Small Bowel Dysmotility in Patients with Postcholecystectomy Sphincter of Oddi Dysfunction

Postcholecystectomy patients (N = 27) withsevere recurrent biliary-like pain who had no evidenceof organic disease were subdivided into those with andthose without objective evidence of sphincter of Oddi dysfunction (SOD) based on two separatecriteria: (1) clinical criteria — elevated liverfunction tests and/or amylase with pain, and/or adilated bile duct, and/or delayed drainage at ERCP (N =14, SOD classes I and II); and (2) abnormal biliary manometry(N = 19). Prolonged (24–48 hr) ambulant recordingof duodenojejunal motor activity was performed in allpatients and interdigestive small bowel motor activity compared between patient subgroups and ahealthy control group. Phase II motor abnormality wasmore frequent in patients with, compared to thosewithout, objective clinical criteria of SOD (7/14 vs0/13, P = 0.003). Phase III abnormality also tendedto be more frequent in these patients (7/14 vs 2/13, P= 0.06). In addition, both phase III (P = 0.03) andphase II (P = 0.03) motility index (MI) was higher inpatients with sphincter dyskinesia compared to controls;phase II MI was also higher in patients with sphincterstenosis (P = 0.005). Disturbances of small bowelinterdigestive motor activity are more prevalent in postcholecystectomy patients with, compared tothose without, objective evidence of SOD, and especiallyin patients with SO dyskinesia. Postcholecystectomy SODin some patients may thus represent a component of a more generalized intestinal motordisorder.     

Effect of Viscous Fiber (Guar) on Postprandial Motor Activity in Human Small Bowel

Both caloric value and chemical composition ofa meal have been shown to regulate postprandial smallbowel motility in dog. In the same species, duration ofand contractile activity within the postprandial period also depends on mean viscosity. It isunknown, however, whether meal viscosity and fibercontent also regulate small bowel motor activity in man.In human volunteers, we therefore studied the effect of guar gum on small bowel motor response toliquid and solid meals. Twenty-six prolonged ambulatorysmall bowel manometry studies were performed in 12volunteers. A total of 620 hr of recording were analyzed visually for phase III of the MMC and avalidated computer program calculated the incidence andamplitude of contractions after ingestion of water (300ml), a pure glucose drink (300 ml/330 kcal) or a solid meal (530 kcal) with and without 5 g of guargum. Addition of 5 g of guar gum did not significantlydelay reappearance of phase III after ingestion of water(59 ± 11 vs 106 ± 21 min; P = 0.09).However, guar gum significantly prolonged duration ofpostprandial motility pattern both after the glucosedrink (123 ± 19 vs 199 ± 24 min; P <0.05) and after the solid meal (310 ± 92 vs 419± 22 min; P = 0.005). Contractile activity during these periods was not affected by guargum. This was true for mean incidence of contractionsafter water (1.9 ± 0.3 vs 1.8 ± 0.5min^-1), after the glucose drink (1.6 ±0.4 vs 1.7 ± 0.3 min^-1) and after the solid meal (2.4 ± 0.4 vs 2.6 ±0.4 min^-1). Likewise, mean amplitude ofcontractions was not affected by guar gum after water(22.8 ± 1.4 vs 20.9 ± 1.9 mm Hg), afterthe glucose drink (20.5 ± 1.4 vs 21.3 ±1.2), and after the solid meal (20.3 ± 1.5 vs 21.5± 1.6 mm Hg). Thus a guar gum-induced increase inchyme viscosity markedly prolonged duration ofpostprandial motor activity in the human small bowel.Contractile activity within the postprandial period, however, wasnot affected. We suggest that the postprandial motilitypattern persisted longer after the more viscous meals,because gastric emptying and intestinal transit were delayed by guar gum. We conclude that itis essential to define meal viscosity and fiber contentwhen studying postprandial small bowelmotility.     

Abnormal Vagal Cholinergic Function and Psychological Behaviors in Irritable Bowel Syndrome Patients A Hospital-Based Oriental Study

Irritable bowel syndrome (IBS) patients inWestern countries usually manifest autonomic nervedysfunctions and abnormal psychological behaviors. Thepurpose of this study was to assess whether Oriental IBS patients with predominant bowel symptomsalso exhibited similar abnormalities. We enrolled 40 IBSpatients from the outpatient clinic and 20 controls withnormal daily bowel habit for study. The IBS patients were further divided according totheir predominant bowel habit: 20 wereconstipation-predominant and 20 werediarrheapredominant. Sympathetic function was evaluatedby sympathetic skin response (SSR) while vagal cholinergic function wasdetermined by measuring R-R interval variation (RRIV) inelectrocardiography during rest and deep breathing.Psychological parameters were assessed by scales of the Minnesota Multiphasic Personality Inventory(MMPI) and the Hopkins Symptom Checklist (HSCL-90). IBSpatients, despite their bowel habit, showed normal SSRresponse. RRIV during deep breathing was significantly lower in constipation-predominant IBS patientsthan in controls or diarrhea-predominant IBS patients(16.5 ± 3.1% vs 20.5 ± 4.8% and 21.5± 4.6%, P < 0.001). IBS patients alsoexhibited abnormal MMPI measuring scores on depression, hysteria,paranoia, and masculinity/femininity scales. Inaddition, they also had more severe psychologicaldistress in the items of HSCL-90 measurement. Inconclusion, vagal dysfunction characterizes Orientalconstipation-predominant IBS patients seeking medicalhelp. Abnormal psychoneurotic profiles also exist inthese IBS patients, irrespective of their bowelhabits.     

Colonic motility and gastric emptying in patients with irritable bowel syndrome effect of pretreatment with octylonium bromide

This study was undertaken to evaluate (1) the colonic response to eating for a prolonged time in healthy subjects and patients with the irritable bowel syndrome (IBS); (2) the effect of octylonium bromide, a new smooth muscle relaxant acting by interfering with calcium ion mobilization, on the postprandial colonic motility; and (3) whether chronic gastric stasis could be responsible for both the dyspeptic symptoms often complained of by IBS patients and the faulty colonic response to eating. The colonic response to a 1000-kcal mixed meal in ten healthy subjects was characterized by two transient (from 0 to 60 and from 120 to 150 min postprandially, respectively) increases in colonic motor activity; ten IBS patients showed a continuous postprandial increase in colonic motor activity that was not terminated 180 min after eating. Treatment of IBS patients with octylonium bromide (80 mg, qid,per os) for 5–7 days reduced their colonic response to eating to a very short increase in colonic motor activity limited to the first 30 min. Finally, gastric emptying was not different in the two groups.     

Effect of a tricyclic antidepressant on small intestinal motility in health and diarrhea-predominant irritable bowel syndrome

Antidepressants are used in irritable bowel syndrome (IBS) and may have effects on the gut independent of improving mood. We have investigated the actions of a tricyclic antidepressant on small intestinal motor function in eight healthy volunteers and in six patients with diarrhea-predominant IBS. Fasting ambulatory motility was recorded from six small intestinal sites for 16–18 hr while on no drug (baseline) and while taking imipramine for five days. Orocecal transit time (OCTT) was measured by lactulose hydrogen breath test, during baseline and imipramine administration. Imipramine did not alter migrating motor complex periodicity, but slowed jejunal phase III propagation velocity in controls from 7.5±1.1 to 3.6±0.5 cm/min (P<0.01) and in IBS from 7.8±0.6 to 4.4±0.5 cm/min (P<0.0001). Phase III duration at each site was increased, and total recorded phase III was greater during imipramine than baseline studies. Imipramine increased the amplitude of phase III contractions. There was no effect of imipramine on non-phase-III motility index or discrete clustered contractions. Imipramine prolonged OCTT from 73±6 min to 97±8 min in controls (P<0.05) and from 61±9 min to 89±8 min in IBS (P<0.05). Although OCTT was shorter in this IBS group, no motility differences were seen between controls and IBS. This demonstration that a tricyclic antidepressant can modify small intestinal motor function in health and in IBS supports the view that these drugs may have therapeutic actions in IBS unrelated to mood improvement.This work was supported by the Priory Hospitals Group.     

Gastric antrectomy with selective gastric vagotomy does not influence gallbladder motility during interdigestive and postprandial periods

Fasting gastrointestinal motility and gallbladder motility during the interdigestive state and in the postprandial period was studied in eight patients who were operated for ulcer disease with an antrectomy and selective gastric vagotomy. Nocturnal motility recording revealed all three phases of the migrating motor complex (MMC) in all but one patient, where no phase III activity was recorded. In the rest of the patients 3–10 events with phase III activity were recorded. At scintigraphy ([⁷⁵Se]HCAT) a cyclic gallbladder filling and emptying in relation to the MMC cycle was found. Episodes with emptying were confined to phase II and a total of 13 episodes with a median duration of 25 min (range 10–70 min) were observed. A median of 10.7% (6.1–17.7%) of the gallbladder contents was emptied. In a control group of eight healthy young men the values were 13.5 min (9–36 min) and 6.9% (3.7–31.1%), respectively. These differences were not significant. During the postprandial period, a lag period in gallbladder emptying of median 15 min (5–20 min) was observed when food ingestion took place during phase I of the MMC. Thereafter a gradual emptying occurred with a rate of 0.95%/min (0.71–1.15%/min). In a control group of healthy young males, the lag period was 13.5 min (9–22.5 min) and the emptying rate 0.61%/min (0.08–0.77%/min). When food ingestion occurred during phase II of the MMC, the lag period of gallbladder emptying in the patient group was median 0 min (0–5 min) and the emptying rate was 0.77%/min (0.33–0.86%/min). The values in the control group were 0 min (–9 to 13.5 min) and 0.76%/min (0.54–2.25%/min), respectively. These differences between the patients and controls were not significant. In conclusion, antrectomy and selective gastric vagotomy do not influence fasting gastrointestinal motility or gallbladder motility during the interdigestive state or in the postprandial period.     

Extending Gastric Emptying Scintigraphy from Two to Four Hours Detects More Patients with Gastroparesis

Gastric emptying scintigraphy (GES) is usually performed for up to 2 hr to measure the gastric emptying (GE) of solids. Symptomatic patients, however, may have borderline results at 2 hr, making it difficult to determine whether a gastric motor disorder is present. The aim of this study was to assess whether extending GES to 4 hr is useful in evaluating patients for gastroparesis and to correlate the results of GES with patient symptoms. We studied 129 patients undergoing GES at Temple University Hospital between July 1998 and March 1999. Solid-phase GE was measured at 0, 0.5, 1, 2, 3, and 4 hr after ingestion of a ^99mTc sulfur colloid-labeled egg meal. Dyspeptic symptoms of upper abdominal discomfort, early satiety, postprandial abdominal bloating, nausea, vomiting, and anorexia were graded as none, mild, moderate and severe (0, 1, 2 and 3, respectively) with the sum representing a total symptom score. Of 129 patients, 86 had normal GE at 2 hr; 26 of the 86 normal scans at 2 hr were delayed at 3 hr. Six of the 60 scans normal at 2 and 3 hr were delayed at 4 hr. Of 43 patients with delayed GE at 2 hr, 39 were delayed at 3 hr and 35 were delayed at 4 hr. Overall, the percentage of patients with delayed GE increased from 33% at 2 hr only to 58% using the results of the 2-, 3-, and 4-hr scans (P < 0.05). There was a significantly greater symptom score in patients with delayed GE compared to patients with normal GE (8.4 ± 0.5 vs 7.1 ± 0.5; P < 0.05). Conclusion, prolonging GES after ingestion of a ^99mTc-labeled egg meal from 2 to 4 hr increased the number of symptomatic patients found to have delayed GE. These results suggest that GES should be performed for up to 4 hrs when the 2-hr result is normal.     

Altered small bowel motility in irritable bowel syndrome is correlated with symptoms

The pathogenesis of irritable bowel syndrome (IBS) has been related more to dysmotility of the colon than to abnormalities of the small intestine. To look for small bowel abnormalities, we recorded ultraluminal pressures in 16 patients with IBS. All patients complained of abdominal pain, and diarrhea (n = 8) or constipation (n = 8) were also prominent symptoms. Comparable studies were performed on 16 age-matched controls. The observations include diurnal and nocturnal fasting recordings and the response to a fatty meal. Periodicities of the interdigestive migrating myoelectric complexes were shorter in IBS (p less than 0.05); this was due to much shorter diurnal cycles in patients with diarrhea (77 +/- 10 min) than those with constipation (118 +/- 15 min) or controls (113 +/- 10 min, both p less than 0.05). All groups exhibited circadian changes, with nocturnal cycles being more frequent. Two specific patterns of small bowel motor activity were more common in IBS--ileal propulsive waves and clusters of jejunal pressure activity (both p less than 0.05 compared to controls). Moreover, cramping abdominal pain was usually noted in IBS when ileal motility was propulsive; jejunal bursts were also sometimes associated with abdominal symptoms. We conclude that motility of the small intestine is modified in some patients with IBS and that certain motor patterns are related to their symptoms.     

Effect of age on human gastric and small bowel motility

To test the hypothesis that age alters fasting and postprandial antral and intestinal motility in humans, we studied 23 patients, aged 18-39 years (median 28), and 13 patients, aged 40-69 years (median 49). All were having gastrointestinal symptoms, but in none was there objective clinical, radiologic, or endoscopic features of bowel disease, and manometry of the stomach and proximal small bowel was normal. We quantitated certain parameters of fasting intestinal motility and postprandial antral and jejunal motility. There were no significant differences in the interval between interdigestive motor complexes (IMC), duration, propagation velocity, or maximum number of contractions during phase III of the IMC, or postprandial antral and jejunal motility indices. The postprandial indices show a very similar distribution in each decade. Thus, in selected patients with unexplained gastrointestinal symptoms but no objective features of gut disease, quantifiable gastric and small bowel motility parameters do not differ in the age groups 18-39 and 40-69 years.     

Ambulatory 24-Hour Jejunal Motility in Diarrhea-Predominant Irritable Bowel Syndrome

Background: Whether small-bowel motility is abnormal in the irritable bowel syndrome (IBS) is a controversy at present. The aim of our study was to compare ambulatory long-term jejunal motility in 35 IBS patients with predominant diarrhea to normal values obtained in 50 healthy controls. Methods: Twenty-four-hour motility was recorded in the proximal jejunum with a portable datalogger and tubemounted miniature pressure sensors. Fasting motility in the waking (W) and sleeping (S) state and the motor response to a standardized evening meal of 600 kcal underwent visual and computer-aided analysis. Results: Fasting motility in patients showed migrating motor complex (MMC) cycles of normal length and composition. Uninterrupted runs of discrete clustered contractions during phase II (W) occurred in 57% of patients and 52% of controls but had a significantly longer duration in patients (33 ± 5 versus 19 ± 7 min; p < 0.005). During phase II (W) IBS patients had an increase in aborally propagated contractions (41 ± 2% versus 35 ± 2%; p < 0.01) and higher contraction amplitudes (26.3 ± 0.8 versus 23.0 ± 0.5 mm Hg; p < 0.01). Similar differences were obtained during postprandial motility (47 ± 3% versus 39 ± 3%; p < 0.01, and 25.9 ± 0.9 versus 23.8 ± 0.05 mm Hg; p < 0.02). In three patients (8.6%) disturbed aboral migration of phase III and irregular burst activity, manometric features of chronic idiopathic intestinal pseudo-obstruction, were identified. Whereas 57% of patients had an entirely normal 24-h manometry, 43% had at least one finding not present in any healthy control. Conclusion: Small-intestinal motility is frequently but not universally abnormal in diarrhea-predominant IBS. The abnormal manometric findings are heterogeneous and range from subtle quantitative changes to severe qualitative abnormalities resembling chronic idiopathic intestinal pseudo-obstruction in a small subset of patients.     

Distal Colonic Motor Activity in Four Subgroups of Patients with Irritable Bowel Syndrome

With the aim of improving end organ treatment, we describe a new system of classifying irritable bowel syndrome (IBS) according to clinical features into four groups, spastic colon syndrome (SCS), functional diarrhea (FD), diarrhea-predominant spastic colon syndrome (DPSCS), and midgut dysmotility (MGD). The aim of the study was to investigate fasting and postprandial distal colonic motility in the four groups of patients and to compare the results with normal controls. Distal colonic motility studies were performed in the unprepared colon. 2.5-hr recordings were made from four channels with a standard meal administered at 0.5 hr. The intubated colon was treated as a study segment and data analyzed for study segment activity index (SSAI) and number and mean amplitude of pressure peaks over 30-min epochs. Patients with SCS had significantly higher (P < 0.05) mean amplitude of pressure peaks (60 min, 120 min) and SSAI (120 min) than controls and patients with FD, DPSCS, and MGD. In contrast, patients with FD and DPSCS had significantly (P < 0.05) lower postprandial SSAI than controls and patients with SCS (60 min, 120 min). With the exception of raised postprandial mean amplitude of pressure peaks (120 min), MGD patients had normal distal colonic motility. Division of IBS patients into subgroups has highlighted significant differences in distal colonic motility that provide insights into etiopathogenesis and should assist targeting of current and newly developed therapies, particularly receptor active agents.     

An evaluation of an ambulatory manometry system in assessment of antroduodenal motor activity

While abnormalities in antroduodenal motor function have been documented in both organic and functional disorders, controversy surrounds the ideal manometric technique. We sought, therefore, to evaluate a digital solid-state ambulatory system. Sixteen normal volunteers underwent 24-hr recordings of antroduodenal motility. Following catheter placement, a standardized meal was ingested in the laboratory; thereafter, subjects were ambulatory and assumed normal diet and activities. The system was well tolerated; subjects reported that it did not affect their usual activities. Migrating motor complex (MMC) activity was identified in each subject (mean frequency: 4.1 MMCs/24 hr, range 1–8); on average 1.9 (range 0–4, frequency 0.1/hr) occurred while awake and 2.1 (range 0–5, 0.3/hr,P<0.05 vs awake) during sleep. The fed response was evaluated by calculating a motility index (MI) at 30-min intervals from 30 min before to 120 min following meal ingestion. Postprandially, MI was maximal during the first 30 min following meal ingestion: MI (mean±sd) 30 min before vs 30 min after meal in the antrum: 4.16±1.42 vs 5.33±0.72 (P<0.05), duodenum: 4.04±0.80 vs 4.57±0.47 (P<0.05), respectively. None of the other postprandial intervals were significantly different from baseline. There was no significant difference in MI between the standard andad libitum meals. Retrograde catheter migration (mean 5.6, range 1–10 cm) occurred in relation to all meals; as a consequence, antral recordings were lost following 60% of all meals, thereby limiting meaningful analysis of the antral fed response. We conclude, firstly, that while an ambulatory antroduodenal manometry system is well tolerated and reliably records duodenal motility, postprandial catheter migration limits antral recordings, and, secondly, that a motility index calculated during the first 30 min following anad libitum meal accurately reflects the fed motor response.Supported in part by the University of Nebraska Hospital.     

Gastroduodenal motility in chronic dyspepsia. 2. Postprandial motility

After ingestion of a solid test meal the postprandial motor activity in 17 dyspeptic patients and 12 healthy controls were examined. In all individuals the gastric emptying was measured by scintigraphy. - The antral pressure activity after food intake was delayed in dyspepsia and showed a distinct reduction with time (antral hypomotility). In contrast the postprandial duodenal motility was increased significantly (duodenal hyperdyskinesia). All 6 dyspeptic patients with prolonged gastric emptying had gastroduodenal manometric abnormalities. - Our results suggest that in chronic dyspepsia the interdigestive and postprandial motility is often disturbed. The delayed gastric emptying occurs because of impaired antral peristalsis and/or increase of duodenal resistance.     

Impaired interdigestive pancreatic polypeptide release

The purpose of this study was to investigate interdigestive cycling and postprandial release of pancreatic polypeptide (PP) in relation to exocrine pancreatic function in chronic pancreatitis (CP). We investigated nine patients with mild-moderate CP (MCP), eight patients with severe CP and steathorrea (SCP), and 17 healthy subjects as controls. Interdigestive antroduodenal motility was monitored by means of manometry. Following two consecutive motility cycles, a standard test meal was administered. Plasma samples were drawn for PP determinations every 15 min throughout the entire study, which concluded 2 hr after ingestion of the meal. Mean interdigestive PP plasma concentrations during phase III motor activity were lower in MCP (146±46 pg/ml) than in controls (270±42 pg/ml) and lower still in SCP (55±8 pg/ml). Accordingly, the percent increase in PP concentrations during phase III over those in phase I was progressively decreased from controls (112%) to MCP (62%) to SCP (19%). Mean interdigestive PP concentrations were also lower during phase I and II in SCP than in controls or MCP. None of the postprandial parameters for PP release was affected in the early stage of disease, while mean, peak, and integrated postprandial values were significantly lower in SCP than in controls or MCP. Thus, we observed a progressive diminution of both interdigestive and postprandial PP release with increasing severity of disease. Interdigestive release parameters, in particular, were tightly correlated with exocrine function. CP appears to alter interdigestive PP release to a greater extent than postprandial PP release; this effect is already apparent in early stages of the disease. Impaired release of PP during phase III motor activity may represent an early hormonal disorder in CP.     

Fasting and postprandial gastrointestinal motility in ulcer and non-ulcer dyspepsia.

This study aimed to compare fasting and postprandial gastrointestinal motor patterns in patients with ulcer and non-ulcer dyspepsia. Forty five subjects were studied: 10 with uncomplicated gastric ulcer, eight with uncomplicated duodenal ulcer, 18 with chronic idiopathic dyspepsia, and nine healthy asymptomatic controls. Gastrointestinal fasting and postprandial motor patterns were recorded using a low compliance perfusion technique. The interdigestive antral cumulative motility index, computed for 30 minutes before the appearance of duodenal activity fronts, and the number of activity fronts with an antral component were significantly less in patients with ulcers and those with non-ulcer dyspepsia compared with asymptomatic controls. The patient groups also had a reduced antral motor response to a solid-liquid test meal compared with healthy controls. Intestinal motor abnormalities (bursts of non-propagated phasic pressure activity and discrete clustered contractions) were recorded in a minority of patients, all with associated irritable bowel symptoms. In conclusion, antral hypomotility is a frequent but nonspecific motor abnormality in dyspepsia; abnormal motor patterns of the small bowel are less frequent and seem to be confined to patients with concomitant irritable bowel syndrome.     

Effects of Medium-Chain and Long-Chain Triglycerides on Antroduodenal Motility and Small Bowel Transit Time in Man

Medium-chain triglycerides are known to inducediarrhea, possibly resulting from accelerated intestinaltransit. We performed antroduodenal manometry andlactulose hydrogen breath testing simultaneously in eight healthy subjects in order to determinethe effects of intraduodenally administered medium-chaintriglycerides (MCT) and long-chain triglycerides (LCT)on gastrointestinal motility and small bowel transit time. LCT (15 mmol/hr) induced a fedmotor pattern. In contrast, during MCT, in bothequimolar (15 mmol/hr; MCT-1) and equicaloric (30mmol/hr; MCT-2) amounts comparable to LCT,interdigestive motility was preserved but with a significantly (P <0.05) shorter MMC cycle length (MCT-1, 65 ± 7min; MCT-2, 53 ± 6 min) compared to control(saline infusion; 127 ± 14 min). Duodenocecaltransit time (DCTT) was significantly (P < 0.05) accelerated during administrationof MCT (MCT-1, 56 ± 6 min; MCT-2, 69 ± 9min) and was not affected by LCT (105 ± 13 min)when compared to control (101 ± 9 min). Inconclusion: MCT, in contrast to LCT, preserve interdigestive motility with a shorterMMC cycle length and accelerate DCTT.     

Disturbed Motilin and Cholecystokinin Release in the Irritable Bowel Syndrome

Background: The irritable bowel syndrome (IBS) is associated with motor abnormalities in the small intestine and colon. Neuropeptides may have an important role in initiating and regulating the intestinal motility. Motilin has been proposed to initiate the peristaltic reflex in the small intestine and cholecystokinin the gastrocolic reflex. Methods: In 18 patients with IBS and 11 healthy control subjects plasma motilin and cholecystokinin (CCK) concentrations were measured after intraluminal stimulation of water and a fat-rich meal. Results: The IBS patients had reduced motilin secretion after both water intake and the fat meal. In contrast, the fat meal elicited an exaggerated and prolonged CCK release in the IBS patients. Conclusions: Disturbed motilin and CCK release may partly be responsible for the intestinal dysmotility in the IBS patients.     

Small intestinal motor abnormalities in patients with functional dyspepsia demonstrated by ambulatory manometry.

AIMS/METHODS--In 30 patients with functional dyspepsia and in 20 healthy volunteers, ambulatory duodenojejunal manometry was performed to examine the interdigestive and postprandial small intestinal motility patterns in relation to symptoms. RESULTS--In the fasting state, the number of migrating motor complex cycles mean (SEM) was significantly lower in patients, especially in patients with dysmotility-like dyspepsia, than in control subjects (3.8 (0.4), 2.6 (0.5), and 5.3 (0.7) cycles, respectively; p < 0.05), due to a longer duration of phase II. Non-propagated and retrogradely propagated phase III activity was more prevalent in patients than in control subjects (48% v 15%; p = 0.020). During phase II and after dinner no differences were found in contraction incidence, mean amplitude or motility index. However, 1 1/2 hours after completing breakfast the motility index was higher in patients at all three recording levels (p < 0.05). Burst activity was more prevalent in patients than in control subjects (22% v 6% of the subjects; p = 0.003). In 41% of the patients the symptom index was > 75%. CONCLUSIONS--These results suggest that small intestinal motor abnormalities, especially during fasting, participate in the pathogenesis of symptoms in patients with functional dyspepsia. Ambulatory manometry of the small intestine is a valuable tool to demonstrate these abnormalities in outpatients pursuing their daily activities.     

Effect of Preinjury Large Bowel Emptying on the Inhibition of Upper Gastrointestinal Motility After Spinal Cord Injury in Rats

Spinal cord transection (SCT) inhibits gastrointestinal motility in rats. We evaluated the effect of preinjury large bowel emptying on this phenomenon. Male Wistar rats (N = 52) were fasted for 24 or 48 hr with water ad libitum and pretreated with lactose (0.8 g) or saline. Next, laminectomy followed or not by complete SCT between T4 and T5 vertebrae was performed. Phenol red recovery in the stomach and proximal, medial, and distal small intestine was determined 1 day later. In animals submitted to 24 hr fasting + saline, SCT increased gastric recovery by 42.8% decreased medial small intestine recovery by 56.2%, while 48 hr fasting + saline or 24 hr fasting + lactose prevented the inhibition of gastric emptying (GE) in SCT animals. The 48 hr fasting + lactose prevented the inhibition of both GE and gastrointestinal transit. SCT-induced inhibition of upper gastrointestinal motility may involve enhancement of inhibitory reflexes, which can be prevented by large bowel emptying.     

Motility disorders in the irritable bowel syndrome

Specific abnormalities of colonic and small bowel motility are identifiable and associated with symptoms in IBS. Characteristic abnormalities in colonic motility include a prolonged increase in 3-cycles/min colonic motor activity after a meal, an exaggerated increase in 3-cycles/min motor activity in response to stressors and CCK, and increased visceral sensitivity and motor activity in response to balloon distention. Symptoms in patients with IBS correlate in some cases with the abnormal gastrocolonic response and with pain induced by distention at various sites in the colon. Small bowel motility abnormalities identified reproducibly in IBS include an increase in daytime jejunal DCCs, an increase in daytime ileal PPCs, and more frequent cycling of daytime MMCs (in diarrhea-predominant IBS only). DCCs and PPCs are strongly associated with symptoms in IBS, and PPCs associated with altered ileocecal transit may be an important mechanism of symptoms in some patients with IBS. Esophageal and gastroduodenal motility abnormalities are inconsistently identified in IBS, and most symptoms in IBS appear to be secondary to small bowel or colonic dysfunction. Because of the paroxysmal nature of these motor abnormalities in IBS, prolonged motility recordings are required to better understand the pathophysiology of this syndrome. Patients with IBS may have altered visceral sensation and changes in afferent reflex mechanisms that modulate GI motility. These patients do not have a generalized increase in pain perception, but may have a distinct sensitivity to visceral afferent stimulation in both gastrointestinal and other viscera. Whether the altered "setpoint" to visceral afferent stimulation in IBS is intrinsic to the smooth muscle of viscera or secondary to CNS and ANS modulation is not known. Many of the symptoms and abnormalities of small bowel and colonic motility in IBS probably result from these changes in afferent sensation and reflex mechanisms. These findings support the concept that IBS is an abnormality of intestinal motility in conjunction with a "sensitive" gut.