Hooshang Meshkinpour

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.

The effect of stress on colon motor and electrical activity in irritable bowel syndrome.

&NA; The present investigation was designed to study the role of stress on the physiologic mechanisms of the colon in irritable bowel syndrome (IBS). Patients with IBS were compared with normal controls during resting and stress (mental arithmetic, cold pressor, and fear stressor). The results indicated that IBS patients had significantly higher motor activity than normals in the resting state but did not differ from them in the mean dominant frequency of the basal electrical rhythm (BER) or the proportion of the time they had 2‐4 cycles per minute (cpm) slow‐wave activity. Stress significantly increased motor activity in both groups although they did not differ significantly from each other during stress. Stress increased the proportion of 2‐4 cpm slow‐wave activity in IBS patients, but decreased in the controls. The type of stressor, however, did not influence either motor or electrical activity. Although IBS patients were significantly older than the controls and scored higher on the MMPI scales of Hypochondriasis, Hysteria, and Depression, these factors did not significantly influence differences in motor or electrical activity between the groups. The results are discussed in terms of the role of learning in the colon.

Effects of regular exercise in management of chronic idiopathic constipation.

Regular physical exercise has long beenconsidered in the management of chronic constipation.This recommendation is probably based on the assumptionthat exercise shortens the transit time through the gastrointestinal tract. However, on the basisof previous studies, the effect of exercise on thetransit remains controversial at best. Therefore, it wasthe goal of the present study to assess the influence of regular physical exercise, what averagepeople may consider routine exercise, in the managementof chronic idiopathic constipation. The study populationconsisted of eight patients, seven women and a man, with chronic idiopathic constipation. Theywere studied for six weeks, including two weeks of restand four weeks of regular exercise. Patients had asubmaximal exercise test, before and after the exercise period, to determine their rate ofperceived exertion (RPE), the target heart rate, and theintensity of exercise they can perform. In addition totheir routine daily activities, they exercised 1 hr a day, five days a week according to theirperformance at the initial exercise tolerance test. Theykept a daily activity log and maintained their normaldietary intake during this period. The patients overall physical activity was assessed by apedometer. They also maintained a diary of the numberand consistency of their bowel movements and the amountof straining required for defecation. The impact of exercise on constipation was assessed byutilizing an index that took into consideration allthree parameters of bowel function. Results of the studyrevealed that patients covered 1.8 ± 0.33 and3.24 ± 0.28 miles/day in the rest period andduring the exercise period, respectively (P = 0.007).The intensity of exercise may have improved the level oftraining as reflected on the mean maximum time before and after exercise period (P = 0.039). Thislevel of exercise did not improve their constipationindices, 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 extentthat people consider “regular exercise,”does not play a role in the management of chronicidiopathic constipation.

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.

Colonic Dysfunction in Multiple Sclerosis

Multiple sclerosis is a central nervous system disease frequently accompanied by urinary symptoms and severe constipation. In order to investigate the pathophysiology of these symptoms, we studied colonic motor and myoelectrical activity, as well as colonic volume-pressure relationships (colonometrograms) and have correlated these data with cystometry and electrophysiologic studies of the central and peripheral somatosensory nervous system. The study group consisted of 7 patients with advanced multiple sclerosis marked by symptoms and signs of somatic and visceral nervous system dysfunction including severe constipation. Ten normal volunteers served as control subjects. The multiple sclerosis group demonstrated electrophysiologic evidence of lesions in the somatosensory neuroaxis central to the lumbosacral spinal cord. Abnormal cystometrograms suggested visceral central nervous system dysfunction. Colonometrograms in the multiple sclerosis group demonstrated a more rapid pressure rise than in the control group (p less than 0.01). The multiple sclerosis group failed to demonstrate the postprandial increase in colonic motor and myoelectrical activity observed in the control group (p less than 0.01). Abnormal colonometrograms and absent postprandial colonic motor and myoelectric responses may be features of visceral neuropathy in patients with advanced multiple sclerosis and severe constipation.

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.

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 leas 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. Moreover, presence of objective findings suggestive of a compromised biliary emptying significantly increases the diagnostic yield of manometry. In our opinion, these criteria must be utilized for selection of the patients for sphincter of Oddi manometry.

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.

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 runners diarrhea and its value in the management of chronic constipation may be questioned.

Effect of Secretin and Cholecystokinin on the Transport of Electrolyte and Water in Human Jejunum

The effect of natural porcine secretin and cholecystokinin on the transport of electrolytes and water in human jejunum was studied in eight normal volunteers utilizing a triple lumen tube technique of perfusion. These hormones were observed to inhibit significantly (P