内吗啡肽对"泻剂结肠"大鼠离体肠肌条收缩反应的影响

目的研究内吗啡肽（EM）对“泻剂结肠”大鼠结肠动力的影响,以探讨慢传输性便秘（STC）的发病机制.方法以“泻剂结肠”大鼠为模型,用电刺激离体肌条收缩反应试验方法观察EM对离体肌条的影响.结果与对照组相比,EM-1和EM-2明显抑制电刺激“泻剂结肠”大鼠离体肌条收缩反应,收缩波振幅降低,对远端结肠抑制尤其明显;EM-1的抑制作用强于EM-2,这种抑制作用与浓度相关,不同浓度的Naloxone（u阿片受体拮抗剂）明显加强EM作用后电刺激“泻剂结肠”大鼠离体肌条的收缩反应,收缩波振幅增加.结论EM-1和EM-2参与“泻剂结肠”动力的调控,可能是STC发病的一个重要因素.     

内吗啡肽1对泻剂结肠大鼠肠道传输功能的影响

目的 研究内吗啡肽(EM)对泻剂结肠大鼠结肠传输功能的影响，探讨慢传输性便秘(STC)的发病机制。方法 建立大鼠“泻剂结肠”模型，采用活性炭悬液推进法测定肠道传输功能。结果 与对照组相比，泻剂结肠组的传输功能明显减慢，内吗啡肽1(EM1)对泻剂结肠传输功能产生浓度相关的抑制作用，纳洛酮能减弱EM1的抑制作用。结论 EM1参与了泻剂结肠动力的调控，是STC的重要致病因素之一。     

便秘小鼠结肠肌的电生理变化

目的观察便秘小鼠结肠肌的电生理变化。方法用复方地芬诺酯混悬液对小鼠进行灌胃建立便秘模型,然后测定其小肠结肠段的肌电,并分析其电生理活动变化。结果与对照组比较,便秘组慢波肌电频率明显增快(P<0.01);结肠肌电慢波频率的变异系数明显增大(P<0.01);结肠肌电慢波振幅明显减少(P<0.01);结肠肌电慢波振幅变异系数明显增大(P<0.01)。结论便秘小鼠结肠肌电慢波频率及振幅的异常改变可能是导致结肠传输减慢的重要原因。     

实验性脾虚证结肠动力肌胃肠肽和一氧

目的观察大鼠在脾虚和应激状态下结肠动力及结肠组织内P物质(SP)、血管活性肠肽(VIP)和神经型一氧化氮合酶(nNOS)改变及治疗后变化.方法实验随机分为五组正常组、脾虚组、自然恢复组、治疗组、冷应激组;其中治疗组以加味四君子汤治疗.实验采用银球三电极和高灵敏度应变片传感器同步记录结肠电-机械活动,即结肠运动、慢波和快波,并采用Ag-AgCl电极记录结肠体表电活动.信号由计算机系统软件采集并分析;放射性免疫方法测定SP,VIP;用免疫组织化学方法显示结肠组织内nNOS.结果脾虚组同正常组相比,结肠组织SP含量增高[(18.31±2.37)ng@g-1,(1.45±0.43)ng@g-1,P<0.05],VIP含量降低[(3.43±1.12)ng@g-1,(6.48±2.56)ng@g-1,P<0.05],结肠肌层中nNOS阳性神经细胞和神经纤维增多,运动频率降低[(3.6±1.1)min-1,(5.8±2.6)min-1,P<0.05].加味四君子汤治疗后各指标基本恢复正常.应激组同正常组相比,SP含量增高[(28.41±11.56)ng@g-1,P<0.05],运动振幅增高(1.6g±0.6g,0.9g±0.4g,P<0.05),体表结肠电活动与慢波的相关性比较,脾虚组和应激组均低于正常组(P<0.05)结论①脾虚状态下结肠SP、VIP含量及nNOS发生改变,结肠动力紊乱,但体内仍存在调节稳态的机制;nNOS升高VIP则降低.②加味四君子汤对脾虚结肠动力紊乱有一定调理作用.③冷束缚应激时SP升高,结肠动力紊乱以振幅升高为主.④体表结肠电活动与慢波的峰值频率相关性在各组间发生的变化,提示脾虚和冷应激皆为包括肌肉和神经系统在内的全身病变,对体表电活动产生影响.     

针刺结合西沙必利对慢传输便秘大鼠结肠肌电的影响

目的:观察针刺、药物西沙必利及二者合用对慢传输便秘大鼠结肠肌电的影响, 探讨这3种治疗方法的效应差异, 以及针药结合的优势.方法:55只SD大鼠, 随机取10只作为正常组,其余45只用大黄小剂量递增灌胃造模. 测定大鼠结肠肌电慢波, 分别采用针刺足三里和照海、药物西沙必利及二者合用治疗14 d, 然后慢波的变化.结果:与正常大鼠比较, 部分模型大鼠慢波频率减慢为每分5.47±3.08次, 振幅降低为0.33±0.19 mV; 部分频率加快为每分26.61±8.99次, 振幅增高为0.69±0.70 mV. 对频率减慢、振幅降低型慢波的改变, 针刺组频率和振幅为每分8.36±5.55次, 0.42±0.21 mV; 药物组频率和振幅为每分6.84±3.44次, 0.20±0.03 mV;针药结合组频率和振幅为每分12.37±2.16次,0.37±0.05 mV. 对频率增快、振幅增高型慢波的改变, 针刺组频率和振幅为每分20.86±4.25次, 0.28±0.06 mV; 药物组频率和振幅为每分28.42±19.79次, 0.47±0.26 mV; 针药结合组频率和振幅为每分21.20±4.72次, 0.46±0.17 mV.结论:西沙必利只能单向地增快频率、升高振幅, 而针刺、针刺与西沙必利合用对模型大鼠频率与振幅的改变具有双向调整的作用.     

芦荟全汁对便秘小鼠结肠肌电生理变化的影响

目的 观察芦荟对便秘小鼠的结肠肌电生理变化的影响.方法 用复方地芬诺酯混悬液对小鼠进行灌胃建立便秘模型,后用芦荟全汁对小鼠进行灌胃,从而探讨芦荟全汁对便秘小鼠结肠肌电生理变化的影响.结果 三组小鼠的结肠慢波表现为近似于正弦波样曲线.对照组频率(43.52±0.71次/min),便秘组频率(47.80±2.66次/min),与对照组相比,便秘组小鼠的结肠慢波频率增快,两组相比较有极显著差异;芦荟组频率(44.45±1.31次/min),与便秘组相比,芦荟组小鼠的结肠慢波频率减慢(P＜0.01);与对照组相比,便秘组小鼠的结肠慢波频率变异系数增大(P＜0.01);与便秘组相比,芦荟组小鼠的结肠慢波频率变异系数减慢(P＜0.01);与对照组相比,便秘组小鼠的结肠慢波振幅减少(P＜0.01);与便秘组相比,芦荟组小鼠的结肠慢波振幅升高(P＜0.01);与对照组相比,便秘组小鼠的结肠慢波振幅变异系数增大(P＜0.01);与便秘组相比,芦荟组小鼠的结肠慢波振幅变异系数减小(P＜0.01).结论 芦荟全汁能有效地改善便秘小鼠结肠运动功能.     

内吗啡肽及μ阿片受体mRNA在"泻剂结肠"大鼠结肠神经丛中的表达及意义

目的观察内吗啡肽（EM）及μ阿片受体mRNA在“泻剂结肠”大鼠结肠神经丛表达和分布,以进一步明确慢传输性便秘（slow tran-sit constipation,STC）的发病机制和病理生理变化。方法建立“泻剂结肠”大鼠动物模型,应用免疫组化法和图像分析系统观察结肠神经丛内EM免疫反应阳性细胞分布和数量变化,用原位杂交法测定结肠中μ阿片受体mRNA的表达水平。结果与对照组相比,泻剂组结肠肌间神经丛EM阳性细胞数量明显增多（10.319&#177;1.612vs7.683&#177;1.359,P〈0.05）,μ阿片受体mRNA的表达增强（0.3034&#177;0.0651vs0.1823&#177;0.0150,P〈0.01）,远端结肠尤甚。结论EM及其受体参与结肠动力的调控,肠神经递质及受体的异常可能是STC发病的一种重要因素,提示长期应用刺激性泻剂可损伤肠神经系统,导致肠动力异常,加速STC的病理生理变化。     

大黄酸对便秘小鼠肠道传输功能和结肠肌电及结肠黏膜水通道蛋白3表达的影响

目的探讨大黄酸对便秘小鼠肠道传输功能、结肠肌电及结肠黏膜水通道蛋白(AQP)3表达的影响。方法 90只小鼠随机分为对照组、便秘组和大黄酸组。用复方地芬诺脂片复制小鼠便秘模型后,大黄酸组用大黄酸灌胃治疗。测量3组首便时间,6 h排便数量,大便性状,小肠推进率,结肠肌电信号和结肠黏膜AQP3的表达。结果便秘组首粒排便时间较对照组显著延长(P<0.01),6 h内排便粒数显著减少(P<0.01),小肠推进率显著降低(P<0.01);大黄酸组首次排便时间较便秘组显著缩短(P<0.01),6 h内排便粒数显著增加(P<0.01),小鼠小肠推进率显著提高(P<0.01)。3组结肠慢波近似于正弦波样曲线,便秘组结肠慢波较不规则。与对照组相比,便秘组结肠慢波频率显著减慢(P<0.05)。与便秘组相比,大黄酸组结肠慢波频率显著增快(P<0.05)。与对照组相比,便秘组结肠慢波频率变异系数显著增大(P<0.05);与便秘组相比,大黄酸组结肠慢波频率变异系数显著降低(P<0.05);与对照组相比,便秘组结肠慢波振幅显著降低(P<0.05);与便秘组相比,大黄酸组结肠慢波振幅显著升高(P<0.05)。与对照组相比,便秘组结肠慢波振幅变异系数显著增大(P<0.05);与便秘组相比,大黄酸组结肠慢波振幅变异系数显著减小(P<0.05)。便秘组结肠AQP3平均光密度值及阳性面积表达率明显高于对照组,大黄酸组结肠AQP3平均光密度值及阳性面积表达率明显低于便秘组(均P<0.05)。结论大黄酸能够有效地提高便秘小鼠的肠道传输功能,减少便秘小鼠结肠黏膜AQP3的表达,对缓解便秘具有显著疗效。     

酚酞对大鼠结肠动力及肠神经系统的影响研究

目的 探讨长期应用酚酞对结肠肌电及肠神经系统(ENS)的影响。方法 建立大鼠“泻剂结肠”模型，应用电生理、组化及免疫组化技术研究酚酞对大鼠结肠动力、ENS多种神经递质及Cajal间质细胞(ICC)的影响。结果 大鼠饲以酚酞3个月后，结肠慢波频率减慢，结肠肌间丛还原型烟酰胺腺嘌呤二核苷磷酸黄递酶阳性神经细胞数目增多，乙酰胆碱酯酶阳性神经细胞数目减少，一氧化氮合酶免疫反应性增强，生长抑素免疫反应性减弱，肌间丛ICC分布不均匀，突起连接杂乱。结论 长期应用酚酞对结肠动力和ENS有损害作用，在临床治疗顽固性便秘时应避免长期应用酚酞等刺激性泻剂。     

慢传输型便秘结肠神经病理改变的意义

目的研究慢传输型便秘结肠肌间神经丛的神经丝蛋白和S-100蛋白的病理改变,探索结肠动力减弱的原因,为临床治疗提供理论依据.方法采用免疫组织化学方法研究33例结肠慢传输型便秘患者(STC组)和25例非便秘性结肠(对照组)的升结肠、横结肠、降结肠、乙状结肠的肌间神经丛内神经丝蛋白和S-100蛋白的表达,利用计算机图象分析系统作定量分析,并与病程及年龄作直线相关性分析.所得数据用t检验进行统计学处理.结果对照组结肠肌间神经丛内神经丝蛋白和S-100蛋白的含量在各段之间无显著性差别(0.09±0.03vs0.10±0.02,P＞0.05),STC组结肠各段与对照组比较,神经丝蛋白的平均光密度值明显高于对照组(0.12±0.03vs0.09±0.02,P＜0.01);S-100蛋白的含量及平均光密度值明显高于对照组(0.10±0.04vs0.08±0.03,P＜0.01).神经丝蛋白和S-100蛋白的改变随着病程的延长而增加,二者呈直线相关(r=0.75).结论慢传输型便秘结肠肌间神经丛存在着全结肠性退行性病理改变,表现为神经丝蛋白的堆积聚集和神经间质的增生,且随着病程的延长而加重,这是造成结肠动力减弱的主要原因.提示,手术切除结肠的范围应是全结肠或次全结肠.     

胶质细胞系源性神经营养因子对泻药性结肠大鼠肠道传输功能的影响

背景：慢传输型便秘（STC）患者长期依赖泻剂排便，导致泻药性结肠，部分患者最终需手术切除结肠。目的：探讨胶质细胞系源性神经营养因子（GDNF）对泻药性结肠大鼠肠道传输功能的影响。方法：以大黄灌胃建立大鼠STC模型。将大鼠随机分为正常NaCl组、正常GDNF组、模型NaCl组和模型GDNF组。正常GDNF组和模型GDNF组大鼠尾静脉注射GDNF，其余两组注射0．9％NaCl溶液。1周后处死大鼠，以墨汁推进试验测定肠道传输功能，并行结肠组织HE染色。结果：模型NaCl组肠道推进率显著低于正常NaCl组（P〈0．01）；模型GDNF组推进率显著高于模型NaCl组（P〈0．01）．结肠黏膜组织学表现较模型NaCl组有所改善。结论：外源性GDNF可明显改善大鼠肠道传输功能。     

Effects of nociceptin/orphanin FQ on rats with cathartic colon

AIM To demonstrate the change and effect of nociceptin/orphanin FQ in the colon of rats with cathartic colon.METHODS The cathartic colon model was established by feeding rats rhubarb for 3 mo, the changes of colonic electromyography were investigated by both suspension muscle strips test and serosal recordings of colonic myoelectrical activity. Immunohistochemical staining (S-P methods) and image analysis were used to determine the changes of nociceptin/orphanin FQ in the proximal colon and distal colon of rats with cathartic colon.RESULTS Suspension muscle strips test in vitro showed OFQ (10-9-10-6 mol/L) concentration dependently caused an immediate tonic contraction in the isolated colon. But the increase of tension in cathartic colon was less than control groups (P＜0.01). Intravenous administration of OFQ (1μg/kg) caused phasic contractions in the proximal colon, while the amplitude of phasic contractions caused by OFQ in cathartic colon was much lower than that in the control groups (2.58 ± 0.41 vs 4.16± 0.53, t= -2.6, P = 0.012). OFQ was highly expressed in the myenteric plexus of the rat colon but not in the muscle cells. The immunoreactivity of OFQ in the proximal colon in cathartic colon rats decreased significantly compared with the control group (P = 0.001).CONCLUSION Colonic smooth muscle of cathartic colon showed low sensitivity to the stimulation of OFQ, suggesting that it might be caused by the abnormal distribution of OFQ or the abnormalities of receptors, leading to the disorganization of dynamic and incoordinated contractions.     

Pan-colonic decrease in interstitial cells of Cajal in patients with slow transit constipation

BACKGROUND: Interstitial cells of Cajal (ICC) are required for normal intestinal motility. ICC are found throughout the human colon and are decreased in the sigmoid colon of patients with slow transit constipation. AIMS: The aims of this study were to determine the normal distribution of ICC within the human colon and to determine if ICC are decreased throughout the colon in slow transit constipation. PATIENTS: The caecum, ascending, transverse, and sigmoid colons from six patients with slow transit constipation and colonic tissue from patients with resected colon cancer were used for this study. METHODS: ICC cells were identified with a polyclonal antibody to c-Kit, serial 0.5 microm sections were obtained by confocal microscopy, and three dimensional software was employed to reconstruct the entire thickness of the colonic muscularis propria and submucosa. RESULTS: ICC were located within both the longitudinal and circular muscle layers. Two networks of ICC were identified, one in the myenteric plexus region and another, less defined network, in the submucosal border. Caecum, ascending colon, transverse colon, and sigmoid colon displayed similar ICC volumes. ICC volume was significantly lower in the slow transit constipation patients across all colonic regions. CONCLUSIONS: The data suggest that ICC distribution is relatively uniform throughout the human colon and that decreased ICC volume is pan-colonic in idiopathic slow transit constipation.     

Are colonic regular contractile frequency patterns in slow transit constipation a relevant pathophysiological phenomenon?

BACKGROUND: Pathogenesis of slow transit constipation still remains elusive. Some studies have shown several colonic motor abnormalities; however, it is not easy to understand the relative importance of the single ones. AIMS: Since it has been hypothesized that an excess of periodic distal motor activity may be of pathophysiological importance in patients with slow transit constipation, we evaluated regular colonic contractile frequencies in a homogeneous cohort of these patients. PATIENTS: A total of 26 female patients (age range 34 to 67 years) fulfilling the Rome II criteria for constipation entered the study. No patient had evidence of secondary forms of constipation and distal obstruction. METHODS: Twenty-four hour colonic manometric studies were obtained for each patient. Regular contractile patterns (with frequencies ranging from 2 to 8 cycles/min) were calculated for the entire recording period and in single colonic segments. RESULTS: Overall, regular patterns accounted for about 3% of the total colonic motor activity (average 30 min/day per subject), with the 3 cycles/min being the predominant contractile rhythm. Most of this activity was present in the sigmoid colon, accounting for >50% of the total amount of motility, and it was more prevalent than in the descending and transverse colon; no differences were revealed in the descending with respect to the transverse colon. No daily fluctuations of regular contractile activity, nor a cyclic pattern, nor migration between recording points were observed. CONCLUSIONS: Regular colonic frequency patterns are probably of minor pathophysiological importance in slow transit constipation, even in the light of the scant amount of such phenomena previously documented in healthy subjects.     

慢传输型便秘外科治疗的主要术式及疗效

近年来,便秘的发病率呈缓慢上升趋势。然而,国际上对于慢传输型便秘的发病原因及发病机理尚未完全认清。虽然经过一段时间的内科保守治疗能够暂时缓解便秘症状,但不能从根本上解决慢传输型便秘的问题。手术可能是最终而有效的治疗慢传输型便秘的方法。现阶段,治疗慢传输型便秘的主要术式有：全结肠切除回直肠吻合术、结肠次全切除盲肠直肠吻合术、结肠旷置术和末端回肠造口术等。本文主要介绍这几种术式及其疗效。     

Fiber intake and colonic transit time in functional constipated patients

BACKGROUND: Patients with functional constipation presenting no response to treatment using fibers supplement represents important clinical issue. AIMS: To evaluate the relations among the amount of ingested fiber, the constipation intensity and the colonic transit time in patients with functional constipation. METHODS: We evaluated 30 patients, presenting no response to treatment using fibers supplement, and 18 healthy volunteers conducting individual inquiry into fibers intake, constipation intensity and the total and segmental colonic transit evaluation using radiopaque markers. RESULTS: In the constipated, despite the good level of fiber intake (26.3 +/- 12.9 g, constipated x 9.3 +/- 5,2 g, control), the symptoms of constipation was serious (score = 21.3 +/- 4.07). Mean total colonic transit was 58.8h. The colonic transit was slower in the constipated group (41.0 +/- 22.8 hours, constipated x 21.8 +/- 18.5h, control). In constipated patients with slow colonic transit (>58.8h) there were colonic inertia (eight), outlet constipation (one) and slow transit in left colon (one), and among constipated patients with normal colonic transit (<58.8h), there were isolated slow transit, in the right colon (nine), left colon (three) and in the rectosigmoid segment (eight). There were no relation among the amount of ingested fiber, constipation intensity and the colon transit. CONCLUSIONS: In the functional constipation the gravity of symptoms does not depend only on the dietary fibers intake, which is not the only responsible for the differences in the colonic transit. The colonic transit can differentiate normal from constipated patients and, among them, those with altered transit that demand approaches distinct of fiber supplementation.     

Dynamic scanning defines a colonic defect in severe idiopathic constipation.

A technique is described in which a chemical stimulus applied to the mucosa of the right colon is used to assess colonic motor function. Peroral intubation of the right colon was achieved using a fine polyvinylchloride (PVC) tube. Bisacodyl was used to initiate colonic motor activity, and colonic transit was monitored using 99mTc-DPTA and a gamma camera. In normal subjects there was rapid movement of the radiopharmaceutical from the right colon to the rectum. In patients with severe idiopathic constipation, a spectrum of colonic abnormality was observed from slow transit involving the rectum and sigmoid only to slow transit involving the whole colon. The hepatic flexure to rectum transit time for the 'head of the isotope column' in normals ranged from 1-10 minutes (mean 5.3 minutes), whereas in patients the transit time was 14-25 minutes in four patients and radioisotope did not reach the rectum by two hours in three other patients (controls v patients, p less than 0.01). Patients also showed relatively impaired transport of the isotope 'mass'. This technique has shown that the normal colon is capable of rapid effective transport in response to a standard stimulus, and that patients with severe idiopathic constipation have a definable colonic motor disorder.     

Regulation of the enteric nervous system in the colon of patients with slow transit constipation

BACKGROUND/AIMS: The cause of impaired motility in patients with slow transit constipation is unknown. To clarify the physiological significance of cholinergic, adrenergic, non-adrenergic non-cholinergic inhibitory nerves in the colon of patients with slow transit constipation, we investigated the enteric nerve responses on lesional and normal bowel segments derived from patients with slow transit constipation and patients who underwent colon resection for colonic cancers. METHODOLOGY: Twenty preparations were taken from the lesional colon of 6 patients with slow transit constipation (2 men and 4 women, aged 23 to 68 years, with a mean age of 44.0 years). Thirty-six preparations were taken from the normal colon of 12 patients with colonic cancer (6 men and 6 women, aged 40 to 60 years, with a mean age of 52.2 years). A mechanographic technique was used to evaluate in vitro muscle responses to acetylcholine, adrenalin, electrical field stimulation of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. RESULTS: The contraction reaction to acetylcholine in the colon with slow transit constipation was significantly weaker than in the normal colon (P < 0.01). The relaxation reaction to adrenalin in the colon with slow transit constipation was stronger than in the normal colon. The colon with slow transit constipation was more strongly innervated by non-adrenergic non-cholinergic inhibitory nerves than the normal colon, significantly (P < 0.05). CONCLUSIONS: These findings suggest that a decrease of cholinergic nerve and an increase of non-adrenergic non-cholinergic inhibitory nerve play an important role in the impaired motility observed in the colon of patients with slow transit constipation.     

Short-term effects of magnetic sacral dermatome stimulation for idiopathic slow transit constipation: Sham-controlled, cross-over pilot study

Background and Aim: An increase in recto‐sigmoid colon activity through electrical stimulation of the sacral dermatomes has previously been reported. It has not been evaluated whether or not sacral dermatome stimulation has beneficial effects on constipation symptoms and anorectal function in constipated patients. Our aim was to evaluate short‐term effects of magnetic stimulation of the sacral dermatomes on constipation symptoms and anorectal function in patients with idiopathic slow transit constipation. Method: Fourteen patients with idiopathic slow transit constipation were enrolled. Constipation symptoms, stool form and anorectal function were assessed before treatment, and at 3 and 6 weeks of treatment. Six‐week treatment consisted of either a 3‐week period of sham treatment or a 3‐week period of magnetic stimulation of the S2‐S3 dermatomes, which was performed in a randomized cross‐over design. Results: During the stimulation period, the frequency score of spontaneous bowel movements decreased in eight of the 14 patients (2.9 [2–3]vs 1.4 [0–2]), whose threshold volumes for urge to defecate and maximum tolerable volumes were significantly greater than those of the non‐responders, and significantly decreased at the end of treatment. The degree of straining on defecation also significantly decreased in the responders. Responders had shorter right colonic transit time and longer left colonic transit time compared to the non‐responders. Sham treatment did not affect constipation symptoms, stool form and rectal sensation. Conclusion: Sacral dermatome stimulation may offer potential for therapeutic benefit for a subset of patients with idiopathic slow transit constipation, particularly constipated patients with rectal hyposensation or hindgut dysfunction.     

Scintigraphic measurement of regional gut transit in idiopathic constipation

In this study, total gut transit and regional colonic transit in patients with idiopathic constipation were measured scintigraphically. Eight patients with severe constipation were studied, none of whom had evidence of abnormal function of the pelvic floor. 99mTc-radiolabeled Amberlite resin particles (average diameter, 1 mm; Sigma Chemical Co., St. Louis, MO) with a mixed meal were used to assess gastric emptying and small bowel transit; similar particles labeled with 111In were ingested in a coated capsule that dispersed in the ileocecal region. These were used to quantify colonic transit. Five healthy volunteers were also studied. Two patients showed delayed gastric emptying and two had slow small bowel transit. Seven of the eight patients had slow colonic transit. In five, delay affected the whole colon ("pancolonic inertia"); in two, transit in the ascending and transverse colon was normal, but solids moved through the left colon slowly. Mean colonic transit was also measured using radiopaque markers; this technique identified the patients with slow transit, as shown by measurements of overall colonic transit by simultaneous scintigraphy. However, estimated transit through the ascending and transverse colons was considerably shorter by the radiopaque marker technique. In conclusion, idiopathic constipation is characterized by either exaggerated reservoir functions of the ascending and transverse colons and/or impairment of propulsive function in the descending colon. Particle size may influence the result of regional colonic transit tests. Transit delays in other parts of the gut suggest that, in some patients, the condition may be a more generalized motor dysfunction.