肠易激综合征患者胃窦十二指肠移行性复合波的研究

目的　观察肠易激综合征 (IBS)患者的胃窦十二指肠移行性复合波 (MMC)变化 ,并分析其与症状之间的关系。方法　 2 0名健康对照者及 17例IBS患者 (8例腹泻型 ,9例便秘型 )禁食 6h以上 ,用瑞典CTD公司生产的灌注式小肠测压管记录至少 2个完整的MMC周期 ,之后给每位受试者服标准餐 ,用餐时间为 15～ 30min ,继续观察餐后波 1～ 2h。结果　腹泻型IBS患者消化间期MMC周期短、Ⅲ相波幅高、时程长 ,便秘型IBS患者MMC周期长、时程短。IBS患者MMCⅡ相小肠离散丛集簇(DCC)波的时程延长 ,但腹泻组与便秘组之间差异无显著性 (P >0 .0 5 )。IBS腹泻组的Ⅱ、Ⅲ相的运动指数高于便秘组和对照组。进餐后IBS患者小肠运动形式无明显改变。结论　IBS患者消化间期MMC的各相时程及波幅异常与IBS症状密切相关 ,DCC可能与IBS腹泻、便秘症状发生的关系较小 ,IBS患者餐后胃肠运动无明显异常 ,可能与病例数较少有关 ,有待今后增加例数进一步观察     

5-HT4受体对人消化间期小肠运动调控及其机制研究

目的通过观察5-羟色胺(5-HT4)受体激动剂对人消化间期移行性复合运动(MMC)及血浆胃肠激素的影响,探讨5-HT4受体激动剂对MMC的调控作用及其可能的介导因素。方法选取健康志愿者18人并观察给予选择性5-HT4受体激动剂后MMC的变化。并且在给药前后检测MMC不同时期血浆胃动素(MOT)、生长抑素(SS)、NO的浓度。结果健康人给药后MMC周期显著缩短[(87.5+24.2)min vs(60.5±18.4)min,P0.001],MMCⅢ期波幅、动力指数、传播速度均比给药前显著升高(P0.05)。MMC不同时期血浆MOT含量无显著变化(P0.05),SS水平显著升高(P0.01),而NO含量显著降低(P0.05)。结论 5-HT4受体激活对人MMC有兴奋性作用,该兴奋作用可能通过SS、NO等胃肠激素起作用。     

肠易激综合征患者肠黏膜CGRP、SP水平的变化与临床症状的关系

[目的]探讨肠易激综合征(IBS)患者结肠黏膜降钙素基因相肽(CGRP)和P物质(SP)表达水平及与IBS临床症状的相关性。[方法]对腹泻型IBS(IBS-D组)20例、便秘型IBS(IBS-C组)8例和正常对照组5例各取乙状结肠黏膜标本,应用免疫组织化学染色法分别检测CGRP和SP;同时以评分法评价消化道症状;分析各组CGRP、SP表达水平与消化道症状的相关性。[结果]IBS-D组CGRP表达水平显著高于IBS-C组、正常对照组(0.27±0.08∶0.21±0.06、0.19±0.04,P0.05),IBS-C组与正常对照组比较差异无统计学意义。IBS-D组SP表达水平显著高于IBS-C组、正常对照组(0.27±0.11∶0.19±0.04、0.17±0.04,P0.05),IBS-C组与正常对照组比较差异无统计学意义。肠黏膜SP表达水平与IBS患者腹痛(r=0.495,P=0.007)、排便变稀(r=0.382,P=0.045)呈正相关,与排便困难(r=-0.485,P=0.009)、排便干结(r=-0.382,P=0.045)负相关;CGRP与排便变稀(r=0.401,P=0.034)正相关,与排便干结(r=-0.401,P=0.034)负相关。[结论]CGRP、SP可能参与IBS的病理生理过程并与临床症状密切相关。     

结肠黏膜褪黑素受体表达与肠易激综合征症状相关性研究

目的研究结肠黏膜褪黑素受体(melatonin receptor,MR)与肠易激综合征(irritable bowel syndrome,IBS)症状的相关性。方法 IBS入选标准参照罗马Ⅲ标准,IBS患者90例(IBS-D 46例,IBS-C 44例),正常对照者19名,进行电子肠镜检查,均在直乙状结肠交界处取活检做MR免疫组化检查,并记录IBS症状积分。结果 IBS-C患者结肠黏膜MR表达(2.48±0.63)高于正常对照组(2.05±0.78)、IBS-D组(1.41±0.50),组间比较,差异有统计学意义(P0.05)。IBS患者MR表达与IBS症状相关(P=0.024,r=0.238)。结论 IBS患者结肠黏膜MR表达异常,与IBS症状相关,提示可能与IBS动力异常、内脏高敏感有关。     

浙江省IBS就诊人群临床分型特点的研究

目的总结浙江省IBS人群不同亚型的发病特点.探讨符合我国IBS人群的临床分型标准.方法通过浙江省消化中心全省网络,从2001年1月至2002年1月,收集各医院消化科门诊就诊的符合罗马Ⅱ诊断标准的IBS患者540例,并按患者的排便习惯分为三型即腹泻为主型(IBS-D),便秘为主型(IBS-C)和腹泻便秘交替型(IBS-A).其中126例接受匹维溴胺100 mgt.i.d 8周治疗,观察匹维溴胺对不同亚型IBS的疗效差异.本研究采用问卷调查方式,问卷内容包括一般资料、症状问卷量表和生活质量量表(SF-36).结果①在IBS-C和IBS-A患者中,女性明显高于男性,而IBS-D患者中,男性更为多见(P＜0.05).IBS-D的患者饮酒的比例明显高于IBS-C的患者(P＜0.05).IBS-D吸烟的比例明显高于IBS-A的患者(P＜0.05).年龄分布在不同亚型患者无显著差异;②不同亚型的IBS中IBS-D占47.8%,IBS-A为32.2%,IBS-C为20.0%.不同亚型IBS患者的结肠症状和结肠外症状分布有所不同.腹痛≥1 h/d和腹痛频率≥2d/周在IBS-A最多见,而IBS-D患者较多出现黏液便、焦虑和消化不良(P＜0.05);③SF-36生活质量显示三个亚型IBS患者均在活力、总体健康和精神健康维度的生活质量下降尤为明显.IBS-C患者的生活质量普遍低于另外两型.IBS-C患者的生理功能、情感职能、总体健康和精神健康维度的生活质量显著低于IBS-D患者(P＜0.05);④匹维溴胺对IBS-C的总有效率和显效率分别60.8%和30.4%,IBS-D分别为94.9%和57.6%,IBS-A分别为77.3%和59.1%.匹维溴胺治疗不同亚型的IBS患者总有效率和显效率比较均有显著差异(P＜0.05).匹维溴胺对IBS-C患者的显效率显著低于另外两型(P＜0.05).结论按排便习惯分型的IBS患者在流行病学、临床表现、生活质量及对治疗反应等方面均有一定的差异,这一分型对临床有一定的指导意义.     

肠易激综合征患者小肠黏膜5-HT信号系统的研究

目的探讨肠易激综合征（IBS）患者不同部位小肠黏膜5-羟色胺（5-HT）水平及肠嗜铬细胞（EC细胞）数量是否改变。方法选取24例便秘型IBS（IBS-C）、26例腹泻型IBS（IBS-D）患者和26名健康人,行小肠镜及结肠镜检查并取十二指肠降段、近端空肠和回肠末段黏膜,用高压液相色谱-电化学法和免疫组织化学检测5-HT含量和EC细胞。结果IBSC患者近端空肠黏膜的5-HT含量与健康人相比有统计学意义（122±54ng／mg蛋白比188±91ng／mg蛋白,P〈0．05）,而十二指肠降段和回肠末段黏膜5-HT含量（182±90ng／mg蛋白、61±35ng／mg蛋白）与健康人相比（256±84ng／mg蛋白、93±45ng／mg蛋白）无统计学意义（P〉0．05）。IBS-D患者不同部位小肠黏膜5-HT含量与健康人相比均无统计学意义（P〉0．05）。IBS-C和IBSD患者不同部位小肠黏膜EC细胞数量与健康人相比均无统计学意义（P〉0．05）。结论上述结果提示1BS患者小肠黏膜5HT信号系统异常是其发病机制之-,但是在IBS-C和IBS-D之间有差异。     

美沙拉秦与曲美布汀联合对肠易激综合征患者结肠黏膜肥大细胞及其相关炎性介质的影响

背景:肠易激综合征(IBS)患者存在肥大细胞活化现象,对结肠黏膜肥大细胞及其相关炎性介质进行研究有助于疾病的评估和治疗。目的:探讨美沙拉秦联合曲美布汀对IBS患者结肠黏膜肥大细胞数量及其相关炎性介质的影响。方法:选取2014年10月—2016年6月上海市嘉定区中心医院40例腹泻型IBS(IBS-D)和40例便秘型IBS(IBS-C)患者,并以20名健康志愿者作为对照。将40例IBS-D和40例IBS-C患者均随机分为美沙拉秦+曲美布汀组和曲美布汀组,疗程均为4周。以改良甲苯胺蓝染色计数肥大细胞,免疫组化染色评估相关炎性介质的评分,评估患者的临床疗效。结果:与健康对照组相比,基线状态IBS-D患者和IBS-C患者肥大细胞数量均显著升高(P0.05);给予美沙拉秦+曲美布汀治疗后,肥大细胞数量均显著降低(P0.05)。基线状态时,IBS患者5-HT、IL-1、TNF-α、组胺和类胰蛋白酶免疫组化染色评分均显著高于健康对照组(P0.000 1);给予美沙拉秦+曲美布汀治疗后,上述炎性介质的免疫组化染色评分均显著降低(P0.05)。IBS-D患者中,美沙拉秦+曲美布汀组总有效率显著高于曲美布汀组(85.0%对45.0%,P=0.008),而IBS-C患者中两组总有效率无明显差异(55.0%对25.0%,P=0.053)。结论:美沙拉秦联合曲美布汀治疗可降低IBS患者结肠黏膜肥大细胞数量以及相关炎性介质的释放,对IBS-D患者的临床疗效更佳。     

肠易激综合征模型大鼠结肠肌间神经丛钙视网膜蛋白阳性神经元增加

目的检测肠易激综合征腹泻型(IBS-D)和便秘型(IBS-C)两种模型大鼠远端回肠、结肠黏膜下神经丛(SMP)和肌间神经丛(MP)钙视网膜蛋白(CALR)阳性神经元的变化,探讨其在IBS发病中的作用。方法分别采用慢急性联合应激、冰水灌胃法建立IBS-D和IBS-C大鼠模型,制作回肠和结肠SMP、MP全层铺片标本,免疫组织荧光双染法检测CALR阳性神经元的改变。结果与对照组相比,IBS-D和IBS-C模型大鼠回肠SMP、MP和结肠SMP中CALR阳性神经元比例的差异无统计学意义(P0.05),结肠MP中CALR阳性神经元的比例显著增加,分别为(17.2±3.2)%vs(13.4±2.9)%、(19.1±5.9)%vs(14.9±3.4)%,差异均有统计学意义(P0.05)。结论 IBS-D、IBS-C模型大鼠结肠MP中CALR阳性神经元增加可能参与IBS肠道敏感性增高。     

大鼠肠易激综合征肠黏膜下神经丛可塑性的研究

目的探讨大鼠肠黏膜下神经丛内肠神经元及兴奋性神经递质在肠易激综合征(IBS)不同亚型发病中的意义及替加色罗干预的结果。方法成年雄性SD大鼠45只,均分为IBS伴腹泻组(IBS-D)、IBS伴便秘组(IBS-C)、替加色罗干预的IBS-D组、替加色罗干预的IBS-C组和空白对照组共5组。分别采用乙酸灌肠和冰水灌胃方法制成IBS-D和IBS-C大鼠模型,替加色罗干预的两组每日加用替加色罗2 mg/kg体质量灌胃7 d。用蛋白基因产物9.5(PGP9.5)的免疫组化方法及兴奋性神经递质乙酰胆碱的组化染色法检测各组大鼠肠黏膜下神经丛内肠神经元及兴奋性神经递质的变化。结果①肠黏膜下神经丛内肠神经元数目IBS-D模型组(13.19±0.93)和IBS-C组(13.17±1.93)显著低于对照组(18.36±1.71)(P值均<0.01);替加色罗干预的IBS-D组(15.48±1.56)高于IBS-D组,替加色罗干预的IBS-C组(14.82±1.61)高于IBS-C组(P值均<0.05)。②肠黏膜下神经丛内胆碱酯酶阳性的神经元数目IBS-C组(7.56±0.39)显著低于对照组(10.43±1.39)及IBS-D组(10.03±1.13)(P值均<0.01),IBS-D组与对照组差异无统计学意义(P>0.05)。替加色罗干预的IBS-C组(9.51±1.47)显著高于IBS-C组(P<0.01),与对照组差异无统计学意义(P>0.05)。结论肠黏膜下神经丛内肠神经元数量的减少可能是实验大鼠IBS-D模型和IBS-C模型发病的共同机制;IBS-C模型组大鼠胆碱酯酶阳性的神经元数目显著减少与其症状相关。     

经导管主动脉瓣置换术治疗重度主动脉瓣狭窄的初步经验及中期随访结果

目的评估经导管主动脉瓣置换术(TAVR)在重度主动脉瓣狭窄(AS)患者中的应用。方法纳入2014年12月至2016年2月厦门大学附属心血管病医院实施TAVR的患者共10例。记录并分析这些患者的基线特征、围术期情况、超声心动图及临床随访资料。结果 10例患者均合并严重心力衰竭(NYHA心功能Ⅲ级4例、Ⅳ级6例),平均年龄(75.1±6.2)岁,平均欧洲心脏手术风险回归评分(logistic Euro SCORE)为(27.2±23.6)%,平均美国胸外医师协会评分(STS)为(9.1±4.8)%,二叶式AS 5例(5/10)。10例手术全部成功,其中1例采用瓣中瓣技术。除1例患者于术后36 d死于消化道大出血,其余9例均随访(22.0±4.8)个月。与术前相比,左心室舒张末期内径术后30 d、3个月、12个月未明显降低,差异均无统计学意义(均P0.05),跨主动脉瓣最大流速术后30 d[(4.58±0.56)m/s比(2.31±0.39)m/s]、3个月[(4.58±0.56)m/s比(2.18±0.49)m/s]、12个月[(4.58±0.56)m/s比(2.23±0.29)m/s]均显著降低,差异均有统计学意义(均P0.001);跨主动脉瓣峰值压差术后30 d[(85.9±22.7)mm Hg比(21.5±7.1)mm Hg]、3个月[(85.9±22.7)mm Hg比(20.3±9.8)mm Hg]、12个月[(85.9±22.7)mm Hg比(20.0±5.2)mm Hg]显著降低,平均跨瓣压差术后30 d[(48.4±10.8)mm Hg比(11.9±3.6)mm Hg]、3个月[(48.4±10.8)mm Hg比(11.8±5.9)mm Hg]、12个月[(48.4±10.8)mm Hg比(10.6±3.1)mm Hg]均显著降低,差异亦均有统计学意义(均P0.05);左心室射血分数术后30 d[(58.9±12.7)%比(46.9±22.2)%]、3个月[(62.0±12.6)%比(46.9±22.2)%]、12个月[(63.7±9.4)%比(46.9±22.2)%]与术前比较,均有显著提升,差异均具有统计学意义(均P0.05)。结论本中心TAVR的初期经验显示,经过严格病例筛选、规范培训及有效团队协作实施TAVR安全、可行,中期结果良好,可进一步推广应用。     

Decreased expression of serotonin in the jejunum and increased numbers of mast cells in the terminal ileum in patients with irritable bowel syndrome

AIM： To investigate if there are changes in serotonin （5-HT） levels, enterochromaffin （EC） cells and mast cells in small intestinal mucosa of patients with irritable bowel syndrome （IBS）. METHODS： Diarrhea-predominant （IBS-D, n = 20）, or constipation-predominant （IBS-C, n = 18） IBS patients and healthy controls （n = 20） underwent colonoscopy and peroral small intestinal endoscopy, and mucosal samples were obtained at the descending part of the duodenum, proximal end of jejunum and terminal ileum. High-performance liquid chromatographyelectrochemistry and immunohistochemical methods were used to detect 5-HT content, EC cells and mast cells. RESULTS： （1） There were no differences in the number and distribution of EC cells between IBS patients and the normal group. （2） The mucosal 5-HT contents at the duodenum, jejunum and ileum in IBS-C patients were 182 ± 90, 122 ± 54, 61 ± 35 ng/mg protein, respectively, which were all lower than those in the normal group （256 ± 84, 188 ± 91, and 93 ± 45 ng/ mg protein, respectively）, with a significant difference at the jejunum （P 〈 0.05）. There were no differences in the small intestinal mucosal 5-HT contents between IBS-D patients and the normal group. The mucosal 5-HT contents at the duodenum were significantly higher than those at the ileum in the three groups （P 〈 0.001）. （3） The numbers of mast cells in patients with IBS-C and IBS-D at the ileum were 38.7 ± 9.4 and 35.8 ± 5.5/highpower field （hpf）, respectively, which were significantly more than that in the normal group （29.8 ± 4.4/hpf） （P 〈 0.001）. There was no significant difference in the numbers of mast cells at the other two parts between IBS patients and the normal group. The numbers of mast cells in IBS-C, IBS-D, and normal groups were all significantly higher at the ileum （38.7 ± 9.4, 35.8 ± 5.5, 29.8 ±4.4/hpf, respectively） than at the duodenum （19.6± 4.7, 18.5 ± 6.3, 19.2 ±3.3/hpf, respectively, P 〈 0.001）. CONCLUSIO     

美沙拉嗪联合马来酸曲美布汀治疗肠易激综合征患者的临床疗效观察

目的评估美沙拉嗪联合马来酸曲美布汀治疗肠易激综合征(IBS)患者的临床疗效。方法根据罗马Ⅲ诊断标准纳入2014年10月至2016年6月在上海市嘉定区中心医院就诊的腹泻型IBS(IBS-D)和便秘型IBS(IBS-C)患者各40例。40例IBS-D患者随机分为美沙拉嗪+马来酸曲美布汀组和马来酸曲美布汀组,每组各20例;40例IBS-C患者随机分为美沙拉嗪+马来酸曲美布汀组和马来酸曲美布汀组,每组各20例。同期选择20名健康体检者作为正常对照。治疗前后均使用肠易激严重程度评分系统(IBSSS)和医院焦虑抑郁量表(HADS)评估患者的临床疗效和情绪障碍的严重程度。结果研究过程中未观察到严重的药物相关不良反应。在IBS-D患者中,美沙拉嗪+马来酸曲美布汀组经过4周治疗后,IBSSS总分由基线时的(194.5±62.6)分下降至(136.3±47.2)分(P0.000 1),而马来酸曲美布汀单药组则由治疗前的(207.3±49.2)分下降至治疗后的(197.5±47.8)分(P=0.01);在IBS-C患者中,美沙拉嗪+马来酸曲美布汀组经过4周治疗后,IBSSS总分由基线时的(245.8±70.4)分下降至(231.3±65.0)分(P=0.005)。基线状态时,IBS患者组的焦虑和(或)抑郁评分均高于健康对照组(P0.000 1)。在IBS-D患者中,美沙拉嗪+马来酸曲美布汀组经过4周治疗后,焦虑和抑郁评分分别由基线时的(11.9±4.1)分下降至(11.3±4.1)分(P=0.019)、(13.6±4.7)分下降至(12.5±4.5)分(P=0.002 6)。结论美沙拉嗪联合马来酸曲美布汀治疗可改善IBS患者,尤其是IBS-D患者的临床症状和精神心理障碍。     

Brain functional magnetic resonance imaging of rectal pain and activation of endogenous inhibitory mechanisms in irritable bowel syndrome patient subgroups and healthy controls

BACKGROUND AND AIMS: Many patients with irritable bowel syndrome (IBS) show intestinal hypersensitivity to distension and sensitisation after repeated intestinal distensions. Abnormalities in endogenous pain inhibitory mechanisms, such as diffuse noxious inhibitory controls (DNIC), may be implicated and were investigated during brain functional magnetic resonance imaging (fMRI). PATIENTS AND METHODS: fMRI was performed in 10 female patients with IBS (five constipated (IBS-C) and five with diarrhoea (IBS-D)) and 10 female healthy controls during rectal balloon distension alone or during activation of DNIC by painful heterotopic stimulation of the foot with ice water. Rectal pain was scored with and without heterotopic stimulation (0 = none, 10 = maximal). RESULTS: Heterotopic stimulation decreased median rectal pain scores significantly in healthy controls (-1.5 (interquartile range -2 to -1); p = 0.001) but not in IBS-C (-0.7 (-1 to 0.5)), IBS-D (-0.5 (-1.5 to 0.5)), or in all IBS patients (0 (-1.5 to 1.3)). Brain activation changes during heterotopic stimulation differed highly significantly between IBS-C, IBS-D, and controls. The main centres affected were the amygdala, anterior cingulate cortex, hippocampus, insula, periaqueductal gray, and prefrontal cortex, which form part of the matrix controlling emotional, autonomic, and descending modulatory responses to pain. CONCLUSIONS: IBS-C and IBS-D appear to have differing abnormal endogenous pain inhibitory mechanisms, involving DNIC and other supraspinal modulatory pathways.     

Impact of upper digestive symptoms in patients with irritable bowel syndrome

BACKGROUND: Functional digestive disorders constitute a sizable proportion of gastroenterology and primary healthcare consultations, and have a negative impact on health-related quality of life. Dyspepsia and heartburn are often associated with irritable bowel syndrome (IBS); however, the incidence of these symptoms and their effect on IBS patients have not been evaluated. AIM: To investigate the clinical, psychological and health-related quality of life impact of upper digestive symptoms on IBS patients. METHODS: A prospective, observational, multicentered study was conducted in Spain: 517 IBS patients (Rome II criteria), grouped according to predominant symptoms of constipation (IBS-C), diarrhea (IBS-D) or alternating bowel habit (IBS-A) and 84 controls without IBS were recruited. Upper digestive symptoms were recorded in a 30-day diary. Health-related quality of life was evaluated by Irritable Bowel Syndrome Quality of Life and Euro-Quality of Life Five-Dimension Questionnaires; psychological well-being was evaluated by the Psychological General Well-Being Index. RESULTS: IBS patients had greater frequencies of upper digestive symptoms (72.3 vs. 6.0%), dyspepsia (21.1 vs. 4.8%) and heartburn (40.0 vs. 13.1%) (all P < 0.05) than controls. Prevalence of upper digestive symptoms was lower in patients with IBS-D than in those with IBS-C or IBS-A (P < 0.05). Health-related quality of life and psychological status were significantly worse in IBS patients with upper digestive symptoms than in those without. CONCLUSIONS: Upper digestive symptoms, frequently present in IBS patients, impair health-related quality of life and psychological status. This effect is greater in patients with IBS-C and IBS-A than in those with IBS-D. These data emphasize the importance of evaluating the presence of upper digestive symptoms in IBS patients.     

Diarrhea- and constipation-predominant IBS patients differ in postprandial autonomic and cortisol responses

OBJECTIVE: As the primary link between brain and gut, autonomic and endocrine dysfunction may play a role in the pathophysiology of the irritable bowel syndrome (IBS). The aim of this study was to assess autonomic, endocrine, and symptomatic responses to food intake in diarrhea-predominant and constipation-predominant IBS patients, compared to normals. METHODS: Twelve women with diarrhea-predominant or alternating IBS (IBS-D), 12 women with constipation predominant IBS (IBS-C), and 20 healthy women participated. GI symptoms, saliva cortisol concentration, heart rate, and heart rate variability were assessed at baseline and after a meal. Spectral analysis of heart rate variability was used as a measure of the sympathovagal regulation of the heart rate. RESULTS: Both groups of IBS patients showed a significant postprandial increase in GI symptoms. IBS-D showed a significant increase in the low frequency/high frequency band ratio and a decrease in the high frequency band power during the first postmeal period, which was significantly different, not only from controls, but also from IBS-C. IBS-D also showed a significant postprandial increase in cortisol, which was not evident in controls or IBS-C. There was a significant correlation between the vagal response and the postprandial increase in GI symptoms in IBS-D (r = 0.6, p < 0.05). CONCLUSIONS: These findings support the notion that the IBS symptom groups are characterized by different physiological responses to visceral stimuli, and point to a role of autonomic pathways in IBS symptomatology.     

Abnormal Propagation Pattern of Duodenal Pressure Waves in the Irritable Bowel Syndrome (IBS)

The propagation pattern of individual pressure waves in the gastroduodenal area in IBS is unexplored. We performed antroduodenojejunal manometry on 26 patients with IBS—13 with diarrhea predominant IBS (IBS-D) and 13 with constipation predominant IBS (IBS-C)—and 32 healthy controls. Neuropathic-like motor abnormalities were found in 38% of the patients with conventional manometric evaluation. With high-resolution analysis additional abnormalities were observed in the majority of the patients, with increased frequency of retrograde pressure waves postprandially in both IBS subgroups and in phase II in IBS-D. A correlation between subjective gastrointestinal symptoms and the frequency of retrograde pressure waves in phase II in IBS-D was demonstrated. Motility indices and the number of long clusters were also higher in patients compared to controls. To conclude, an abnormal propagation pattern of individual duodenal pressure waves in IBS patients was demonstrated and found to be related to symptom severity in diarrhea-predominant IBS. High-resolution analysis adds information to standard manometry.     

Molecular defects in mucosal serotonin content and decreased serotonin reuptake transporter in ulcerative colitis and irritable bowel syndrome

BACKGROUND & AIMS: Serotonin (5-HT) is a critical signaling molecule in the gut. 5-HT released from enterochromaffin cells initiates peristaltic, secretory, vasodilatory, vagal, and nociceptive reflexes. Despite being pathophysiologically divergent, ulcerative colitis (UC) and irritable bowel syndrome (IBS) are both associated with clinical symptoms that include alterations in the normal patterns of motility, secretion, and sensation. Our aim was to test whether enteric 5-HT signaling is defective in these disorders. METHODS: Rectal biopsy specimens were obtained from healthy controls and patients with UC, IBS with diarrhea (IBS-D), and IBS with constipation (IBS-C). Key elements of 5-HT signaling, including measures of 5-HT content, release, and reuptake, were analyzed with these samples. RESULTS: Mucosal 5-HT, tryptophan hydroxylase 1 messenger RNA, serotonin transporter messenger RNA, and serotonin transporter immunoreactivity were all significantly reduced in UC, IBS-C, and IBS-D. The enterochromaffin cell population was decreased in severe UC samples but was unchanged in IBS-C and IBS-D. When 5-HT release was investigated under basal and mechanical stimulation conditions, no changes were detected in any of the groups relative to controls. CONCLUSIONS: These data show that UC and IBS are associated with similar molecular changes in serotonergic signaling mechanisms. While UC and IBS have distinct pathophysiologic properties, these data suggest that shared defects in 5-HT signaling may underlie the altered motility, secretion, and sensation. These findings represent the first demonstration of significant molecular alterations specific to the gut in patients with IBS and support the assertion that disordered gastrointestinal function in IBS involves changes intrinsic to the bowel.     

Visceral sensitivity and symptoms in patients with constipation- or diarrhea-predominant irritable bowel syndrome (IBS): effect of a low-fat intraduodenal infusion

BACKGROUND: Visceral hypersensitivity is common in Irritable Bowel Syndrome (IBS) patients, and symptoms exacerbate postprandially. Yet the effects of nutrients on visceral sensitivity and symptoms in these patients have not been fully explored. AIMS: To evaluate the differences of visceral sensitivity and symptoms in healthy subjects and IBS patients during fasting and intraduodenal lipids infusion. METHODS: Graded rectal distensions at fixed tension levels were performed in 16 IBS patients (8 IBS-C and 8 IBS-D) and 6 healthy subjects before and during intraduodenal lipids infusion at 0.5 kcal/min. Tension levels were increased in 4 gr increments up to 64 gr or discomfort during both conditions. At each step, perception and symptoms were measured by means of a validated questionnaire. RESULTS: In basal conditions, perception thresholds in IBS patients and health were, respectively, 8 +/- 2 gr versus 32 +/- 9 gr (p < 0.001) with no changes during lipids. Intraduodenal lipids infusion significantly lowered threshold of discomfort in IBS patients in comparison to fasting (24 +/- 6 gr vs 34 +/- 4 gr; p < 0.05), while health tolerated all distension without discomfort. No differences of compliance, perception, or discomfort were observed between the two subgroups of patients at each tension step. The predominant symptom elicited in patients with IBS-C was abdominal pain (54%), while patients with IBS-D exhibited urgency (63%, p < 0.005); this pattern was maintained during lipids. CONCLUSIONS: Intraduodenal lipids increase visceral sensitivity in both IBS-C and IBS-D; symptoms specificity in response to rectal distension is maintained in the postprandial period. Lipids may be responsible for the postprandial symptoms exacerbation in IBS.