Differences in colonic tone and phasic response to a meal in the transverse and sigmoid human colon.

It is not yet clear whether the regional differences in the physical properties of the colon influence its motor responses. Tonic and phasic colonic motility and compliance of the transverse and sigmoid colon were therefore assessed using a combined barostat-manometry assembly in 22 healthy subjects. Measured colonic compliance was corrected by subtraction of the compliance of the closed barostat system. The mean (SEM) preprandial colonic volumes in the transverse and sigmoid colon were similar (150 (12) and 128 (13) ml, p = NS), corresponding to calculated mean (SEM) colonic diameters of 4.3 cm and 4.0 cm respectively. The mean increase in colonic tone postprandially was significantly greater in the transverse (24.1% (3.5)) than in the sigmoid colon (13.1% (3.0), p < 0.01). The mean increase in phasic contractility was significantly greater, however, in the sigmoid than in the transverse colon (1270 (210) and 425 (60) mm Hg/90 min respectively, p < 0.01). Compliance was greater in the transverse than sigmoid colon (7.6 (0.44) and 4.1 (0.15) ml/mm Hg, p < 0.001). The fasting volume of the colon was significantly correlated with the magnitude of the tonic response to the meal in the transverse and sigmoid colon (p < 0.001 for both). In conclusion, there are quantitatively different but qualitatively similar phasic and tonic responses to the meal in the two colonic regions. Differences in the viscoelastic and luminal dimensions may partly account for these differences in tonic responses.     

Effect of eating on colonic motility and transit in patients with functional diarrhea. Simultaneous scintigraphic and manometric evaluations

The aim of this study was to correlate colonic motility with transit in 8 patients with functional diarrhea compared to 12 healthy subjects. Intraluminal pressure was measured with perfused catheter ports in the transverse colon, splenic flexure, and descending and sigmoid colons. Transit of the luminal contents was measured by following the movement of 99mTC-diethylenetriaminepentaacetic acid instilled as a bolus in the splenic flexure. In patients with diarrhea, the intraluminal marker moved in and out of the transverse and sigmoid colon regions of interest during fasting, unlike healthy subjects, in whom the marker remained in the splenic flexure. After eating, radioactivity immediately increased in both the transverse and sigmoid colons in healthy subjects. In the patients with diarrhea, eating did not alter the marker movement into the different regions of the colon compared with fasting. Within 100 minutes of eating, the intraluminal marker almost disappeared from the regions of interest in patients with diarrhea. Postprandial colonic nonpropagating contractions increased in each region of the colon in healthy subjects; there was only a small postprandial increase in colonic motility in patients with diarrhea. However, the numbers of fasting and postprandial propagating contractions were increased in patients with diarrhea compared with healthy subjects (P less than 0.02). Each propagating contraction moved more tracer in patients with diarrhea than in healthy subjects (P less than 0.05). These studies suggest that (a) in patients with diarrhea, the fluctuation of marker in both transverse and sigmoid colons during the fasting and postprandial periods is associated with decreased nonsegmenting contractions and frequent propagating contractions; and (b) in healthy subjects, the intraluminal marker moved after eating because of a pressure gradient caused by nonpropagating contractions.     

Postprandial colonic transit and motor activity in chronic constipation

The aim of this study was to correlate colonic motility and transit in patients with constipation and symptoms of the irritable bowel syndrome. Studies were performed in 16 patients with constipation and compared with the results in 12 healthy subjects. Intraluminal pressure was measured with perfused catheter ports in the transverse colon, splenic flexure, and descending and sigmoid colon. Movement of the luminal contents was measured by following the movement of Technetium-99m-DTPA that was instilled as a bolus in the splenic flexure. In both healthy subjects and patients with constipation there was no movement of the intraluminal tracer and no increase in intraluminal pressure during fasting. After eating a meal, healthy subjects and one group of the constipated patients had an increase in the radioactive marker in the transverse colon (p less than 0.03) and in the sigmoid colon (p less than 0.03). The movement of the intraluminal contents was associated with a positive pressure gradient between the descending colon and the transverse and sigmoid colon. There was no retrograde movement of the intraluminal contents and no postprandial increase in intraluminal pressure in the second group of patients with constipation. In healthy subjects, propagating contractions, which were associated with the rapid movement of intraluminal contents, began 60 min after eating. There were no propagating contractions in patients with constipation. These studies suggest that (a) the movement of intraluminal contents in healthy and constipated patients is determined by the postprandial pressure gradients within the colon, and (b) the propagating contraction is necessary for a normal bowel habit.     

Autonomic control of colonic tone and the cold pressore test.

BACKGROUND: Cardiovascular responses to cold stimulation are well characterised. It is unclear, however, whether cold pain stimulates responses in colonic tone in the transverse and sigmoid regions. AIMS: To assess the effects of cold stimulation on tone nd motility in the transverse and sigmoid colon and on cardiovascular autonomic activity. METHODS: Phasic and tonic motility of the transverse and sigmoid colon, pulse rate, and beat to beat pulse variability (which are measures of centrally mediated changes in autonomic function) were measured before, during, and after a standard cold pressor test in 22 healthy volunteers. RESULTS: Cold pain induced a significant increase in colonic tone but not phasic contractility in the transverse and sigmoid regions. Simultaneously, cold pain increased pulse interval variability. CONCLUSION: The findings are consistent with the hypotheses that cold pain produces coactivation of both the sympathetic and parasympathetic limbs of the autonomic nervous system and that cold induced changes in colonic tone are temporally associated with alterations in central autonomic nervous activity.     

Colonic Motor Response to Eating: A Manometric Investigation in Proximal and Distal Portions of the Viscus in Man

The motor response of the human colon to a meal is still poorly characterized. Such data as are available were obtained chiefly for the distal colonic portions with myoelectrical techniques. For these reasons, we investigated proximal and distal colonic motor responses to food ingestion in a rather large group of healthy subjects. Twenty-nine healthy volunteers were studied with a colonoscopically positioned multilumen manometric probe and low-compliance infusion system. Recordings were obtained for 2 h during fasting and for 3 h after the subjects had eaten a 1000-kcal standard mixed meal. During fasting, motility was quite low, and no significant differences between proximal and distal portions were seen. After eating, each portion significantly increased its motor activity throughout the subsequent recording period, but there were differences in the time course in the response to eating for different colonic segments. Proximal portions (especially the transverse colon) had first a sudden maximal increase and then a decrease, whereas the distal ones had a slower and more sustained increase in activity. These findings are of interest, especially for comparison with those of patients with suspected motor dysfunction of the large bowel.     

Ion transport in human cecum, transverse colon, and sigmoid colon in vitro. Baseline and response to electrical stimulation of intrinsic nerves

In a flux chamber study of ion transport in human colon, we compared baseline rates with those measured during electrical stimulation of intrinsic nerves. In baseline studies, sodium was absorbed throughout, but maximally in transverse colon. In cecum, sodium absorption accounted for the short circuit current and chloride was not absorbed. Chloride was absorbed in transverse and sigmoid colon, however. Residual current was minimal in cecum and transverse colon, but increased in sigmoid colon. Neural stimulation caused chloride secretion in cecum, reduced chloride absorption in sigmoid colon, but caused no change in transverse colon; sodium absorption decreased in cecum. A neurotransmitter of unknown identity affects baseline short circuit current in sigmoid colon. Half of the increase in short circuit caused by neural stimulation in sigmoid colon is mediated by muscarinic receptors. The identity of the other transmitter(s) is not known. It is not substance P or histamine. The three divisions of the colon differ in relative rates of baseline ion transport and in their transport responses to intrinsic nerve stimulation.     

Effect of CCK-OP and intraduodenal administration of essential amino acids on intraluminal pressures of sigmoid and rectum in patients with Chagasic megacolon

The motility of the sigmoid colon and rectum was studied by manometry in patients with Chagasic megacolon and in control individuals using two different experimental procedures: (1) intravenous infusion of saline, followed by intravenous infusion of cholecystokinin octapeptide (OP-CCK) at the dose of 20 ng/kg/hr; and (2) intraduodenal instillation of saline followed by a solution of essential amino acids at a flow of 10 ml/min. CCK-OP induced an increase in motility index in the sigmoid colon (P less than 0.05) and rectum (P less than 0.05) in the controls, whereas intraduodenal infusion of amino acids produced a significant increase in motility index exclusively in the sigmoid colon (P less than 0.005). A significant increase (P less than 0.05) in sigmoid colon motility also occurred in the control group after duodenal saline infusion was interrupted. The release of other substances in addition to CCK must have been responsible for the different behavior of sigmoid colon and rectum in response to the stimuli used. Neither procedure caused significant changes in the motility of the sigmoid colon or the rectum of the Chagasic patients. The extensive intramural denervation occurring in Chagasic megacolon probably destroys the neural pathway through which OP-CCK and the substances released by the duodenum by the infusion of essential amino acids activate the motor cells of the human terminal intestine.     

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.     

Intact colonic motor response to sudden awakening from sleep in patients with chronic idiopathic (slow-transit) constipation

PURPOSE: There are few data about the relationships between colonic motor behavior and higher brain functions, such as sleep. Previous studies were done in healthy subjects, and it is unknown whether patients with functional motor disorders of the colon behave differently. This study was designed to characterize colonic motor activity in patients with constipation, both during sleep and after sudden awakening, and to compare it with that of healthy subjects. Our working hypothesis was that patients with constipation would have an impaired response to sudden awakening. PATIENTS AND METHODS: Twelve chronically constipated women, 22 to 49 years old, were recruited for the study, and their data were compared with those obtained from 12 healthy female volunteers, 21 to 38 years old. Manometric studies were performed in the descending and sigmoid colon for 30 minutes during sleep (immediately before awakening) and 30 minutes after being awakened suddenly. A motility index was calculated before and after the stimulus. RESULTS: In both groups motility in the descending and the sigmoid colon was almost absent during sleep and significantly increased after sudden awakening. No difference in postawakening values was found between patients with constipation and controls. CONCLUSIONS: In patients with chronic constipation, the brain-gut control of some fundamental mechanisms governing colonic motility is preserved. These data suggest that the alterations of colonic motility described in chronic constipation may be caused by an intrinsic dysfunction of the viscus.     

Long-duration stress

No extensive information exists in literature concerning the late or residual effects of stress on motility of small bowel and colon. Moreover, the duration and magnitude of the intestinal motor response to stress are still ignored. Therefore, the aim of our work was to determine, in rat, the effect of long-duration stress induced by restraint on the motility of small bowel and colon. Observations were made during physical restraint and 60 h later. Bipolar electrodes were implanted on the gastrointestinal serosa from the pylorus to the sigmoid colon in male Wistar rats. Electromyographic (EMG) recordings were made during fasting state, and a control EMG recording session was performed during 12 hr, followed by a 12-hr recording during restraint stress. After a 60-hr resting period, another EMG recording session was performed during 3 hr. During stress in the pylorus and small bowel, the recurrence of migrating myoelectrical complexes (MMCs) was immediately interrupted and replaced by a continuous and irregular activity. The motility index (number of spike bursts/10 min) was augmented rapidly on the jejunum and ileum, but it increased only gradually on the pylorus. Only on the transverse colon were the number of spike bursts/hour and their relative duration increased after 7 hr of physical restraint. In contrast, the sigmoid colon displayed a gradual decrease in the relative duration of contractile activity during the first 6–7 hr of stress. At 60 hr after stress in the pylorus and small bowel, a normal control motor activity was restored (MMC, motility index) on the jejunum and on the ileum, but the motility index on the pylorus was decreased. Throughout the colon, a faster motor activity as well as an increase in the number of spike bursts/hour was observed. In conclusion, a 12hr physical restraint stress induced instant drastic changes in small bowel motility, but a normal motility pattern was rapidly restored after the end of the stress period. However, on the colon, the motor changes are moderate at the beginning of the restraint period, then gradually increased with time, and were still largely persistent three days after the cessation of physical restraint.     

Bile acids and colonic motility in the rabbit and the human.

Colonic motor activity was initiated by infusions of bile salts into the caecum or rectum of the anaesthetized rabbit. Primary bile acids were examined proximally and distally in the colon and elicited marked motor responses. Sinc dihydroxy bile acids are known to be potent inhibitors of electrolyte and water absorption in the colon, the secondary bile acid deoxycholic acid, the dihydroxyl compound most related to cholic acid which is the main bile acid in the rabbit, was examined distally and was also active, but to a lesser extent than cholic acid conjugates in this species. In man, a relationship was found between the faecal bile acid excretion and colonic motility: the introduction of bile acids directly into the human sigmoid colon and rectum also stimulated colonic motility. In man, the dihydroxy compound chenodeoxycholic acid was slightly more active than conjugates of cholic acid.     

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

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

Colonic motility abnormality in patients with irritable bowel syndrome exhibiting abdominal pain and diarrhea

OBJECTIVES: Although colon dysmotility is recognized as a pathophysiological factor in irritable bowel syndrome (IBS), it has not been characterized. We have investigated motility patterns in IBS patients with abdominal pain and frequent defecation or diarrhea and in healthy volunteers. METHODS: A recording catheter that had six polyvinyl tubes with infusion ports was placed in the transverse, descending, and sigmoid colon under fluoroscopy. After 2-h basal recordings, motility responses to cholecystokinin octapeptide (CCK-8) and a meal were studied for 3 h. The motility index (MI) and number of high amplitude propagating contractions (HAPCs) in 10 IBS patients were compared with those of 10 controls. HAPCs were correlated with abdominal pain, and colon transit time using radio-opaque markers was determined. Using human colon muscle strips, the effect of CCK-8 on muscle contractions was also studied. RESULTS: The MI and mean number and peak amplitude of HAPCs in IBS patients were significantly greater than in controls. These abnormalities paralleled markedly shortened colonic transit time. Abdominal pain coincided with >90% of HAPCs. Dose-dependent muscle contraction by CCK-8 was profoundly suppressed both by loxiglumide and atropine. CONCLUSIONS: The dysmotility in this subset of IBS patients was characterized by significantly increased occurrences of powerful HAPCs that paralleled rapid colon transit and were accompanied by abdominal pain. Thus, it is suggested that this powerful contraction is one of the causes of abdominal pain. The action of CCK-8 seems to be mediated via the colon enteric nervous system.     

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.     

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

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

Serotonergic mediation of postprandial colonic tonic and phasic responses in humans.

This study examined the hypothesis that 5HT3 mechanisms mediate the postprandial gastrocolonic response in humans. Fasting and postprandial colonic tone and motility were studied in 12 healthy volunteers and the effects of a selective 5HT3 antagonist, ondansetron assessed in a double blind, randomised, placebo controlled fashion. A manometry barostat assembly was positioned in the transverse or descending colon to quantitate contractile activity fasting, after drug infusion and postprandially after a 1000 kcal meal. Fasting colonic tone and motility indices were similar in the placebo and ondansetron groups; ondansetron did not affect fasting motility. The placebo group showed a significant reduction in barostat balloon volume (signifying increased tone) from 232 ml (median, interquartile range (IQR) 179-261) during fasting to 181 ml (median, IQR 128-208) (postprandially) (p = 0.02). In contrast, the ondansetron group did not have a tonic colonic response (median 248 ml (IQR 199-300) fasting to median, 226 ml (IQR 185-290) postprandially) after the meal. Phasic volume events measured by the barostat increased postprandially in both groups. Postprandial motor activity measured by manometry increased significantly in the placebo group, but not in the ondansetron group. In conclusion, a 5HT3 mechanism participates in the physiological contractile responses in the human transverse and descending colon after ingestion of a high energy meal.     

Transverse loop colostomy and colonic motility

Background

The motility of the defunctionalized colon, distal to transverse loop colostomy, has never been studied “in vivo.” The aim of our study was to evaluate the influence of transverse loop colostomy on colonic motility.

Methods

Thirteen patients were examined before stoma closure by means of clinical evaluation and colonic manometry; we studied both the right and distal colon in both fasting and fed patients in order to detect motor activity.

Results

Quantitative and qualitative manometric analyses showed that the diverted colon had motor activity even if no regular colonic motor pattern was observed. The spreading of aboral propagated contractions (PCs) was sometimes recorded from the right colon to the distal colon. The response of the proximal and distal colon to a standard meal, when compared to fasting values, increased more than 40 and 35 %, respectively. Stool and gas ejections from the colostomy were never related to a particular type of colonic motility: Motor quiescence such as PCs was chaotically related to stool escape.

Conclusions

In conclusion, motility of the defunctionalized colon is preserved in patients with transverse loop colostomy.     

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.     

Studies on the Defecation Reflex in Man

In patients with cecostomies and in patients with urinary bladder substitutes obtained from either the sigmoid colon or the cecum, the motor activity in different parts of the large bowel was recorded with the aid of open tip tubes and a pressure-recording apparatus after administration of a contact laxative (Dulcolax®). Administration of Dulcolax® into the cecum of patients with cecostomy produced motor activity locally as well as in the transverse colon and in the sigmoid. When the drug was administered into the cecum of patients with isolated cecal bladder replacements, motor activity was recorded in the cecum but not in the sigmoid. Rectal application of Dulcolax® initiated motor activity in the intact sigmoid as well as in the isolated sigmoid bladder substitute but not in the cecum in patients with cecostomies nor in the cecal bladder replacements. The experiments indicate that only the left colon is engaged in the defecation mechanism elicited by rectal stimulation. The motor response in the left colon after rectal stimulation is mediated by a reflex with its afferent limb from the rectal ampulla. The motor response in the sigmoid after cecal stimulation is elicited by impulses mediated by intrinsic nervous pathways in the intestinal wall.     

Effects of a meal on the motility of the sigmoid colon and rectum in healthy adults

Motility in the sigmoid and rectal areas was studied before, during, and after a 900-cal meal in 11 healthy subjects. A Honeywell esophageal pressure transducer with three transducers was used for the recording. A 900-cal meal significantly stimulated colonic motility during eating. The frequency of contractions was responsible for this increase while the amplitude of the contractions remained the same. Colonic motility returned to fasting levels immediately after the meal. Recording periods of 30 min were not capable of distinguishing individual variations in colonic motility because of long periods of inactivity but were adequate when groups of subjects were compared. Body position did not affect colonic motility. These studies suggest that a meal stimulates sigmoid and rectal motility in healthy subjects, but only during the consumption of the meal.