肠道微生态影响动脉粥样硬化发生发展的机制

动脉粥样硬化(AS)不仅是一种炎症性疾病,而且属于一种代谢性疾病。肠道微生态的改变可对AS的发生发展产生双面影响。一方面,肠道菌群紊乱可以通过影响机体的胆碱代谢、氧化应激、炎症反应等机制直接促进AS产生发展,此外,可通过导致AS危险因素肥胖、高脂血症、糖尿病等的产生这些间接机制促AS的进展。另一方面,益生菌及益生元的增加则可有效地降低肠道微生物内毒素产生、增强肠道屏障、减轻机体质量、缓解炎症反应、改善胰岛素抵抗,进而在AS的进展方面发挥重要作用。因此,合理调控机体肠道微生态环境成为AS防治的新型重要手段。     

PNPLA3 I148M polymorphism and progressive liver disease

The 148 Isoleucine to Methionine protein variant(I148M)of patatin-like phospholipase domain-containing 3(PNPLA3),a protein is expressed in the liver and is involved in lipid metabolism,has recently been identified as a major determinant of liver fat content.Several studies confirmed that the I148M variant predisposes towards the full spectrum of liver damage associated with fatty liver:from simple steatosis to steatohepatitis and progressive fibrosis.Furthermore,the I148M variant represents a major determinant of progression of alcohol related steatohepatitis to cirrhosis,and to influence fibrogenesis and related clinical outcomes in chronic hepatitis C virus hepatitis,and possibly chronic hepatitis B virus hepatitis,hereditary hemochromatosis and primary sclerosing cholangitis.All in all,studies suggest that the I148M polymorphism may represent a general modifier of fibrogenesis in liver diseases.Remarkably,the effect of the I148M variant on fibrosis was independent of that on hepatic steatosis and inflammation,suggesting that it may affect both the quantity and quality of hepatic lipids and the biology of non-parenchymal liver cells besides hepatocytes,directly promoting fibrogenesis.Therefore,PNPLA3 is a key player in liver disease progression.Assessment of the I148M polymorphism will possibly inform clinical practice in the future,whereas the determination of the effect of the 148M variant will reveal mechanisms involved in hepatic fibrogenesis.     

Endoscopic resection techniques for colorectal neoplasia:Current developments

Endoscopic polypectomy and endoscopic mucosal resection(EMR) are the established treatment standards for colorectal polyps. Current research aims at the reduction of both complication and recurrence rates as well as on shortening procedure times. Cold snare resection is the emerging standard for the treatment of smaller(< 5 mm) polyps and is possibly also suitable for the removal of noncancerous polyps up to 9 mm. The method avoids thermal damage, has reduced procedure times and probably also a lower risk for delayed bleeding. On the other end of the treatment spectrum, endoscopic submucosal dissection(ESD)offers en bloc resection of larger flat or sessile lesions. The technique has obvious advantages in the treatment of high-grade dysplasia and early cancer. Due to its minimal recurrence rate, it may also be an alternative to fractionated EMR of larger flat or sessile lesions. However, ESD is technically demanding and burdened by longer procedure times and higher costs. It should therefore be restricted to lesions suspicious for high-grade dysplasia or early invasive cancer.The latest addition to endoscopic resection techniques is endoscopic fullthickness resection with specifically developed devices for flexible endoscopy.This method is very useful for the treatment of smaller difficult-to-resect lesions,e.g., recurrence with scar formation after previous endoscopic resections.     

Lymph node staging in colorectal cancer:Old controversies and recent advances

Outcome prediction based on tumor stage reflected by the American Joint Committee on Cancer(AJCC)/Union for International Cancer Control(UICC)tumor node metastasis(TNM)system is currently regarded as the strongest prognostic parameter for patients with colorectal cancer.For affected patients,the indication for adjuvant therapy is mainly guided by the presence of regional lymph node metastasis.In addition to the extent of surgical lymph node removal and the thoroughness of the pathologist in dissecting the resection specimen,several parameters that are related to the pathological work-up of the dissected nodes may affect the clinical significance of lymph node staging.These include changing definitions of lymph nodes,involved lymph nodes,and tumor deposits in different editions of the AJCC/UICC TNM system as well as the minimum number of nodes to be dissected.Methods to increase the lymph node yield in the fatty tissue include methylene blue injection and acetone compression.Outcome prediction based on the lymph node ratio,defined as the number of positive lymph nodes divided by the total number of retrieved nodes,may be superior to the absolute numbers of involved nodes.Extracapsular invasion has been identified as additional prognostic factor.Adding step sectioning and immunohistochemistry to the pathological work-up may result in higher accuracy of histological diagnosis.The clinical value of more recent technical advances,such as sentinel lymph node biopsy and molecular analysis of lymph nodes tissue still remains to be defined.     

Role of endoscopic ultrasound in the screening and follow-up of high-risk individuals for familial pancreatic cancer

Managing familial pancreatic cancer(FPC)is challenging for gastroenterologists,surgeons and oncologists.High-risk individuals(HRI)for pancreatic cancer(PC)(FPC or with germline mutations)are a heterogeneous group of subjects with a theoretical lifetime cumulative risk of PC over 5%.Screening is mainly based on annual magnetic resonance imaging(MRI)and endoscopic ultrasound(EUS).The goal of screening is to identify early-stage operable cancers or high-risk precancerous lesions(pancreatic intraepithelial neoplasia or intraductal papillary mucinous neoplasms with high-grade dysplasia).In the literature,target lesions are identified in 2%-5%of HRI who undergo screening.EUS appears to provide better identification of small solid lesions(0%-46%of HRI)and chronicpancreatitis-like parenchymal changes(14%-77%of HRI),while MRI is probably the best modality to identify small cystic lesions(13%-49%of HRI).There are no specific studies in HRI on the use of contrast-enhanced harmonic EUS.EUS can also be used to obtain tissue samples.Nevertheless,there is still limited evidence on the accuracy of imaging procedures used for screening or agreement on which patients to treat.The cost-effectiveness of screening is also unclear.Certain new EUS-related techniques,such as searching for DNA abnormalities or protein markers in pancreatic fluid,appear to be promising.     

Prophecy about post-endoscopic retrograde cholangiopancreatography pancreatitis:From divination to science

One unresolved issue of endoscopic retrograde cholangiopancreatography(ERCP)is post-ERCP pancreatitis (PEP),which occurs in up to 40%of patients.Identification of risk factors for PEP is especially important in the field of ERCP practice because it may assist physicians in taking protective measures in situations with high risk.A decade ago,Freeman et al meticulously evaluated a large number of potentially relevant risk factors for PEP,which can be divided into patient-relat-ed and procedure-related issues.In this commentary, we summarize this classic article and reevaluate the risk factors for PEP from the current point of view.This is followed by assessment of strategies for prevention of PEP that can be divided into mechanical and pharmacologic methods.     

Issues and controversies in esophageal inlet patch

The proximal esophagus is rarely examined,and its inspection is often inadequate.Optical chromoendoscopy techniques such as narrow band imaging improve the detection rate of inlet patches in the proximal esophagus,a region in which their prevalence is likely underestimated.Various studies have reported correlations between these esophageal marks with different issues such as Barrett’s esophagus,but these findings remain controversial.Conflicting reports complicate the process of interpreting the clinical features of esophageal inlet patches and underestimate their importance.Unfortunately,the limited clinical data and statistical analyses make reaching any conclusions difficult.It is hypothesized that inlet patches are correlated with various esophageal and extraesophageal symptoms,diagnoses and the personalized therapeutic management of patients with inlet patches as well as the differential diagnosis for premalignant lesions or early cancers.Due to its potential underdiagnosis,there are no consensus guidelines for the management and follow up of inlet patches.This review focuses on questions that were raised from published literature on esophageal inlet patches in adults.     

Obstructive sleep apnea increases heart rhythm disorders and worsens subsequent outcomes in elderly patients with subacute myocardial infarction

OBJECTIVE Obstructive sleep apnea(OSA)is a potential cardiovascular risk.We aimed to investigate the association of OSA with heart rhythm disorders and prognosis in elderly patients with new-onset acute myocardial infarction(AMI).METHODS We prospectively enrolled 252 AMI elderly patients(mean age,68.5±6.9 years)who were undergoing revascularization and completed a sleep study during their hospitalization.All subjects were categorized into non-OSA(apnea–hypopnea index(AHI)<15,n=130)and OSA(AHI≥15,n=122)groups based on the AHI.The changes in the autonomic nervous system,incidence of arrhythmia during nocturnal sleep,and major adverse cardiovascular and cerebrovascular events(MACCEs)were compared between the groups.RESULTS The mean AHI value in all AMI patients was 22.8±10.9.OSA patients showed higher levels of body mass index and peak high-sensitivity C-reactive protein and lower levels of minimum nocturnal oxygen saturation(Min Sa O2),as well as greater proportion of multivessel coronary artery disease(all P<0.05).The OSA group also showed significant increases in heart rate variability and heart rate turbulence onset(both P<0.05)and higher incidence of arrhythmia(including sinus,atrial,and ventricular in origin).At a median follow-up of 6 months(mean 0.8–1.6 years),OSA(AHI≥15)combined with hypoxia(Min Sa O2≤80%)was independently associated with the incidence of MACCEs(hazard ratio[HR]:4.536;95%confidence interval[CI]:1.461-14.084,P=0.009)after adjusting for traditional risk factors.CONCLUSIONS OSA and OSA-induced hypoxia may correlate with the severity of myocardial infarction,increase the occurrence of heart rhythm disorders in elderly subacute MI patients,and worsen their short-term poor outcomes.     

Endoscopic management of difficult common bile duct stones

Endoscopy is widely accepted as the first treatment option in the management of bile duct stones.In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones.Most biliary stones can be removed with an extraction balloon,extraction basket or mechanical lithotripsy after endoscopic sphincterotomy.Endoscopic papillary balloon dilation with or without endoscopic sphincterotomy or mechanical lithotripsy has been shown to be effective for management of difficult to remove bile duct stones in selected patients.Ductal clearance can be safely achieved with peroral cholangioscopy guided laser or electrohydraulic lithotripsy in most cases where other endoscopic treatment modalities have failed.Biliary stenting may be an alternative treatment option for frail and elderly patients or those with serious co morbidities.     

Rare cystic liver lesions: A diagnostic and managing challenge

Cystic formations within the liver are a frequent finding among populations.Besides the common cystic lesions,like simple liver cysts,rare cystic liver lesions like cystadenocarcinoma should also be considered in the differential diagnosis.Thorough knowledge of each entity’s nature and course are key elements to successful treatment.Detailed search in PubMed,Cochrane Database,and international published literature regarding rare cystic liver lesions was carried out.In our research are included not only primary rare lesions like cystadenoma,hydatid cyst,and polycystic liver disease,but also secondary ones like metastasis from gastrointestinal stromal tumors lesions.Up-to date knowledge regarding diagnosis and management of rare cystic liver lesions is provided.A diagnostic and therapeutic algorithm is also proposed.The need for a multidisciplinary approach by a team including radiologists and surgeons familiar with liver cystic entities,diagnostic tools,and treatment modalities is stressed.Patients with cystic liver lesions must be carefully evaluated by a multidisciplinary team,in order to receive the most appropriate treatment,since many cystic liver lesions have a malignant potential and evolution.     

肠易激综合征患者脑部痛觉功能区域的变化

目的应用血氧水平依赖性功能性磁共振(BOLD fMRI)技术研究肠易激综合征(irritablebowelsyndrome ,IBS)患者颅内痛觉功能区的变化及临床意义并比较与正常人的差异。方法2 0 0 2年1月～2 0 0 4年2月期间,参照罗马II诊断标准纳入67例肠易激综合征患者和10例正常志愿者,其中腹泻型肠易激综合征44例,男19例,女2 5例。年龄3 4～73岁,平均年龄5 3 0 7±8 44岁。便秘型肠易激综合征2 3例,其中男12例,女11例,年龄2 1～74岁,平均年龄46 2 2±14 64岁。直肠注气试验记录感觉阈值和感觉评分;功能性磁共振(fMRI)分析直肠扩张3 0ml、60ml、90ml和12 0ml时颅内痛觉功能区扣带前皮质(ACC)、脑岛皮质(IC)、额前皮质(PFC)及丘脑(THAL)的激活面积和强度。结果腹泻型IBS患者排便急迫和疼痛阈值显著低于便秘型患者和正常志愿者(P <0 0 5 ) ;腹泻型IBS患者在直肠注气90ml和12 0ml时视觉模拟评分(VAS)显著高于正常志愿者(P <0 0 5 ) ;便秘型IBS患者直肠扩张12 0ml时额前皮质、右侧丘脑兴奋面积较正常对照组显著增高(P <0 0 5 ) ,腹泻型IBS患者直肠扩张12 0ml时右侧脑岛皮质、额前皮质和右侧丘脑的兴奋面积较正常对照组显著增高(P <0 0 5 ) ;所有IBS患者直肠扩张90ml时脑岛皮质、直肠扩张12 0ml时脑岛皮质、额前皮质和丘脑     

肠吉安口服液对肝脾不和腹泻型肠易激综合征患者大脑功能区激活面积的影响

[目的]研究中药复方制剂肠吉安治疗前后肝脾不和腹泻型肠易激综合征(IBS)患者大脑痛觉功能区激活面积的变化.[方法]24例肝脾不和腹泻型IBS患者随机分为两组,分别给予肠吉安口服液(14例)和安慰剂(10例).通过直肠注气试验记录两组患者的感觉阈值和感觉评分,并应用功能性磁共振(fMRI)分析直肠扩张30、60、90和120ml时大脑痛觉功能区的激活面积.[结果]肠吉安组治疗后症状评分明显下降(P＜0.05),两组治疗前后比较差异有统计学意义(P＜0.05).直肠注气试验中两组治疗前后组间比较急迫排便阈值、疼痛阈值差异有统计学意义(P＜0.05);视觉模拟评分治疗前后组间比较,直肠注气＞30 ml时差异有统计学意义(P＜0.05);直肠注气120 ml时,肠吉安组治疗后大脑痛觉功能区右侧脑岛皮质和额前皮质的激活面积显著减少(P＜0.05),而安慰剂组治疗前后未见显著改变(P＞0.05).[结论]肠吉安通过调节大脑痛觉功能区的激活面积发挥对肝脾不和型IBS患者的显著疗效.     

Uneven acute non-alcoholic fatty change of the liver after percutaneous transhepatic portal vein embolization in a patient with hilar cholangiocarcinoma – a case report

Irritable bowel syndrome (IBS) is a common functional disease of the gastrointestinal tract. The current study aimed to examine the association between visceral hypersensitivity in IBS and cortical activation using functional magnetic resonance imaging (fMRI), and to elucidate the role of psychological factors in the pathogenesis of IBS. The present study included 31 patients with IBS and 20 healthy controls. Cerebral function was assessed using fMRI. During imaging, a Sengstaken-Blakemore tube was placed within the rectum approximately 10 cm from the anus, following which gas was rapidly injected into the airbag using a 150-ml syringe. Images were obtained at 40 ml, 80 ml, and 120 ml of expansion. Psychological status was evaluated using the Hospital Anxiety and Depression Scale (HADS). Anxiety and depression scores were higher among patients with IBSthan among controls (both P < 0.05), although scores in both groups were below the level of clinical diagnosis. Brain activation in regions of interest (parietal areas, prefrontal cortex, cerebellum, anterior cingulate cortex, insular cortex, and thalamus) increased along with increases in rectal balloon dilation, except in women with IBS and patients with disease duration less than 5 years. Furthermore, region of interest (ROI) activation (such as the parietal region, prefrontal cortex, cerebellum, anterior cingulate cortex, insular cortex, and thalamus) differed significantly between the 40-ml and 120-ml conditions, and between the 80-ml and 120-ml conditions (P < 0.05), among patients with IBS with anxiety or depression scores less than 9 points. Overall, our findings indicate that changes in brain activation due to changes in rectal balloon distension can be objectively and accurately measured using fMRI. Although our results indicated that visceral hypersensitivity during IBS is associated with changes in cortical activation, further studies utilizing larger sample sizes are required to more fully elucidate the association between psychological factors and visceral hypersensitivity in IBS.     

Regional cerebral activation in irritable bowel syndrome and control subjects with painful and nonpainful rectal distention

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is characterized by visceral hypersensitivity, possibly related to abnormal brain-gut communication. Positron emission tomography imaging has suggested specific central nervous system (CNS) abnormalities in visceral pain processing in IBS. This study aimed to determine (1) if functional magnetic resonance imaging (fMRI) detects CNS activity during painful and nonpainful visceral stimulation; and (2) if CNS pain centers in IBS respond abnormally. METHODS: fMRI was performed during nonpainful and painful rectal distention in 18 patients with IBS and 16 controls. RESULTS: Rectal stimulation increased the activity of anterior cingulate (33/34), prefrontal (32/34), insular cortices (33/34), and thalamus (32/34) in most subjects. In IBS subjects, but not controls, pain led to greater activation of the anterior cingulate cortex (ACC) than did nonpainful stimuli. IBS patients had a greater number of pixels activated in the ACC and reported greater intensity of pain at 55-mm Hg distention than controls. CONCLUSIONS: IBS patients activate the ACC, a critical CNS pain center, to a greater extent than controls in response to a painful rectal stimulus. Contrary to previous reports, these data suggest heightened pain sensitivity of the brain-gut axis in IBS, with a normal pattern of activation.     

Visceral hypersensitivity following cold water intake in subjects with irritable bowel syndrome

Background Visceral hypersensitivity has been shown to be present in irritable bowel syndrome (IBS). This study sought to investigate rectal sensitivity and abdominal symptoms in IBS patients before and after 220 ml cold water intake. Methods A total of 60 IBS patients and 18 healthy controls participated in this study. Both the perception thresholds and defecation thresholds to rectal balloon distension were measured. Then, all subjects were asked to drink 220 ml 37°C warm water or 4°C cold water, and these steps were repeated 20 min later. Symptoms including abdominal pain/discomfort, bloating, and diarrhea were recorded during the study. Results Compared with the controls, the thresholds of initial sensation to rectal balloon distention in IBS patients were significantly lower while the defecation thresholds were higher in constipation-predominant IBS patients. After drinking cold water, the perception thresholds in IBS patients and the defecation thresholds in diarrhea-predominant IBS patients were further decreased. However, warm water intake did not change the perception thresholds significantly in either IBS patients or controls. A negative linear correlation was found between the symptoms and the visceral perception thresholds in diarrhea-predominant IBS patients who showed significant symptoms after cold water intake. Conclusion The results indicated that cold water intake leads to lowered visceral perception thresholds in IBS patients that were inversely relevant to the abdominal symptoms in symptomatic diarrhea-predominant IBS patients. The alteration of rectal sensitivity and abdominal symptoms following cold water stimulation provided further objective evidence for visceral hypersensitivity in IBS patients.     

Abnormal endogenous pain modulation and somatic and visceral hypersensitivity in female patients with irritable bowel syndrome

AIM： To investigate the role of endogenous pain modulatory mechanisms in the central sensitization implicated by the visceral hypersensitivity demonstrated in patients with irritable bowel syndrome （IBS）. Dysfunction of modulatory mechanisms would be expected to also result in changes of somatic sensory function.
METHODS： Endogenous pain modulatory mechanisms were assessed using heterotopic stimulation and somatic and visceral sensory testing in IBS. Pain intensities （visual analogue scale, VAS 0-100） during suprathreshold rectal distension with a barostat, cold pressor stimulation of the foot and during both stimuli simultaneously （heterotopic stimulation） were recorded in 40 female patients with IBS and 20 female healthy controls.
RESULTS： Rectal hypersensitivity （defined by 95% Cl of controls） was seen in 21 （53%）, somatic hypersensitivity in 22 （55%） and both rectal and somatic hypersensitivity in 14 of these IBS patients. Heterotopic stimulation decreased rectal pain intensity by 6 （-11 to -1） in controls, but increased rectal pain by 2 （-3 to ＋6） in all IBS patients （P 〈 0.05） and by 8 （-2 to ＋19） in IBS patients with somatic and visceral hypersensitivity （P 〈 0.02）.
CONCLUSION： A majority of IBS patients had abnormal endogenous pain modulation and somatic hypersensitivity as evidence of central sensitization.     

Evidence for autonomic dysregulation in the irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by chronic abdominal pain and visceral hypersensitivity. In this study, resting blood pressure and heart rate were recorded in 20 IBS patients and 23 controls. We assessed pain intensity and unpleasantness to visceral and cutaneous stimuli using rectal distension and immersion of the foot in hot water. Mean resting heart rate was higher in IBS patients compared to controls. IBS patients rated pain intensity and unpleasantness to visceral and cutaneous stimuli significantly higher than controls. In IBS patients, blood pressure was significantly inversely associated with visceral pain and only weakly and positively associated with cutaneous pain; there were no relationships in controls. Sex and anxiety did not explain these relationships. In conclusion, we found evidence suggestive of central autonomic dysregulation in IBS patients.     

Visceral hypersensitivity in irritable bowel syndrome

Altered central processing, abnormal gastrointestinal motility and visceral hypersensitivity may be possible major pathophysiology of irritable bowel syndrome (IBS). These factors affect each other and are probably associated with development of IBS symptoms. It has been confirmed that lower pain threshold to colonic distention was observed in most of patients with IBS than healthy subjects. We have investigated pain perception of the descending colon among different subtypes of IBS. There was no difference in pain threshold to colonic distention between IBS with diarrhea and constipation. Some brain regions such as the anterior cingulate cortex (ACC) may play a major role for generating pain and/or pain-related emotion in humans. IBS patients showed greater activation in the perigenual ACC during painful rectal distention compared with healthy subjects. Inflammation, stress and the combination of both stimuli can induce significant increase in visceral sensitivity in animal models. Serotonin (5-HT) can modulate visceral perception. It has been thought that 5-HT(3) receptors may play an important role for conveying visceral sensation from the gut. Corticotropin-releasing hormone (CRH) may also modulate visceral pain hypersensitivity in IBS. CRH receptor-1 antagonist significantly prevented an increase in gut sensitivity in rats. It has been demonstrated that non-specific CRH receptor antagonist α-helical CRH significantly reduced abdominal pain score during gut stimulus in patients with IBS. In conclusion, visceral hypersensitivity is common in IBS patients and probably plays a major role in development of the symptoms and both central and peripheral factors may enhance the pain sensitivity.     

Repetitive rectal painful distention induces rectal hypersensitivity in patients with irritable bowel syndrome

Background A reduced rectal perceptual threshold has been reported in patients with irritable bowel syndrome (IBS), but this phenomenon may be induced by a comorbid psychological state. We evaluated the rectal pain threshold at baseline and after conditioning (repetitive rectal painful distention: RRD) in patients with IBS or functional abdominal pain syndrome (FAPS), which is an abdominal pain disorder, and in healthy controls, and determined whether rectal hypersensitivity is a reliable marker for IBS. Methods The rectal sensory threshold was assessed by a barostat. First, a ramp distention of 40 ml/min was induced, and the threshold of pain and the maximum tolerable pressure (mmHg) were measured. Next, RRD (phasic distentions of 60-s duration separated by 30-s intervals) was given with a tracking method until the subjects had complained of pain six times. Finally, ramp distention was induced again, and the same parameters were measured. The normal value was defined by calculating the 95% confidence intervals of controls. Results Five or six of the seven IBS patients showed a reduced rectal pain threshold or maximum tolerable pressure, respectively, at baseline. In all patients with IBS, both thresholds were reduced after RRD load, but they were reduced in none of the patients with FAPS. RRD significantly reduced both thresholds in the IBS group (P < 0.05), but it had no effect in the control or FAPS groups. Conclusions Rectal hypersensitivity induced by RRD may be a reliable marker for IBS. Conditioning-induced visceral hypersensitivity may play a pathophysiologic role in IBS.     

直肠内温度变化影响肠易激综合征患者内脏感觉阈值

目的 探讨直肠内温度及压力变化对肠易激综合征(IBS)患者内脏感觉阈值的影响，进一步研究IBS的发病机制。方法 通过直肠球囊内注入空气(压力刺激)、38℃温水、4℃冰水(温度刺激)及脐部放置冰袋加直肠球囊内充气，研究直肠温度和压力变化刺激对初始感觉阈值和排便阈值的影响。结果 (1)直肠球囊内注气后，IBS组患者的初始感觉阈值明显低于对照组，排便阈值差异不明显。IBS组中腹泻型与交替型患者的初始感觉阈值及排便阈值均明显降低；便秘型患者的初始感觉阈值稍低于对照组，排便阈值明显增高。(2)直肠球囊内注入4℃冰水后，除便秘型IBS的排便阈值稍有所增加外，其余患者初始感觉阈值及排便阈值均显著降低，以腹泻型变化最明显。(3)脐部放置冰袋可诱发部分患者产生症状，但对初始感觉阈值和排便阈值无明显影响。结论 直肠温度和压力刺激可明显降低IBS患者的初始感觉阈值和排便阈值，以腹泻型患者最显著。内脏对压力和温度的敏感性增高可能是IBS发病的重要机制之一。