Abnormal colonic propagated activity in patients with slow transit constipation and constipation-predominant irritable bowel syndrome

BACKGROUND: The pathophysiological basis of constipation is still unclear, and the role of colonic dysfunction is debated, especially in irritable bowel syndrome. Objective data are quite scarce, especially concerning colonic propulsive activity. AIMS: To evaluate high- and low-amplitude colonic propulsive activity in constipated patients (slow-transit type and irritable bowel syndrome) in comparison with normal controls. PATIENTS AND METHODS: Forty-five constipated patients (35 with slow-transit constipation and 10 with constipation-predominant irritable bowel syndrome) were recruited, and their data compared to those of 18 healthy subjects. Twenty-four-hour colonic manometric recordings were obtained in the three groups of subjects, and data concerning high- and low-amplitude colonic propulsive activity were then compared. RESULTS: High-amplitude propagated contractions were significantly (p < 0.05) decreased in patients with slow-transit constipation and constipation-predominant irritable bowel syndrome with respect to controls (1.5 +/- 0.4, 3.7 +/- 2, and 6 +/- 1 events/subject/day, respectively). In slow-transit constipation, a significant decrease of contractions' amplitude was also observed. Concerning low-amplitude propagated contractions, patients with slow-transit constipation had significantly less events with respect to patients with constipation-predominant irritable bowel syndrome (46 +/- 7 vs. 87.4 +/- 19, p = 0.015); no differences were found between patients with slow-transit constipation and controls and between patients with constipation-predominant irritable bowel syndrome and controls. All three groups displayed a significant increase of low-amplitude propagated contractions after meals (6.3 +/- 2 vs. 18.2 +/- 5 for controls, p < 0.005; 6.4 +/- 1.4 vs. 16.3 +/- 2.4 for slow-transit constipation, p < 0.005; 10.5 +/- 3.2 vs. 32.6 +/- 7 for constipation-predominant irritable bowel syndrome, p = 0.001). CONCLUSIONS: Low-amplitude propagated contractions may represent an important physiologic motor event in constipated patients, reducing the severity of constipation in patients with irritable bowel syndrome and preserving a residual colonic propulsive activity in patients with slow-transit constipation.     

Impaired Colonic Motor Response to Eating in Patients with Slow-Transit Constipation

Because little is known about the pathophysiological mechanisms responsible for chronic idiopathic constipation, we studied colon motor response to eating, one of the most physiological and reproducible stimuli, in a clinically homogeneous group of severely constipated subjects. Fifteen patients (14 women, one man) with slow transit constipation (average duration of symptoms 18 +/- 2 yr) entered the study. After colonoscopic positioning of a manometric probe, 2-h basal and 3-h postprandial (1000 kcal standard mixed meal) recordings were obtained. Comparison of tracings with those of 29 healthy volunteers showed that motor response to eating was decreased in constipated subjects. Patients' response was characterized by a shorter duration of contractile activity in all three colon segments studied, after ingestion of the meal, and significantly less high-amplitude propagated contractions (7% vs. 45%). We conclude that several mechanisms are involved in the pathophysiology of colon contractile motor function of patients with chronic idiopathic constipation.     

Colonic propulsive and postprandial motor activity in patients with ulcerative colitis in remission

BACKGROUND: Although it is known that colon motility is abnormal in ulcerative colitis, data are still scarce with regard to the underlying mechanisms. Recent evidence suggests that the propulsive activity is highly increased during the active phase of the disease, probably contributing to the diarrhoea. However, data are even scarcer in the quiescent phase of the disease. AIMS: To assess the colonic high-amplitude and low-amplitude propulsive activity and the colonic motor response to eating in patients with ulcerative colitis in remission. PATIENTS AND METHODS: Fourteen patients were recruited, all with the disease in remission as documented by clinical and endoscopic criteria. Twenty-four hour manometric recordings were obtained in these patients, and compared to those of 16 healthy controls. RESULTS: The high-amplitude propagated contractions were similar in both groups (5.8+/-2.6 events in ulcerative colitis patients and 5.5+/-0.8 in controls (P=0.13)), whereas patients tended to display a higher number of low-amplitude propagated events (134.4+/-34 vs. 60.9+/-16 in controls (P=0.058)). No differences were found in the colonic motor response to eating between patients and controls. CONCLUSIONS: Colonic propulsive activity in ulcerative colitis in remission is almost normal, even though the low-amplitude propagated activity tends to be similar to that observed in patients with the irritable bowel syndrome, thus possibly contributing to the persistence of abdominal symptoms in a subgroup of patients.     

Twenty-four-hour manometric study of colonic propulsive activity in patients with diarrhea due to inflammatory (ulcerative colitis) and non-inflammatory (irritable bowel syndrome) conditions

Background Little is known concerning colonic motility and almost nothing is known concerning propulsive activity in pathological conditions characterized by diarrhea of both inflammatory and non-inflammatory origin.Aims The purpose of the present study was to investigate colonic propulsive activity in ulcerative colitis and diarrhea-predominant irritable bowel syndrome (IBS) patients.Patients and methods Seven patients with active, moderate ulcerative colitis and nine diarrhea-predominant IBS patients entered the study. Sixteen healthy volunteers were recruited as a control group. In all subjects, 24-h colonic motility was recorded by a colonoscopically positioned manometric catheter. Both high- (mass movements) and low-amplitude propagated contractions were analyzed.Results High-amplitude propagated contractions were significantly increased in ulcerative colitis with respect to controls; no significant differences were found with respect to IBS patients, and between IBS and controls. Concerning amplitude, no significant difference was found between groups, although IBS patients approached the statistical difference with respect to controls. Low-amplitude propagated contractions were significantly increased in ulcerative colitis with respect to controls; no significant differences were found compared with IBS patients. The latter, however, displayed a trend toward an increase with respect to controls that approached but did not reach statistical significance.Conclusions Both inflammatory and non-inflammatory diarrheal conditions are characterized by an overall increase of colonic propulsive activity. This observation may be useful for a better understanding of the pathophysiologic mechanisms of these disorders.     

Twenty four hour manometric recording of colonic motor activity in healthy man.

The motor activity of the transverse, descending, and sigmoid colon was recorded for 24 hours in 14 healthy volunteers with a colonoscope positioned catheter. During the study the patients ate two 1000 kcal mixed meals and one continental breakfast. Colonic motor activity was low before meals and minimal during sleep; the motility index increased significantly after meals and at morning awakening. Most of the motor activity was represented by low amplitude contractions present singly or in bursts, which showed no recognisable pattern. All but two subjects also showed isolated high amplitude (up to 200 mmHg) contractions that propagated peristaltically over long distances at approximately 1 cm/sec. Most of these contractions occurred after morning awakening, and some in the late postprandial period, with a mean of 4.4/subject/24 h. The peristaltic contractions were often felt as an urge to defecate or preceded defecation, and could represent the manometric equivalent of the mass movements.     

Twenty-four hour recordings of colonic motility in patients with diverticular disease

INTRODUCTION: Diverticular disease of the colon is one of the most common pathologic entities in western countries. Although altered motility of the large bowel is commonly believed to be one of the major pathophysiologic mechanisms, no convincing evidence has been reported yet. In fact, only a few conflicting studies concerning distal colonic motility (with no information on forceful propulsive activity) are available in the literature. PURPOSE: The purpose of the present study was to investigate basal and stimulated (postprandial) colonic motility from the transverse (not affected), descending, and sigmoid colon in patients with diverticular disease, together with detection of high-amplitude propagated contractions (mass movements). Motility data from patients were compared with those obtained in healthy control subjects. METHODS: Ten patients and 16 control subjects of both sexes were recruited for the study. In all subjects, colonic motility was recorded for a 24-hour period by a colonoscopically positioned manometric catheter. Two 1000-kcal mixed meals were served during the study. RESULTS: Compared with control subjects, patients with diverticular disease displayed significantly increased amounts of motility in the affected segments; the response to a physiologic stimulus (meal) was also abnormal in the patients' group. Diverticular disease patients also had a significant increase of forceful propulsive activity compared with control subjects (average = 10.3±2.7/subject/day high-amplitude propagated contractions for patients and 5.5±0.8/subject/day for control subjects;P=0.051); interestingly, about 20 percent of such activity was abnormal, being propagated in a retrograde fashion. CONCLUSIONS: We concluded that patients with diverticular disease of the colon have abnormal motor and propulsive activities of the large bowel, which are confined to the affected segments.During the period this study was performed, Dr. Battaglia was on leave from the Department of Clinical Pathophysiology, University of Torino Medical School.     

Ineffective oesophageal motility： Manometric subsets exhibit different symptom profiles

AIM： To compare the demographic and clinical features of different manometric subsets of ineffective oesophageal motility （IOM; defined as ≥ 30% wet swallows with distal contractile amplitude 〈 30 mmHg）, and to determine whether the prevalence of gastro-oesophageal reflux differs between IOM subsets.
METHODS： Clinical characteristics of manometric subsets were determined in 100 IOM patients （73 female, median age 58 years） and compared to those of 100 age-and gender-matched patient controls with oesophageal symptoms, but normal manometry. Supine oesophageal manometry was performed with an eight-channel DentSleeve water-perfused catheter, and an ambulatory pH study assessed gastrooesophageal reflux.
RESULTS： Patients in the IOM subset featuring a majority of low-amplitude simultaneous contractions （LASC） experienced less heartburn （prevalence 26%）, but more dysphagia （57%） than those in the IOM subset featuring low-amplitude propagated contractions （LAP; heartburn 70%, dysphagia 24%; both P ≤ 0.01）. LASC patients also experienced less heartburn and more dysphagia than patient controls （heartburn 68%, dysphagia 11%; both P 〈 0.001）. The prevalence of heartburn and dysphagia in IOM patients featuring a majority of non-transmitted sequences （NT） was 54% （P = 0.04 vs LASC） and 36% （P 〈 0.01 vs controls）, respectively. No differences in age and gender distribution, chest pain prevalence, acid exposure time （AET） and symptom/reflux association existed between IOM subsets, or between subsets and controls.
CONCLUSION： IOM patients with LASC exhibit a different symptom profile to those with LAP, but do not differ in gastro-oesophageal reflux prevalence. These findings raise the possibility of different pathophysiological mechanisms in IOM subsets, which warrants further investigation.     

Normal aspects of colorectal motility and abnormalities in slow transit constipation

Human colonic motility is a relatively difficult topic to investigate. However, the refinement of manometric techniques in recent years enabled us to study both the proximal and distal segments of the viscus. The present paper reviews our knowledge about normal aspects of colorectal motility in man and the abnormalities found in slow transit constipation (STC), one of the most frequent and difficult to treat subtypes of constipation. An internetbased search strategy of the Medline and Science Citation Index was performed using the keywords colon, colonic, colorectal, constipation, slow transit, motility, rectal, rectum in various combinations with the Boolean operators AND, OR and NOT. Only articles related to human studies were used, and manual cross-referencing was also performed. Most of colonic motor activity is represented by single nonpropagated contractions, rarely organized in bursts; this activity is maximal during the day, especially after waking and following meals. In addition, a specialized propagated activity with propulsive features is detectable, represented by high-and low-amplitude propagated contractions. In the severe form of constipation represented by the slow transit type, the above motor activity is completely deranged. In fact, both basal segmental activity (especially in response to meals) and propagated activity (especially that of high amplitude) are usually decreased, and this may represent a physiologic marker of this disorder. Human colonic motor activity is quite a complex issue, still only partly understood and investigated, due to anatomic and physiological difficulties. In recent years, however, some more data have been obtained, even in proximal segments. These data have helped in elucidating, although only in part, some pathophysiological mechanisms of chronic constipation, and especially of the STC subtype.     

Distension-stimulated propagated contractions in human colon

To investigate the mechanisms for elicitation of peristaltic activity in the human colon, we studied the effect of balloon distension of the transverse, descending, and sigmoid colon and the rectum. Fifteen healthy subjects were studied by means of a colonoscopically positioned probe carrying a 5-cm latex balloon. After positioning of the probe, stepwise distension was performed for each colonic segment (transverse, descending, sigmoid, rectum), and the onset of large (>50 mm Hg) and small (<50 mm Hg) propagated waves was observed. Analysis of the tracings showed: (1) In 8/15 subjects (53.3%), balloon distension elicited propagated contractions, but these contractions were qualitatively different from the spontaneously occurring high-amplitude propagated contractions previously found to occur in association with defecation. Therefore, intraluminal distension is probably not the cause of defecation-associated high-amplitude propagated contractions. (2) Pain reports were poorly correlated with propagated contractions elicited by balloon distension, suggesting that these contractions are not the cause of the pain produced by balloon distension. (3) The transverse colon shows lower pressures, fewer pain reports, and fewer large propagated contractions in response to balloon distension as compared to the descending and the sigmoid colon.     

Abnormalities of left colonic motility in ambulant nonconstipated patients with irritable bowel syndrome

Our objective was to evaluate left colonic motility patterns recorded under physiological conditions during 24 hr in fully ambulant nonconstipated IBS patients compared to healthy controls. A 42-hr manometry of the left colon was performed in 11 nonconstipated IBS patients and 10 age- and sex-matched healthy volunteers. On day 1, a 6-channel, 10-cm interval, solid-state catheter was positioned. Frequency, amplitude, and motility index (MI) of segmenting pressure waves in the descending and sigmoid colon were calculated during the 24-hr study period on day 2. High-amplitude propagated contractions (HAPCs) were identified visually and their characteristics were calculated. In IBS patients a higher frequency of segmenting pressure waves was observed in the sigmoid colon compared to the descending colon (P = 0.006). In contrast, no regional differences were observed in controls. Awakening (P = 0.048) as well as having a meal (P = 0.024) was associated with a smaller increase of contraction frequency in the descending colon of IBS patients compared to controls. HAPCs occurred more frequently in IBS patients than in controls (P = 0.035$). HAPCs in IBS patients reached a more distal colonic level and occurred more frequently in clusters. Defecation in IBS patients, but not in controls was always preceded by a cluster of HAPCs. In conclusion, left colonic segmenting pressure waves and HAPC characteristics are altered in nonconstipated IBS patients.     

Postprandial transduodenal bolus transport is regulated by complex peristaltic sequence

INTRODUCTION The spatial and temporal organization of gastrointestinal contraction waves seems to be a more important determinant of the flow of luminal contents than their number and amplitude[1,2]. Therefore, significant advances in understanding intest…     

Normal Esophageal Body Function: A Study Using Ambulatory Esophageal Manometry

Objective : The objective of this study was to establish normative ambulatory manometric data for contractions and contraction propagation in three levels of the esophagus. Methods : Twenty-five healthy volunteers underwent simultaneous ambulatory 24 h manometry. Concomitant 24 h pH studies were performed to exclude the presence of increased esophageal acid exposure. Pressures were recorded over a complete circadian cycle while patients continued with their normal lifestyles including eating and sleeping. Data were analyzed with a software program that was previously modified and validated and that enables quantitation of contractions in terms of efficacy. Results : The frequency of contractions was lowest during sleep, was increased when awake, and was highest during meals. Contraction amplitude increased during meals, providing a greater propulsive force for bolus transport. Similarly, the prevalence of peristaltic waves varied according to different physiologic states, i.e. , while eating, upright, awake, and sleeping. An increased amplitude and prevalence of peristalsis resulted in an increase in manometric efficacy during meals. Conclusions : This study provides normative data for ambulatory manometry for comparison when studying patients with disease.     

Long-term esophageal manometry in healthy subjects

Although long-term esophageal manometry is increasingly used in clinical practice, the normal values of contraction parameters are poorly defined. In addition, limited data are available on the effect of age on esophageal motility. Therefore, 44 healthy subjects (age range: 22–85 years) were investigated with a probe combining two pressure transducers 10 cm apart. All subjects were asked to follow their normal daily routine. The characteristics of contraction events (amplitude, duration) and type of propagation (propulsive, simultaneous) were analyzed for the total time and predefined periods: meal, daytime (interprandial), and supine. Equally high distal and proximal median pressure amplitudes (39.5 and 37 hPa) and durations (3.4 and 3.2 sec) were observed. The median percentages of propulsive and simultaneous waves were 56% and 10%. The individual contraction characteristics differed significantly in these three selected periods for most motility parameters: distal and proximal pressure amplitudes, distal duration, and propulsive contractions. To evaluate the influence of age on normal values, the subjects were divided into two age groups (median age: 28.5 and 62.4 years). In the elderly group the distal pressure amplitude, the distal duration, and the percentage of simultaneous waves increased, whereas the percentage of propulsive waves, the proximal pressure amplitude, and the proximal duration decreased. However, the differences observed were only minor and rarely reached the level of statistical significance (distal pressure amplitude and duration in the supine period). In conclusion, the physiological motor activity of the esophagus is characterized by significant diurnal variation. Furthermore the motility data are little influenced by age. Therefore, individual contraction characteristics should be considered in the analysis of motility data. Since age is of minor influence on esophageal motility, we believe that it is not required to create age-related control data for study populations of this size.     

Gastrointestinal transit and prolonged ambulatory colonic motility in health and faecal incontinence

Background—Colonic motor function has not beenstudied in the ambulatory setting over a prolonged period in theunprepared state. Furthermore, the disturbance of this function inpatients with faecal incontinence is unknown.
Aim—To study colonic function over two to threedays in the ambulatory, unprepared state in health and in patientswith idiopathic faecal incontinence.
Methods—Six healthy women and six women withfaecal incontinence and a structurally intact anal sphincter ingested adual radioisotope meal, and had a six sensor, solid state manometric probe colonoscopically inserted into the left colon. Scanning wasperformed until radioisotope left the gut and pressure was recorded fora median of 44hours.
Results—Three of six patients showed abnormalgastric emptying. Patients showed no disturbance of colonicradioisotope transit. Controls had a median of 12, whereas patients hada median of 16, high amplitude propagated waves per 24 hours. In threepatients urge incontinence was associated with high amplitude (up to500 cm water) propagated waves which often reached the rectum. These high pressure waves were identical to those occuring in healthy subjects, the only difference being the lack of adequate sphincter response. Passive incontinence was not associated with colonic motor activity. Defaecation in all subjects was associated with identical propagated waves, and distal movement of 13%(median) of right colonic content and excretion of 32% from the leftcolon and rectum. The urge to defaecate was associated with eitherpropagated waves (45%) or non-propagated contractions (55%). Rectalmotor complexes were recorded in both groups of subjects, but similar rhythmic activity was also recorded in the sigmoid and descending colon.
Conclusions—Normal colonic function consists offrequent high pressure propagated waves. Rhythmic activity occurs bothproximal to and in the rectum. Defaecation is characterised by highpressure propagated waves associated with coordinated anal sphincterrelaxation. Patients with faecal incontinence may have a widespreaddisturbance of gut function. Urge incontinence, an urge to defaecate,and defaecation can all be associated with identical high amplitude propagated pressure waves.

Keywords:colonic motility; gastric emptying; faecalincontinence

     

Characterization of Propagating Contractions in Proximal Colon of Ambulatory Mini Pigs

The aim of this study was to characterizepropagating contractions in the unprepared colon offreely ambulating mini pigs. A telemetric method wasused to record colonic motility continuously for sixconsecutive days in a 40-cm segment of proximal colon.Propagating contractions occurred over a wide range ofpropagation rates (0.4-16.7 cm/sec), peak amplitudes(10-116 mm Hg) and pressure wave durations (5.3-40.0 sec). Propagating contractions were dividedinto two groups by duration and wave-form:short-duration symmetrical and long-durationasymmetrical. Short-duration (7.8 ± 0.9 sec)symmetrical wave-from propagating contractions exhibited a higher frequency (27.9± 2.6 events/day), more rapid propagation rate(3-16.7 cm/sec; mean SEM: 4.9 ± 1.7 cm/sec), anda lower peak amplitude (31.2 ± 0.9 mm Hg)compared to long-duration (19.2 ± 5.1 sec) asymmetricalpropagating contractions, which were less frequent (6.1± 0.7 events/day), slower in propagation rate(0.4-2 cm/sec; mean SEM: 1.5 ± 0.7 cm/sec), andhigher in peak amplitude (51.6 ± 2.4 mm Hg). Theresults show that propagating contractions occur over awide spectrum, from short-duration, low-amplitude,rapidly propagating contractions to longduration,high-amplitude, slowly propagating contractions.     

Small bowel motor activity in response to physiological meals of different chemical composition in man

Meals disrupt the interdigestive pattern of small bowel motor activity and convert it into the more irregular postprandial pattern. Previous animal studies suggest that the duration of and contractile activity within the postprandial period depend on the chemical composition of a meal. It is not clear whether this is also true for man. In 8 healthy volunteers I investigated how physiological and isocaloric meals of different chemical composition affect small bowel motor activity. Volunteers underwent two separate, ambulatory 24-hour small bowel manometry studies. Volunteers had a total of four meals on the two study days. They ingested two identical fish meals rich in protein, a pasta meal rich in carbohydrates, and a meat meal rich in fat. Records were analyzed visually for the reappearance of phase III of the migrating motor complex, and a validated computer program calculated the incidence of contractions during the postprandial period, as well as the amplitude and propagation of contractions. The durations of the postprandial periods were similar after the two protein meals (238 +/- 35 and 227 +/- 25 min), the carbohydrate (220 +/- 23 min) and the fat meal (242 +/- 43 min). The incidence of contractions was not significantly different after the protein meals (1.6 +/- 0.3 and 1.0 +/- 0.2 contractions per min), the carbohydrate meal (1.0 +/- 0.2 contractions per min) and the fat meal (1.5 +/- 0.2 contractions per min). The amplitude of contractions was similar after the protein meals (14 +/- 0.1 and 13 +/- 0.1 mmHg), the carbohydrate meal (14 +/- 0.1 mmHg) and the fat meal (14 +/- 0.1 mmHg). Propagation of contractions was similar after the protein meals (13 +/- 3 and 18 +/- 3 %), after the carbohydrate meal (15 +/- 2 %) and after the fat meal (13 +/- 2 %). Contractile activity within consecutive 30-min periods of the postprandial period was also not different between the meals. I conclude that physiological, isocaloric meals of different chemical composition elicit a similar postprandial motor response in the human small bowel.     

Case report: colonic manometry reveals abnormal propulsive behaviour after anterior resection of the rectum

Anterior resection of the rectum is a frequent surgical procedure. However, abnormal bowel habits following this procedure are frequently reported. The functional evaluation of these patients is usually limited to the anorectal area. By means of colonic manometry, we have evaluated a patient with frequent urge for defecation and increased bowel frequency following anterior resection of the rectum with straight coloanal anastomosis and almost normal anorectal function. Analysis of the tracing revealed a reduction of contractile segmental activity and much more high-amplitude propagated contractions than which occur in healthy subjects. These high-amplitude propagated contractions, representing the manometric equivalent of mass movements, were always in association with urge for defecation and, sometimes, with loose stools. High-amplitude simultaneous contractions were also observed. We feel that the surgical resection of a potential physiological brake may be responsible for these observations.     

Colonic motility and transit in health and ulcerative colitis

Preprandial and postprandial colonic motility and transit (scintigraphy), with respect to the splenic flexure, were studied in 10 patients with ulcerative colitis and in 9 healthy subjects. The healthy subjects had a postprandial increase in intraluminal pressure that was significantly (P less than 0.03) greater in the descending colon than in other regions of the colon. In ulcerative colitis, the pressure was decreased in all regions compared with healthy subjects, with no significant pressure gradient among different regions. In normal subjects, transit was quiescent during fasting; eating stimulated both antegrade and retrograde transit. In ulcerative colitis, transit was variable before as well as after the meal. Both healthy subjects and patients with ulcerative colitis had more rapid emptying from the splenic flexure into the sigmoid than into the transverse colon. More frequent, low-amplitude, postprandial propagating contractions occurred in ulcerative colitis (P less than 0.05) than in healthy subjects. Propagating contractions were always antegrade and caused a rapid movement of the tracer into the sigmoid. In conclusion, ulcerative colitis is characterized by (a) decreased contractility, (b) increased low-amplitude propagating contractions, and (c) variable transit. These disturbances may accentuate the diarrhea in ulcerative colitis.     

Effect of food and anti-cholinergic drugs on the pattern of rectosigmoid contractions.

The colonic response to a meal is often used to test the effect of drugs on colonic motility, but this test is hindered by its inconsistency. This study has used multiple manometric sensors situated in the rectosigmoid region to investigate whether recording of the site and type of contraction offers a clear discrimination of the colonic response to a meal and the effect of drugs. Two studies were carried out on 16 healthy volunteers. Before the meal, rectosigmoid motility consisted mainly of isolated contractions occurring in a single manometric channel. The motility index increased in every subject after the meal (p < 0.05), but this increase entirely consisted of a massive increase in contractions occurring simultaneously in three or more manometric channels (multiple channel contractions), the number increasing from 9 per hour preprandially to 57 per hour (p < 0.01). There was a concomitant decrease in the number of the single channel contractions from 65 to 56 per hour. In a second study an infusion of an antispasmodic drug, mebeverine hydrochloride, into the sigmoid colon of healthy volunteers stopped the postprandial increase in the multiple channel contractions and prevented the significant rise in the motility index. The decrease in single channel contractions was unaffected. These results show that the colonic response to a meal consists of a change in the pattern of rectosigmoid contractions and suggest that multiple channel contractions may be a more sensitive indicator of the effect of a meal on the rectosigmoid colon than the motility index.     

5-Hydroxytryptophan and cisapride stimulate propulsive jejunal motility and transit of chyme in dogs

We investigated in conscious dogs the effects of intravenously administered 5-hydroxytryptophan (5-HTP) and cisapride on the postprandial jejunal mechanical activity by means of six closely spaced extraluminal strain gauge transducers. Drugs were given after administration of a nutrient meal. 5-HTP was given additionally after the administration of a noncaloric cellulose meal. Computer assistance was used to determine the temporal and spatial relationship of contractions and thereby to evaluate the length of spread of contractile waves. Both substances increased the propulsive activity, the contractile force and the motility index and fastened the transit rate of digesta. 5-HTP exhibited the most potent effect when given after administration of the nutrient meal.