Distinctive motor responses to human acute salmonellosis in the jejunum and ileum

Given the differences that normally exist in jejunal and Heal motility patterns, we wished to determine whether these regions respond differently to acute enteric infections. In 10 patients with acute gastroenteritis induced by Salmonella infection and 12 healthy individuals jejunal and Heal motility was recorded at eight equidistant sites by a manometric system for 6 h during fasting. All were healthy individuals, but only three of 10 patients exhibited the cyclic inter digestive motor complex; 82 ± 9 min duration in healthy individuals (mean ± SE). In the jejenum, patients exhibited short bursts of intense activity (6.3 ± 1.6 bursts/subject in patients vs. 1.8 ± 0.5 in controls; P < 0.05); burst activity was scarce in the ileum. In contrast to healthy subjects, patients exhibited prolonged periods (64 ± 3 min duration) of Heal motor quiescence, that accounted for 32 ± 11% of recording time; such silent periods were not observed in the jejunum. Prolonged propagated ileal contractions were observed only in two healthy subjects, but in seven out of 10 patients. These data indicate that acute Salmonella infection magnifies the motor differences between the jejunum and the ileum; both regions generate aberrant and markedly different dysmotility patterns.     

Ambulatory long-term jejunal manometry in diabetic patients with cardiac autonomic neuropathy

Concerning alteration of small bowel motility in diabetic patients with autonomic neuropathy controversial data were obtained with stationary manometry and over a limited period of time. The aim of our study was to examine ambulatory 24 h jejunal motility in 15 diabetic patients with cardiac autonomic neuropathy compared with data obtained in 50 healthy controls. Twenty-four hour motility was recorded in the proximal jejunum with a portable datalogger and tube-mounted miniature pressure sensors. Diurnal and nocturnal fasting motility and the motor response to a standardized evening meal of 600 kcal were evaluated by visual and computer-aided analysis. The following abnormalities were found during fasting motility (n = number of patients): absence of phase III over 24 h (n = 2), retrograde migration or simultaneous occurrence of phase III (n = 5). During postprandial motility irregular bursts with tonic baseline elevation (n = 3) and contraction frequencies below the range of controls (n = 8) occurred. Furthermore patients exhibited an inversion of the normal relationship between phase I and phase II during nocturnal MMC – cycles, and discrete clustered contractions were diminished (P < 0.01) in the fasting and digestive state. All patients showed at least one abnormal manometric finding. We conclude that small bowel motility in diabetic autonomic neuropathy is characterized by disturbances in the generation and aboral migration of phase III, an altered circadian variability of the MMC cycle and by postprandial hypomotility.     

Dysmotility of the small intestine in achalasia

During recent years there has been increasing evidence for extraoesophageal dysfunction in achalasia. The aim was to investigate whether motility of the small intestine is abnormal in achalasia. Thirteen patients (eight men, five women) aged 52 (33-85) years were studied. They had all previously undergone treatment with pneumatic balloon dilatation and were free of dysphagia when examined. Ambulatory 24-h motility was recorded in the upper jejunum under standardized caloric intake with a digital datalogger and catheter-mounted pressure transducers located beyond the ligament of Treitz. Visual analysis was performed by two observers and data underwent quantitative analysis of phasic contractile events using a computer program. Normal values were obtained from 50 healthy controls. In the fasting state, a complete loss of cyclic MMC activity (n = 2), an abnormally prolonged phase II (n = 2) and disturbances in the aboral migration of phase III (n = 5) were observed. Postprandial motor response was absent (n = 2) or frequently showed a contraction frequency below the normal range (n = 5). Further abnormalities consisted in hypomotility during phase II (n = 3) and in a reduced frequency of migrating clustered contractions in the fasting (n = 2) or postprandial state (n = 2). In addition, motor events not present in any healthy subject, giant migrating contractions (n = 5), retrograde clustered contractions (n = 6) and repetitive retrograde contractions (n = 3) were identified. Each patient exhibited findings out of the range of normal. Dysmotility of the proximal small intestine is present in achalasia.     

The effect of osmolarity and caloric load on small bowel motility

Background Although there is profound knowledge about cyclic fasting motility, the postprandial intestinal motor response is not well investigated. It is intriguing to speculate that nutrient composition alters small bowel motility significantly and, in a clinical setting, may account for adverse gastrointestinal symptoms in enteral nutrition (EN). We aimed to assess the impact of different caloric loads and osmolarities of EN on human jejunal motility. Methods Sixteen healthy subjects underwent a series of duodenal infusions of EN solutions, either with iso‐osmolar solution with different caloric loads (1.32, 2.64, or 3.96 kcal min^?1), or with solutions of different osmolarities with constant caloric loads (300, 600, or 1200 mosmol). Jejunal solid‐state manometry was analyzed over 90 min both visually and using dedicated computer software. Key Results All tested nutrient solutions were able to trigger conversion to a postprandial jejunal motility pattern after a mean lag phase of 9.4 + 2.3 min (P = NS between different nutrient solutions). Different caloric loads did not result in significant differences in small bowel motility. However, increasing osmolarities caused a significant inhibition of contractile and propagative activity. Conclusions & Inferences Small bowel motility under duodenal infusion of nutrient solutions is not influenced by caloric load in a physiological range, whereas high osmolarities inhibit small bowel motility.     

Motility of the oesophagus and small bowel in adults treated for Hirschsprung’s disease during early childhood

Background Dysmotility of the upper gastrointestinal (GI) tract has been reported in children with Hirschsprung’s disease (HD). In the present study, motility of the oesophagus and the small bowel was studied in adults treated for HD during early childhood to elucidate whether there are alterations in motility of the upper GI tract in this patient group. [Correction added after online publication 15 Sep: The preceding sentence has been rephrased for better clarity.] Methods Ambulatory small bowel manometry with recording sites in duodenum/jejunum was performed in 16 adult patients with surgically treated HD and 17 healthy controls. In addition, oesophageal manometry was performed with station pull‐through technique. Key Results The essential patterns of small bowel motility were recognized in all patients and controls. During fasting, phase III of the migrating motor complex (MMC) was more prominent in patients with HD than in controls when accounting for duration and propagation velocity (P = 0.006). Phase I of the MMC was of shorter duration (P = 0.008), and phase II tended to be of longer duration (P = 0.05) in the patients. During daytime fasting, propagated clustered contractions (PCCs) were more frequent in the patients (P = 0.01). Postprandially, the patients demonstrated a higher contractile frequency (P = 0.02), a shorter duration of contractions (P = 0.008) and more frequent PCCs (P < 0.001). The patients had normal oesophageal motility. Conclusions & Inferences This study demonstrates that adult patients with HD have preserved essential patterns of oesophageal and small bowel motility. However, abnormalities mainly characterized by increased contractile activity of the small bowel during fasting and postprandially are evident. These findings indicate alterations in neuronal control of motility and persistent involvement of the upper GI tract in this disease.     

Factors in the Control of Interdigestive and Postprandial Myoelectric Patterns of Canine Jejunoileum: Role of Extrinsic and Intrinsic Nerves

Our aim was to determine the roles of extrinsic and intrinsic (enteric) neural continuity to the jejunoileum in control of postprandial and fasting motility patterns. Four groups of dogs were prepared: control, neurally intact; intrinsic transection, distal duodenal transection to disrupt intrinsic myoneural continuity with jejunum; extrinsic transection, transection of all extrinsic nerves to jejunoileum; and intrinsic/extrinsic transection, disruption of both intrinsic myoneural and extrinsic neural continuity to jejunoileum. Duodenal and jejunal electrodes were placed to monitor motility. After 2 weeks, the dogs were studied while fasting, after meals, and during intravenous infusions of cholecystokinin octapeptide at 0.5μg/(kg · h) and pentagastrin at 2μg/(kg · h). During fasting, although the migrating motor complex (MMC) occurred in each region, coordination between duodenum and jejunoileum was disrupted in intrinsic/extrinsic transection dogs, but only partially in intrinsic transection dogs. Small meals (50 g of liver) interrupted the duodenal MMC in all groups and the jejunoileal MMC only in control dogs. A larger (500-g) meal disrupted the MMC in both regions for comparable durations in all groups. Cholecystokinin octapeptide and pentagastrin inhibited the MMC in duodenum and jejunoileum in all groups. Both intrinsic myoneural and extrinsic neural continuity play a role in regional coordination of interdigestive and digestive gut motility. Both hormonal and neural factors (central, enteric) participate in the regulation of onset of postprandial motor patterns.     

Effects of ileal bile salts on fasting small intestinal and gallbladder motility

In the fasting state, gallbladder emptying is related to phase III of the intestinal migrating motor complex. The effects of ileal infusion of mixed taurocholate-phospholipid micelles on fasting small intestinal motility (by a 17-channel catheter with side holes located in duodenum, jejunum and ileum) and gallbladder motility (by ultrasound) were investigated in eight healthy volunteers. After bile salt depletion by cholestyramine, 0.9% NaCl or mixed micelles were infused in the ileum during phase II of the migrating motor complex. Time to onset of subsequent phase III was significantly shorter after infusion of mixed micelles compared with 0.9% NaCl (32 +/- 5 min vs. 60 +/- 5 min, P = 0.01). Distal to the infusion port, numbers of pressure waves and their amplitudes were significantly lower during bile salt infusion compared with 15 min before infusion (11 +/- 6 per 15 min vs. 21 +/- 8 per 15 min, and 2.4 +/- 0.6 kPa vs. 2.8 +/- 0.5 kPa, respectively). Micellar infusions increased fasting gallbladder volumes to 170 +/- 5% of starting volumes (P < 0.0001). In conclusion, ileal infusion of mixed micelles influences the timing of phase III of the intestinal migrating motor complex, inhibits ileal motility and increases fasting gallbladder volumes. These findings may have important consequences for enterohepatic circulation of bile salts.     

Sham feeding disrupts phase III of the duodenal migrating motor complex in humans

The role of the vagus nerve in the control of the intestinal migrating motor complex (MMC) is unclear. This study aimed to evaluate the effect of physiological vagal stimulation with sham feeding on phase III of the MMC. Antroduodenal motility was recorded in six healthy volunteers. The first phase III was used as a control, and sham feeding was performed during the second phase III. The MMC was disrupted within 1.5 ± 0.4 min of sham feeding and its duration was shorter than the control phase III. Phase III propagation was inhibited in all subjects, most of them exhibiting no propagation beyond the third duodenal recording site. During sham feeding, the antrum exhibited transient phasic contractions in five out of six subjects. The duodenal motility index recorded for up to 30 min after the onset of the sham feeding was unchanged in five out of six subjects. We conclude that sham feeding consistently interrupted phase III of the duodenal MMC and induced antral contractions, but failed to provoke significant motor events in the duodenum.     

Intestinal and colonic motor alterations associated with irradiation-induced diarrhoea in rats

Localized application of ionizing radiation to the gastrointestinal tract frequently elicits responses, which include diarrhoea. The origin of this symptom is not clear but has been attributed to loss of epithelial integrity, together with alterations in motility and increased secretion. The purpose of this study was to examine whether a 10 Gy abdominal gamma irradiation leads to an inflammatory reaction, and to compare intestinal and colonic motility in controls and abdominally irradiated rats 1, 3 and 7 days after irradiation, using an electromyographic technique. The motility parameters analysed were the frequency and velocity of propagation of migrating myoelectric complexes (MMC) in the jejunum and colonic spike activity (long spike bursts; LSB) per 10 min in fasted rats. The MMC frequency was significantly reduced on days 1 and 7 after irradiation and the MMC pattern was markedly disrupted on day 3. The frequency of colonic LSB was significantly reduced on days 1, 3 and 7. Mouth to anus transit was significantly accelerated on day 3 only and diarrhoea was observed at this time. Myeloperoxidase activity in the jejunum and colon was also increased on this day only. It is concluded that irradiation-induced diarrhoea occurs contemporaneously with disruption of MMC in the small intestine.     

Small bowel motility in functional chronic constipation

Abstract  In functional constipation, three pathophysiological subgroups have been identified: slow-transit constipation (STC); normal-transit constipation (NTC) and outlet delay (OD). Extracolonic manifestations, especially disturbed small bowel motility, are well known to occur in STC, but have rarely been studied in NTC and OD. To perform 24-h-ambulatory jejunal manometry in a large prospective series of clinical patients with chronic constipation of all subtypes. A total of 61 consecutive patients, referred to our tertiary gastroenterologic centre for chronic constipation (48 female, 13 male; mean age 57 (range 20–87) years), underwent jejunal 24-h-ambulatory manometry (standardized meal) after a transit-time study (radio-opaque markers), anorectal manometry, defecography and colonoscopy. Computerized and visual analysis by two independent observers was compared with the normal range of manometric variables, defined by data previously obtained in 50 healthy subjects (Gut 1996;38:859). Five patients were excluded from the study because of coexistence of OD and STC. No patient with OD ( n  = 8), but all patients with STC ( n  = 32) and 94% of patients with NTC ( n  = 16) showed small bowel motor abnormalities; both in postprandial response and fasting motility. The abnormal findings ranged from severe disturbances with complete loss of MMC to subtle changes of contraction parameters that could only be assessed by computerized analysis. No significant differences between STC- and NTC-patients were found. Most findings pointed to an underlying enteric neuropathy. Intestinal prolonged-ambulatory manometry adds valuable information to the pathophysiologic understanding of functional chronic constipation of STC- and NTC-type, however there are no distinct manometric features to differentiate between both.     

Inhibition of the migrating motor complex by duodenal drainage in man

Abstract The effect of varying bile acid output on fasting small intestinal motility was investigated in healthy male volunteers. Biliary output was manipulated by jejunal infusion of isotonic mannitol, which resulted in increased output, and by prolonged drainage of duodenal contents, which resulted in decreased output. Intestinal motility was measured by manometric recordings performed at four levels in the proximal small intestine. A marker dilution technique was used to measure pancreatico-biliary output. There were three experimental groups: duodenal drainage, non-drainage and control. Both duodenal drainage and non-drainage groups underwent jejunal saline infusion, followed by mannitol infusion. The control group did not receive drainage or infusions. In the drainage group, 0.41 (0.13-0.68) activity fronts of the migrating motor complex (MMC) per hour were recorded during saline infusion, but only 0.06 (0-0.19) activity fronts per hour were observed during mannitol infusion. In the nondrainage group, 0.71 (0.61-0.81) activity fronts per hour were observed during saline infusion and 0.50 (0.18-0.82) activity fronts per hour were recorded during mannitol infusion. In the control group, 0.58 (0.33–0.84) activity fronts per hour were recorded during the first 4-h session and 0.58 (0.45-0.71) activity fronts per hour during the second session. There was no difference between the number of activity fronts per hour observed in the control group and those observed in the saline infusion of the drainage group. In contrast, there was a significant decrease in the number of activity fronts per hour in the drainage group during mannitol infusion, compared to both non-drainage group during mannitol infusion (P < 0.01) and controls (P < 0.05). In conclusion, decreased biliary output caused by duodenal drainage in combination with mannitol infusion is associated with inhibition of the cyclic activity of MMC in the proximal small intestine in man.     

Effects of enteral infusion of nutrients on canine intestinal motor-patterns

Little is known on the effects of enteral nutrition on intestinal motor patterns. In dogs, intestinal motility was recorded with multiple extra-luminal strain-gauges. An elemental diet was infused into the jejunum (0.5–2.5 kcal min^?1) over 6 h. The elemental diet or dog food were also administered orally for comparison. Jejunal infusion of the elemental diet stimulated jejunal motility; the motor pattern was characterized by clustered contractions. During enteral feeding, stimulation of jejunal motility was initially less (lower motility index, lower incidence of contraction waves and shorter spread of contractions) compared with oral feeding. Jejunal motility declined linearly with time, the decline being less profound during enteral than after oral feeding. Linear correlations also existed between motility parameters and energy loads; increasing energy loads produced reduction instead of enhancement of motility. Strong inhibition of motility followed by vomiting occurred with energy loads ≥ 2 kcal min^?1. The following conclusions were reached: (a) jejunal feeding evoked different patterns of jejunal motility compared with oral feeding; (b) jejunal motility was the result of both a local stimulation and an inhibitory feedback mechanism; (c) intestinal overload of nutrients was indicated by marked inhibition of motility. These results indicate that recording of motility during enteral nutrition might be a useful diagnostic tool for predicting gastrointestinal sequelae.     

Gastric motor disturbances in patients with idiopathic rapid gastric emptying

Background The mechanisms of ‘idiopathic’ rapid gastric emptying, which are associated with functional dyspepsia and functional diarrhea, are not understood. Our hypotheses were that increased gastric motility and reduced postprandial gastric accommodation contribute to rapid gastric emptying. Methods Fasting and postprandial (300 kcal nutrient meal) gastric volumes were measured by magnetic resonance imaging (MRI) in 20 healthy people and 17 with functional dyspepsia; seven had normal and 10 had rapid gastric emptying. In 17 healthy people and patients, contractility was analyzed by spectral analysis of a time‐series of gastric cross‐sectional areas. Logistic regression models analyzed whether contractile parameters, fasting volume, and postprandial volume change could discriminate between health and patients with normal or rapid gastric emptying. Key Results While upper gastrointestinal symptoms were comparable, patients with rapid emptying had a higher (P = 0.002) body mass index than normal gastric emptying. MRI visualized propagating contractions at ～3 cpm in healthy people and patients. Compared with controls (0.32 ± 0.04, Mean ± SEM), the amplitude of gastric contractions in the entire stomach was higher (OR 4.1, 95% CI 1.2–14.0) in patients with rapid (0.48 ± 0.06), but not normal gastric emptying (0.20 ± 0.06). Similar differences were observed in the distal stomach. However, the propagation velocity, fasting gastric volume, and the postprandial volume change were not significantly different between patients and controls. Conclusions & Inferences MRI provides a non‐invasive and refined assessment of gastric volumes and contractility in humans. Increased gastric contractility may contribute to rapid gastric emptying in functional dyspepsia.     

Ileal manometry in children following ileostomies and pull-through operations

Our aim was to analyse the patterns of ileal contractions in children. We reviewed the charts of 23 children who had ileal manometry studies (16 males), mean age 7 years (range 2 months to 17 years). We positioned the manometry catheters with 4-8 recording sites, 5 or 15 cm apart, through ileostomies fashioned for clinically indicated reasons. We studied six additional children with persistent faecal soiling following endorectal pull through for Hirschsprung's disease; the catheters were positioned through the anus and colon into the ileum. We recorded phasic and tonic intermittent contractions in all the subjects, clustered contractions (rate 5-9 min-1, duration 20-120 s) in 19 subjects with ileostomies and four with endorectal pull throughs. In 13 children there were prolonged propagated contractions, > 60 mmHg in amplitude, > 15 s in duration, propagating at rates of 2-6 cm s-1 over at least 20 cm. The migrating motor complex was rare; in 55 h of fasting recording there were two phase III sequences. There are four distinctive features of ileal manometry recordings in children: random intermittent contractions, clustered contractions, prolonged propagated contractions and tonic contractions. The features of ileal motility differ from motility in the proximal small bowel.     

Oxyntomodulin and glicentin are potent inhibitors of the fed motility pattern in small intestine

Glicentin (GLIC) and oxyntomodulin (OXM or GLIC 33-69) are gut hormones which regulate digestion. They are known to reduce digestive secretions and to delay gastric emptying. Their biological activities on intestinal motility are still unknown. The effect of a systemic GLIC or OXM increase was investigated in rats on the food intake, the postprandial myoelectrical activity of small intestine and the orocaecal transit. An OXM or GLIC i.v. infusion was applied during the 5 min preceding food onset and during the first 15 min of food intake. This determined a three- to fourfold increase of the preprandial OXM-GLIC level. The OXM or GLIC plasma increase did not modify food intake. OXM infusion slowed down gastric emptying when the stomach contained 3/4 of the ingested food (before T 3 h). The quantity of food delivered in jejunum was subsequently smaller (P < 0.05). In the small intestine, the duration of postprandial myoelectrical activity (50-60 min g(-1) of ingested food) was reduced by 70% (P < 0.001) on duodenum or jejunum and by 54% (P < 0.01) on ileum in OXM-treated rats. An interdigestive motility profile was settled and an acceleration of both gastric emptying and transit rate was thereafter evidenced (after T 3 h). GLIC also reduced the duration of the postprandial myoelectrical activity on duodenum and jejunum (65 and 63% respectively, P < 0.05), but was not as efficient as OXM on ileum. In pathological states such as acute adult gastroenteritis, OXM and GLIC exhibit a two- to fivefold increase in their plasma concentrations. The present findings suggest that OXM and GLIC could, in that disease, contribute to exclude pathogens, due to their joined action on gut motility.     

MMC-related duodenojejunal antegrade and retrograde peristalsis in humans

Abstract According to recent manometric studies the last part of phase III of the migrating motor complex (MMC) shows the features of a retroperistaltic pump in the proximal duodenum in most healthy humans. In the present study, individual contractions in phase II and phase III of the MMC were investigated in ten healthy subjects (four males, six females), focusing on the distal duodenum and the jejunum. Motility was recorded on two different days with eight-channel catheters. On one day a standard antroduodenojejunal fasting recording was performed for 5 h, allowing detailed analysis of pressure waves in the proximal duodenum. On another day a two-station measurement was performed in the proximal jejunum and the distal duodenum. The propagated pressure waves were analysed for late phase II (last 30 min) and for the first and the last part (I min) of phase III in the three intestinal segments. Antegrade peristalsis predominated at all levels in phase II and in the first part of phase III. In contrast, 84 ± 11% of all propagated contractions were retrograde in the last part of phase III in the proximal duodenum and 75 ± 16% in the distal duodenum. The proportions of retrograde contractions in early phase III and in late phase III differed significantly, from 11 ± 11% to 84 ± 11% and from 32 ± 16% to 75 ± 16% in the proximal and distal duodenum, respectively (P < 0.01 and P < 0.05). In the proximal jejunum such retroperistalsis was not observed, neither in the beginning nor at the end of phase III. In phase II the proportions of retrograde pressure waves were small (3–10%) in the three segments studied. The migration velocity of the pressure waves showed a gradient in this phase, with the lowest values in the jejunum. It is concluded that the last part of phase III shows the pressure pattern of a retroperistaltic pump through out the duodenum. In contrast, no distinct MMC-related retroperistalsis was observed in the jejunum.     

CCK8 neurons of the ventromedial (VMH) hypothalamus mediate the upper gut motor changes associated with feeding in rats

The effect of microinfusions of cholecystokinin octapeptide (CCK8) and its antagonist L364,718 on duodenal and jejunal motility were evaluated by electromyography in fasted and fed rats. The rats were chronically fitted with electrodes implanted on the duodeno-jejunal wall. Steel cannulas were placed bilaterally in either the ventromedial (VMH) and lateral (LHA) hypothalamus. In 8 h fasted rats, microinfusion of CCK8 (1 ng/kg) into the VMH disrupted the migrating myoelectric complex (MMC) and replaced it by irregular spiking activity for 45.0 +/- 4.9 min at the duodenal level without affecting the jejunal MMC pattern. The duration of these effects were dose-related between 1 and 50 ng/kg. When injected into the LHA at 1, 10 or 50 ng/kg, CCK8 had no effect on either duodenal or jejunal motility. When infused bilaterally into the VMH 10 min before feeding, L364,718 (1 or 10 micrograms/kg) significantly reduced the duration of the postprandial disruption of MMCs by 29.1% and 35.9%, respectively, in the duodenum but not the jejunum (P less than 0.05). Infused into the LHA at similar and higher dosages (1 and 10 micrograms/kg) L364,718 had no effect on the duration of the duodeno-jejunal fed pattern. These results suggest that, in rats, (i) CCK8 is involved in the maintenance of the typical postprandial disruption of duodenal MMCs observed after a meal, and (ii) these effects are selectively mediated through CCK8 receptors located in the ventromedial hypothalamic nuclei.     

Elevated motility-related transmucosal potential difference in the upper small intestine in the irritable bowel syndrome

The pathophysiology of irritable bowel syndrome (IBS) is complex and incompletely known. Very little has been studied regarding the role of submucous neuronal activity. We therefore measured small intestinal transmural potential difference (PD, reflecting mainly electrogenic chloride secretion), and its linkage with fasting motor activity [migrating motor complex (MMC)] in controls (n = 16) and patients with IBS [n = 23, 14 diarrhoea predominant (d-IBS) and nine constipation predominant (c-IBS)]. Transmural-PD and its relation to MMC phase III was measured by modified multilumen manometry for 3 h in the fasting state using one jejunal and one duodenal infusion line as flowing electrodes. The amplitude and duration of motor phase III was similar in controls and IBS patients, but the propagation speed of phase III was higher in IBS patients. In IBS patients, maximal PD during MMC phase III was significantly elevated in both the duodenum and jejunum (P < 0.05) and the PD decline after phase III was significantly prolonged in the jejunum (P < 0.01). The PD elevation was seen in both duodenum and jejunum in d-IBS patients, but only in the jejunum in the c-IBS patients. On the basis of previous modelling studies, we propose that the enhanced secretion may reflect disturbed enteric network behaviour in some patients with IBS.     

Vagal control of fasting somatostatin levels

Abstract The relationship between fasting intestinal motility, plasma concentration of somatostatin and vagal integrity was examined in four conscious dogs. Small intestinal motility was recorded using subserosally implanted bipolar electrodes. The cervical vagosympathetic trunks, previously isolated in skin loops, were blocked by cooling. In the fasted state, peaks in somatostatin concentration were observed during phase III of the migrating myoelectric complex (MMC). During vagal blockade, small intestinal MM***Cs persisted but with phase II being absent or decreased in duration in the duodenum and upper jejunum. Somatostatin levels significantly decreased to below the basal levels observed prior to blockade. No cycling of somatostatin levels was evident during the period of vagal blockade. Upon termination of vagal cooling, normal motility returned and somatostatin levels returned to their pre-blockade levels. In conclusion: (1) plasma somatostatin levels cycle with phase III of the MMC in the upper small intestine; (2) the cycling of fasting somatostatin concentrations is primarily dependent upon intact vagal pathways; and (3) basal plasma somatostatin levels are in part vagally dependent.     

Gastrointestinal motor activity associated with postoperative ileus and emesis

The gastrointestinal motor activity associated with post-operative ileus and emesis has not been fully elucidated. This study has evaluated gastric and small-bowel motility in six patients before and after cholecystectomy and in six healthy volunteers, by solid-state manometry. Nausea and vomiting were recorded post-operatively. After surgery, fasting motor abnormalities including (a) total gastric quiescence and (b) small-bowel ‘phasic-bursts’ of contractions were observed in all patients. Phasic bursts (PB) resembled phase III of the migrating motor complex (MMC) on initial visual inspection, but further analysis revealed that they were of shorter duration (3.4 ±.2 min [PB] vs 6.4 ± 0.8 min [MMC], [mean ± SEM] P < 0.01), lower contraction frequency (6.4 ± 0.1 contractions min ^?1 [PBj vs 10 ± 0.3 contractions min^?1 [MMC] [mean ± SEM] P < 0.01) and shorter periodicity (36.4 ± 3 min [PB] vs 70.0 ± 6 min [MMC] [mean ± SEM] P < 0.01). Four patients experienced nausea during phasic burst activity. Vomiting was only observed in association with retrograde phasic-bursts, which migrated through the duodenum to the stomach. This study has shown consistent gastrointestinal motor abnormalities in the immediate post-operative state.