Small bowel motility following major intra-abdominal surgery: the effects of opiates and rectal cisapride

Postoperative Ileus: a Pharmacological Perspective

Post-operative ileus (POI) is a frequent complication after abdominal surgery. The consequences of POI can be potentially serious such as bronchial inhalation or acute functional renal failure. Numerous advances in peri-operative management, particularly early rehabilitation, have made it possible to decrease POI. Despite this, the rate of prolonged POI ileus remains high and can be as high as 25% of patients in colorectal surgery. From a pathophysiological point of view, POI has two phases, an early neurological phase and a later inflammatory phase, to which we could add a "pharmacological" phase during which analgesic drugs, particularly opiates, play a central role. The aim of this review article is to describe the phases of the pathophysiology of POI, to analyse the pharmacological treatments currently available through published clinical trials and finally to discuss the different research areas for potential pharmacological targets.

Epidural analgesia is associated with earlier gastrointestinal transit after radical cystectomy but does not reduce the incidence of postoperative ileus: A retrospective cohort study

Objective:

To compare the effect of combined epidural thoracic analgesia and general anaesthesia (CEGA) in radical cystectomy (RC) with respect to the return of gastrointestinal passage, the incidence of paralytic postoperative ileus (POI) compared to general anaesthesia (GA) only.

Patients and methods:

We conducted a retrospective review using the electronic medical records of 236 patients who underwent RCs between July 2011 and September 2018 at the Medical Center – University of Freiburg.

Results:

A CEGA was administered to 202 patients, while 34 patients received only GA. The baseline characteristics of patients with and without CEGA showed no significant differences. CEGA will decrease the time required for return of gastrointestinal transit as measured by time to first defecation by about 13 hours. In the first 90 days after surgery, 82 (34.7%) patients had a POI. There was no significant difference between complications in the CEGA and GA groups.

Conclusion:

A CEGA accelerates the return of the gastrointestinal transit but does not reduce the incidence of postoperative ileus.

Level of evidence:

2b

Impact of gastrointestinal tract variability on oral drug absorption and pharmacokinetics: An UNGAP review

The absorption of oral drugs is frequently plagued by significant variability with potentially serious therapeutic consequences. The source of variability can be traced back to interindividual variability in physiology, differences in special populations (age- and disease-dependent), drug and formulation properties, or food-drug interactions. Clinical evidence for the impact of some of these factors on drug pharmacokinetic variability is mounting: e.g. gastric pH and emptying time, small intestinal fluid properties, differences in pediatrics and the elderly, and surgical changes in gastrointestinal anatomy. However, the link of colonic factors variability (transit time, fluid composition, microbiome), sex differences (male vs. female) and gut-related diseases (chronic constipation, anorexia and cachexia) to drug absorption variability has not been firmly established yet. At the same time, a way to decrease oral drug pharmacokinetic variability is provided by the pharmaceutical industry: clinical evidence suggests that formulation approaches employed during drug development can decrease the variability in oral exposure. This review outlines the main drivers of oral drug exposure variability and potential approaches to overcome them, while highlighting existing knowledge gaps and guiding future studies in this area.

Gastrointestinal dysmotility: clinical consequences and management of the critically ill patient

Gastrointestinal dysmotility is a common feature of critical illness, with a number of significant implications that include malnutrition secondary to reduced feed tolerance and absorption, reflux and aspiration resulting in reduced lung function and ventilator-associated pneumonia, bacterial overgrowth and possible translocation causing nosocomial sepsis. Prokinetic agent administration can improve gastric emptying and caloric delivery, but its effect on nutrient absorption and clinical outcomes is, as yet, unclear. Postpyloric delivery of nutrition has not yet been demonstrated to increase caloric intake or improve clinical outcomes.

Cisapride: what can we learn from the rise and fall of a prokinetic?

Cisapride, the prototype serotonergic agent, evolved from a body of research that defined the key roles of serotonergic receptors in gastrointestinal motor and sensory function. Impressed by its in vitro properties and encouraged by clinical trial data, cisapride became the drug of choice for the treatment of a wide range of motility disorders and clinicians appeared impressed by its efficacy and comfortable with its side-effect profile. Once serious cardiac events began to be reported in association with cisapride therapy, dark clouds rapidly gathered and soon enveloped the drug, leading to its widespread withdrawal from markets. What lessons can we learn from the story of cisapride? How can its brief but spectacular rise and equally sensational demise inform the development of new drugs which are so sorely needed in the management of motility and functional gastrointestinal disorders? This review explores the background to the development of cisapride, its history in clinical trials and the experience with adverse events and, in so doing, attempts to identify lessons for the future in the therapeutics of enteric neuromodulatory drugs.

The hungry stomach: physiology, disease, and drug development opportunities

During hunger, a series of high-amplitude contractions of the stomach and small intestine (phase III), which form part of a cycle of quiescence and contractions (known as the migrating motor complex, MMC), play a "housekeeping" role prior to the next meal, and may contribute toward the development of hunger. Several gastrointestinal (GI) hormones are associated with phase III MMC activity, but currently the most prominent is motilin, thought to at least partly mediate phase III contractions of the gastric MMC. Additional GI endocrine and neuronal systems play even more powerful roles in the development of hunger. In particular, the ghrelin-precursor gene is proving to have a complex physiology, giving rise to three different products: ghrelin itself, which is formed from a post-translational modification of des-acyl-ghrelin, and obestatin. The receptors acted on by des-acyl-ghrelin and by obestatin are currently unknown but both these peptides seem able to exert actions which oppose that of ghrelin, either indirectly or directly. An increased understanding of the actions of these peptides is helping to unravel a number of different eating disorders and providing opportunities for the discovery of new drugs to regulate dysfunctional gastric behaviors and appetite. To date, ghrelin and motilin receptor agonists and antagonists have been described. The most advanced are compounds which activate the ghrelin and motilin receptors which are being progressed for disorders associated with gastric hypomotility.

Artificial nutrition: principles and practice of enteral feeding

Enteral feeding is a commonly used form of nutritional supplementation for patients with intestinal failure, both in hospitals and in the community. This article concentrates on the basic principles of enteral feeding, including the physiological effects of feeding into the intestinal tract. It covers the indications for enteral feeding, the different methods of supplying enteral feeds to the gastrointestinal tract, and the potential complications. There is also a discussion of the indications for and practice of home enteral nutrition.

Impact of bolus volume on small intestinal intra-luminal impedance in healthy subjects

AIM: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance signals.

METHODS: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the pattern of proximal jejunal fluid bolus movement over a 14 cm-segment. Each subject was given 34 boluses of normal saline (volume from 1 to 30 mL) via the feeding tube placed immediately above the proximal margin of the studied segment. A bolus-induced impedance event occurred if there was > 12% impedance drop from baseline, over ≥ 3 consecutive segments within 10 s of bolus injection. A minor or major impedance event was defined as a duration of impedance drop < 60 s or ≥ 60 s, respectively.

RESULTS: The minimum volume required for a detectable SI impedance event was 2 mL. A direct linear relationship between the SI bolus volume and the occurrence of impedance events was noted until SI bolus volume reached 10 mL, a volume which always produced an impedance flow event. There was a moderate correlation between the bolus volume and the duration of impedance drop (r = 0.63, P < 0.0001) and the number of propagated channels (r = 0.50, P < 0.0001). High volume boluses were associated with more major impedance events (≥ 10 mL boluses = 63%, 3 mL boluses = 17%, and < 3 mL boluses = 0%, P = 0.02).

CONCLUSION: Bolus volume had an impact on the type and length of propagation of SI impedance events and a threshold of 2 mL is required to produce an event.

Abdominal surgery affects small bowel transit time and completeness of capsule endoscopy

The aim of the study was to evaluate bowel dysmotility in patients with a history of abdominal surgery by measuring both gastric transit time and small bowel transit time during capsule endoscopy and assessing the completeness of the examination. The study included 26 patients who had undergone abdominal surgery (postoperative group) and 52 patients who had not (control group). The capsule reached the cecum in 50.0% of the postoperative group and 80.8% of the control group (P=0.005). While there was no significant difference in gastric transit time between the two groups (P=0.882), small bowel transit time was significantly longer in the postoperative group (338.3+/-119.2 min) than in the control group (266.4+/-110.8 min, P=0.010). This is the first study to report that the small bowel transit time during capsule endoscopy is prolonged in patients who had a history of abdominal surgery, resulting in a lower frequency of complete examination.

The effects of intestinal ischemia on colonic motility in conscious rats

BACKGROUND

The present study aimed to examine whether and how colonic motility is affected by mild ischemia-induced intestinal injury in conscious rats through in vivo monitoring of colonic contractions, specifically with regard to the interstitial cells of Cajal (ICC) and the effect of nitric oxide (NO).

METHODS

Using miniature strain-gauge transducers, colonic motility with or without ischemia was recorded in conscious rats on the 4th, 7th, and 14th days after surgery. Histological examination for c-kit-positive cells was performed.

RESULTS

In control nonischemic rats, the number and duration of contractions (NC and DC, respectively) decreased gradually, but the mean amplitude of contractions (MC) and motility index (MI) did not change. On the 7th day, the NC in the ischemic group increased significantly when compared with that in the control group (P = 0.037). The DC in the ischemic group was lower than that in the control group; the difference was significant on the 4th day (P = 0.008). The MIs in the ischemic group were lower than those in the control group. In both groups, administration of NGnitro-L: -arginine methyl ester on the 7th day increased only the resting cecal motility. Pathological examinations revealed c-kit-positive cells in both groups.

CONCLUSIONS

Changes such as increased NC with shortened DC accompanied with decreased MI must have occurred at the ischemic site and might have been induced by an ischemic event. However, there exists a possibility that ICC and NO do not play a role in mild ischemia-induced dysmotility.

Systemic prokinetic pharmacologic treatment for postoperative adynamic ileus following abdominal surgery in adults

BACKGROUND

Postoperative adynamic bowel atony interferes with recovery following abdominal surgery. Prokinetic pharmacologic drugs are widely used to accelerate postoperative recovery.

OBJECTIVES

To evaluate the benefits and harms of systemic acting prokinetic drugs to treat postoperative adynamic ileus in patients undergoing abdominal surgery.

SEARCH STRATEGY

Trials were identified by computerised searches of the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and the Cochrane Colorectal Cancer Group specialised register. The reference lists of included trials and review articles were tracked and authors contacted.

SELECTION CRITERIA

Randomised controlled parallel-group trials (RCT) comparing the effect of systemically acting prokinetic drugs against placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Four reviewers independently extracted the data and assessed trial quality. Trial authors were contacted for additional information if needed.

MAIN RESULTS

Thirty-nine RCTs met the inclusion criteria contributing a total of 4615 participants. Most trials enrolled a small number of patients and showed moderate to poor (reporting of) methodological quality, in particular regarding allocation concealment and intention-to-treat analysis. Fifteen systemic acting prokinetic drugs were investigated and ten comparisons could be summarized. Six RCTs support the effect of Alvimopan, a novel peripheral mu receptor antagonist. However, the trials do not meet reporting guidelines and the drug is still in an investigational stage. Erythromycin showed homogenous and consistent absence of effect across all included trials and outcomes. The evidence is insufficient to recommend the use of cholecystokinin-like drugs, cisapride, dopamine-antagonists, propranolol or vasopressin. Effects are either inconsistent across outcomes, or trials are too small and often of poor methodological quality. Cisapride has been withdrawn from the market due to adverse cardiac events in many countries. Intravenous lidocaine and neostigmine might show a potential effect, but more evidence on clinically relevant outcomes is needed. Heterogeneity among included trials was seen in 10 comparisons. No major adverse drug effects were evident.

AUTHORS' CONCLUSIONS

Alvimopan may prove to be beneficial but proper judgement needs adherence to reporting standards. Further trials are needed on intravenous lidocaine and neostigmine. The remaining drugs can not be recommended due to lack of evidence or absence of effect.

Nutritional interventions in critical illness

The metabolism of critical illness is characterised by a combination of starvation and stress. There is increased production of cortisol, catecholamines, glucagon and growth hormone and increased insulin-like growth factor-binding protein-1. Phagocytic, epithelial and endothelial cells elaborate reactive oxygen and nitrogen species, chemokines, pro-inflammatory cytokines and lipid mediators, and antioxidant depletion ensues. There is hyperglycaemia, hyperinsulinaemia, hyperlactataemia, increased gluconeogenesis and decreased glycogen production. Insulin resistance, particularly in relation to the liver, is marked. The purpose of nutritional support is primarily to save life and secondarily to speed recovery by reducing neuropathy and maintaining muscle mass and function. There is debate about the optimal timing of nutritional support for the patient in the intensive care unit. It is generally agreed that the enteral route is preferable if possible, but the dangers of the parenteral route, a route of feeding that remains important in the context of critical illness, may have been over-emphasised. Control of hyperglycaemia is beneficial, and avoidance of overfeeding is emphasised. Growth hormone is harmful. The refeeding syndrome needs to be considered, although it has been little studied in the context of critical illness. Achieving energy balance may not be necessary in the early stages of critical illness, particularly in patients who are overweight or obese. Protein turnover is increased and N balance is often negative in the face of normal nutrient intake; optimal N intakes are the subject of some debate. Supplementation of particular amino acids able to support or regulate the immune response, such as glutamine, may have a role not only for their potential metabolic effect but also for their potential antioxidant role. Doubt remains in relation to arginine supplementation. High-dose mineral and vitamin antioxidant therapy may have a place.

Listening to Bowel Sounds: An Evidence-Based Practice Project

Nurses' practice of listening to bowel sounds was first proposed in 1905 and continues today, largely unquestioned. The authors developed a project to determine whether any compelling evidence exists for using this method to assess for the return of gastrointestinal (GI) motility following abdominal surgery. Literature on the subject was evaluated and an assessment of nursing practice was conducted. Based on the literature review and the assessment, a nursing practice guideline was developed, implemented, and evaluated. (Note that the nursing practice guideline outlined in this article was evaluated for use with abdominal surgery patients only and has not been evaluated in and may not be appropriate for other patient populations). The results were positive and indicate that clinical parameters other than bowel sounds, such as the return of flatus and the first postoperative bowel movement, are appropriate in assessing for the return of GI motility after abdominal surgery. Bowel sound assessment was discontinued and patient outcomes were evaluated to make sure that the practice change had no adverse effect on patients' recovery.

Postoperative ileus: a review

PURPOSE

Postoperatively, some patients experience a prolonged inhibition of coordinated bowel activity, which causes accumulation of secretions and gas, resulting in nausea, vomiting, abdominal distension, and pain. This prolonged inhibition can take days or weeks to resolve and often is referred to as postoperative paralytic ileus lasting more than three days after surgery. This article reviews the etiology, pathophysiology, and treatment options of postoperative ileus.

METHODS

The relevant literature from 1965 to 2003 was identified and reviewed using MEDLINE database of the U.S. Medical Library of Medicine. Both retrospective and prospective studies were included in this review.

RESULTS

The pathophysiology of postoperative ileus is multifactorial. The duration of postoperative ileus correlates with the degree of surgical trauma and is most extensive after colonic surgery. However, postoperative ileus can develop after all types of surgery including extraperitoneal surgery. A variety of treatment options have been used to decrease the duration of postoperative ileus. However, it is difficult to compare these studies because of small sample sizes and differences in operations performed, anesthesia protocols provided both intraoperatively and postoperatively, patient comorbidities, and in the measured end points, such as the time to the presence of bowel sounds, flatus, or bowel movements, tolerance of solid food, or discharge from the hospital. However, despite these drawbacks, some conclusions can be made.

CONCLUSIONS

Paralytic postoperative ileus continues to be a significant problem after abdominal and other types of surgery. The etiology is multifactorial and is best treated with a combination of different approaches. Currently, the important factors that could effect the duration and recovery from postoperative ileus include limitation of narcotic use by substituting alternative medications such as nonsteroidals and placing a thoracic epidural with local anesthetic when possible. The selective use of nasogastric decompression and correction of electrolyte imbalances also are important factors to consider.

Study of intestinal flow by combined videofluoroscopy, manometry, and multiple intraluminal impedance

Assessment of patterns of flow in the small bowel is difficult. Multiple intraluminal impedance has been recently used for study of flow dynamics in the esophagus. Our aims were 1) to validate multiple intraluminal impedance by correlating impedance events with intestinal flow as detected by fluoroscopy and 2) to determine intestinal flow patterns in the fasting and postprandial period and their correspondence with manometry. First, six healthy subjects underwent simultaneous video-fluoroscopic, manometric, and impedance recording from the duodenum. Videofluoroscopy was used to validate impedance patterns corresponding with barium flow in the fasting and postprandial periods. Next, 16 healthy subjects underwent prolonged simultaneous recording of impedance and manometry in both periods. Most flow events were short (10 cm or less), with antegrade flow being the most common. Correspondence between impedance and videofluoroscopy increased with increasing length of barium flow. Impedance corresponded better with flow, at any distance, than manometry. However, impedance and manometric events, when analyzed separately as index events, always corresponded with fluoroscopic flow. The fasting and postprandial periods showed comparable patterns of flow, with frequent, highly propulsive manometric and impedance sequences. Motility index was positively and significantly associated with length of impedance events. Phase 3 of the migrating motor complex could be easily recognized by impedance. Multiple intraluminal impedance can detect intestinal flow events and corresponds better with fluoroscopic flow than manometry.

Methods for decreasing postoperative gut dysmotility

Postoperative disturbances of gastrointestinal function (postoperative ileus) are among the most significant side-effects of abdominal surgery for cancer. Without specific treatment, major abdominal surgery causes a predictable gastrointestinal dysfunction which endures for 4-5 days and results in an average hospital stay of 7-8 days. Ileus occurs because of initially absent and subsequently abnormal motor function of the stomach, small bowel, and colon. This disruption results in delayed transit of gastrointestinal content, intolerance of food, and gas retention. The aetiology of ileus is multifactorial, and includes autonomic neural dysfunction, inflammatory mediators, narcotics, gastrointestinal hormone disruptions, and anaesthetics. In the past, treatment has consisted of nasogastric suction, intravenous fluids, correction of electrolyte abnormalities, and observation. Currently, the most effective treatment is a multimodal approach. Median stays of 2-3 days after removal of all or part of the colon (colectomy) are now achievable. Recent discoveries have the potential to significantly reduce postoperative ileus in patients with cancer who have had abdominal surgery.

Postoperative ileus: progress towards effective management

The pathogenesis of postoperative ileus (PI) is multifactorial, and includes activation of inhibitory reflexes, inflammatory mediators and opioids (endogenous and exogenous). Accordingly, various strategies have been employed to prevent PI. As single-modality treatment, continuous postoperative epidural analgesia including local anaesthetics has been most effective in the prevention of PI. Choice of anaesthetic technique has no major impact on PI. Minimally invasive surgery reduces PI, in accordance with the sustained reduction in the inflammatory responses, while the effects of early institution of oral nutrition on PI per se are minor. Several pharmacological agents have been employed to resolve PI (propranolol, dihydroergotamine, neostigmine, erythromycin, cisapride, metoclopramide, cholecystokinin, ceruletide and vasopressin), most with either limited effect or limited applicability because of adverse effects. The development of new peripheral selective opioid antagonists is promising and has been demonstrated to shorten PI significantly. A multi-modal rehabilitation programme including continuous epidural analgesia with local anaesthetics, enforced nutrition and mobilisation may reduce PI to 1-2 days after colonic surgery.

Relative efficacy of some prokinetic drugs in morphine-induced gastrointestinal transit delay in mice

AIM: To study the relative efficacy of cisapride, metoclopramide, domperidone, erythromycin and mosapride on gastric emptying (GE) and small intestinal transit (SIT) in morphine treated mice.

METHODS: Phenol red marker meal was employed to estimate GE and SIT in Swiss albino mice of either sex. The groups included were control, morphine 1 mg/kg (s.c. 15 min before test meal) alone or with (45 min before test meal p.o.) cisapride 10 mg/kg, metoclopramide 20 mg/kg, domperidone 20 mg/kg, erythromycin 6 mg/kg and mosapride 20 mg/kg.

RESULTS: Cisapride, metoclopramide and mosapride were effective in enhancing gastric emptying significantly (P < 0.001) whereas other prokinetic agents failed to do so in normal mice. Metoclopramide completely reversed morphine induced delay in gastric emptying followed by mosapride. Metoclopramide alone was effective when given to normal mice in increasing the SIT. Cisapride, though it did not show any significant effect on SIT in normal mice, was able to reverse morphine induced delay in SIT significantly (P < 0.001) followed by metoclopramide and mosapride.

CONCLUSION: Metoclopramide and cisapride are most effective in reversing morphine-induced delay in gastric emptying and small intestinal transit in mice respectively.

Postoperative ileus: etiologies and interventions

This article will review the pathophysiology of postoperative ileus, with emphasis on potential therapeutic targets, and examine the efficacy of pharmacologic and nonpharmacologic interventions. Proposed mechanisms include actuation of spinal and local sympathetic neural reflexes, inflammatory mediation, and exacerbation by anesthetic or surgical procedures. Some procedures or agents have shown clinical benefit, and these include use of laparoscopic surgery, thoracic epidurals, nonsteroidal anti-inflammatory drugs, and opiate antagonists. Other procedures may be helpful with low risk of adverse effects. These include early feeding and ambulation, laxatives, and possibly neostigmine.

Small intestinal transit does not adequately represent postoperative paralytic ileus in rats

Small intestinal transit (SIT) has often been regarded as an index of pathophysiological state of postoperative ileus (PI) in rats. The reliability of SIT as an index of PI was examined in the present study. PI was induced via abdominal surgery (i.e., laparotomy with evisceration and manipulation) in rats. For one group of PI-induced rats, SIT of a charcoal test meal was measured. When necessary, the physical state (i.e., severity and site of distension) of the gastrointestinal (GI) tract in each rat was visually examined. For another group of PI-induced rats, abdominal X-ray radiographs were obtained after introducing the barium sulfate suspension. The abdomen was then opened and the physical state of the GI tract was visually examined. The SIT was decreased in most of the PI-induced rats, and the GI distension was observed, with substantial intersubject variations, in all of the PI-induced rats. However, no linear relationship was evident between the SIT and the severity of GI distension (e.g., at 20 h after PI induction). Instead, the severity and site of GI distension could be monitored by the X-ray radiology. Therefore, the use of SIT as an index of Pi should be substantially limited.

Can a pain management and palliative care curriculum improve the opioid prescribing practices of medical residents?

BACKGROUND

Although opioids are central to acute pain management, numerous studies have shown that many physicians prescribe them incorrectly, resulting in inadequate pain management and side effects. We assessed whether a case-based palliative medicine curriculum could improve medical house staff opioid prescribing practices.

DESIGN

Prospective chart review of consecutive pharmacy and billing records of patients who received an opioid during hospitalization before and after the implementation of a curricular intervention, consisting of 10 one-hour case-based modules, including 2 pain management seminars.

MEASUREMENTS

Consecutive pharmacy and billing records of patients who were cared for by medical residents (n = 733) and a comparison group of neurology and rehabilitative medicine patients (n = 273) that received an opioid during hospitalization in 8-month periods before (1/1/97 to 4/30/97) and after (1/1/99 to 4/30/99) the implementation of the curriculum on the medical service were reviewed. Three outcomes were measured: 1) percent of opioid orders for meperidine; 2) percent of opioid orders with concomminant bowel regimen; and 3) percent of opioid orders using adjuvant nonsteroidal anti-inflammatory drugs (NSAIDs).

MAIN RESULTS

The percentage of patients receiving meperidine decreased in the study group, but not in the comparison group. The percentages receiving NSAIDs and bowel medications increased in both groups. In multivariate logistic models controlling for age and race, the odds of an experimental group patient receiving meperidine in the post-period decreased to 0.55 (95% confidence interval [95% CI], 0.32 to 0.96), while the odds of receiving a bowel medication or NSAID increased to 1.48 (95% CI, 1.07 to 2.03) and 1.53 (95% CI, 1.01 to 2.32), respectively. In the comparison group models, the odds of receiving a NSAID in the post-period increased significantly to 2.27 (95% CI, 1.10 to 4.67), but the odds of receiving a bowel medication (0.45; 95% CI, 0.74 to 2.00) or meperidine (0.85; 95% CI, 0.51 to 2.30) were not significantly different from baseline.

CONCLUSIONS

This palliative care curriculum was associated with a sustained (>6 months) improvement in medical residents' opioid prescribing practices. Further research is needed to understand the changes that occurred and how they can be translated into improved patient outcomes.

Review of postoperative ileus

Postoperative ileus (POI) is an inevitable adverse consequence of surgical procedures. In fact, prolonged POI can lead to patient discomfort, decreased mobility, delayed enteral feeding, and ultimately, prolonged hospitalizations and increased costs. It is believed that POI occurs as a result of inhibitory neural reflexes and inflammatory processes. The use of postoperative opioids also appears to contribute to ileus. Recently, the potential influence of endogenous opioids, in addition to exogenous opioids, on the pathogenesis of ileus has come to light and spurred investigations into new treatment strategies. Over the years, several treatment modalities have become accepted management options for POI; chief among these are nasogastric suction and prokinetic agents. However, data demonstrating that these agents reduce the duration of POI are limited. Of current treatment modalities, use of epidural local anesthetics appears to be the most effective means of reducing POI. Other potentially effective treatments include early enteral feeding and less invasive surgical procedures. Together, these techniques have reduced the length of stay after colonic surgery to 2 to 3 days. Future studies, including those incorporating investigational agents, such as kappa-opioid agonists and peripheral mu-opioid antagonists, into a multimodal regimen, may offer new treatment options to further impact POI duration.

Small intestinal motor patterns in critically ill patients after major abdominal surgery

OBJECTIVES

In patients who have had major surgery or trauma, early enteral feeding is safer and more effective than parenteral or nasogastric feeding but is frequently associated with diarrhea. Limited recordings have shown that the patterning of duodenal interdigestive motor activity is frequently abnormal after surgery or in patients who are critically ill. The aims of this study were to evaluate the effects of major abdominal surgery on small intestinal motility, and to elucidate the motor patterns that occur postoperatively in critically ill patients in response to enteral feeding.

METHODS

The effects of elective aortic aneurysm repair on small intestinal motility were studied in 11 patients aged 63-77 yr. A 3.5-mm diameter multilumen extrusion was used to monitor pressures at 12 points, distributed between the antrum and 100 cm distal to the pylorus. An additional lumen allowed enteral feeding into the duodenum. Recordings commenced immediately postoperatively and continued for up to 4 days. Data are given as means and SEMs.

RESULTS

Bursts (frequency > 10/min) of small intestinal pressure waves that resembled phase III interdigestive motor activity occurred in all patients immediately after surgery. During mechanical ventilation, the timing of bursts along the segment evaluated was frequently abnormal for true interdigestive phase III activity, with simultaneous onset in multiple channels (46%), multiple or distal origins (8%), or retrograde migration (20%). When patients were not being ventilated, the migration pattern of the bursts was more typical of interdigestive phase III activity. The interval between bursts was unusually short for interdigestive motor activity, although it increased from 30+/-12 min on day 1 to 41+/-18 min on day 3 (p < 0.05). A phase II pattern of pressure waves was virtually absent in all patients on all study days. In six patients who received postoperative enteral nutrition, the bursts of pressure waves were not abolished by feeding, contrary to normal phase III activity.

CONCLUSIONS

Small intestinal pressure wave bursts are seen immediately after elective aortic aneurysm repair, but the migration of these bursts is frequently abnormal for phase III interdigestive activity. Duodenal nutrient delivery did not interrupt the occurrence of these bursts. Persistence of pressure wave bursts in this setting may be important in the delivery of enteral nutrition.

Impacts and patterns of disturbed gastrointestinal function in critically ill patients

Disordered upper gastrointestinal tract motility occurs frequently in intensive care unit patients and often represents a substantial treatment challenge. In addition to specific complications such as pulmonary aspiration and diarrhea, abnormal gastrointestinal motility is a limiting factor for delivery and success of enteral nutrition. The pathophysiologies involved are incompletely understood because of the difficulties of making measurements of gastrointestinal function in critically ill patients. With the recent development of techniques that overcome some of these difficulties, the prospects are brighter for significant advances in this field.

Postoperative ileus: a preventable event

BACKGROUND

Postoperative ileus has traditionally been accepted as a normal response to tissue injury. No data support any beneficial effect of ileus and indeed it may contribute to delayed recovery and prolonged hospital stay. Efforts should, therefore, be made to reduce such ileus.

METHODS

Material was identified from a Medline search of the literature, previous review articles and references cited in original papers. This paper updates knowledge on the pathophysiology and treatment of postoperative ileus.

RESULTS AND CONCLUSION

Pathogenesis mainly involves inhibitory neural reflexes and inflammatory mediators released from the site of injury. The most effective method of reducing ileus is thoracic epidural blockade with local anaesthetic. Opioid-sparing analgesic techniques and non-steroidal anti-inflammatory agents also reduce ileus, as does laparoscopic surgery. Of the prokinetic agents only cisapride is proven beneficial; the effect of early enteral feeding remains unclear. However, postoperative ileus may be greatly reduced when all of the above are combined in a multimodal rehabilitation strategy.

Small bowel motility: ready for prime time?

The primary function of the small bowel is the absorption of nutrients, and the motor patterns of the healthy bowel are intended to promote that function. The motor patterns of the small bowel are the result of close interaction between the enteric nervous system, extrinsic nerves, regulatory peptides, and the intestinal smooth muscle. The basic electrical rhythm governing intestinal contractions is determined by specialized pacemaker cells called the interstitial cells of Cajal. Diseases affecting any of these components may result in intestinal dysmotility and its associated symptoms. Although transit studies and intestinal manometry are helpful in the diagnosis of dysmotility, our understanding of pathophysiology is hampered by the difficulties involved in obtaining and analyzing intestinal tissue. Treatment of intestinal dysmotility relies on dietary manipulations and nutritional support (enteral or parenteral) because there is no drug therapy that can effectively enhance the propulsive function of the small bowel. Small bowel transplantation remains a life-saving intervention for patients who fail to respond to other therapies.

Prokinetic effect of erythromycin after colorectal surgery: randomized, placebo-controlled, double-blind study

PURPOSE

Nausea and vomiting three to seven days after an elective operation on the colon and rectum remain a persistent clinical problem. Erythromycin, a safe, inexpensive drug that stimulates intestinal motilin receptors, has previously been shown to accelerate gastric emptying significantly after upper gastrointestinal surgery. We aimed to evaluate the effect of postoperative intravenous erythromycin on postoperative ileus in patients undergoing elective surgery for primary colorectal cancer.

METHODS

Between May 1998 and April 1999, 150 patients undergoing primary resection of colon or rectal cancer were enrolled in this prospective, randomized, placebo-controlled trial. One hundred thirty-four patients completed the study. Patients were excluded if they had extensive metastatic disease, were taking medications known to interact with erythromycin, or if they required an ileostomy. Patients received either 200 mg of intravenous erythromycin or placebo every six hours. Clinical endpoints were recorded and continuous end-points are presented as mean +/- standard deviation.

RESULTS

There were no significant complications related to erythromycin. The erythromycin (n = 65) and placebo (n = 69) groups were comparable regarding demographic and operative factors. The erythromycin group had a slightly shorter length of time to passage of flatus (4.1 +/- 1.3 vs. 4.4 +/- 1.1 days; P = 0.03). There was no significant difference between erythromycin and placebo in time to first solid food (5.6 +/- 1.9 vs. 5.4 +/- 1.8 days), time to first bowel movement (5.2 +/- 1.9 vs. 5.4 +/- 1.3 days), or time to discharge from hospital (7.5 +/- 2.0 vs. 7.6 +/- 2.8 days). There was no difference in the rate of clinically significant nausea (26 vs. 26 percent; P = 0.99), vomiting (17 vs. 16 percent; P = 0.88), or nasogastric tube placement (9 vs. 7 percent; P = 0.68).

CONCLUSIONS

Erythromycin does not seem to alter clinically important outcomes related to postoperative ileus in patients undergoing resection for colorectal cancer.

Analysis of gastrointestinal sounds in infants with pyloric stenosis before and after pyloromyotomy

BACKGROUND

Although recent advances in computer technology enable us to analyze gastrointestinal sounds data objectively with ease, this clinical application has been investigated in only a few disorders. To investigate one potential role of this approach in pediatric practice, we recorded and analyzed gastrointestinal sounds in infants with hypertrophic pyloric stenosis (HPS), a motility-related disorder that is common in children.

METHODS

In 15 infants with pyloric stenosis, gastrointestinal sounds were collected with a microphone placed 3 cm below the umbilicus for 60 minutes before pyloromyotomy and at 9 to 12 hours, 20 to 24 hours, 40 to 48 hours, and 112 to 120 hours after the operation. Data were entered into a computer to sum the amplitude of sound signals as a sound index (SI; mV per minute). In 12 infants, gastric emptying was measured immediately before each sound recording, using a marker dilution-double sampling method.

RESULTS

Before surgery, the mean SI was 4.6 +/- 1.0 mV per minute, significantly less than in healthy controls (31.7 +/- 8.4 mV per minute). The SI remained in a similar range until 12 hours after operation, after which it began increasing to reach the normal range by 48 hours after operation (30. 0 +/- 9.4 mV per minute). Gastric emptying, also low in HPS before pyloromyotomy, increased by 4 to 5 times after surgery. There was a significant positive correlation between SI and gastric emptying. The incidence of postoperative symptoms (such as vomiting) were correlated significantly with SI at 24 hours after surgery.

CONCLUSION

This study found decreased gastrointestinal sounds to be among physical findings suggestive of HPS and a useful indicator of gastric emptying and bowel motility after pyloromyotomy. Computer-assisted analysis of gastrointestinal sounds might be helpful in clinical practice for pediatric patients with some gastrointestinal disorders.

Is rectally administered cisapride an effective prokinetic agent?

OBJECTIVE

To summarize the published data on the efficacy of rectally administered cisapride.

DATA SOURCES

Published double-blind, placebo-controlled trials on rectally administered cisapride identified by MEDLINE (January 1966-December 1998) and International Pharmaceutical Abstracts (January 1970-December 1998) searches.

DATA SYNTHESIS

Cisapride is an oral prokinetic agent that increases lower esophageal sphincter tone, accelerates gastric emptying, and increases small-bowel motility. Clinical trials of rectal cisapride have used both single- and multiple-dosing regimens. Typically, patients received one or two 30-mg suppositories (provided by the manufacturer). Rectal cisapride was effective in enhancing gastric emptying of solid or semisolid meals in healthy patients or patients with chronic gastric emptying disorders. Rectal cisapride was not effective in antagonizing the gastrointestinal effects of narcotic analgesics or promoting the return of small-bowel activity in adults with postoperative ileus. Mixed results were seen when rectal cisapride was used to promote enteral feedings in patients with persistent ileus.

CONCLUSIONS

The use of rectal cisapride cannot be recommended at this time. Rectal cisapride was effective only in patients who could have otherwise taken either cisapride tablets or suspension but it was not effective in patients who are physically unable to swallow or restricted from ingesting anything orally following surgical procedures. Considering the varied patient populations and evaluation methods used in these studies, the lack of a commercially available cisapride suppository, and absence of studies involving extemporaneously prepared cisapride suppositories, the use of suppositories should be limited to investigational trials.

Products of cyclooxygenase-2 catalysis regulate postoperative bowel motility

Laparotomy involving manipulation of the small intestine causes injury, initiating an inflammatory cascade in the small bowel wall, which generates eicosanoids and proinflammatory cytokines. We have shown that ketorolac and salsalate, nonselective cyclooxygenase (COX) inhibitors, ameliorate postoperative small bowel ileus in a rodent model. Others have shown that interleukin-1 receptor antagonism improves postoperative gastric emptying. We examined whether inhibition of the proinflammatory cytokines, tumor necrosis factor alpha (TNFalpha) and interleukin-1 (IL-1), or selective blockade of cyclooxygenase-2 (COX-2), the COX isoform induced during inflammation, would accelerate postoperative small bowel transit in our model. Duodenostomy tubes were inserted into male Sprague-Dawley rats. One week later, animals were randomized to receive TNF-binding protein (TNF-bp), IL-1 receptor antagonist (IL-1ra), or saline (NS) prior to standardized laparotomy. Additional rats were gavaged preoperatively with a selective COX-2 inhibitor (NS-398) or NS. Small intestinal transit was measured as the geometric center (GC) of distribution of (51)CrO(4) at 30 min, 3 h, or 6 h (n = 5-9 rats/group) following laparotomy. Selective inhibition of COX-2 significantly increased postoperative small bowel transit compared to controls (GC 2.9 +/- 0.3 vs 2.2 +/- 0.1 at 30 min, GC 2.9 +/- 0.3 vs 2.5 +/- 0.2 at 3 h, and GC 3.3 +/- 0.3 vs 2.8 +/- 0.2 at 6 h, P < 0.05). In contrast, neither TNF-bp nor IL-1ra altered postoperative small intestinal transit in this model. Use of selective COX-2 inhibitors may accelerate recovery of postoperative bowel dysmotility without the undesirable effects (e.g., gastrointestinal irritation and anti-platelet effect) of nonselective COX inhibitors.

The patterns of small bowel motility: physiology and implications in organic disease and functional disorders

The physiology and pathophysiology of small bowel motility are reviewed with particular focus on the motility patterns and periods that are detected by intraluminal manometry. Motility patterns are groups of phasic pressure waves resulting from contractions of the circular muscle layer of the small bowel that are organized by the enteric nervous system. Phase III of the migrating motor complex, the hallmark of the fasting motility period, thus reflects enteric neuromuscular function. Response to meal challenge also involves the CNS, reflexes beyond the gut and endocrine responses. Although specific disease diagnosis cannot be made by motility studies of the small bowel, the functional integrity is revealed. The normal occurrence of the essential patterns and periods of motility and the absence of distinctly abnormal patterns evidence preserved function, whereas the opposite indicates clinically significant dysmotility. Certain motility patterns are occasionally seen both in health and disease, and increased prevalence indicates a moderate dysfunction of yet unclear significance. Bacterial overgrowth with Gram-negative bacilli is the consequence of severe small bowel dysmotility, and a diagnosis that can be predicted by a motility study. Testing can be useful in the clinical management of paediatric and adult patients also by predicting the prognosis and response to enteral nutrition and medical therapy. Further studies are, however, needed to take full advantage of motility testing in clinical practise.

Gastrointestinal motility after pancreatoduodenectomy

Pancreatoduodenectomy (PD) is a major surgical procedure which is accompanied by a high morbidity of between 30 and 50%. A large part of this morbidity is caused by delayed gastric emptying (DGE), which is reported to have an incidence of between 30 and 40% and is associated with prolonged hospital stay. Several pathophysiological mechanisms are thought to cause this complication. Peroperative trauma of the pylorus and the occurrence of intra-abdominal abscesses play a role. Neuronal changes and disruption of the gastrointestinal (GI) intramural nervous plexus may be especially important regarding the pivotal role of the duodenum in the initiation and coordination of antroduodenal motor activity. Another important factor is the postoperative administration of enteral nutrition. Recently, it was demonstrated that cyclic enteral nutrition through a catheter jejunostomy led to a faster return to normal diet and shorter hospital stay than patients on continuous enteral nutrition; this might be partly caused by continuously elevated cholecystokinin levels. The effect of prokinetic agents has not been studied extensively, but a beneficial action on the return of postoperative gastric function after gastrointestinal surgery seems limited.

Homeopathy for postoperative ileus? A meta-analysis

Homeopathic remedies are advocated for the treatment of postoperative ileus, yet data from clinical trials are inconclusive. We therefore performed meta-analyses of existing clinical trials to determine whether homeopathic treatment has any greater effect than placebo administration on the restoration of intestinal peristalsis in patients after abdominal or gynecologic surgery. We conducted systematic literature searches to identify relevant clinical trials. Meta-analyses were conducted using RevMan software. Separate meta-analyses were conducted for any homeopathic treatment versus placebo; homeopathic remedies of < 12C potency versus placebo; homeopathic remedies of > or = 12C potency versus placebo. A "sensitivity analysis" was performed to test the effect of excluding studies of low methodologic quality. Our endpoint was time to first flatus. Meta-analyses indicated a statistically significant (p < 0.05) weighted mean difference (WMD) in favor of homeopathy (compared with placebo) on the time to first flatus. Meta-analyses of the three studies that compared homeopathic remedies > or = 12C versus placebo showed no significant difference (p > 0.05). Meta-analyses of studies comparing homeopathic remedies < 12C with placebo indicated a statistically significant (p < 0.05) WMD in favor of homeopathy on the time to first flatus. Excluding methodologically weak trials did not substantially change any of the results. There is evidence that homeopathic treatment can reduce the duration of ileus after abdominal or gynecologic surgery. However, several caveats preclude a definitive judgment. These results should form the basis of a randomized controlled trial to resolve the issue.

Effects of mu- and kappa-opioid receptors on postoperative ileus in rats

In a rat model of postoperative ileus, induced by abdominal surgery, we investigated the effect of mu- and kappa-opioid receptors. Different degrees of inhibition of the gastrointestinal transit, measured by the migration of Evans blue, were achieved by skin incision, laparotomy or laparotomy plus manipulation of the gut. Morphine (1 mg/kg), a preferential mu-opioid receptor agonist, significantly inhibited the transit after skin incision, while the transit after the laparotomy with or without manipulation was not significantly affected. Fedotozine (5 mg/kg), a peripheral kappa-opioid receptor agonist, enhanced the transit after laparotomy plus manipulation, while naloxone (1 mg/kg), a non-specific opioid receptor antagonist, further inhibited the transit after laparotomy plus manipulation. Naloxone and fedotozine alone had no effect on the transit after skin incision or laparotomy without manipulation. However, naloxone prevented the effect of morphine on the transit after skin incision and of fedotozine on the laparotomy plus manipulation. These results support a role for peripheral kappa-opioid receptors in the pathogenesis of postoperative ileus induced by abdominal surgery.

Analysis of fasting antroduodenal manometry in children

Antroduodenal manometry has been used to determine the pathophysiology associated with signs and symptoms of gastrointestinal motility disorders. The diagnostic value of antroduodenal manomentry has been limited by the paucity of data from normal children. In this study, we compared antroduodenal manometry findings from 95 patients with symptoms suggesting a gastrointestinal motility disorder to 20 control children. Phase III of the migrating motor complex (MMC) was less frequent in patients (P < 0.05), especially in those who required total parenteral nutrition (P < 0.001), than in controls. Abnormal migration of phase III and short intervals between phase IIIs were more frequent in patients than in controls (P < 0.01 and P < 0.05, respectively). During phase II, persistent low-amplitude contractions and sustained tonic-phasic contraction were found only in parenteral-nutrition-dependent children. Short or prolonged duration of phase III, absence of phase I following phase III, tonic contractions during phase III, low amplitude of phase III contractions in a single recording site and clusters of contractions or prolonged propagating contractions during phase II were not more frequent in patients than in controls. We conclude that there are five manometric features having a clear association with pediatric gastrointestinal motility disorders: (1) absence of phase III of the MMC, (2) abnormal migration of phase III, (3) short intervals between phase III episodes, (4) persistent low-amplitude contractions, and (5) sustained tonic-phasic contractions.

Recovery of fasted and fed gastrointestinal motility after open versus laparoscopic cholecystectomy in dogs

OBJECTIVE

The authors investigate the recovery of gastrointestinal motility in the fed and fasted state after laparoscopic and open cholecystectomy.

SUMMARY BACKGROUND DATA

Clinical recovery after laparoscopic cholecystectomy is known to be more rapid than after conventional open cholecystectomy. However, the actual effect of a laparoscopic approach on gastrointestinal motility, particularly fed-state motility, is not well investigated.

METHODS

Laparoscopic (LAP, n=6) or open (OPEN, n=6) cholecystectomy was performed in 12 dogs. Bipolar recording electrodes were placed on the antrum, small intestine, and the transverse and descending colon, and fasting myoelectric data were recorded after operation. Solid meal gastric emptying studies were performed before surgery and on postoperative days 1 and 2. Transit time studies were performed using 10 radiopaque markers.

RESULTS

Gastric emptying was significantly delayed in the OPEN group at 120 minutes on postoperative day 1 compared with pre-operative emptying (p<0.05), but was not delayed on postoperative day 2. Gastric emptying was not delayed in the LAP group after operation. Transit time was the same between groups. Gastric dysrhythmias were more frequent on postoperative day 3 (p<0.05) in the OPEN group. There were no significant differences in the presence, cycle length, or propagation velocity of the migrating motor complex on any postoperative day. Discrete or continuous electrical response activity in the colon was observed by postoperative day 1 in both groups.

CONCLUSIONS

Fed-state motility is the only parameter for which laparoscopic cholecystectomy showed an improvement in postoperative recovery. Recovery of fasted gastrointestinal motility in dogs is equally rapid after either operation.

Systemic and central effects of morphine on gastroduodenal motility

Gastrointestinal side effects still constitute a major drawback in both acute and chronic use of opioids. The exact mechanism behind the gastrointestinal effects is not known, but experimental studies indicate both central and peripheral actions. In an attempt to clarify to what extent the systemic effects of morphine after epidural administration contribute to the action on gastrointestinal motility, a study aiming to resemble the situation with epidural morphine was designed. Twenty healthy male volunteers were randomly allocated to two groups. Group one (n = 10) received intrathecal (0.4 mg) and intramuscular (4 mg) morphine (IT-IM-group). Group two (n = 10) received intrathecal (0.4 mg) morphine and i.m. saline (IT-group). Gastroduodenal activity was assessed by gastric emptying, manometry and electrogastrography. The plasma and urine concentrations of morphine and its inactive metabolite morphine-3-and active metabolite morphine-6-glucuronide were also determined. During the fasted state the gastrointestinal activity is characterised by a cyclic pattern with a duration of 80-120 min in the duodenum comprising three different phases with intense activity during Phase III. This pattern was seen in all volunteers. After the intrathecal administration the Phase III activity occurred significantly earlier in the IT-IM group (median 31 min; IR 34 min) compared to IT group (82 min; 37 min) (P < 0.01). The number of Phase IIIs was higher in the IT-IM group during the first 4 h after the morphine administration, compared to the IT group. However, after 6 h, there was no difference between the groups. The propagation velocity of Phase III decreased significantly in both groups (P < 0.001), but there was no difference between the groups. Tachygastria increased significantly with time in both groups. The acetaminophen absorption test showed that the area under the concentration curve (120 min) was significantly smaller in the IT-IM group compared to the IT group (P < 0.05). There were no measurable plasma concentrations of morphine or the glucoronidated metabolites M3G and M6G in the group that only received intrathecal morphine. This study showed that intrathecal morphine (0.4 mg) influenced gastroduodenal motility and that intramuscular morphine (4 mg) gave additional effects. These results might be applicable to the epidural situation and are indirect evidence that the gastroduodenal effects of epidural morphine are caused by both central and systemic effects of morphine.

Recovery of gastrointestinal motility from post-operative ileus in dogs: effects of Leu13-motilin (KW-5139) and prostaglandin F2 alpha

Cyclical motor activity of the gastrointestinal tract, normally occurring during the interdigestive period in several mammals, is disrupted in the post-operative ileus. We determined the recovery from the disappearance of cyclical motor activity, from the stomach to the colon, in dogs after laparotomy with the force transducers. Moreover, we examined the effects of Leu13-motilin (KW-5139) and prostaglandin F2 alpha (PGF2 alpha), administered in the early post-operative period, on the gastrointestinal motility. Following laparotomy, the cyclical motor activity reappeared firstly in the ileum and the colon, then in the jejunum and the duodenum, and finally in the stomach. The reappearance time of the phase III contractions in the stomach was 105.8 +/- 10.6 h (n = 4). In the early post-operative period, KW-5139 (0.5 microgram kg-1, i.v.) induced phase-III-like contractions, whereas PGF2 alpha (50 micrograms kg-1, i.v.) induced simultaneously occurring contractions over the whole gastrointestine. The treatment with KW-5139 (0.5 microgram kg-1, i.v.) four times (twice daily on the first and the second post-operative day) significantly (P < 0.05) shortened the time required to recover the phase III contractions in the stomach (64.2 +/- 2.2 h, n = 4), whereas that with PGF2 alpha (50 micrograms kg-1, i.v.) four times did not (111.3 +/- 17.2 h, n = 4). The present results indicate that, after laparotomy, the cyclical motor activity recovers faster in the distal intestine than in the proximal intestine and the stomach, and that KW-5139, but not PGF2 alpha, shortens the reappearance time of the phase III activity in the stomach.

A risk-benefit assessment of cisapride in the treatment of gastrointestinal disorders

Cisapride is a substituted benzamide compound that stimulates motor activity in all segments of the gastrointestinal tract by enhancing the release of acetylcholine from the enteric nervous system. Cisapride is administered orally in the treatment of gastro-oesophageal reflux disease, functional dyspepsia, gastroparesis, chronic intestinal pseudo-obstruction syndromes and chronic constipation. In gastro-oesophageal reflux disease in both adults and children, cisapride provides symptomatic improvement and mucosal healing. Long term treatment with cisapride is effective in the prevention of relapse of oesophagitis. Cisapride improves gastric emptying rates and improves symptoms in patients with gastroparesis of various origins. Unlike domperidone and metoclopramide, long term administration of cisapride seems to result in persistently enhanced gastric emptying. Cisapride is also effective in improving symptoms in patients with functional dyspepsia. In comparative studies in patients with functional dyspepsia, cisapride was at least as effective as metoclopramide, domperidone, clebopride, ranitidine and cimetidine. Cisapride increases stool frequency and reduces laxative consumption in patients with idiopathic constipation. Severe cases of slow transit constipation seem refractory to cisapride. Clinical studies also indicate that cisapride might be effective in the treatment of chronic intestinal pseudo-obstruction, postoperative ileus, peptic ulcer and irritable bowel syndrome. Further clinical studies are warranted to define the role of cisapride in these conditions. The dosage of cisapride ranges from 5mg 3 times daily to 20mg twice daily. Cisapride is generally well tolerated, both during short and long term treatment. In children, cisapride is also well tolerated in doses of 0.2 to 0.3 mg/kg, 3 to 4 times daily.(ABSTRACT TRUNCATED AT 250 WORDS)