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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the irritable bowel syndrome is characterized as an abnormality in colonic motor activity occurring in response to certain stimuli, the etiology of this disorder is unclear. The purpose of this study is to determine the relationship of altered slow wave activity and the abnormal motility of the distal colon seen in patients with the irritable bowel syndrome. Myoelectrical activity was recorded using a bipolar electrode clipped to the distal colonic mucosa and motor activity was measured by perfused catheters. Colonic slow waves and contractions were present at two frequencies, 6 and 3 cycles per min. The slow wave frequency seemed to determine the frequency of colonic motor activity. Patients with the irritable bowel syndrome had increased 3-cycle per min slow wave activity in the basal state (P less than 0.001). However, no difference in basal 3-cycle per min motor activity was present between the two groups (P greater than 0.05). When colonic motor activity was increased with cholecystokinin or pentagastrin, patients with irritable bowel syndrome showed a marked increase in 3-cycle per min contractile activity, occurring simultaneously with 3-cycle per min slow wave activity. These studies suggest that increased colonic 3-cycle per min slow wave activity in patients with the irritable bowel syndrome may be the basic abnormality that leads to colonic motor dysfunction in response to various physiological stimuli.
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PMID:Evidence that abnormal myoelectrical activity produces colonic motor dysfunction in the irritable bowel syndrome. 83 84

Distal colonic motor activity was measured in 12 control subjects and seven constipation-predominant irritable bowel syndrome patients to examine the effects of intravenous administration of cholecystokinin. In the basal state, no significant motility differences were noted between these two groups. Following the intravenous administration of the hormone cholecystokinin, a statistically significant reduction in colonic motility in control subjects and a non-significant decrease in motility in irritable bowel syndrome patients was seen. Our results do not suggest an exaggeration of the colonic motor response to cholecystokinin occurs in irritable bowel syndrome.
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PMID:Inhibition of colonic motility by cholecystokinin. 141 16

Colonic motor activity and plasma concentrations of cholecystokinin (CCK) both increase after oral intake of a meal. Thus, CCK had been thought to mediate the postprandial increase in colonic motor activity, which is termed gastrocolonic response. The present study used the substance loxiglumide, which acts as a specific antagonist at the CCK-A receptor, to evaluate this hypothesis. In the first set of experiments, eight healthy subjects were studied four times on separate days. A multilumen catheter was endoscopically placed with its tip lying in the descending colon. Motor activity was recorded by a low-compliance perfusion manometry system at six locations 60-45 cm from the anus. Basal activity was recorded for at least 2 hours to achieve steady-state conditions. The order of the following four experiments was randomized: (a) intravenous infusion of the CCK analogue cerulein at increasing doses (7.5, 15, 30, and 60 ng/kg.h, each given for 30 minutes); (b) intravenous cerulein plus 5 mg/kg.h loxiglumide; (c) a 1000-kcal solid/liquid meal consisting of regular German food; and (d) a meal plus 5 mg/kg.h loxiglumide. In the second set of experiments, eight patients with irritable bowel syndrome were studied twice on two separate days, and two experiments were performed n randomized order: (a) a 1000-kcal solid/liquid meal consisting of regular German food; or (b) a meal plus 5 mg/kg.h loxiglumide. The motor index was calculated as the area under contractions by a computerized system. The 1000-kcal meal markedly increased colonic motor activity. This gastrocolonic response was significantly greater in patients with irritable bowel syndrome than in healthy volunteers. Cerulein stimulated motor activity only at pharmacological doses (30-60 ng/kg.h), which resulted in plasma CCK levels markedly exceeding postprandial values. Loxiglumide abolished the effects of cerulein even at pharmacological doses. However, loxiglumide did not inhibit the gastrocolonic response to a regular meal either in healthy volunteers or in patients with irritable bowel syndrome. Loxiglumide also failed to alter the interdigestive colonic motor activity. Therefore, effects mediated by the CCK-A receptor do not play a major physiological role in the regulation of the interdigestive and postprandial motility of the left colon.
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PMID:Cholecystokinin's role in regulation of colonic motility in health and in irritable bowel syndrome. 158 8

Clues to the pathogenesis of functional pain syndromes may be derived from the study of stimuli that precipitate or aggravate symptoms. In this study, cholecystokinin octapeptide (CCK-8, 0.06 microgram/kg) and placebo were given by intravenous infusion (5 min) in random order to control subjects and four groups of patients with unexplained abdominal pain. Induction of pain and nausea were assessed by linear analogue scales while sympathoadrenomedullary responses were assessed by serial changes in plasma concentrations of noradrenaline, adrenaline and dopamine. Scores for pain and nausea were low after infusion of placebo. After infusion of CCK-8, pain scores were significantly higher in patients with spontaneous pain than in control subjects, but significant increases in nausea were restricted to patients with irritable bowel syndrome and a subgroup of patients with pain after cholecystectomy. Although some groups showed increases in plasma concentrations of catecholamines after the infusion of CCK-8, the size of these increases was neither consistent among patients within each group nor predictive of scores of pain and nausea in individual subjects. Pain during the infusion of CCK-8 was a feature common to patients with diverse functional pain syndromes, and did not appear to be attributable to activation of the sympathetic nervous system.
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PMID:Responses to cholecystokinin octapeptide in patients with functional abdominal pain syndromes. 161 Oct 17

We have described previously that the gallbladder responds abnormally to infusions of cholecystokinin octapeptide (CCK-8) in patients with irritable bowel syndrome (IBS). To confirm these results and to examine the possible mechanisms, patients with IBS and predominant symptoms of diarrhea or constipation were compared with matched controls. During infusions of CCK-8 at one of three doses, the response of the gallbladder was measured ultrasonographically. The levels of CCK-8 reached in the peripheral circulation and degradation of the peptide in vitro and in vivo were used to evaluate metabolism of cholecystokinin. We confirmed that the gallbladders of patients with IBS responded abnormally to CCK-8; however, the differences were not due to any prereceptor event. Instead, this abnormality in IBS must be explained by an atypical response at the level of the target tissues.
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PMID:Abnormal gallbladder motility in irritable bowel syndrome: evidence for target-organ defect. 153 72

The irritable bowel syndrome (IBS) is an umbrella for the diagnosis of heterogeneous conditions that are awaiting better identification of specific manometric causes. This article focuses on the concept that future therapy for IBS will rely on identification of subgroups and in turn tailor the specific therapeutic approaches to an appreciation of the pathophysiology and symptom predominance of these subgroups. Future therapies will rely on the following principles: (1) prokinetic agents to coordinate upper gastrointestinal and colonic motility as well as improve the propulsive nature of colonic contractions; (2) gastrointestinal hormone agonists such as erythromycin and antagonists such as sandostatin and cholecystokinin antagonists; (3) spasmolytic therapy incorporating calcium channel blocking and anticholinergic agents; (4) inhibition of ovulatory cycle changes in circulating concentrations of gonadal hormones in women, who tend to dominate the IBS population; (5) incorporation of concepts relating to the role of subtypes of 5-hydroxytryptamine receptors in control of neural and myogenic function; (6) reassessment of food intolerance and sensitivity; and (7) incorporation of concepts relating to psychologic profiles and psychologic treatment approaches. IBS is a rich and fertile area for application of the exciting new pharmacologic advances relating to gastrointestinal smooth-muscle and neural innervation of the gut. Improvement in the understanding and treatment of IBS will be one of the major accomplishments of this decade.
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PMID:New directions in the irritable bowel syndrome. 206 57

The presently available methods of study of small bowel motility in humans include manometry (or electromyography) which records the temporospatial organization of bowel contractions and determination of intestinal transit time. Investigation of subjects with the irritable bowel syndrome has shown that the small intestine has its part in the motor disturbances. The characteristics of normal motility of the small intestine are well known: the migrating motor complex (MMC) develops during the interdigestive period, typical contractions are seen during phases 2 and 3 of the MMC, the nature and the duration of the motor response to alimentation have been described. In patients with IBS, the production of the MMC is irregular during the day hours; this is most likely due to environmental solicitations and it is recognized that intensive aliess can cause transient interruption of the development of cycles. On the other hand, the MMC develops normally during sleeping hours. Contraction derangements such as non propulsed repeated contractions in the proximal intestine and contractions propulsed too frequently in the small intestine may be found during phase 2. Some of the abnormal contractions coincide with abdominal pain. After meals, the duration of interruption of the MMC is shorter than in the normal subject. Transit time is shortened in patients with diarrhea, lengthened in patients with constipation. Patients with IBS respond excessively to certain stimuli: for instance, the motor response to cholecystokinin is increased compared to the normal subject. Intake of fatty ingesta is followed by the same type of reaction: pain is often associated with abnormal contractions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Small bowel motility in the irritable bowel syndrome]. 221 Jan 78

Long neglected in the past, the study of visceral sensitivity (interoception) has progressed in recent years because of advances in neurobiological techniques. Dealing with the structure or the function of single neurons, these techniques have profoundly increased our knowledge about the sensitive mechanisms in the digestive tract. According to recent data, the visceral sensitivity organs are richer and more complex than imagined previously. Microphysiological techniques have shown that intestinal sensitive terminations are capable of transmitting information concerning visceral activity and physicochemical modifications of intestinal contents directly to the central nervous system. This means that visceral sensitivity intervenes under physiological as well as pathological conditions. This notion is new and of great interest. As progress was being made concerning the morphologic and electrophysiologic aspects and contemporaneous studies were establishing the richness of visceral, and particularly, intestinal, sensitive receptors, basic science research in humans and animals have emphasized the diversity of the implication of the extrinsic nervous system in pain, regulation of digestive motility, homeostasis and alimentary behaviour. Our present knowledge on the nervous and neurohumoral mechanisms has shed new light on the determinisms in digestive tract pathology. This is especially true in the irritable bowel syndrome which can be considered as an extrinsic nervous system derangement. Due to abnormal sensitivity by modification of the threshold values of sensitivity to distension, and/or to stimulation by substances such as cholecystokinin, for example, motor disorders occur. Other factors, such as stress, can be responsible for revelation or exacerbation of neurohumoral disorders.
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PMID:[Intestinal sensitivity disorders and irritable bowel syndrome]. 221 Jan 79

Patients with chronic right upper quadrant pain who do not have gallstones on ultrasound or cholecystography are often referred for surgery for presumed acalculous chronic cholecystitis. We followed 26 patients who had cholecystokinin (CCK) cholescintigraphy for evaluation of chronic right upper quadrant pain without demonstrable gallstones on ultrasound who underwent cholecystectomy so that it could be determined whether there was any relation between a low ejection fraction (EF), morphological features of chronic cholecystitis, and clinical outcome. Eighteen patients (69%) were considered therapeutic successes, whereas eight (31%) were failures after an average 2-yr follow-up. Both patient groups had significantly reduced EF: the successful group at 0.39 and the failures at 0.25. Thus, a low EF did not predict clinical outcome, since the failure group had an even lower EF than the success group. Seven gallbladders demonstrated chronic acalculous cholecystitis; the average EF of this group was 0.35. The remaining 19 gallbladders were normal, yet also had an EF of 0.35. Thus, decreased EF does not predict the histologic features of chronic cholecystitis without gallstones. The diagnostic value of cholescintigraphy in patients with acalculous right upper quadrant pain is low, probably because this entity represents a variety of processes, including inflammation, gallbladder dysmotility, and the irritable bowel syndrome.
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PMID:Chronic right upper quadrant pain without gallstones: does HIDA scan predict outcome after cholecystectomy? 237 27

Gastrointestinal (GI) motility is centrally controlled through the sympathetic and parasympathetic nerves, sympathetic effects being partly mediated by beta adrenoceptors. Although beta adrenoceptor agonists and antagonists are widely used for different disorders, little is known about the influence of these agents on GI motility. The present study was initiated to investigate whether there is a physiological, beta adrenergic influence on human GI motility and to describe the effects of selective beta adrenoceptor stimulation on motility in the proximal and distal parts of the GI tract. Esophageal peristalsis was measured in healthy subjects using electronic catheters. Distal colonic motility was measured with an open-tipped, water-perfused catheter in the sigmoid colon and from an air-filled balloon in the rectum in healthy subjects and in patients with the irritable bowel syndrome (IBS). In one study, colonic motility was stimulated with continuous infusion of the octapeptide of cholecystokinin (CCK-OP). Esophagus: Peristaltic amplitude was increased in the distal smooth muscle part of the esophageal body after infusion of both the nonselective beta blocker propranolol and the beta-1 selective blocker metoprolol. After infusion of the beta-1 agonist prenalterol and the beta-2 selective agonist terbutaline, a profound decrease in esophageal peristaltic amplitude was seen. Pretreatment with metoprolol selectively blocked the response to a moderate dose of prenalterol but did not block the response to terbutaline. The latter response was blocked by propranolol. Peristaltic velocity in the proximal part of the esophagus was decreased by beta-1 stimulation and in the distal part by beta-2 stimulation. Distal colon: In healthy subjects the sigmoid motility index showed a dose-dependent increase after metoprolol and propranolol, respectively. The increase was more marked after propranolol infusion. Terbutaline decreased the sigmoid motility index both in healthy subjects and in patients with the IBS. Furthermore, the rectal motility index was decreased in the group of healthy subjects. The effects of prenalterol on rectal and sigmoid motility did not differ from those of placebo. The IBS patient group showed larger intraindividual variations in sigmoid motility from day to day and also lower rectal motility indices than the healthy subjects. Infusion of CCK-OP increased the sigmoid motility index compared to non-stimulated conditions. No effects on CCK-OP stimulated motility were seen after either terbutaline, prenalterol or placebo.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Beta adrenergic influence on esophageal and colonic motility in man. 286 39


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