect. AA-5-HT decreased VMR by ~50%-60%; these effects were not blocked by SR141716 or 5`-IRTX. AA-5-HT increased AEA in the colon. The effects of AA-5-HT on visceral sensation and colonic motility are differentially mediated by CB1, TRPV1 and non-CB1/TRPV1 mechanisms, possibly reflecting the distinct neuromodulatory roles of endocannabinoid and endovanilloid FAAH substrates in the mouse intestine.

Mapping of Brain Activations to Rectal Balloon Distension Stimuli in Male Patients with Irritable Bowel Syndrome Using Functional Magnetic Resonance Imaging.

Background/AimsIrritable bowel syndrome (IBS) is associated with exaggerated cerebral response including emotional processing following visceral stimulation; though data on this issue is available in female IBS patients, it is scanty among males. Hence, we aimed to study brain response of male IBS patients following rectal balloon distension as compared to healthy controls using functional magnetic resonance imaging (fMRI). Data between diarrhea and constipation predominant IBS (IBS-D and IBS-C) were also compared.MethodsRectal balloon distension threshold was assessed in 20 male IBS patients (10 IBS-C and 10 IBS-D) and 10 age-matched male healthy controls. Subsequently, fMRI on all the participants was performed at their respective rectal pain threshold. The fMRI data were analysed using the Statistical Parametric Mapping software.ResultsIBS patients showed greater cerebral activations in insula, middle temporal gyrus, and cerebellum in the left hemisphere compared to healthy controls. Neural activation was found in bilateral precuneus/superior parietal lobules in controls but not in patients with IBS. The brain activation differed among IBS-C and IBS-D patients; while the right mid-cingulate cortex was activated in IBS-C, the left inferior orbito-frontal cortex, left calcarine, and bilateral fusiform gyri were activated among patients with IBS-D following rectal balloon distension.ConclusionsBrain response to rectal balloon distension differed among male patients with IBS and controls and among patients with IBS-C and IBS-D. Differential activation among patients with IBS-C and IBS-D was seen in the brain regions controlling affective motivation, homeostatic emotions, and autonomic responses to pain.

Visceral sensitivity, gut barrier function and autonomic nerve function in patients with diarrhea-predominant irritable bowel syndrome

To evaluate visceral sensitivity, gut barrier function and autonomic nerve function (ANF) in patients with diarrhea-predominant irritable bowel syndrome (IBS-D), and to explore their roles in IBS-D pathophysiology. Methods: A total of 46 IBS-D patients (IBS-D group) were selected from the Department of Gastroenterology of China-Japan Friendship Hospital from October 2015 to March 2016, and 20 healthy volunteer were served as a control group (HC group). Clinical and psychological symptoms were evaluated by questionnaire, and visceral sensitivity to rectal balloon distention, gut barrier function and autonomic nerve function (ANF) were examined. The difference in the above-mentioned indexes were compared between the 2 groups, and the correlations in the parameters were analyzed in the IBS-D group. Results: The scores of IBS symptom severity scale (IBS-SSS), Hamilton anxiety scale (HAMA), Hamilton depression scale (HAMD) and visceral sensitivity index (VSI) were significantly higher in the IBS-D group than those in the HC group (P<0.01). In the visceral sensitivity test, maximum tolerable threshold in the IBS-D group was significantly decreased compared to that in the HC group (P<0.01); there was no significant difference in first sensation threshold and defecating sensation threshold between the two groups (P>0.05). As gut barrier function markers, the serum diamine oxidase (DAO) and d-lactate were significantly increased in the IBS-D group (P<0.05). In ANF test, the total score and parasympathetic score as well as the proportion of abnormal scores in the IBS-D group were significantly higher than those in the HC group (P<0.05). In IBS-D group, the HAMA, VSI and serum DAO were positively correlated with IBS-SSS (r=0.528, 0.575, 0.507; P<0.01), while the 3 visceral sensitivity thresholds were negatively correlated with IBS-SSS (r= -0.636, -0.476, -0.697; P<0.01); in addition to the IBS-SSS, the HAMA, HAMD, VSI and serum DAO were also significant negatively correlated with the visceral sensitivity thresholds (all P<0.05); no significant correlations were found between the ANF and the other parameters. Conclusion: IBS-D patients show psychological symptoms, visceral hypersensitivity, impaired gut barrier function and abnormal ANF characterized by parasympathetic dysfunction; the former 3 factors are all associated with disease severity, and thus may play vital roles in IBS-D pathophysiology.

Effects of acute psychological stress on placebo and nocebo responses in a clinically relevant model of visceroception.

There is evidence to suggest a role of emotions in placebo and nocebo effects, but whether acute psychological stress changes the magnitude of placebo or nocebo responses has not been tested. In a clinically relevant model of visceroception, we assessed effects of acute psychological stress on changes in urgency and pain in response to positive or negative treatment suggestions. In 120 healthy volunteers, perceived urge-to-defecate and pain in response to individually calibrated rectal distensions were measured with visual analogue scales during a BASELINE. Participants then underwent the Trier Social Stress Test (N = 60) or a simple cognitive task (control, N = 60) and were randomized to positive (placebo), negative (nocebo), or neutral treatment information regarding intravenous administration of saline. The series of distensions was repeated, and changes in visual analogue scales from BASELINE to TEST were compared between groups using analysis of covariance and planned post hoc tests. Treatment information emerged as a main factor (P <0.001), supporting treatment information effects for both urgency and pain. Effects for urgency were modulated by stress (interaction effect: P <0.05): Positive information reduced urgency (P = 0.025), while negative information increased urgency (P = 0.026) only in stressed groups. For pain, effects of stress emerged for nocebo responses, which were only evident in stressed groups (P = 0.009). This is the first experimental study supporting effects of acute psychological stress on placebo and nocebo responses in visceroception. Results call for mechanistic as well as patient studies to assess how psychological stress shapes patients' treatment expectations and thereby affects health outcomes.

Greater fear of visceral pain contributes to differences between visceral and somatic pain in healthy women.

This functional magnetic resonance imaging study addressed similarities and differences in behavioral and neural responses to experimental visceral compared with somatic pain stimuli and explored the contribution of fear of pain to differences between pain modalities. In N = 22 healthy women, we assessed blood oxygen level-dependent responses to rectal distensions and cutaneous heat stimuli matched for perceived pain intensity. Fear of pain and pain unpleasantness were assessed before and after scanning. Visceral pain was more fear evoking and more unpleasant, and trial-by-trial intensity ratings failed to habituate across trials (all interactions modality × time: P < 0.01). Differences in fear of pain and pain intensity independently contributed to greater visceral pain unpleasantness (combined regression model: R(2) = 0.59). We observed joint neural activations in somatosensory cortex and frontoparietal attention network (conjunction analysis: all pFWE <0.05), but distensions induced greater activation in somatosensory cortex, dorsal and ventral anterior insula, dorsal anterior and midcingulate cortices, and brainstem, whereas cutaneous heat pain led to enhanced activation in posterior insula and hippocampus (all pFWE <0.05). Fear of visceral pain correlated with prefrontal activation, but did not consistently contribute to neural differences between modalities. These findings in healthy women support marked differences between phasic pain induced by rectal distensions vs cutaneous heat, likely reflecting the higher salience of visceral pain. More studies with clinically relevant pain models are needed to discern the role of fear in normal interindividual differences in the response to different types of pain and as a putative risk factor in the transition from acute to chronic pain.

Sa1644 - Effect of Rectal Distention on Anal Pressures During Simulated Defecation in Patients with Defecatory Disorders

Sa1644 - Effect of Rectal Distention on Anal Pressures During Simulated Defecation in Patients with Defecatory Disorders

Does calprotectin level identify a subgroup among patients suffering from irritable bowel syndrome? Results of a prospective study.

Irritable bowel syndrome is a multifactorial disease. Although faecal calprotectin has been shown to be a reliable marker of intestinal inflammation, its role in irritable bowel syndrome remains debated. The aims of this prospective study were to select a subgroup of irritable bowel syndrome patients and to characterise those patients with high faecal calprotectin by systematic work-up. Calprotectin levels were determined by enzyme-linked immunosorbent assay test in consecutive irritable bowel syndrome patients fulfilling Rome III criteria in whom normal colonoscopy and appropriate tests had excluded organic disease. Calprotectin levels were compared in irritable bowel syndrome patients, healthy controls and patients with active and quiescent Crohn's disease. When the calprotectin level was higher than 50 µg/g, the absence of ANCA/ASCA antibodies and a normal small bowel examination were required to confirm irritable bowel syndrome diagnosis. Additional explorations included assessment of irritable bowel syndrome severity, anxiety and depression, impact on quality of life, glucose and fructose breath tests, rectal distension test by barostat and quantitative and qualitative assessment of inflammation on colonic biopsies. Among the 93 irritable bowel syndrome patients (73% women; 66.7% with diarrhoea) recruited, 34 (36.6%) had reproducibly elevated calprotectin. Although they tended to be older than those with normal calprotectin (P = 0.06), there were no other differences between the two groups. When elevated, calprotectin was correlated with age (P = 0.03, r = 0.22). Elevated faecal calprotectin was observed in one third of patients in this series, without any significant association with a specific clinical phenotype (except age) or specific abnormalities.

Evaluating the effect of rectal distension on prostate multiparametric MRI image quality

PurposeTo evaluate the effect of rectal distension on the quality of anatomical and functional prostate multiparametric (mp) MRI. Materials and methodsMultiparametric (mp) 3T-MRI images of 173 patients were independently evaluated by two radiologists in this retrospective study. Planimetry rectal volumes were derived and a subjective assessment of rectal distension was made using a 5-point Likert scale (1=no stool/gas, 5=large amount of stool/gas). Image quality of diffusion-weighted imaging (DWI) was evaluated using a 5-point Likert scale. DWI was further scored for distortion and artefact. T2W images were evaluated for image sharpness and the presence of motion artefact. The stability of the dynamic contrast-enhancement acquisition was assessed by recording the number of corrupt data points during the wash-out phase. ResultsThere was a strong correlation between subjective scoring of rectal loading and objectively measured rectal volume (r=0.82), p<0.001. A significant correlation was shown between increased rectal distension and both reduced DW image quality (r=−0.628, p<0.001), and increased DW image distortion (r=0.814, p<0.001). There was also a significant trend for rectal distension to increase artefact at DWI (r=0.154, p=0.042). Increased rectal distension led to increased motion artefact on T2 (p=0.0096), but did not have a significant effect on T2-sharpness (p=0.0638). There was no relationship between rectal distension and DCE image quality (p=0.693). 63 patients underwent lesion-targeted biopsy post MRI, there was a trend to higher positive predictive values in patients with minor rectal distension (34/38, 89.5%) compared to those with moderate/marked distension (18/25, 72%), p=0.09. ConclusionRectal distension has a significant negative effect on the quality of both T2W and DW images. Consideration should therefore be given to bowel preparation prior to prostate mpMRI to optimise image quality.

Learning by experience? Visceral pain-related neural and behavioral responses in a classical conditioning paradigm.

Studies investigating mechanisms underlying nocebo responses in pain have mainly focused on negative expectations induced by verbal suggestions. Herein, we addressed neural and behavioral correlates of nocebo responses induced by classical conditioning in a visceral pain model. In two independent studies, a total of 40 healthy volunteers underwent classical conditioning, consisting of repeated pairings of one visual cue (CSHigh ) with rectal distensions of high intensity, while a second cue (CSLow ) was always followed by low-intensity distensions. During subsequent test, only low-intensity distensions were delivered, preceded by either CSHigh or CSLow . Distension intensity ratings were assessed in both samples and functional magnetic resonance imaging data were available from one study (N=16). As a consequence of conditioning, we hypothesized CSHigh -cued distensions to be perceived as more intense and expected enhanced cue- and distension-related neural responses in regions encoding sensory and affective dimensions of pain and in structures associated with pain-related fear memory. During test, distension intensity ratings did not differ depending on preceding cue. Greater distension-induced neural activation was observed in somatosensory, prefrontal, and cingulate cortices and caudate when preceded by CSHigh . Analysis of cue-related responses revealed strikingly similar activation patterns. We report changes in neural activation patterns during anticipation and visceral stimulation induced by prior conditioning. In the absence of behavioral effects, markedly altered neural responses may indicate conditioning with visceral signals to induce hypervigilance rather than hyperalgesia, involving altered attention, reappraisal, and perceptual acuity as processes contributing to the pathophysiology of visceral pain.

Brain function in patients with diarrhea type irritable bowel syndrome after rectal balloon distention

Objective To investigate the correlation between activated brain regions examined by functional magnetic resonance imaging (fMRI) after rectal balloon distention and intestinal symptoms, psychological status, and quality of life in patients with diarrhea type irritable bowel syndrome (IBS-D) at different stages of disease. Methods According to the symptoms status, patients with IBS-D were divided into onset group (seven patients), remission group (five patients) and persistence group (six patients), and six healthy individuals were selected as healthy controls at the same time. After stimulated with rectal balloon distention at first sensation thresholds, continual defecation thresholds or 80% of maximum tolerable thresholds, patients received fMRI examination. Analysis of variance and two-sample t test were used to compare the difference in activated brain areas between two groups. Pearson analysis was performed to analyze the correlations between activated brain areas and scores of irritable bowel syndrome (IBS) intestinal symptom, Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA) and irritable bowel syndrome special quality of life scale (IBS-QOL). Results There was no significant difference in first sensation thresholds, continual defecation thresholds or 80% of maximum tolerable thresholds between patients of different groups. After rectal balloon distention, there were differences in such brain areas: bilateral anterior cingulate cortex (ACC), left inferior parietal lobe, and left middle frontal gyrus. Compared with those of control group, the activation of ACC, inferior parietal lobe and middle frontal gyrus lowered in patients of onset group (both P<0.05). There was positive correlation between the activation of middle frontal gyrus and intestinal symptom scores in persistence group(r=0.823, P=0.048). There were negative correlations between the activation of inferior parietal lobe (r =-0.816, P=0.048), middle frontal gyrus(r=-0.860, P=0.028) of persistence group, activation of middle frontal gyrus (r=-0.892, P=0.042) of remission group and HAMD score. There were positive correlations between the activation of inferior parietal lobe (r =0.818, P=0.047), middle frontal gyrus(r = 0.907, P=0.013) of persistence group, activation of midfrontal gyrus (r = 0.914, P=0.030) of remission group and scores of IBS-QOL. Conclusion The brain regions were activated during the rectal balloon distention both in IBS-D patients and healthy controls, and there were differences in activated brain regions among different stages of IBS-D. Key words: Irritable bowel syndrome; diarrhea; Magnetic resonance imaging; Brain region activities; Rectal balloon distention

Face-to-Face Cognitive-Behavioral Therapy for Irritable Bowel Syndrome: The Effects on Gastrointestinal and Psychiatric Symptoms.

Irritable bowel syndrome (IBS) is a gastrointestinal disorder linked to disturbances in the gut-brain axis. Visceral hypersensitivity and pain are hallmarks of IBS and linked to the physiological and psychological burden and to the nonadaptive coping with stress. Cognitive-behavioral therapy (CBT) for IBS has proven effective in reducing gastrointestinal and psychiatric symptoms in IBS by means of coping with stress. The present pilot study evaluated for the first time whether CBT for IBS affected visceral sensitivity and pain. Individual CBT was performed for 12 weeks in 18 subjects with IBS and evaluated in terms of visceral sensitivity and pain during rectal distensions using the barostat method and self-rated visceral sensitivity and gastrointestinal and psychiatric symptoms. Visceral discomfort, urge, and pain induced by the barostat were not affected by CBT but were stable across the study. However, the level of self-rated visceral sensitivity and gastrointestinal and psychiatric symptoms decreased after the intervention. Central working mechanisms and increased ability to cope with IBS-symptoms are suggested to play a key role in the alleviation of IBS symptoms produced by CBT.

The Effects of Auricular Electro-Acupuncture on Ameliorating the Dysfunction of Interstitial Cells of Cajal Networks and nNOSmRNA Expression in Antrum of STZ-Induced Diabetic Rats.

BackgroudInterstitial cells of Cajal (ICCs) and nNOS play a crucial role in diabetic gastrointestinal dysmotility(DGD). Our previous study found that electro-acupuncture(EA) on ear point ‘stomach’ could repair the gastric dysrhythmias in rats induced by rectal distention(RD) after meal. However, little were known about the possible effect of auricular electro-acupuncture (AEA) on diabetic rats. Thus, we designed this study to investigate the effect of AEA on streptozotocin(STZ)-induced diabetic rats.MethodForty male Sprague_Dawley (SD) rats were injected with STZ, at the end of 8th week after injection, animals were randomly divided into four groups and received 2 weeks-treatment(10 times) respectively: control group(CON,n = 10, no stimulation), sham auricular electro-acupuncture group(SEA,n = 10, low frequency EA on earlobes), auricular eletro-acupuncture group(AEA,n = 10, low frequency EA on ear point ‘stomach’), and ST-36 group(ST-36,n = 10, low frequency EA on ST-36). Gastrointestinal (GI) motility was measured by GI transit rate. ICCs(c-kit+ expression) in antrum were analyzed by Immunohistochemistry and western blotting. NO level in blood serum were detected by Griess Reagent, and nNOSmRNA expression in antrum were determined by Real-time PCR.ResultsGI transit rate and ICCs(c-kit+ expression) in antrum of AEA group have the tendency to increase compared with CON group, but had no statistics difference (P>0.05). nNOSmRNA expression in antrum of AEA group was dramatically increased compared with CON group (P = 0.037).ConclusionsLow frequency EA on ear ‘stomach’ point could significantly up-regulate nNOS mRNA expression and ameliorate the ICCs networks partly in gastric antrum of STZ -induced diabetic rats, which may has benefits on regulating the GI motility.

Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension

ObjectivesTo compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel. MethodsFrom January 2014 to July 2016, 25 patients (average age 63.7, range 41–85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5T MRI. Diffusion MRI was obtained using echo-planar imaging with b=800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers − for each type of ADC measurement − were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis. ResultsBorder ADC mean value for diffusion MR sequences without endorectal contrast was 1.122mm2/sec, with 95% Confidence Interval (CI)=1.02–1.22; using gel lumen distension, higher border ADC mean value of 1.269mm2/s (95% CI=1.16–1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p<0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038mm2/s (95% CI=0.91–1.16) for diffusion sequences acquired without endorectal distension and 1.127mm2/s (95% CI=0.98–1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p=0.13). A very strong positive correlation was observed, with r value of 0.81. ConclusionsADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to investigate better reliability of ADC in rectal cancer MRI using sonographic gel intraluminal distension.

Increased expression of nerve growth factor correlates with visceral hypersensitivity and impaired gut barrier function in diarrhoea-predominant irritable bowel syndrome: a preliminary explorative study.

Neural-immune-endocrine network mechanism has attracted increased attention in diarrhoea-predominant irritable bowel syndrome (IBS-D). Pre-clinical evidence indicates that nerve growth factor (NGF) mediates visceral hypersensitivity and gut barrier dysfunction, via interactions with mast cells and sensory nerve fibres. To explore the role of nerve growth factor, as well as mast cell-nerve growth factor-nerve interaction in IBS-D pathophysiology. In this cross-sectional study, IBS-D patients and healthy controls first underwent clinical and psychological assessments. Visceral sensitivity to rectal distension was tested. As gut barrier function markers, serum diamine oxidase and d-lactate were detected. Rectosigmoid biopsies were taken for the analyses of nerve growth factor expression, mast cell count and activation, and sensory nerve fibres expressing transient receptor potential vanilloid 1 and calcitonin gene-related peptide. Correlations between these parameters were examined in patients. Thirty-eight IBS-D patients (28 males, 10 females; average age 30.2 years) and 20 healthy controls (12 males, 8 females; average age 26.8 years) participated in the study. The patients presented increased psychological symptoms, visceral hypersensitivity and impaired gut barrier function. NGF gene expression, mast cell count and sensory nerve fibres were significantly increased in the patients (P < 0.05). In correlation analysis, NGF expression was positively correlated with the disease severity, anxiety and serum diamine oxidase; visceral sensitivity thresholds were negatively associated with NGF expression (Bonferroni corrected P < 0.0029). Elevated mucosal NGF may interact with mast cells and sensory nerve fibres, contributing to visceral hypersensitivity and impaired gut barrier function in IBS-D.