Effects of lactulose and polyethylene glycol on colonic transit

BACKGROUND: The effects of lactulose and polyethylene glycol on colonic transit are poorly established. AIM: To assess the effects of these laxatives on colonic transit in normal subjects. METHODS: Colonic transit (mean residence time, cumulative counts in stool, counts remaining in the proximal or distal colon) was measured scintigraphically in normal subjects on the second and third day of a 3-day ingestion of 67-134 g/day lactulose, or 59 g/day polyethylene glycol. RESULTS: At similar stool weight (lactulose: 653 +/- 120 g/day; polyethylene glycol: 522 +/- 66 g/day), transit was significantly slower during 99 g/day lactulose when compared with 59 g/day polyethylene glycol; this was most pronounced in the distal colon (mean residence time: lactulose - 403 +/- 55 min; polyethylene glycol - 160 +/- 41.9 min). Short chain fatty acid concentration in 24-h stool correlated significantly with counts remaining in the distal colon at 12 h (r = 0.79, P = 0.001). Increasing lactulose doses were significantly associated with increasing stool weight (r = 0.79) and shorter mean residence time in the total (r = -0.56) and distal colon (r = -0.64). The sum of faecal carbohydrates plus short chain fatty acids was associated with stool weight (r = 0.95, P < 0.001). CONCLUSION: Lactulose accelerates colonic transit. However, compared with polyethylene glycol, transit during lactulose is prolonged.     

Motilides accelerate regional gastrointestinal transit in the dog

BACKGROUND: Motilides have prokinetic effects on the upper gut during fasting, increasing the strength of antral contractions and stimulating gastroduodenal phase 3 sequences. Effects on the distal gut, and postprandially, are less well documented. AIM: To evaluate dose-response effects of motilin and erythromycin on gastric emptying, small bowel and colonic transit in the dog using a validated scintigraphic technique. METHODS: For gastric emptying and small bowel transit, 99mTc labelled beads were added to a meal of dog chow (450 kcal). Regional colonic transit was measured by 111In labelled beads placed in a capsule which dissolved and released radiation into the proximal colon. Scintiscans were taken at regular intervals and indices of whole-gut transit were calculated. Drugs were given by slow intravenous administration. RESULTS: In the doses used, motilin accelerated regional colonic transit but did not hasten gastric emptying or small bowel transit. Single or repeated doses of motilin had similar effects on colonic transit. Erythromycin accelerated gastric emptying, small bowel transit and regional colonic transit. CONCLUSIONS: Motilin receptors are apparently present in the canine small bowel and colon. Postprandially, motilides accelerate transit in the distal gut.     

Polyethylene glycol 4000 vs. lactulose for the treatment of neurogenic constipation in myelomeningocele children: a randomized-controlled clinical trial

AIM: To compare the therapeutic effectiveness and tolerability of low daily doses of polyethylene glycol 4000 vs. lactulose in the treatment of neurogenic constipation in children with myelomeningocele. METHODS: Sixty-seven children with chronic neurogenic constipation were randomized allocated to receive either polyethylene glycol 4000 (0.50 g/kg) or lactulose (1.5 g/kg) for 6 months. Patients or their parents reported frequency and modality of evacuation and side effects on a diary card. Primary outcome was bowel frequency > or =3/week, and the second one was side effects at the end of treatment. RESULTS: Complete remission of constipation was reported by a significantly (P < 0.01) higher number of patients treated with polyethylene glycol compared with lactulose. At the end of the study, 46% patients of polyethylene glycol group and 22% of the lactulose group were asymptomatic. Compared with lactulose, patients treated with polyethylene glycol reported higher bowel frequency (5.1 vs. 2.9 bowel movements/week, P < 0.01) and reduction of encopresis. Neither lactulose nor polyethylene glycol caused clinically-significant serious side effects and palatability was similar. CONCLUSIONS: Polyethylene glycol 4000 compared with lactulose provided a higher success rate, without significant side effects, for the treatment of constipation in myelomeningocele children.     

Effects of bisacodyl on ascending colon emptying and overall colonic transit in healthy volunteers

Background  The mechanism of action of bisacodyl in the unprepared human colon remains unclear.
Aim  To evaluate the effect of oral bisacodyl on the overall and regional colonic transit in humans.
Methods  In a double-blind, randomized, placebo-controlled study of 25 healthy participants, effects of oral bisacodyl (5 mg p.o. per day) and placebo on colonic transit were compared. A validated scintigraphy method was used to measure colonic transit. The primary transit endpoints, ascending colon emptying t _1/2 and geometric centre of colon isotope at 24 h (overall transit), were compared (Wilcoxon rank sum test).
Results  There were significant treatment effects on ascending colon t _1/2, with the bisacodyl group demonstrating accelerated emptying [median 6.5 h, interquartile range 5.0–8.0 h] relative to the placebo group [11.0 h (7.0–17.1); P  = 0.03]. Numerical differences in colonic geometric centre 24 h [bisacodyl median 3.0 (2.2–3.8), placebo 4.0 (3.1–4.6)] were not significant ( P  = 0.19). There were no significant differences observed in geometric centre 4 h.
Conclusion  Oral 5 mg bisacodyl accelerates ascending colon in the unprepared colon in healthy adults; this action may contribute to the drug's efficacy in constipation.     

Tegaserod, a 5-HT4 receptor partial agonist, accelerates gastric emptying and gastrointestinal transit in healthy male subjects

BACKGROUND: Serotonin and its type-4 (5-hydroxytryptamine4) receptor play a major role in the physiology of the gastrointestinal tract. The effect of intravenous and/or oral tegaserod, a 5-hydroxytryptamine4 receptor partial agonist, on gastric emptying, small bowel transit and colonic transit has not been studied in detail in humans. AIM: To assess the pharmacodynamic effects of repeated oral and intravenous administration of tegaserod on gastric emptying and small intestine and colonic transit. METHODS: A randomized, placebo-controlled, double-blind, three-way, crossover study of 6 mg oral and 0.6 mg intravenous tegaserod in 12 healthy male subjects was performed. Each treatment arm of the study involved 3 days of twice-daily administration and 1 day of daily administration of the study drugs. RESULTS: In comparison with placebo, oral and intravenous tegaserod significantly increased the gastric emptying rate (P < 0.01), accelerated colonic filling (P < 0.01) and shortened colonic transit at 48 h (P < 0.05). Tegaserod shortened the small intestine transit time by 30% after oral and by 37% after intravenous administration. CONCLUSIONS: In healthy subjects, tegaserod markedly accelerated gastric emptying and small intestinal transit, and induced a small but significant acceleration of colonic transit. Tegaserod can act as a promotile agent throughout the gastrointestinal tract.     

Behaviour and transit of tamsulosin Oral Controlled Absorption System in the gastrointestinal tract

ABSTRACT

Objective: To assess the in vivo behaviour, gastric emptying time and gastrointestinal transit of the new tablet formulation of tamsulosin which uses the Oral Controlled Absorption System (OCAS) technology and to relate gastrointestinal transit parameters to the profile of the plasma concentration time curve.

Research design and methods: After breakfast, 8 healthy male subjects received a single tamsulosin OCAS 0.4?mg tablet labelled with 4MBq technetium-99m. Scintigraphic images were taken immediately after dosing, every 15?min until 15?h post-dose and at 24?h post-dose. Blood samples for pharmacokinetic analysis were taken up to 24?h after dosing. Safety was assessed by physical examinations, vital signs, laboratory safety evaluations and adverse events monitoring.

Results: A mean C_max of 7.84 ± 2.54?ng/mL was achieved after 5.13 ± 1.25?h (t_max). The mean gastric emptying time for the tablet was 4.1 ± 2.5?h. Mean transit time through the small intestine was 3.6 ± 2.9?h; the mean colonic arrival time 7.7 ± 2.9?h post-dose and the mean release time (spread of the technetium-99m label from the tablet core) 12.3 ± 1.7?h post-dose. In all cases where release of the radiolabelled tablet was observed, this occurred within the colon. Variations in gastric residence, small intestinal transit or colonic residence did not apparently influence release time or site.

Conclusions: The results suggest that tamsulosin is released from the OCAS formulation throughout the entire gastrointestinal tract, including the colon, indicating consistent and continued 24‐h drug release. This correlates with a more consistent pharmacokinetic profile.     

Prospective, randomized, parallel-group trial to evaluate the effects of lactulose and polyethylene glycol-4000 on colonic flora in chronic idiopathic constipation

BACKGROUND: Although lactulose and polyethylene glycol are osmotic laxatives widely used in the treatment of chronic constipation, no study has been conducted to compare their actions on the colonic bacterial ecosystem, which has an important influence on host health. AIM: To assess the effects of lactulose and polyethylene glycol on the composition and metabolic indices of the faecal flora in patients with chronic idiopathic constipation. METHODS: Sixty-five patients with chronic idiopathic constipation were included in this controlled, multi-centre, randomized, parallel-group study. Participants received lactulose (Duphalac) or polyethylene glycol-4000 (Forlax) powders for the first week at a fixed dosage at night (20 g/day); in the second week, patients were given the option to vary the dose according to efficacy and tolerance (10-30 g/day); for the last 2 weeks, treatment was administered at a fixed dosage based on the results of the second week (10-30 g/day). Stools were recovered for bacteriological analysis at days -1, 21 and 28. RESULTS: Clinical efficacy and tolerance were similar with both treatments. In the lactulose group, an increase in faecal bifidobacteria counts (P = 0.04) and beta-galactosidase activity (P < 0.001) was observed from day -1 to day 28, whereas, in the polyethylene glycol group, there was a decrease in total short-chain fatty acids (P = 0.02), butyrate (P = 0.04), acetate (P = 0.02) and faecal bacterial mass (P = 0.001). No differences were observed in stools with regard to the following parameters: counts of Lactobacillus, clostridial spores, Bacteroides and enterobacteria, pH, biliary acids and neutral sterol concentrations. CONCLUSIONS: Both lactulose and polyethylene glycol are efficacious and well tolerated. However, although lactulose can be considered as a pre-biotic in constipated patients, polyethylene glycol produces signs of decreased colonic fermentation in the stool.     

The Effect of Polyethylene Glycol 400 on Gastrointestinal Transit: Implications for the Formulation of Poorly-Water Soluble Drugs

Purpose. To assess the effect of polyethylene glycol 400 (PEG 400), a pharmaceutical excipient frequently employed to enhance the solubility and bioavailability of poorly water-soluble drugs, on the gastrointestinal transit of liquid and pellet preparations in human subjects using gamma scintigraphy. Methods. Ten, healthy male volunteers each received, on separate occasions, a liquid preparation consisting of 150 ml orange juice (control) or 150 ml orange juice containing 10 g PEG 400 (test). Non-disintegrating pellets of size 1.4-1.7 mm, encapsulated within a hard gelatin capsule, were simultaneously administered on both occasions to act as a marker for solid dosage form transit. The liquid and pellet preparations were radiolabelled with ¹¹¹In and ^99mTc respectively thus enabling their positions within the gastrointestinal tract to be followed using a gamma camera. Results. Rapid liquid emptying from the stomach was observed, with no significant difference noted in the gastric residence times of the two preparations. Caecum arrival times for the liquid preparations were significantly different by virtue of their differential rates of transit through the small intestine. The mean small intestinal liquid transit time for the control preparation was 236 min whereas the corresponding value for the PEG 400-containing test preparation was 153 min. This 35% reduction in transit time was attributed to the presence of PEG 400. Pellet transit was largely unaffected by the presence of PEG 400. Conclusions. These findings clearly demonstrate that PEG 400 has a marked accelerating effect on small intestinal liquid transit, which in turn has implications for the formulation of poorly water-soluble drugs with PEG 400.     

Effect of octreotide on mouth-to-caecum transit time in healthy subjects and in the irritable bowel syndrome

The effect of a single subcutaneous injection of octreotide (50 micrograms) on mouth-to-caecum transit time was determined in patients with the irritable bowel syndrome who complained of bowel frequency, and in healthy volunteers. The assessment of mouth-to-caecum transit time was performed by monitoring breath hydrogen concentration and noting a sustained 10 p.p.m. rise after ingestion of lactulose 40 ml. Measurements were performed fasting, and on a separate day, after a standard breakfast which included 40 ml lactulose. The studies were performed double-blind in a pre-determined random order. Octreotide prolonged mouth-to-caecum transit time in irritable bowel syndrome patients and healthy subjects by factors of 2.4 and 2.6 after lactulose when fasting, respectively, and by factors of 2.8 and 2.6 after the breakfast which contained lactulose. The upper gastrointestinal transit rate was similar in irritable bowel syndrome patients and healthy controls.     

Mebeverine decreases mass movements and stool frequency in lactulose-induced diarrhoea

Background:

In spite of its frequent use in the treatment of irritable bowel disease little is known about mebeverine’s mode of action in man.

Aim:

To examine mebeverine’s effect on transit though the gut during lactulose-induced diarrhoea.

Methods:

Nine healthy volunteers undertook a two-way randomized crossover study. Diarrhoea was induced using lactulose pre-treatment (20 m t.d.s., 4 days) and subjects received either mebeverine (135 mg t.d.s.) or no treatment. Transit of two enteric-coated capsules containing radiolabelled 8.4 mm tablets and 180–250 μM ion exchange resin were followed using gamma scintigraphy. Stool frequency and symptoms were assessed by diary cards.

Results:

Mebeverine reduced mean daily stool frequency associated with lactulose ingestion from a median of 2.25 (interquartile range (IQR) 1.75–2.75) to 1.5 (IQR 1.25–2.25) movements. Mebeverine significantly reduced the number of mass movements observed in the colon during the 11 h of the study from 2 (2–2) to 1 (1–2), and the number of retrograde movements from 1 (0–2) to 0 (0–0) (P < 0.05). Mebeverine did not significantly alter the gastric emptying rate of the intact capsule (2.9 (1.9–3.2) to 2.8 (2.6–4.0) h) however it induced a small but significant acceleration in small intestinal transit of the capsule (1.6 (0.8–2.0) h to 1.0 (0.52–1.32) h, P = 0.02).

Conclusion:

Mebeverine reduces the diarrhoeal effect of lactulose by decreasing the mass movements induced in the ascending colon. This effect may contribute to its clinical effect in irritable bowel syndrome.

     

Clinical trial: 2‐L polyethylene glycol‐based lavage solutions for colonoscopy preparation – a randomized,single‐blind study of two formulations

Aliment Pharmacol Ther 2010; 32: 637–644

Summary

Background The 2‐L polyethylene glycol (PEG) lavage solutions provide efficacy similar to that of standard 4‐L PEG formulations in spite of the reduced volume. The comparative efficacy and tolerability of two formulations of 2‐L PEG solution remain unknown. Aims To assess the efficacy, safety and tolerability of PEG + Bis compared with PEG + Asc, and to study the effect of bowel cleansing quality on adenoma detection rates. Methods Patients were randomized to receive either 2‐L PEG with ascorbic acid (PEG + Asc) or 2‐L PEG plus bisacodyl 10 mg (PEG + Bis). The primary endpoint was overall colon cleansing score, assessed by blinded investigators using a validated four‐point scale. Secondary endpoints included adenoma detection rate, patient tolerability and compliance and adverse events. Results Fifty‐two patients received PEG + Asc and 55 patients received PEG + Bis. Overall colon cleansing scores (±s.d.) were 1.40 ± 0.69 and 1.75 ± 0.70 (P < 0.003) in the PEG + Asc and PEG + Bis groups, respectively. Excellent and good ratings were recorded in 69% and 23% receiving PEG + Asc compared to 38% and 51% (P = 0.01) of patients receiving PEG + Bis. More adenomas were detected in colonoscopies performed with PEG + Asc (39%) than in those performed with PEG + Bis (20%) (P = 0.04). Patient tolerability and safety were similar with both preparations. Conclusion The use of PEG + Asc resulted in better colon cleansing and higher adenoma detection rates compared with PEG + Bis.     

Concentration-Dependent Effects of Polyethylene Glycol 400 on Gastrointestinal Transit and Drug Absorption

Purpose. The aim of the study was to investigate the effect of different concentrations of polyethylene glycol 400 (PEG 400) on liquid transit through, and ranitidine absorption from, the gastrointestinal tract. Methods. Six healthy male volunteers received, on four separate occasions, 150 mL water containing 150 mg ranitidine and either 0 (control), 1, 2.5, or 5 g PEG 400. The solutions were radiolabeled with technetium-99m to allow their gastrointestinal transit to be followed using a gamma camera. Urine samples were collected over a 24-h period to assess the amount of ranitidine excreted and hence absorbed. Results. No significant differences in gastric emptying were noted between the four solutions. In contrast, the presence of 1, 2.5, and 5 g PEG 400 reduced the mean small intestinal transit times of the solutions by 9, 20, and 23%, respectively, against the control. In terms of drug absorption, the mean cumulative amount of ranitidine excreted was reduced by 38% in the presence of both 2.5 and 5 g PEG 400, although it was significantly increased by 41% in the presence of 1 g PEG 400. Conclusions. The results show that low concentrations of PEG 400 enhance the absorption of ranitidine possibly via modulation of intestinal permeability, while high concentrations have a detrimental effect on ranitidine absorption presumably via a reduction in the small intestinal transit time.     

A randomised controlled trial of a new 2 litre polyethylene glycol solution versus sodium picosulphate + magnesium citrate solution for bowel cleansing prior to colonoscopy*

ABSTRACT

Background: A new 2?L polyethylene glycol (PEG) solution containing ascorbic acid (Asc) and electrolytes (Moviprep^?) has been developed for bowel cleansing.

Objectives: To compare the efficacy, safety and acceptability of PEG + Asc versus sodium picosulphate + magnesium citrate in patients scheduled to undergo colonoscopy.

Design and methods: This single blind, parallel group pilot study included 65 adult male and female patients. A blinded assessment of cleansing was made for each bowel segment by the colonoscopist and the scores determined an overall grading of bowel cleansing. Patients completed a questionnaire on the acceptability of the preparation.

Results: Successful bowel preparation was reported in 84.4% of patients who received PEG + Asc and 72.7% of patients who received sodium picosulphate + magnesium citrate (treatment difference +11.6, 95% CI –11.2, +34.5; p = 0.367). Patients were more likely to have a higher overall quality of bowel cleansing with PEG + Asc (?p = 0.018), with specifically better cleansing in the ascending colon (?p = 0.024) and caecum (?p = 0.003) compared with patients who received sodium picosulphate + magnesium citrate. The adverse event profile of the two treatments was similar, with headache and gastrointestinal effects being the most commonly reported. Some patient acceptability results favoured sodium picosulphate + magnesium citrate for those patients who had experience of previous bowel preparation, but were similar for those patients who had not had a previous bowel preparation.

Conclusions: PEG + Asc provided effective bowel cleansing, which was equivalent to that of sodium picosulphate + magnesium citrate in terms of grading cleansing as overall success or failure. In the proximal colon (ascending colon and caecum) PEG + Asc provided significantly better cleansing to that achieved with sodium picosulphate + magnesium citrate.

Trial registration: ClinicalTrials.gov identifier: NCT00312481.     

Gastrointestinal transit of an enteric-coated delayed-release 5-aminosalicylic acid tablet

Gastrointestinal transit of an enteric-coated, delayed-release 5-aminosalicylic acid tablet radiolabelled with indium-111 has been monitored in a preliminary study with eight healthy subjects using gamma scintigraphy. Gastric emptying of the tablet was delayed by the presence of food in the stomach. Disintegration occurred about 5 hours after the tablet left the stomach. There was close agreement between the tablet disintegration times and the initial detection of drug in the blood. The site of disintegration could be established in most instances; approximately 80% of the doses resulted in drug dispersion within the ascending colon. The coated tablets provide an effective means of drug delivery to the proximal colon.     

Stool Water Content and Colonic Drug Absorption: Contrasting Effects of Lactulose and Codeine

Purpose. By varying stool water content using lactulose and codeine, we investigated the influence of luminal water content on the absorption of quinine, a transcellular probe, and ^5lCr-EDTA, a paracellular probe, from the distal gut. Methods. Sixteen volunteers entered a three-way cross-over trial in which absorption of probe markers from a timed-release delivery system was determined following treatment with lactulose 20 mls tds (increasing water content), or codeine 30 gms qds (decreasing water content), and compared with control untreated values. Stool water content was assessed by freeze drying stool samples. Site of release was determined by gamma scintigraphy, and absorption was measured by plasma levels and urinary recovery of the marker probes. Results. Lactulose accelerated ascending colon transit (3.7 ± 0.8 vs 4.5 ± 1.4 hrs, p < 0.05), increased stool water content (75 ± 2 vs 71 ± 2%, p < 0.01), caused greater dispersion of released material (dispersion score 3.4 ± 0.3 vs 1.8 ± 0.2, p < 0.01), and enhanced absorption of the transcellular probe quinine (4.66 ± 0.78 vs 3.02 ± 0.63%, p < 0.05) compared to control. Conversely codeine slowed ascending colon transit (8.9 ± 1.8 hrs), reduced stool water content (61 ± 2 vs 71.2%, p < 0.05), and tended to diminish absorption (2.60 ± 0.77 vs 3.02 ± 0.63%, p = 0.20). Within the ascending colon specifically, there was a significant trend for treatments increasing luminal water content to enhance quinine absorption (medians: codeine = 1.2%, [n = 8] < control = 2.3%, [n = 5] < lactulose = 3.2%, [n = 7], p < 0.01). Delivery site also had an important influence on absorption, with more distal release resulting in less absorption in the control arm (medians: small intestine = 4.4% [n = 5] > ascending colon = 2.3% [n = 5] > transverse colon = 1.5% [n = 6], p < 0.005). Conclusions. Lactulose accelerates transit, increases stool water content, and enhances drug absorption from the distal gut whilst codeine slows transit, decreases stool water content, and tends to diminish absorption, compared to controls. We conclude that water content may be an important determinant in colonic drug absorption.     

Gamma scintigraphic evaluation of film-coated tablets intended for colonic or biphasic release

The gastrointestinal transit and in vivo drug release behaviour of a film-coated tablet formulation was investigated in five healthy human subjects using the technique of gamma scintigraphy. The film coating system consisted of a mixture of pectin, chitosan and HPMC in a ratio of 6:1:0.37 applied to 750 mg cores at a coat weight gain of 9%. The estimated mean values of the gastric emptying time (62±17 min), small intestinal transit time (219±53 min), ileocaecal junction lag time (79±30 min) and the colon arrival time (345±33 min), were similar to published values for the transit of similar sized tablets in humans. The amount of radioactive tracer released from the labelled tablets was minimal when the tablets were in the stomach and the small intestine. There was increased release of radioactivity when the tablets were in the colon due to increased degradation of the film coatings by pectinolytic enzymes resident in the colon. The pectin/chitosan/HPMC film coating system thus acts as a colonic delivery system.     

Review article: colonic sensorimotor physiology in health, and its alteration in constipation and diarrhoeal disorders

Aim:

To review the physiology of colonic motility and sensation in healthy humans and the pathophysiological changes associated with constipation and diarrhoea.

Source:

Medline Search from 1965 using the index terms: human, colonic motility, sensation, pharmacology, neurohormonal control, gastrointestinal transit, constipation, diarrhoea and combinations of these.

Results:

In health, the ascending and transverse regions of colon function as reservoirs to accommodate ileal chyme and the descending colon acts as a conduit; the neuromuscular functions and transmitters control colonic motility and sensation and play pivotal roles in disorders associated with constipation and/or diarrhoea. Disorders of proximal colonic transit contribute to symptoms in idiopathic constipation, diarrhoea-predominant irritable bowel syndrome and carcinoid diarrhoea. Colonic function in patients presenting with constipation is best assessed clinically by colonic transit time using radiopaque markers ingested orally. Measurements of colonic contractility are less useful clinically but they can help identify motor abnormalities including colonic inertia; in some patients with irritable bowel syndrome, abdominal pain, urgency and diarrhoea are temporally associated with high amplitude contractions, which originate in the proximal colon and traverse the distal conduit at very high propagation velocities. Visceral hypersensitivity contributes to the urgency and tenesmus in irritable bowel syndrome and inflammatory bowel disease. Colonic motility and sensation can be reduced by anticholinergic agents, somatostatin analogues and 5HT₃ antagonists.

Conclusion:

Physiological and pharmacological studies of the human colon have provided new insights into the pathophysiology of colonic disorders, and offer possibilities of novel therapeutic approaches for constipation or diarrhoea associated with colonic motor or sensory dysfunction.

     

The assessment of regional gut transit times in healthy controls and patients with gastroparesis using wireless motility technology

Background Wireless pH and pressure motility capsule (wireless motility capsule) technology provides a method to assess regional gastrointestinal transit times. Aims To analyse data from a multi‐centre study of gastroparetic patients and healthy controls and to compare regional transit times measured by wireless motility capsule in healthy controls and gastroparetics (GP). Methods A total of 66 healthy controls and 34 patients with GP (15 diabetic and 19 idiopathic) swallowed wireless motility capsule together with standardized meal (255 kcal). Gastric emptying time (GET), small bowel transit time (SBTT), colon transit time (CTT) and whole gut transit time (WGTT) were calculated using the wireless motility capsule. Results Gastric emptying time, CTT and WGTT but not SBTT were significantly longer in GP than in controls. Eighteen percent of gastroparetic patients had delayed WGTT. Both diabetic and idiopathic aetiologies of gastroparetics had significantly slower WGTT (P < 0.0001) in addition to significantly slower GET than healthy controls. Diabetic gastroparetics additionally had significantly slower CTT than healthy controls (P = 0.0054). Conclusions In addition to assessing gastric emptying, regional transit times can be measured using wireless motility capsule. The prolongation of CTT in gastroparetic patients indicates that dysmotility beyond the stomach in GP is present, and it could be contributing to symptom presentation. Aliment Pharmacol Ther 31 , 313–322     

The effect of oral cisapride on colonic transit

A prospective double-blind cross-over trial of oral cisapride 10 mg and placebo was performed to determine the effects of cisapride on the transit of colonic contents in normal humans. Six male volunteers were studied twice using colonic transit scintigraphy. After passing a tube to the caecum, 50 mu Ci of 111Indium diethylene triamine pentaacetic acid were instilled into the bowel lumen. The movement of radiolabelled material was followed using a gamma camera interfaced to a digital computer. Cisapride decreased the half-emptying of the caecum and ascending colon from 1.68 +/- 0.4 hours to 0.72 +/- 0.15 hours (P less than 0.05). The total colon half-emptying time was reduced from 38.5 +/- 7.2 hours to 11.1 +/- 2.9 hours on cisapride (P less than 0.05). Cisapride accelerated transit through the transverse colon, but not the descending colon. The progression of the geometric centre was faster during cisapride administration than with placebo (P less than 0.05). The number of bowel movements 48-hours-1 increased after cisapride from 2.5 +/- 0.8 to 5.0 +/- 0.4 (P less than 0.05). This study demonstrates that cisapride has a marked prokinetic effect on colonic transit in normal subjects. Cisapride may be a useful agent in the treatment of constipation.     

不同肠道准备方式对结肠镜检查病人结肠动力学、Boston肠道准备量表评分及应用耐受度的影响比较

目的 探讨不同肠道准备方式对结肠镜检查病人结肠动力学、Boston肠道准备量表(BBPS)及应用耐受度的影响,以期寻找最理想肠道准备方法.方法 收集进行结肠镜检查病人200例,随机单盲取法将病人分为三组,对照组46例,给予清洁灌肠肠道准备,观察A组84例,给予复方聚乙二醇电解质散(PEG)联合酚酞片口服灌肠,观察B组70例,在观察A组基础上给予联合莫沙必利口服观察,由内镜操作师详细观察三组病人全结肠、左半结肠、横结肠及右半结肠清洁情况.检查毕由专人询问病人不适情况,以评定胃肠蠕动功能,同时询问病人可以承受情况,以评定耐受度.结果 观察A、B组不同结肠段BBPS评分、肠腔内液体量评分、总分、耐受度均高于对照组(P<0.05),其中,对照组、观察A组、观察B组BBPS总分分别为(7.13±1.05)分、(8.73±0.95)分、(8.92±0.85)分,三组BBPS总分差异有统计学意义(F=57.678,P=0.000);耐受度分别为58.70%、90.48%、90.00%,A、B组与对照组耐受度差异有统计学意义(χ2=18.240、15.643,P=0.000).观察A、B组检查后不良反应发生率低于对照组(χ2=18.243、30.934,P=0.000).结论 PEG联合胃肠蠕动剂和缓泻药物疗效满意,可提高BBPS评分、提高病人耐受度、减低检查后不良反应及对胃肠动力学的影响,值得临床推广.