Role of anger in antral motor activity in irritable bowel syndrome.

There is considerable evidence indicating that patients with irritable bowel syndrome respond to emotional and environmental stimulation with increased colon motor activity. It has been suggested also that increased colon motor activity is not confined to the colon and may be representative of a broader disorder affecting the rest of the gastrointestinal tract in this population. The results of our current study suggest that anger may have a significant, although differential effect on antral motor activity in IBS patients compared to normal controls. We found that while antral motor activity did not differ significantly in our groups during rest, anger decreased antral motor activity in IBS patients and increased antral motor activity in normal controls. The difference was not attributable to a difference in anger levels since the groups did not differ in their response to the standardized anger stressor. Rather, the difference in the antral motor response appears to be qualitative and a possible marker for irritable bowel syndrome. Our data further suggest that increased colon motor activity in IBS patients during emotional stress is not a result of a rise in motor activity throughout the gastrointestinal tract, but a phenomenon that may be unique to the colon in this patient population.

Effects of regular exercise in management of chronic idiopathic constipation.

Regular physical exercise has long been considered in the management of chronic constipation. This recommendation is probably based on the assumption that exercise shortens the transit time through the gastrointestinal tract. However, on the basis of previous studies, the effect of exercise on the transit remains controversial at best. Therefore, it was the goal of the present study to assess the influence of regular physical exercise, what average people may consider routine exercise, in the management of chronic idiopathic constipation. The study population consisted of eight patients, seven women and a man, with chronic idiopathic constipation. They were studied for six weeks, including two weeks of rest and four weeks of regular exercise. Patients had a submaximal exercise test, before and after the exercise period, to determine their rate of perceived exertion (RPE), the target heart rate, and the intensity of exercise they can perform. In addition to their routine daily activities, they exercised 1 hr a day, five days a week according to their performance at the initial exercise tolerance test. They kept a daily activity log and maintained their normal dietary intake during this period. The patients overall physical activity was assessed by a pedometer. They also maintained a diary of the number and consistency of their bowel movements and the amount of straining required for defecation. The impact of exercise on constipation was assessed by utilizing an index that took into consideration all three parameters of bowel function. Results of the study revealed that patients covered 1.8+/-0.33 and 3.24+/-0.28 miles/day in the rest period and during the exercise period, respectively (P = 0.007). The intensity of exercise may have improved the level of training as reflected on the mean maximum time before and after exercise period (P = 0.039). This level of exercise did not improve their constipation indices, which were 9.11+/-0.65 and 8.57+/-1.08 in the rest and exercise periods, respectively (P = 0.68). In conclusion, physical activity, to the extent that people consider "regular exercise," does not play a role in the management of chronic idiopathic constipation.

Clinical value of anorectal manometry index in neurogenic fecal incontinence.

PURPOSE: The present communication is an endeavor to assess the value of a simple motility index to separate patients with neurogenic or idiopathic fecal incontinence from those patients with the secondary form of the disease. METHODS: Study population consisted of 23 patients with idiopathic fecal incontinence and 13 patients with fecal incontinence secondary to surgical or obstetric trauma. They all had a standard anorectal manometric study after a 12-hour fast. A motility index was then prepared taking into consideration the peak sphincter pressure values, contractility endurance, and rectal sensory threshold. RESULTS: Despite differences in the mean peak squeeze pressure and sensory threshold between the two groups, there were significant overlaps for all parameters of standard anorectal manometry in both groups. However, patients with idiopathic incontinence had an index of smaller than 28, and the group with the secondary form of incontinence had indexes higher than 30. CONCLUSIONS: 1) None of the four parameters of a conventional anorectal manometry can accurately separate patients with neurogenic incontinence from those with secondary forms of the disorder. 2) The anorectal motility index presented here can accurately separate the two groups. 3) This index is superior to the standard anorectal manometry in evaluating patients with fecal incontinence.

Effect of exercise on mouth-to-cecum transit in trained athletes: a case against the role of runners' abdominal bouncing.

The role of exercise on the gastrointestinal motor function and in particular on transit time is a matter of hard debate. Numerous studies in the past have failed to demonstrate a consistent effect of short term exercise on transit time in untrained subjects and trained athletes. It has been, however, suggested that running, with its constant jostling of the abdomen, may have a different effect than exercise performed in a stationary setting. To examine the effect of running on gastrointestinal transit time, 8 healthy male trained runners ingested a lactulose meal and assigned to rest or exercise on separate days. Exercise consisted of running 9.6 km in an hour, while exhaled gas was sampled every 10 minutes for volume, minute ventilation and hydrogen concentration. The mean O2 consumption was 36.8 ml/min/kg during exercise session and 4.7 ml/min/kg during rest period. Post lactulose rise in hydrogen concentration occurred at a mean of 85 +/- 25.1 and 84 +/- 18.1 minutes for resting and exercise sessions respectively (p = 0.732). On the basis of the present data we conclude that (1) mouth-to-cecum transit time is not affected by short term intense exercise in trained athletes; (2) that bouncing of the abdominal content in case of running probably does not change the transit time; and finally, (3) the impact of moderate to intense short term exercise on the mouth-to-cecum transit is not influenced by the subject's fitness state.

Effects of experimental hemosiderosis on intestinal morphology, permeability, and tissue iron content.

Effects of iron overload on intestinal function and structure are unknown and were, therefore, investigated. Sprague-Dawley rats were randomized into an iron-overloaded group, which received a single subcutaneous injection of 1.2 g/kg elemental iron-dextran complex, and placebo-treated pair-fed controls. Animals were studied after a 10-month observation period. Intestinal permeability was assessed by measuring the urinary excretion of lactulose, rhamnose, and mannitol after oral administration. In addition, tissue nonheme iron content was measured, and histologic examination and morphometric measurements were carried out. The chronic iron-overloaded group showed a significant increase in intestine tissue iron content and stainable iron in the submucosa and muscularis propria and adipose tissue of the small intestine and lamina propria and muscularis mucosa of the large intestine. There was a significant decrease in the crypt depths without discernible change in the intestine permeability to any of the markers used. In addition, the iron-overloaded animals showed a significant number of iron-laden cells, which primarily consisted of macrophages, fibroblasts, myocytes, and adipocytes. In contrast, no iron-laden cells were present in tissues obtained from the normal control group. Thus, chronic experimental iron overload in rats leads to significant morphologic, but no permeability, alterations of the alimentary tract.

Quality of life among patients treated for achalasia.

The present study is an attempt to capture the quality of life of achalasia patients after a successful treatment. It is also an effort to assess the extent of the subsequent restrictions achalasia may have imposed upon the patients' life-style. All achalasia patients who were successfully treated between 1984 and 1992 were identified. Qualified patients were supplied with a 12-item quality-of-life questionnaire that had been designed to assess the patients' perceptions of their swallowing function and their general health; the restrictions achalasia had imposed on five areas of performance, which encompassed social activities, family relationships, travel experiences, sports and housework activities, were also assessed. Sixty-six patients were offered the questionnaire and 52 (77.6%) returned a completed form. Forty-one of the group had pneumatic dilatation and the remaining 11 had cardiomyotomy. Some form of dysphagia was reported by 36 patients (69%) and a dietary modification was exercised by 29 (56%) of them. Heartburn was reported by 31 (59%) of the patients. Fifteen percent of the patients felt that the disease interfered with their social activities, 8% experienced difficulty in their family relations, 13% believed that the disease restricted travel and athletics, and finally, 9% stated that their symptoms placed restrictions on their ability to do housework. The group that received pneumatic dilation experienced less restriction in the performance areas of sports, travel, and housework. However, this difference was only significant in the area of sports (P = 0.04). It is concluded that: (1) The restoration of the normal swallowing mechanism is not often achieved after treatment for achalasia. The majority of patients who have been treated continue to have a component of difficulty for the rest of their lives. (2) These residual symptoms leave an impact on the patients' life-style. This impact is least important in the performance area of family relationship and most impressive in the area of sports. (3) Finally, those patients who have been treated with cardiomyotomy are more restricted in sport activities than those who received pneumatic dilatation.

Unexplained dysphagia: viscous swallow-induced esophageal dysmotility.

Dysphagia is a manifestation of several clinical conditions of diverse origin. In spite of the variation in these disease entities in terms of their etiology, clinical presentation, natural history, and treatment, the mechanism of this clinical complaint is not always clear. We studied a group of patients with dysphagia for solids in whom no anatomic or motor abnormalities were encountered on standard studies. The group consisted of 37 patients, 25 women and 12 men, who were complaining of dysphagia of 6 months or longer duration and they did not demonstrate structural or motor abnormalities on barium esophagogram, esophagoscopy, and standard esophageal manometry. A group of 24 age-matched patients, 14 women and 10 men, with noncardiac chest pain served as the patient control. Esophageal contractile activities were studied after 10 wet swallows (5 ml of water) and 10 viscous swallows (5 cubic cm of marshmallow). Resting lower esophageal sphincter pressure and its relaxation response to swallows, amplitude of peristaltic activities, rate of dysphagia provoked during the study, and the frequency of abnormal esophageal contractions were evaluated. Six abnormal esophageal contractile activities-failed peristalsis, dropout, repetitive, simultaneous, spontaneous contractions, and aperistalsis-were utilized to generate an esophageal peristaltic dysfunction index. The mean LESP was 8.1 +/- 4.7 in the dysphagia group and 16.1 +/- 4.3 in the chest pain group. The mean amplitude of peristaltic contractions was 47.1 +/- 16.1 and 89.0 +/- 27.0 mmHg after wet swallows for dysphagia and chest pain groups, respectively. These values were 58.2 +/- 12.4 and 92.4 +/- 22.1 for viscous swallows. Swallowing provoked dysphagia in 89% of the dysphagia group after viscous swallows and 9% after wet swallows. In contrast, only 11% and 3% of control group complained of dysphagia during the study. This group of patients probably represent a cohort of patients with a nonspecific esophageal motor disorder in whom both clinical symptom and their esophageal motor counterpart can only be elicited in response to viscous swallows. We strongly believe in addition of viscous swallows in evaluating dysphagic patients in whom symptoms remain unexplained in light of standard studies.

Esophageal aperistalsis and gastroesophageal reflux disorder: return of peristalsis after H2-blocker therapy.

OBJECTIVES: Distal esophageal aperistalsis has rarely been reported among patients with gastroesophageal reflux disorder. The purpose of this study, therefore, was to address the frequency with which disorders of peristalsis in general--and distal esophageal aperistalsis in particular--occur in adults with gastroesophageal reflux disorder. PATIENTS AND METHODS: We studied 314 patients who were referred to our gastrointestinal motility laboratory. On the basis of the endoscopic data, they were divided into three groups: group I, symptomatic patients without endoscopic esophagitis; group II, patients with mild endoscopic esophagitis; and group III, patients with erosive esophagitis. An age-matched group of patients with chest pain unrelated to reflux served as the control. RESULTS: Some form of peristaltic dysfunction was recorded in 56% of the patients with gastroesophageal reflux disorder, significantly more than in the control group (p < 0.01). A significant correlation existed between the esophageal motor dysfunction scores and the severity of reflux disease. Distal esophageal aperistalsis was present in 3.1% of the reflux groups. There was a correlation between severity of reflux disease and the prevalence of aperistalsis. Aperistalsis occurred in none of the patients in group I, in 3.6% of group II, and in 12.5% of group III (p < 0.0001). Seven of the patients with aperistalsis who has been treated with H2-blockers were reexamined 4 months later. Return of peristalsis was seen in three of them. CONCLUSION: Esophageal aperistalsis can be seen in a minority of patients with severe gastroesophageal reflux disorder and is probably a reversible condition.

Clinical spectrum of esophageal aperistalsis in the elderly.

OBJECTIVES: Our inability to explain the swallowing difficulty that is associated with esophageal motor dysfunction in a number of otherwise healthy elderly patients prompted us to assess the prevalence of esophageal aperistalsis among an elderly population and to investigate prospectively how frequently aperistalsis can be explained by factors other than age. METHODS: During the 5-yr period from 1987 to 1992 we performed esophageal manometry in 562 patients. Recordings were assessed for the presence of complete esophageal aperistalsis. As an effort to explain the aperistalsis, patients then underwent a battery of clinical, radiological, and laboratory studies. RESULTS: Complete aperistalsis was present in 121 patients; 73 of them were 65 yr or older, and 48 were 40 yr or younger. Further investigations into the cause of the aperistalsis in the aged group revealed achalasia in 31, vigorous achalasia in six, symptomatic diffuse spasm in four, systemic sclerosis in one, and diabetes mellitus in five. In the younger group, 40 cases of achalasia, one case of vigorous achalasia, one case of diffuse esophageal spasm, two cases of systemic sclerosis, and one case of diabetes were identified. In 29 patients, 26 of the aged group and three of the younger group, no explanation for aperistalsis was found. Aperistalsis of obscure origin was significantly more common in the aged group (p < 0.05). CONCLUSION: In a distinct minority of otherwise healthy elderly patients, no significant disease process can explain dysphagia and complete esophageal aperistalsis. In this context, aging remains as a possible factor.

Dose de-escalation chemoprevention trial of alpha-difluoromethylornithine in patients with colon polyps.

BACKGROUND: alpha-Difluoromethylornithine (DFMO) is a potent inhibitor of carcinogenesis in experimental animal models. In these animal models, DFMO has been especially active in preventing carcinogen-induced epithelial cancers, including those of the skin, colon, breast, and urinary bladder. Although DFMO is known to exert its diverse biological effects by suppressing intracellular pools of the polyamines putrescine and spermidine, the precise mechanism by which polyamine depletion, induced by DFMO, suppresses carcinogenesis is unknown. PURPOSE: The specific aim of our study was to determine the lowest dose of DFMO that would deplete target tissue (colorectal mucosa) levels of these polyamines in humans who had undergone prior removal of colon polyps while producing minimal toxic effects. METHODS: A dose de-escalation chemoprevention trial of DFMO was conducted in 111 patients (36 female and 75 male) who were in generally good health, aged 39-79, and who had undergone colonoscopy for surgical removal of an adenomatous colon polyp greater than 3 mm within 5 years prior to entering the study. Groups of patients (12-20 patients per group) were orally treated with single, daily doses of DFMO ranging from 3.0 to 0.1 g/m2 for 4 weeks (28 days). Prior to initiation of DFMO treatment and at the end of treatment, six colorectal biopsy specimens were collected from each patient, along with serum samples. All biopsies were performed between 9 AM and noon to avoid possible effects of diurnal variations in laboratory end points. Samples for analysis of plasma DFMO levels were also collected during this time period on the day after the last day of drug administration. RESULTS: DFMO caused a decrease in both putrescine content and the ratio of spermidine to spermine for all dose groups down to 0.25 g/m2. Both putrescine content and the ratio of spermidine to spermine and changes in these parameters as a function of DFMO treatment decreased as a function of donor age. None of the 30 patients receiving either 0.25 or 0.5 g/m2 experienced any clinical ototoxicity in this trial. CONCLUSIONS: DFMO is both safe and effective in reducing colorectal mucosal polyamine contents when it is administered orally to patients at doses as low as 0.25 g/m2 for 28 days. No ototoxicity was observed at doses up to twice this amount. IMPLICATIONS: If DFMO is also found to be effective in suppressing polyamine contents in other target tissues, it may be useful in preventing a wide range of human epithelial cancers, including those of the prostate and breast.

Effects of exercise on total and segmental colon transit.

To investigate the effect of aerobic exercise on total gastrointestinal and segmental colon transit, 16 male health care workers with a sedentary life-style were studied during 1 week of rest and 1 week of exercise. The exercise phase consisted of walking 4.5 km on a level treadmill for 1 h on each of 3 days. Total gastrointestinal and segmental colon transit times were measured using radiopaque markers ingested on each of 3 consecutive days with an abdominal radiograph obtained on the fourth day. With exercise, total gastrointestinal transit time decreased in 5, increased in 6, and did not change in 5 subjects. Using a paired t test, total transit did not show a significant change from rest (24.5 +/- 21.8 h) to exercise (20.9 +/- 16.8 h), p = 0.50. These observations support our previous findings that physical activity to the extent that average people consider routine exercise does not necessarily improve gastrointestinal transit. Therefore, the role of such exercise in the management of chronic constipation can be seriously questioned.

Manometric and radiologic correlations in achalasia.

Achalasia is an esophageal motor disorder distinguished by clinical, radiologic, and manometric features. To evaluate the correlation among these features, we studied 109 achalasia patients. The four most common clinical complaints, the four most commonly encountered radiologic findings, and two manometric parameters were analyzed with a correlation matrix test and a multiple regression analysis. Significant correlation existed among symptoms of dysphagia, regurgitation, and weight loss. In contrast, chest pain inversely correlated with these symptoms. Dysphagia and weight loss significantly correlated with a bird-beak deformity but not with esophageal dilatation or a sigmoid esophagus. Moreover, no significant relationship between lower esophageal sphincter pressure and esophageal dilatation or sphincter pressure and sigmoid esophagus was found. However, in those patients with a resting lower esophageal sphincter pressure greater than 45 mm Hg, a reasonable correlation among clinical, radiologic, and manometric parameters did exist. In conclusion, although in a subset of patients with markedly increased lower esophageal sphincter pressure, a good correlation between clinical, radiologic, and manometric findings exists, such a correlation cannot be established in all of the achalasia patients; esophageal dilatation or a sigmoid esophagus may not be due to a hypertensive sphincter, and their presence must not necessarily be interpreted as an indication of severity of the disease; there is an inverse correlation between chest pain and symptoms of dysphagia, regurgitation, and weight loss; and finally, achalasia and hiatal hernia may coexist in 6% of the patients.

The role of the flow rate of the pneumohydraulic system on post-sphincter of Oddi manometry pancreatitis.

Manometry of sphincter of Oddi (SO) carries a risk of acute pancreatitis by a mechanism not yet clearly understood. This study attempted to evaluate the role of the flow rate of the perfusion system in the development of acute pancreatitis. During the past 60 months, we have performed 81 manometry studies of SO in 79 patients, 61 women and 18 men, who were referred for recurrent attacks of abdominal pain suggestive of SO dysfunction. All procedures were done by the same operator, utilizing the same instrumentation and similar premedication. In the first 54 studies, the pneumohydraulic system had a flow rate of 0.55 ml/min and a tank pressure of 15 lb/in2 while in the last 27 studies a flow rate of 0.27 ml/min and a pressure of 7.5 lb/in2 were employed. Acute pancreatitis was diagnosed after 16 (19.7%) procedures. Fourteen (26%) of them occurred after high-flow-rate perfusion. In contrast, only 2 (7%) of the 27 patients who had the procedure done at the flow rate developed this complication (p less than 0.05). There was no correlation between the occurrence of pancreatitis, clinical suspicion of SO dysfunction, and the underlying manometric profile of the sphincter. We conclude that the incidence of procedure-related pancreatitis after manometry of SO is higher than following diagnostic endoscopic retrograde cholangiopancreatography and that the flow rate in the perfusion system is a precipitating factor in the development of this complication.

Sphincter of Oddi dysfunction and unexplained abdominal pain: clinical and manometric study.

Unexplained, biliary-type abdominal pain is often attributed to an abnormal pressure profile of the sphincter of Oddi. In spite of this assumption, the true prevalence of this type of motor dysfunction among cholecystectomized patients with unexplained abdominal pain is not known. We studied 64 postcholecystectomy patients who were thought to have sphincter of Oddi dysfunction. Radiologically, other than a dilated common bile duct in some, they had no anatomic derangement of their pancreatobiliary tract to explain their symptoms. They were categorized into three groups on the basis of four objective findings suggesting abnormal biliary emptying mechanism. Basal sphincter of Oddi pressure, frequency of phasic contractions, and proportion of retrograde contractions were determined in all patients. Twenty-six (41%) of the patients demonstrated at least one motor abnormality, 16 (25%) had two, and 10 (16%) had all three abnormal parameters. The pressure profile of the sphincter was normal in 38 or 59% of the patients. Seventy-three percent (73%) of the patients in group I, who had three or four of the objective findings for sphincter of Oddi dysfunction, demonstrated at least one motor abnormality. Sixty percent of this group demonstrated an increased basal sphincter of Oddi pressure. On the other hand, only 19% of the patients in group III, who had none of the objective findings, revealed a motor abnormality. Increased basal sphincter of Oddi pressure was noted in 7% of this group. We conclude that, sphincter of Oddi dysfunction, as diagnosed manometrically, explains the recurrent biliary type abdominal pain in a minority of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Achalasia evolving from segmental aperistalsis.

A 17-year-old woman was evaluated for dysphagia. Radiologic study revealed a rigid segment 10 cm long in the midesophagus, which was found to be aperistaltic on manometric evaluation. The rest of the esophagus and the lower esophageal sphincter were manometrically normal. Four years later the patient was seen for evaluation of severe dysphagia and symptoms of esophageal overflow. Characteristic radiologic and manometric findings of classic achalasia were noted. The case is discussed as an atypical form of achalasia evolving from a segmental esophageal aperistalsis.

Effect of aerobic exercise on mouth-to-cecum transit time.

To examine the premise that exercise reduces the gastrointestinal transit time, we evaluated the effect of walking 4.5 km in an hour on mouth-to-cecum transit time. Twenty-three healthy volunteers, 9 men and 14 women, with an age range of 19-28 yr, were studied. After an overnight fast, the subjects ingested 10 g of lactulose in 150 ml of water while breath hydrogen concentrations were analyzed at 15-min intervals. On separate days, in random sequence, subjects either sat in a chair or walked on a treadmill for 60 min. Mean transit time was 55 +/- 8 min when resting and 89 +/- 4 min when exercising (p less than 0.001). In conclusion, light aerobic exercise prolonged the mouth-to-cecum transit time. On the basis of this observation, exercise as a causative factor in runner's diarrhea and its value in the management of chronic constipation may be questioned.

Effect of gastric bubble as a weight reduction device: a controlled, crossover study.

In spite of the widespread use of the Garren-Edwards gastric bubble as an adjuvant device in weight reduction, its efficacy has not been established. Therefore, our purpose was to conduct a randomized, double-blind, crossover study of this device in the management of exogenous obesity. The study group consisted of 23 patients, 21 women and 2 men, ranging in age from 21 to 53 yr. Patients were 25%-111% above their ideal body weight. They were studied for 24 wk, consisting of two separate 12-wk evaluation periods. Patients were randomly assigned either to receive the gastric bubble or to have a sham procedure. After the first 12-wk evaluation period, the gastric bubble and sham were administered in crossover fashion, so that those who had received the gastric bubble initially received the sham later and vice versa. The study coordinator remained blind to the kind of treatment, weighed each patient biweekly, enforced dietary counseling, and provided behavior modification. Those who had passed or were found to have a deflated bubble at the end of the treatment period were excluded from the study. Mean weight reduction in the two evaluation periods did not differ significantly. Patients lost 5.4 +/- 1.7 kg (mean +/- SE) during the gastric bubble period and 5.20 +/- 0.8 kg during the sham period. The order of administration of the gastric bubble and sham did not significantly affect the result. The time-course of mean biweekly values, however, revealed that with the gastric bubble, weight loss was significantly greater only during first (p less than 0.005) and second (p less than 0.025) 2-wk evaluation periods. This difference, however, disappeared after the initial 4 wk of treatment. These observations suggest that although gastric bubble implantation reduced weight significantly more than the sham procedure initially, the mean weight loss during 12 wk of evaluation was not different between the two periods. In our opinion, the gastric bubble is of no value as an adjuvant device in weight reduction.

Effect of anger on colon motor and myoelectric activity in irritable bowel syndrome.

The present investigation was designed to study the effect of anger on colon motor and myoelectric activity in irritable bowel syndrome. Patients with irritable bowel syndrome were compared with normal controls during resting and two anger stressors: criticism of performance on an intelligence test and during a delay of assistance for a diagnostic procedure. At rest patients with irritable bowel syndrome had higher motor and spike potential activity than normal subjects; however, the difference was only significant for spike activity. Anger significantly increased colon motor and spike potential activity in the groups compared with the resting state. Patients with irritable bowel syndrome produced significantly higher motor and spike potential activity when angered. They also reported themselves to be more hostile and appeared angrier than normal controls after the study. However, they did not report themselves to be more anxious or depressed, suggesting that the observed changes in colonic function of both groups were due to anger. Patients with irritable bowel syndrome scored significantly higher than controls on the Minnesota Multiphasic Personality Inventory scales of hypochondriasis, hysteria, and depression, but these personality factors did not significantly influence their anger level before the study. The results are discussed in terms of the role of learning in the colon and the abnormal reinforcement of bowel behavior in patients with irritable bowel syndrome.

Impact of neodecortication on colon motor response to a meal in the rat.

The colon motor response to a meal consisting of 100 mM of sodium oleate was assessed before and after neodecortication in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low-compliance perfusion system. A motility index took into account the amplitude, duration, and frequency of contractions. Neodecortication increased the motility index of the distal colon in the fasting state. However, removal of the cerebral cortex did not affect significantly the colon motor response to a meal. Meal stimulation increased the motility index before and after neodecortication. These findings suggest that resting colonic motor activity is increased after neodecortication, probably through the loss of an inhibitory influence of the central nervous system; and the cerebral cortex is not required for the colon response to a meal in the rat.