Study of human gastroduodenojejunal motility. Applied physiology in clinical practice

Simulating human gastrointestinal motility in dynamic in vitro models

The application of dynamic in vitro gastrointestinal (GI) models has grown in popularity to understand the impact of food structure and composition on human health. Given that GI motility is integral to digestion and absorption, a predictive in vitro model should faithfully replicate the motility patterns and motor functions in vivo. In this review, typical characteristics of gastric and small intestinal motility in humans as well as the biomechanical and hydrodynamic events pertinent to gut motility are summarized. The simulation of GI motility in the presently existing dynamic in vitro models is discussed from an engineering perspective and categorized into hydraulic, piston/probe-driven, roller-driven, pneumatic, and other systems. Each system and its representative models are evaluated in terms of their motility patterns, the key hydrodynamic characteristics concerning gut motility, their performance in simulating the key physiological events, and their ability to establish in vitro-in vivo correlations. Practical Application: The review paper provided useful information in the design of dynamic GI models and the simulation of human gastric and small intestinal motility which are important for understanding food and health.

A single-center audit of the indications and clinical impact of prolonged ambulatory small intestinal manometry

BACKGROUND

Small bowel manometry is a diagnostic test available only in a few specialized referral centers. Its exact place in the management of refractory symptoms is controversial.

METHODS

The records of all patients who underwent 24-hour ambulatory duodenojejunal manometry over a 6-year period were retrospectively reviewed. We studied the clinical indications for small bowel manometry, and reviewed the impact of manometric findings on the clinical outcome. One hundred and forty-six studies were performed in 137 patients (46M, 91F) with a mean age of 44.9 ± 15.7 years. Mean follow-up duration was 15.1 ± 22.6 months. Appropriate endoscopic, radiological and gastric scintigraphy studies were performed in all patients prior to small bowel manometry. Criteria for abnormal motor activity were based on Bharucha's classification.

KEY RESULTS

The indications for small bowel manometry were chronic abdominal pain (n = 43), slow-transit constipation (n = 17), refractory gastroparesis (n = 16), chronic diarrhea (n = 7), recurrent episodes of subocclusion (n = 16), postsurgical evaluation (n = 36), suspicion of gut involvement in systemic disease (n = 9), and unexplained nausea (n = 2). The most common finding was a normal 24-hour ambulatory small bowel manometry (n = 113). Thirty-three studies yielded abnormal findings which included extrinsic neuropathy (n = 6), intrinsic neuropathy (n = 18), intestinal myopathy (n = 2), and subocclusion (n = 7). Ambulatory small bowel manometry excluded a generalized motility disorder in 77% and had a significant impact on the subsequent clinical course in 23%.

CONCLUSIONS & INFERENCES

Ambulatory small bowel manometry is a useful and safe diagnostic tool to complement traditional investigative modalities in patients with severe unexplained abdominal symptoms.

A novel dynamic scintigraphic technique for assessing duodenal contractions during gastric emptying in humans: a feasibility study

Duodenal contractions are thought to play a role in the control of gastric emptying. Although noninvasive techniques, such as ultrasonography and MRI, have been proposed for studying duodenal contractile activity in humans, there are no reports on the use of scintigraphy for this purpose. This work aimed to describe a novel scintigraphic technique for assessing duodenal contractility during gastric emptying in humans, and to present preliminary data on the frequency and amplitude of contractions detected in three different duodenal segments. Fasted young healthy volunteers (N=12) were given either a liquid or a solid test meal of similar calorie content (400 kcal) labeled with 99mTc-phytate. Static images were collected to determine gastric emptying. Dynamic images of the anterior aspect of the abdomen (1 frame/s) were also acquired periodically in a standard position for 256 s at 15-30 min intervals. 'Activity versus time' curves were generated for regions of interest corresponding to the proximal, middle, and distal duodenal segments. Curves were digitally filtered and processed to estimate both dominant frequency (fast Fourier transform) and amplitude (mean ejection fraction) of postprandial duodenal contractions. There were no significant differences regarding dominant frequency among proximal, middle, and distal duodenal regions of interest. In addition, there were no significant differences between the liquid and the solid meal in terms of either frequency or amplitude of duodenal contractions. Characterization of duodenal contractions in humans using scintigraphy is feasible and yields consistent data for both the frequency and the amplitude of postprandial contractions, which seems to be rather independent of meal consistency.

Gastroparesis: from concepts to management

While the symptoms of gastroparesis are common, an accurate diagnosis is based on a combination of those symptoms with a documented delay in gastric emptying. Typical symptoms include nausea, vomiting, early satiety, postprandial fullness, bloating, and abdominal discomfort. Patients with gastroparesis face many diagnostic and therapeutic challenges. The most common origins of gastroparesis are idiopathic causes and diabetes mellitus. The increased use of certain medications in medicine today, including opiates and drugs with anticholinergic properties, can alter gastrointestinal functions and mimic symptoms of gastroparesis. Accordingly, alternative explanations for symptoms and altered gastrointestinal function need to be considered. Numerous clinical sequelae, including weight loss and severe protein-calorie malnutrition, may be seen in advanced stages of gastroparesis. This article provides an overview of gut sensorimotor function to help the reader better understand the clinical presentation of patients with dyspepsia and those who may have accompanying delayed gastric emptying that meets criteria for gastroparesis. Techniques available for diagnosing motor dysfunction and the principles of gastroparesis management are reviewed. Nutrition recommendations and a review of pharmacologic agents, nonpharmacologic techniques, and novel treatment modalities are provided.

Advances in motility testing--current and novel approaches

Disorders of gastrointestinal motility are frequently seen in clinical practice. Apart from motility disorders, factors leading to lowered visceroperception thresholds are recognized as commonly involved in the pathogenesis of functional gastrointestinal disorders. The wide array of gastrointestinal motility and viscerosensitivity tests available is in contrast with the relatively limited number of tests used universally in clinical practice. The main reason for this discrepancy is that the outcome of a test only becomes truly important when it carries clinical consequences. The main goal of this Review is to assess the place of the presently available gastrointestinal motility and sensitivity tests in the clinical armamentarium of the gastroenterologist.

What are the important subsets of gastroparesis?

Gastroparesis is often divided into subsets based on etiology and pathophysiology; however, the utility of these subsets in the diagnosis and treatment of gastro-paresis is not well defined. The objectives are to consider the subsets of gastroparesis from the perspectives of etiology and pathogenesis, pathophysiology, histopathology, and clinical associations, with particular focus on similarities and differences between diabetic and idiopathic gastroparesis and consideration of the potential subset of painful gastroparesis. We conclude that idiopathic and diabetic gastroparesis has similar initial presentations and manifestations, except that idiopathic gastroparesis tends to be associated more frequently with pain. Myopathic disorders are uncommon. Extrinsic denervation was considered the most common etiology; however, with the decline in surgery for peptic ulceration and in-depth study of full-thickness gastric biopsies, the most common intrinsic defects are being recognized in the interstitial cells of Cajal (ICC-opathy) and with immune infiltration and neuronal changes (intrinsic neuropathic gastroparesis). Histomorphological differences at the microscopic level between diabetic and idiopathic gastroparesis are still of unclear significance. Two gastroparesis subsets worthy of special mention, because they are potentially reversible with identification of the cause, are postviral gastroparesis, which has a generally good prognosis, and iatrogenic gastroparesis, especially in patients with non-surgical gastroparesis, such as diabetics exposed to incretins such as pramlintide and exenatide.

Motility of the antroduodenum in healthy and gastroparetics characterized by wireless motility capsule

BACKGROUND

The wireless motility capsule (WMC) measures intraluminal pH and pressure, and records transit time and contractile activity throughout the gastrointestinal tract. Our hypothesis is that WMC can differentiate antroduodenal pressure profiles between healthy people and patients with upper gut motility dysfunctions. This study aims to analyze differences in the phasic pressure profiles of the stomach and small intestine in healthy and gastroparetic subjects.

METHODS

Data from 71 healthy and 42 gastroparetic subjects were analyzed. The number of contractions (Ct), area under the pressure curve and motility index (MI = Ln (Ct *sum amplitudes +1)) were analyzed for 60 min before gastric emptying of the capsule (GET), (gastric window) and after GET (small bowel window) and results between groups were compared with the Wilcoxon rank sum test.

KEY RESULTS

Significant differences were observed between healthy and gastroparetic subjects for Ct and MI (P < 0.05). Median values of the motility parameters in gastric window were Ct = 72, MI = 11.83 for healthy and Ct = 47, MI = 11.12 for gastroparetics. In the small bowel, median values were Ct = 144.5, MI = 12.78 for healthy and Ct = 93, MI = 12.12 for gastroparetics. Diabetic subjects with gastroparesis showed significantly lower Ct and MI compared with healthy subjects in both gastric and small bowel windows while idiopathic gastroparetic subjects did not show significant differences.

CONCLUSIONS & INFERENCES

The WMC is able to differentiate between healthy and gastroparetic subjects based on gastric and small bowel motility profiles.

Small bowel motility in functional chronic constipation

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.

Mandatory and optional function tests in gastroduodenal disorders

A number of patients have symptoms suggestive of a disturbance of gastroduodenal function. Current gastric function tests allow us to study gastric emptying, motor activity, gastroduodenal sensitivity to distention and accommodation to a meal. The best application of these tests seems to be in the explanation of symptoms. However, most of the available tests have a low diagnostic specificity, and their results usually have no major impact on the choice of therapy. In rare or refractory cases, small bowel manometry may lead to specific diagnoses and gastric emptying testing may prompt the decision to consider more invasive therapies. Gastroduodenal function tests do not seem to predict the response to therapy or the prognosis of patients with presumed gastric sensory or motor disorders. The main limitation to a greater clinical usefulness of gastroduodenal function testing is the lack of therapeutic alternatives.

Tests of gastric neuromuscular function

Tests of gastric neuromuscular function are used to evaluate patients with symptoms referable to the upper digestive tract. These symptoms can be associated with alterations in the rates of gastric emptying, impaired accommodation, heightened gastric sensation, or alterations in gastric myoelectrical function and contractility. Management of gastric neuromuscular disorders requires an understanding of pathophysiology and treatment options as well as the appropriate use and interpretation of diagnostic tests. These tests include measures of gastric emptying; contractility; electrical activity; regional gastric motility of the fundus, antrum, and pylorus; and tests of sensation and compliance. Tests are also being developed to improve our understanding of the afferent sensory pathways from the stomach to the central nervous system that mediate gastric sensation in health and gastric disorders. This article reviews tests of gastric function and provides a basic description of the tests, the methodologies behind them, descriptions of the physiology that they assess, and their clinical utility.

Comparison between manual and automated techniques for assessment of data from dynamic antral scintigraphy

OBJECTIVE

This work aimed at determining whether data from dynamic antral scintigraphy (DAS) yielded by a simple, manual technique are as accurate as those generated by a conventional automated technique (fast Fourier transform) for assessing gastric contractility.

METHODS

Seventy-one stretches (4 min) of "activity versus time" curves obtained by DAS from 10 healthy volunteers and 11 functional dyspepsia patients, after ingesting a liquid meal (320 ml, 437 kcal) labeled with technetium-99m (99mTc)-phytate, were independently analyzed by manual and automated techniques.

RESULTS

Data obtained by both techniques for the frequency of antral contractions were similar. Contraction amplitude determined by the manual technique was significantly higher than that estimated by the automated method, in both patients and controls. The contraction frequency 30 min post-meal was significantly lower in patients than in controls, which was correctly shown by both techniques.

CONCLUSIONS

A manual technique using ordinary resources of the gamma camera workstation, despite yielding higher figures for the amplitude of gastric contractions, is as accurate as the conventional automated technique of DAS analysis. These findings may favor a more intensive use of DAS coupled to gastric emptying studies, which would provide a more comprehensive assessment of gastric motor function in disease.

Dynamic antral scintigraphy following solid and liquid meals in healthy human subjects

AIMS

Dynamic antral scintigraphy (DAS), a non-invasive technique for the assessment of post-prandial gastric contractions, has been used to demonstrate abnormal contractility in several clinical conditions. The objective of the present study was to assess differences between solid and liquid meals regarding gastric contractions in healthy volunteers using DAS.

METHODS

Ten healthy male volunteers were studied after ingesting solid or liquid meals [approximately 1670 kJ (approximately 400 kcal)] labelled with 99mTc phytate and administered in a random order. Gastric images were acquired for 120 min for gastric emptying half-time (T1/2) measurement. Dynamic (1 frame x s(-1)) images of the gastric antrum were acquired at 30 min intervals for 4 min for the assessment of antral contractility.

RESULTS

Gastric emptying T1/2 values for solid and liquid meals were similar (58.1+/-19.06 min vs. 69.4+/-6.76 min; P=0.13). For the solid meal, average values for both frequency (3.08+/-0.15 cycles x min(-1) vs. 2.78+/-0.18 cycles x min(-1); P=0.003) and amplitude (33.94+/-5.2% variation vs. 24.09+/-7.37% variation; P=0.002) of antral contractions were significantly higher than those obtained with the liquid meal. For either of the test meals, none of the antral contractility variables correlated with gastric emptying T1/2.

CONCLUSIONS

Dynamic antral scintigraphy is capable of detecting differences between solid and liquid meals concerning post-prandial gastric antral contractions under physiological conditions. The frequency and amplitude of gastric antral contractions after a solid meal are greater than after an exclusively liquid meal of similar calorie content, in spite of lack of a difference regarding gastric emptying.

High-resolution solid-state manometry of the antropyloroduodenal region

Manometric recording from the pyloric channel is challenging and is usually performed with a sleeve device. Recently, a solid-state manometry system was developed, which incorporates 36 circumferential pressure sensors spaced at 1-cm intervals. Our aim was to use this system to determine whether it provided useful manometric measurements of the pyloric region. We recruited 10 healthy subjects (7 males:3 females). The catheter (ManoScan(360)) was introduced transnasally and, in the final position, 15-20 sensors were in the stomach and the remainder distributed across the pylorus and duodenum. Patients were recorded fasting and then given a meal and recorded postprandially. Using pressure data and isocontour plots, the pylorus was identified in all subjects. Mean pyloric width was 2.1 +/- 0.1 cm (95% CI: 1.40-2.40). Basal pyloric pressure during phase I was 9.4 +/- 1.1 mmHg, while basal antral pressure was significantly lower (P = 0.003; 95% CI: 2.4-8.4). Pyloric pressure was always elevated relative to antral pressure in phase I. For phases II and III, pyloric pressure was 7.7 +/- 2.3 mmHg and 9.4 +/- 1.1 mmHg, respectively. Pyloric pressure increased similarly after both the liquid and solid meal. In addition, isolated pressure events and waves, which involve the pylorus, were readily identified.

Postprandial transduodenal bolus transport is regulated by complex peristaltic sequence

AIM: To study the relationship between the patterns of postprandial peristalsis and transduodenal bolus transport in healthy subjects.

METHODS: Synchronous recording of chyme transport and peristaltic activity was performed during the fasting state and after administration of a test meal using a special catheter device with cascade configuration of impedance electrodes and solid-state pressure transducers. The catheter was placed into the duodenum, where the first channel was located in the first part of the duodenum and the last channel at the duodenojejunal junction. After identification of previously defined chyme transport patterns the associated peristaltic patterns were analyzed.

RESULTS: The interdigestive phase 3 complex was reliably recorded with both techniques. Of 497 analyzed impedance bolus transport events, 110 (22%) were short-spanned propulsive, 307 (62%) long-spanned propulsive, 70 (14%) complex propulsive, and 10 (2%) retrograde transport. Short-spanned chyme transports were predominantly associated with stationary or propagated contractions propagated over short distance. Long-spanned and complex chyme transports were predominantly associated with propulsive peristaltic patterns, which were frequently complex and comprised multiple contractions. Propagated double wave contraction, propagated contraction with a clustered contraction, and propagated cluster of contractions have been identified to be an integralted part of a peristaltic sequence in human duodenum.

CONCLUSION: Combined impedancometry and manometry improves the analysis of the peristaltic patterns that are associated with postprandial transduodenal chyme transport. Postprandial transduodenal bolus transport is regulated by propulsive peristaltic patterns, which are frequently complex but well organized. This finding should be taken into consideration in the analysis of intestinal motility studies.

Clinical, radiologic, and manometric characteristics of chronic intestinal dysmotility: the Stanford experience

BACKGROUND AND AIMS

The clinical spectrum of chronic intestinal dysmotility (CID) is not well known. We determined the spectrum of motor abnormalities, underlying pathology, clinical course, and response to treatment of adults with CID at a tertiary referral center.

METHODS

This was a descriptive retrospective analysis of a CID cohort conducted at a tertiary referral gastrointestinal (GI) motility center. A total of 113 referred patients underwent gastroduodenal manometry, other motility studies as appropriate, and radiologic and/or endoscopic assessment to exclude mechanical intestinal obstruction.

RESULTS

Common symptoms included abdominal distention, abdominal pain, nausea, and constipation. The course was chronic with intermittent symptoms. Gastroduodenal manometry was abnormal in all patients; a pattern suggestive of a neuropathic process was the most common. Other GI motility studies showed delayed gastric, gallbladder, and colonic transit, nonspecific esophageal dysmotility, sphincter of Oddi hypertonicity, and poor rectal balloon sensation/expulsion. Treatment involved nutritional support, prokinetics, analgesics, antinausea agents, and laxatives, with variable response and high morbidity, multiple emergency admissions, need for nutritional support, and poor response to surgery. Nearly 40% of the patients underwent abdominal surgery.

CONCLUSIONS

Patients with CID have a chronic course and high morbidity. Because any segment of the GI tract may be involved in CID, functional assessment of the entire GI tract is recommended. CID presents several unmet clinical needs even in tertiary centers with expertise.

Gastroparesis: clinical update

Gastroparesis refers to chronically abnormal gastric motility characterized by symptoms suggestive of mechanical obstruction and delayed gastric emptying in the absence of mechanical obstruction. It may be idiopathic or attributable to neuropathic or myopathic abnormalities, such as diabetes mellitus, postvagotomy, postviral infection, and scleroderma. Dietary and behavioral modification, prokinetic drugs, and surgical interventions have been used in managing patients with gastroparesis. Although mild gastroparesis is usually well managed with these treatment options, severe gastroparesis may be very difficult to control and may require referral to a specialist center if symptoms are intractable despite pharmacological therapy and dietetic support. New advances in drug therapy, botulinum toxin injection, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. This article critically reviews the advances in the field from the perspective of the clinician.

The pathogenesis of gastrointestinal bacterial overgrowth

The normal indigenous intestinal microflora consists of about 10(15) bacteria that under physiological conditions reside mainly in the lower gastrointestinal tract. Bacterial overgrowth implies abnormal bacterial colonization of the upper gut, resulting from failure of specific defense mechanisms restricting colonization under physiological conditions. At present two types of bacterial overgrowth with defined pathogenesis can be distinguished: (1) gastric overgrowth with upper respiratory tract microflora resulting from selective failure of the gastric acid barrier, and (2) gastrointestinal overgrowth with Gram-negative bacilli (enteric bacteria) resulting from failure of intestinal clearance. Helicobacter pylori-induced gastritis of the oxyntic mucosa is the main cause of acquired failure of the gastric acid barrier, which is common among the healthy elderly. Intestinal clearance may fail as the result of impaired intestinal peristalsis or anatomical abnormalities that alter luminal flow. Impaired peristalsis is associated with conditions interfering with intestinal neuromuscular function including myopathic, neuropathic, autoimmune, infectious, inflammatory, metabolic, endocrine, and neoplastic diseases. Anatomical abnormalities are mainly the result of gastrointestinal surgery, intestinal diverticula or fistula. Combined failure of intestinal clearance and the gastric acid barrier results in more severe colonization with Gram-negative bacilli. Gram-negative bacilli are uncommon in the upper gut of otherwise healthy individuals with gastric hypochlorhydria, being acquired (H. pylori) or drug-induced. Significant bacterial overgrowth with Gram-negative bacilli is a rational in the search for an explanation to optimize clinical management. The clinical significance of colonization with upper respiratory tract microflora remains unclear. Translocation of live bacteria, their metabolic products, or antigens from a small bowel colonized by Gram-negative bacilli play a role in the pathogenesis of spontaneous bacterial peritonitis in hepatic disease and in certain types of sepsis, indicating that further studies can point to new patient populations with potential benefit from medical treatment.

American Gastroenterological Association technical review on the diagnosis and treatment of gastroparesis

This literature review and the recommendations herein were prepared for the American Gastroenterological Association Clinical Practice Committee. The paper was approved by the Committee on May 16, 2004, and by the AGA Governing Board on September 23, 2004.

Gastric motility disorders: management that optimizes nutritional status

Gastric motility disorders are relatively common, and treatment is often challenging. Various etiologies account for numerous clinical sequelae, with weight loss and severe protein-calorie malnutrition often seen in advanced stages of these disorders. In addition to gastrointestinal motor function, an appreciation of visceral sensation is essential to better understand the symptoms found in these patients, as well as possible therapeutic alternatives. This article provides an overview of gut motor and sensory function, techniques available for diagnosing motor disorders, and the principles of nutritional and medical management. Specific nutritional recommendations and a review of pharmacologic agents and novel treatment modalities are provided.

Alterations of sensori-motor functions of the digestive tract in the pathophysiology of irritable bowel syndrome

Pathophysiology of irritable bowel syndrome (IBS) is based upon multiple factors that have been organised in a comprehensive model centred around the brain-gut axis. The brain-gut axis encompasses nerve pathways linking the enteric and the central nervous systems and contains a large proportion of afferent fibres. Functionally and anatomically, visceral nerves are divided in to two categories: the parasympathetic pathways distributing to the upper gut through the vagi and to the hindgut, through the pelvic and pudendal nerves, and the sympathetic pathways, arising form the spinal cord and distributing to the midgut via the paravertebral ganglia. Several abnormalities of gut sensori-motor function have been described in patients with IBS. Abnormal motility patterns have been described at the intestinal and colonic levels. Changes in colonic motility are mainly related to bowel disturbances linked to IBS but do not correlate with pain. More recently, visceral hypersensitivity has been recognised as a main characteristic of patients with IBS. It is defined by an exaggerated perception of luminal distension of various segments of the gut and related to peripheral changes in the processing of visceral sensations as well as modulation of perception by centrally acting factors including mood and stress. Viscero-visceral reflexes link the two edges of the brain-gut axis and may account for the origin of symptoms in some pathological conditions. Recent advances in the understanding of the role of myenteric plexus allowed recognition of several neurotransmitters involved at the level of both the afferent and efferent pathways. Targeting the receptors of these neurotransmitters is a promising way for development of new treatments for IBS.

Small intestinal motility disturbances and bacterial overgrowth in patients with liver cirrhosis and portal hypertension

OBJECTIVE

Altered small bowel motility and a high prevalence of small intestinal bacterial overgrowth (SIBO) has been observed in patients with liver cirrhosis. Our aim was to explore the relationship between motility abnormalities, portal hypertension, and SIBO.

METHODS

Twenty-four patients with liver cirrhosis were included. Twelve had portal hypertension (PH) and 12 had liver cirrhosis (LC) alone. Child-Pugh score was the same in the groups. Antroduodenojejunal pressure recordings were performed, and noninvasive variceal pressure measurements were undertaken. Thirty-two healthy volunteers served as a reference group. Bacterial cultures were obtained from jejunal aspirates.

RESULTS

The PH group had a higher proportion of individual pressure waves that were retrograde in the proximal duodenum during phase II (52% vs 13% vs 8% of propagated contractions; p < 0.001) as well as postprandially (49% vs 18% vs 13%; p < 0.01) compared with LC and controls, respectively. Long clusters were more common in PH than in controls (9.1 +/- 2.1 vs 4.9 +/- 0.8; p < 0.05), and a higher motility index in phase III in the proximal and distal duodenum was seen in the PH as compared with the other groups. The mean variceal pressure was 21 +/- 1 mm Hg. Motor abnormalities were not correlated to the level of variceal pressure. Thirty-three percent of the patients in the PH group but none in the LC group had SIBO.

CONCLUSIONS

Abnormal small bowel motility and SIBO is common in patients with liver cirrhosis with concomitant portal hypertension. Portal hypertension per se might be significantly related to small bowel abnormalities observed in patients with liver cirrhosis.

Direct clinical evidence for spinal hyperalgesia in a patient with irritable bowel syndrome

OBJECTIVE

Our objective was to evaluate GI motor and sensory function and spinal cord testing in a patient with severe irritable bowel syndrome.

METHODS

A patient is described who underwent an extensive assessment of GI motor and sensory function including transit studies, colonic and rectal barostat studies, sensory and manometric studies of the small bowel, and colon and anorectal physiology testing. The patient also underwent testing with spinal cord stimulation and spinal drug delivery as part of a pain management assessment.

RESULTS

The viscerosomatic referral pain pattern resulting from rectal distention was consistent with spinal hyperalgesia. The patient underwent testing for spinal cord stimulation and spinal drug delivery.

CONCLUSION

This novel finding provides direct clinical evidence for the presence of spinal hyperalgesia in a patient with irritable bowel syndrome, consistent with the existing indirect clinical evidence and animal data.

Manometric artefacts suggesting compression of the duodenum by the superior mesenteric artery in healthy humans

Multi-channel manometry offers the opportunity to study intestinal motor activity with high spatiotemporal resolution. We report tonic and phasic intraluminal pressure changes in the mid-portion of the horizontal part of the duodenum. In 10 healthy volunteers, we recorded 2 h of interdigestive duodenal motility using a water-perfused catheter. The assembly incorporated 12 duodenal sideholes at 1.5-cm intervals (D1-D12). Measurement of the antral and duodenal transmucosal potential difference (TMPD) was used to maintain a correct position of the catheter. The incidence of pressure waves (PWs) increased gradually from proximal (D1) to distal (D12) (P < 0.0001), while the mean amplitude of PWs decreased (P < 0.0001). In eight of 10 subjects, the signals recorded from D9 showed tonic pressure elevations with superimposed phasic pressure changes at heart-rate frequency, comprising 13.8% of total recording time. In the other two subjects, this phenomenon occurred in D8 (9.9% of time). D10 showed a lower incidence of PWs compared with neighbouring sideholes (D6-D9/D11-D12) (P < 0.035), with normal amplitudes. Fluoroscopy was performed in three subjects and showed that D9 was located at the midline. In healthy subjects manometric signals recorded from the horizontal part of the duodenum showed localized artefacts, presumably caused by compression by the superior mesenteric artery. In addition, a 'silent' region was present just distal to this site, the origin of which is uncertain.

Novel testing of human gastric motor and sensory functions: rationale, methods, and potential applications in clinical practice

Sensitive and reproducible tests are essential to investigate the mechanisms of gastric motility and sensation in healthy humans and patients with unexplained upper gastrointestinal symptoms. Electrogastrography, manometry, scintigraphic emptying, and barostat studies with an intragastric balloon were initially used to understand physiology and pathophysiology of gastric motility. However, manometry and barostat studies are time-consuming, costly, and invasive, thus reducing their widespread clinical application. To overcome these shortcomings, several novel approaches have been proposed: water/nutrient drink test, paracetamol absorption test, 13C-octanoic acid or spirulina breath tests, ultrasonography, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and tensostat. The water/nutrient (satiety) test is a noninvasive test proposed as an alternative to sensory studies performed with an intragastric balloon. The satiety test cannot measure gastric accommodation; interpretation of sensory tests usually has required independent assessment of accommodation or compliance. The tensostat can be used as a gastric sensation test because it measures gastric wall tension, which is related to the perception of gastric distention. To measure gastric emptying, the paracetamol absorption test, 13C breath tests, ultrasound, or MRI can be used. The paracetamol absorption test can measure the gastric emptying of liquids. 13C breath test can measure the gastric emptying of solids or liquids and can achieve accuracy comparable with gastric scintigraphy. Ultrasonography requires special skills, and MRI requires costly equipment. To measure gastric accommodation to a meal, ultrasound, MRI, and SPECT have been proposed. The recently introduced SPECT requires an intravenous injection of 99mTc-pertechnetate, which the gastric mucosa specifically takes up, and specialized imaging and analysis, which have potential to be automated. Thus, novel, noninvasive approaches assess different dimensions of gastric motility and sensation testing. With further development of these techniques, refinement of their conduct and analysis, and validation of clinical usefulness, they are likely to be applicable in clinical practice to enhance cost-effective, evidence-based management of upper gastrointestinal symptoms. Such applications may provide an alternative to sequential empirical trials for symptoms.

Intestinal motility in small bowel diverticulosis: a case report and review of the literature

Small bowel diverticulosis is a rare disease that is usually associated with recurrent pseudo-obstruction, bacterial overgrowth, and malabsorption. The more severe complications include hemorrhage and perforation. There is evidence to suggest that this entity is a result of small bowel motor dysfunction. For this reason, it has been associated with disorders in which a myopathic or neuropathic process is involved, such as scleroderma. The majority of patients with jejunal diverticulosis do not require surgery and can be managed medically. We report a case of jejunal diverticulosis in a 63-year-old gentleman who presented with symptoms of pseudo-obstruction. Ambulatory duodenojejunal manometry revealed several abnormalities suggestive of small bowel motor dysfunction. Enteroclysis, however, did not find evidence of mechanical obstruction, and the patient had marked improvement with cisapride and antibiotics.

The patterns of small bowel motility: physiology and implications in organic disease and functional disorders

The physiology and pathophysiology of small bowel motility are reviewed with particular focus on the motility patterns and periods that are detected by intraluminal manometry. Motility patterns are groups of phasic pressure waves resulting from contractions of the circular muscle layer of the small bowel that are organized by the enteric nervous system. Phase III of the migrating motor complex, the hallmark of the fasting motility period, thus reflects enteric neuromuscular function. Response to meal challenge also involves the CNS, reflexes beyond the gut and endocrine responses. Although specific disease diagnosis cannot be made by motility studies of the small bowel, the functional integrity is revealed. The normal occurrence of the essential patterns and periods of motility and the absence of distinctly abnormal patterns evidence preserved function, whereas the opposite indicates clinically significant dysmotility. Certain motility patterns are occasionally seen both in health and disease, and increased prevalence indicates a moderate dysfunction of yet unclear significance. Bacterial overgrowth with Gram-negative bacilli is the consequence of severe small bowel dysmotility, and a diagnosis that can be predicted by a motility study. Testing can be useful in the clinical management of paediatric and adult patients also by predicting the prognosis and response to enteral nutrition and medical therapy. Further studies are, however, needed to take full advantage of motility testing in clinical practise.

Multiple intraluminal electrical impedancometry for recording of upper gastrointestinal motility: current results and further implications

This review focuses on current aspects of the novel technology of multiple intraluminal electrical impedance measurement. It presents methodological features, summarizes current results, and discusses potential implications for further research. The impedance technique assesses a bolus transport and its associated peristalsis. Validation studies showed a good analogy between physically deduced impedance characteristics and characteristics derived from cineradiography and manometry. From the impedance tracings, it is possible to distinguish between resting states, bolus transit, and wall contraction. Characteristics of a peristaltic wave can be obtained. In human studies, esophageal and small intestinal peristaltic patterns can quantitatively and qualitatively be assessed. A high resolution recording of bolus movements with interesting details of transport and mixing can be obtained. On the basis of several prior characterized impedance tracings duodenal contractile patterns have been classified, and the interdigestive and postprandial states characterized. For reflux evaluation the impedance technique was especially useful for the detection of nonacid gastroesophageal reflux, which is not detectable by pH monitoring. In summary, the main impact of the impedance technique is its capability to characterize esophageal and intestinal chyme transport. Important data on luminal chyme transport have been obtained. This technique is developing into an interesting investigative tool to complement standard techniques for study of upper GI motility, in particular for basic research.

Contractile patterns in patients with severe chronic dyspepsia

OBJECTIVE

Antroduodenojejunal interdigestive and postprandial pressure recordings were analyzed in 41 consecutive patients referred for evaluation of severe chronic dyspepsia. In addition to traditional manometric evaluation we also focused on the propagation pattern of individual pressure waves in the proximal duodenum.

METHODS

Catheters with closely spaced side holes for temporospatial analysis of the computerized recordings were used. The dominating symptoms were unexplained nausea and vomiting (n = 18), chronic abdominal pain (n = 16), or both (n = 7). The patients' mean age was 45 yr (31 women and 10 men). Gastric surgery had been performed on 11 patients. Results from 20 healthy volunteers served as a reference range.

RESULTS

Findings were suggestive of neuropathy in 16 (39%) and myopathy in 1 (2.4%) using conventional criteria. Another 19 patients of the 24 with normal condensed recordings showed abnormalities in the propagation pattern of individual pressure waves in phase II and/or during the fed state, when compared with the controls. Absence of phase III of the migrating motor complex was found in 12 patients during the 5-h fasting recording, compared with none in the controls (p < 0.01). Retroperistalsis at the end of phase III in the duodenum was present in at least one of the activity fronts in all patients having migrating motor complex except one, which was similar to the controls. During phase II, unpropagated bursts of phasic and tonic activity were more frequent in patients than in controls (mean 13.2% vs 3.7% of the time; p < 0.05), and a higher proportion of individual contractions was retrograde in patients than in controls (17.4% vs 5% of propagated contractions; p < 0.05). Patients had higher postprandial motility index in the distal duodenum than did controls (p < 0.05). Moreover, after feeding more individual contractions were retrograde in patients than in controls (33.1% vs 10% of propagated contractions; p < 0.01). Sequences of localized supratachyarrythmia, 25-35/min in the antrum and 50-60/min in the small bowel associated with symptoms, were observed in two patients.

CONCLUSION

Manometry is important for demonstration of pathophysiology in patients with unexplained abdominal pain, nausea, and vomiting. Simultaneous analysis of the propagation of individual contractions of interdigestive and fed motility is superior to conventional manometry alone.

Manometry of the upper intestinal tract in patients with systemic sclerosis: a prospective study

OBJECTIVE

To assess both the prevalence and the characteristics of motor disorders of the small bowel in patients with systemic sclerosis (SSc) and to investigate for an association between clinical manifestations in the upper intestinal tract, capillaroscopic features, esophageal motor impairment, and manometric evidence of motor disturbances.

METHODS

Fasting and postprandial motor activity of the upper intestinal tract was studied in 17 consecutive patients with SSc (6 with and 11 without clinical manifestations of small bowel involvement) and 17 age- and sex-matched healthy control subjects.

RESULTS

The prevalence of manometric evidence of intestinal involvement was as high as 88% in the SSc patients; normal motor activity was present in only 2 patients. The median values for duodenal and jejunal interdigestive phase III migrating motor complex duration, amplitude, and velocity and the postprandial motility index were therefore lower in SSc patients compared with controls. Our manometric findings indicated that there are both neuropathic and myopathic stages of upper intestinal tract dysfunction in SSc. Furthermore, no association could be found between the severity of the intestinal manometric abnormalities and clinical presentation, SSc subsets, disease score, capillaroscopic findings, or esophageal manometric impairment.

CONCLUSION

We suggest that manometry of the upper intestinal tract may be useful in SSc patients with clinical manifestations in the small bowel (i.e., malabsorption syndrome or pseudoobstruction) in that it can be used to accurately evaluate both the nature and the severity of motor disturbances. Furthermore, this procedure can be used to assist in the selection of patients who may require octreotide therapy.

Measurement of gastrointestinal motility in the GI laboratory

Current tests of gastric and small intestinal motor function provide relevant physiological information, but their clinical utility is controversial. This article reviews the current procedures, indications, significance, pitfalls, and guidelines for gastrointestinal motility measurements by scintigraphy, gastroduodenojejunal manometry, and surface electrogastrography in humans. Methods included review of literature and discussions in closed and open fora among investigators, including presentations for peer review at focused (Iowa City American Motility Society Symposium, December 1995) and national meetings (American Gastroenterological Association, May 1996, and American Motility Society, September 1996). The current tests are generally complementary; scintigraphy is typically the first test in the evaluation of gastric motor function and often confirms the clinical suspicion of dysmotility. Manometry identifies patterns suggestive of myopathy, neuropathy, or obstruction but may be most helpful when it shows entirely normal findings, because manometry helps in part to exclude dysmotility as a cause of symptoms. Electrogastrography may identify dysrhythmias or failure of signal power to increase postprandially; rhythm abnormalities may be independent of impaired emptying among dyspeptic patients. The best validated and clinically most significant results pertain to transit tests; manometry may contribute importantly to the diagnostic process; and the significance of electrogastrography remains to be fully elucidated.

Prolonged ambulatory duodeno-jejunal manometry in humans: normal values and gender effect

OBJECTIVE

The aim of this study was to provide a detailed comparison of motor activity in the duodenum and jejunum and between men and women studied by prolonged ambulatory manometry.

METHODS

Thirty healthy volunteers (17 males) underwent prolonged ambulatory recording of duodeno-jejunal motility using a catheter with five built-in strain-gauge transducers (two duodenal and three jejunal). Manometric data was obtained during an extended period of fasting, the postprandial period and during sleep.

RESULTS

There was a wide range of durations of the migrating motor complex (MMC), but at least one phase III was detected during 6 h of fasting, or 6 h of sleep in each subject (0.52+/-0.04 phase III/hour during fasting vs 0.59+/-0.04 during sleep, p=0.1). There was marked variation in the duration and pattern of phase III. Postprandially, frequency of contractions and motility index were maximal in the first 2 h after the meal, in both the duodenum and jejunum. There were no substantive differences between males and females or between the duodenum and jejunum.

CONCLUSION

We conclude that upper small bowel motility is little affected by gender or segment.

Discrimination of irritable bowel syndrome by non-linear analysis of 24-h jejunal motility

Conventional analysis of ambulatory longterm manometry of the small intestine has revealed abnormalities in patients with the irritable bowel syndrome (IBS). The aim was to use methods from non-linear dynamics, in particular the concepts of symbolic dynamics and entropy, in order to discriminate motility in IBS from healthy subjects. 24-h jejunal motility was recorded in 30 IBS patients and 30 healthy subjects. Computerized analysis of contraction amplitudes and intercontractile intervals was performed. Both time series were analysed by symbolic dynamics and entropy to quantify the degree of randomness inherent in the signal. During phase II IBS patients exhibited significantly increased entropies for the intercontractile intervals (IBS: 0.978 +/- 0.016, C: 0.965 +/- 0.020, P = 0.004) and for the contraction amplitudes (IBS: 0.978 +/- 0.008, C: 0.970 +/- 0.026, P = 0.05) compared with healthy subjects. In addition, a significantly increased mean contraction amplitude (mmHg) was found in patients (IBS: 25.2 +/- 4.8, C: 22.2 +/- 3.1, P = 0.003). Considering a combination of both parameters, a diagnostic accuracy of 82% was achieved. We conclude that phase II motility of the small intestine is more random in IBS than in health. Symbolic dynamics seems to be a promising new concept for the analysis of long-term gastrointestinal motility recordings.

A novel portable perfused manometric system for recording of small intestinal motility

The development of solid-state catheters with miniature pressure transducers and portable dataloggers with a large memory capacity has allowed recording of gastrointestinal motility in ambulant subjects. Developments in silicone rubber extrusion technology made it possible to build a perfused manometric system, using a perfused manometric assembly requiring a low volume of perfusate. In the present study the feasibility of recording and automated analysis of small intestinal motility using a perfused multiple lumen manometric system was evaluated in seven healthy volunteers. Pressures were recorded from 12 sideholes arranged in four clusters spaced at 10-cm intervals from the catheter tip. Each channel was perfused at 0.15 mL min-1 with degassed water by a portable, low-compliance, perfusion pump. The 12 sidehole recording channels were connected to external transducers mounted on a belt. Pressure data were stored in two dataloggers. Motility was recorded in the sitting (30 min), and supine (30 min) position, during walking (30 min) and postprandially (90 min). Using purpose-built software baseline variations were corrected for and manometric variables (number of pressure waves, mean amplitude and motility index) calculated. Bench testing of the manometric assembly showed a median baseline pressure offset of 4.2 kPa (range 3.7-10.1) and upon occlusion a rise rate of 27.8 kPa sec-1 (range 19.7-30.8). Changes in body position affected baseline pressures so that compared to the supine position changes in baseline pressure varied between 1.5 +/- 0.7 kPa and 1.9 +/- 0.6 kPa during sitting (P < 0.02), and between 1.7 +/- 0.7 kPa and 1.5 +/- 0.9 kPa during walking (P < 0.03). Manometric recordings obtained during the fasting period showed an increase in small intestinal motor activity during walking. In the postprandial period no differences in motility variables were observed within one cluster and in time. Recording of small intestinal motility with a multiple-channel silicone rubber manometric assembly with a portable perfusion system is a feasible technique which is relatively inexpensive. Computer-assisted data processing allows for adequate elimination of artefacts and automated numerical analysis.

Gastrointestinal motility disorders in patients with inactive Crohn's disease

BACKGROUND

Although some symptoms of Crohn's disease may be related to gastrointestinal motility disorders, studies on gastrointestinal motility in inactive Crohn's disease are lacking.

METHODS

Fasting and postprandial motor activity (1 h) was recorded in the gastric antrum and upper small intestine of 35 patients with inactive Crohn's disease and 18 controls, using conventional manometry.

RESULTS

Motor disorders were observed in 26 of 35 patients. The number of phase-II contractions was reduced (1.3 +/- 0.7/min versus 1.8 +/- 0.6/min in controls; P < 0.02) (mean +/- standard deviation), whereas the incidence of propagated single (2.2 +/- 3.2/h versus 0.5 +/- 0.6/h; P < 0.03) and clustered contractions (3.8 +/- 7/h versus 1.1 +/- 1.4, P < 0.04) was markedly increased. Motor abnormalities were more frequent and severe in patients with Crohn's ileitis than in controls, and in patients with gastrointestinal symptoms than in asymptomatic patients.

CONCLUSION

Most patients with inactive, uncomplicated Crohn's disease show marked gastrointestinal motor disorders, characterized either by reduced incidence of small-bowel contractions and increased incidence of single or clustered propagated contractions.

Duodenal obstruction: diagnosis by gastroduodenal manometry

Establishing the diagnosis of adenocarcinoma of the distal duodenum is often difficult based on findings on barium radiography and routine endoscopy of the upper gastrointestinal tract. A characteristic manometric pattern of simultaneous, prolonged contractions of the small intestine after a meal has been associated with mechanical obstruction of the small intestine. Herein we describe a 68-year-old woman who had a 4-month history of nausea, vomiting, and weight loss. Findings on endoscopy of the upper gastrointestinal tract and a barium contrast examination of the stomach, duodenum, and small bowel were interpreted as normal. A radionuclide scan suggested mildly delayed gastric emptying. Gastroduodenal manometry revealed high-amplitude, simultaneous contractions in the third and fourth portions of the duodenum but not in the jejunum, findings highly suggestive of a mechanical obstruction in the distal duodenum. At laparotomy, an obstructing adenocarcinoma of the duodenum proximal to the ligament of Treitz was resected. Subtle abnormalities were detected retrospectively on the barium contrast study of the small bowel. In patients with features suggestive of intestinal obstruction, gastroduodenal manometry may be helpful in distinguishing mechanical causes from pseudo-obstruction.

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 and ad 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 an ad libitum meal accurately reflects the fed motor response.

Clinical value of duodenojejunal manometry. Its usefulness in diagnosis and management of patients with gastrointestinal symptoms

The records of all patients who had duodenojejunal manometry (DJM) from 1989 to 1995 were retrospectively reviewed. We evaluated the main symptoms of the patients, the indication for the study, its result, and the impact on therapy and management. One hundred sixteen patients out of 154 were included in the study, of whom 96 were women and 20 were men, with a mean age of 41.2 years. Twenty-five had perfused tube studies, and 91 had prolonged ambulatory recordings. Forty-one patients were referred for evaluation of abdominal pain, 34 for chronic constipation, 24 for nausea and vomiting, 8 for pseudoobstruction, and the remaining 9 for other reasons. All patients had appropriate endoscopic, radiographic, or scintigraphic studies prior to manometry. Forty-seven (40.5%) had abnormal manometry: 20 of 41 (48.8%) for abdominal pain, 7 of 34 (20.6%) for chronic constipation, 10 of 24 (41.7%) for nausea and vomiting, 5 of 8 (62.5%) for pseudoobstruction, and 5 of 9 (55.6%) for the miscellaneous group. The various subgroups did not have specific patterns of motor abnormalities. In 22 patients (18.9%) manometry helped in the choice of therapy: in 15 patients by affecting surgical approach, particularly in the constipation group, and in 7 patients by affecting feeding options and prokinetic agents. Detection of motor abnormalities was helpful in patients with severe symptoms thought to have functional disease even when no specific therapy was rendered. Thus, DJM was abnormal in 2/5 patients referred for evaluation of suspected motility disorders. It directly affected therapy in approximately 1/5 patients, particularly in those with constipation. It is helpful in the management of patients even when specific therapy is not rendered, particularly in those with abdominal pain. The modest impact on specific therapy is related to limited availability of effective prokinetic drugs and the limited specificity and predictive value of tests results.

Antral axial forces postprandially and after erythromycin in organic and functional dysmotilities

Our aims were to measure antral axial forces in patients with suspected upper gut dysmotilities and to compare the number of antral contractions detected by an axial force catheter and by manometric sensors in the distal antrum and pylorus. Fifteen patients (2 men, 13 women; mean age 42 years) underwent studies for 3 hr fasting, 2 hr postprandially, and up to 60 min after intravenous erythromycin (3mg/kg). Seven patients had gastroparesis or chronic intestinal pseudoobstruction, five functional disease, and three subacute obstruction. Postprandially, the number of peaks detected by the two methods was not significantly different; however, after erythromycin, the axial catheter detected more contractions (P = 0.02). Erythromycin significantly increased the number of postprandial axial forces (from 1.2 +/- 0.3/min to 2.5 +/- 0.3/min, P < or = 0.01) in the whole group and in the organic dysmotility group (P = 0.01). Erythromycin significantly increases the number of axial forces in functional and organic upper gut dysmotilities, but the axial force catheter is not advantageous over manometry for postprandial measurements of antral motility.

Gastrointestinal motility in neonatal and pediatric practice

Caring for children with gastrointestinal motility disorders requires an understanding of age-related changes in gastrointestinal function and in the clinical expression of disease. Successful evaluation of the child with a gastrointestinal motility disorder necessitates an approach that takes into account not only the child's symptoms, but also the stage of development. This article reviews the ontogeny of gastrointestinal motility; the techniques available for the study of gastrointestinal motility in children; and the presentation, pathophysiology, and treatment of pediatric functional bowel diseases. Differences in children compared to adults in performing and analyzing motility testing and in evaluating motility disorders are emphasized. A more complete understanding of pediatric motility disorders may provide important insights in approaching functional bowel diseases in adults.

Abnormal intestinal motor patterns explain enteric colonization with gram-negative bacilli in late radiation enteropathy

BACKGROUND & AIMS

Bacterial overgrowth and intestinal pseudo-obstruction may succeed abdominal radiotherapy, and absence of intestinal migrating motor complex (MMC) has been reported in bacterial overgrowth. The aims of this study were to address the relationship between intestinal patterns of motility and gastrointestinal microflora and to elucidate the pathogenesis of late radiation enteropathy.

METHODS

Forty-one consecutive female patients with symptoms of late radiation enteropathy were examined by prolonged ambulatory manometry, culture of gastric and duodenal samples with quantification of gram-negative bacilli (GNB) by the glucose gas test, the [14C]D-xylose breath test, and determination of pH and short-chain fatty acids in gastric juice.

RESULTS

The intensity of MMC explained 61% (P < 0.001) and 71% (P < 0.001) of the variability of GNB in the stomach and duodenum, respectively, corresponding to the severity of disease. Abnormal MMC index and presence of irregular bursts were the best predictors of GNB (86%; P < 0.001, multiple regression). Fasting gastric pH explained gastric bacterial counts (63%; P < 0.001) but did not predict GNB.

CONCLUSIONS

Impaired motility emerges as a causal factor for gastrointestinal colonization with GNB, whereas hypochlorhydria facilitates unspecific gastric colonization. Abnormal motility and GNB in the proximal small intestine are essential factors in the pathogenesis of severe late radiation enteropathy.

Role of nuclear medicine in evaluating patients with suspected gastrointestinal motility disorders

Functional symptoms caused by gastrointestinal motility disorders are relatively common in the general population. Knowledge of the relationship between symptoms and the underlying gastrointestinal dysmotility provides physicians with a framework for successful evaluation and treatment of patients with possible motor disorders of the gastrointestinal tract. Scintigraphy provides for noninvasive and quantitative assessment of physiological transit throughout the gastrointestinal tract, and it is extremely useful for diagnosing gastrointestinal motor dysfunction. The wide range of scintigraphic studies now available supplement other diagnostic tests for evaluation of all segments of the gastrointestinal tract.

Mechanism of accelerated gastric emptying of liquids and hyperglycemia in patients with type II diabetes mellitus

BACKGROUND & AIMS

The roles of hyperglycemia in diabetic gastroparesis and gastric delivery in postprandial hyperglycemia of diabetic patients are unclear. The aims of this study were to assess gastric emptying and its relation to postprandial glucose metabolism in patients with asymptomatic non-insulin-dependent diabetes mellitus (NIDDM) and no autonomic neuropathy and to identify motor mechanisms responsible for any accelerated gastric emptying.

METHODS

Autonomic function, gastric emptying, postprandial glucose metabolism, and hormone levels (glucagon, insulin, cholecystokinin, glucose-dependent insulinotropic polypeptide, neurotensin, and peptide YY) were assessed in healthy volunteers and patients with NIDDM. In a second study, gastric tone and motility were measured in patients with accelerated gastric emptying and in controls.

RESULTS

Gastric emptying of solids did not differ in the two groups, but liquids emptied faster in patients with NIDDM (P < 0.02). The rate of entry of ingested glucose into the systemic circulation was similar, but higher postprandial glucagon and lower insulin concentrations led to greater (P < 0.01) postprandial hepatic glucose release. Levels of other enteropeptides, gastric accommodation, and antral motility were similar, but patients with NIDDM had greater proximal gastric phasic contractions than controls (P < 0.05).

CONCLUSIONS

Excessive hepatic glucose release, not rapid entry of ingested glucose, is the primary cause of postprandial hyperglycemia in patients with NIDDM. Accelerated gastric emptying in patients with nonneuropathic NIDDM is associated with increased proximal stomach phasic contractions.

Intestinal motility and jejunal feeding in children with chronic intestinal pseudo-obstruction

BACKGROUND/AIMS

Total parenteral nutrition is responsible for most of the morbidity and mortality of childhood chronic intestinal pseudo-obstruction (CIP). The aim of this study was to determine if there are manometric patterns associated with the success of jejunal feedings in children with CIP.

METHODS

Eighteen children with CIP (age range, 1-9 years; mean, 4 years; 11 boys and 7 girls) were studied. All patients required parenteral nutrition or failed to thrive while receiving gastrostomy feedings. All underwent an antroduodenal manometry before surgical placement of a jejunostomy. Continuous drip jejunal feeding with an elemental formula was subsequently initiated. Follow-up after jejunal feeding was 1.6 years (range, 6 months to 4 years). Jejunal manometry was performed 2 months to 1 year after jejunostomy.

RESULTS

Jejunal feeding eliminated the need for parenteral nutrition in all 9 patients with migrating motor complex (MMC) and in 3 of 9 patients without MMC (P < 0.01). The MMC was present or absent in both antroduodenal and jejunal manometry in 14 of 18 children (77.7%). In 10 of 18 children (55%), duodenal and jejunal manometry showed similar qualitative abnormalities.

CONCLUSIONS

In selected children with CIP who fail gastrostomy feeding, jejunal tube feeding is an alternative to parenteral nutrition. The presence of MMCs is associated with a successful adaptation to jejunal feeding.

Abnormalities in the shape of the duodenal loop on X-ray. Associated with idiopathic antral hypomotility?

We aimed to determine if abnormalities in the shape of the duodenal loop would be useful in identifying patients with gastroduodenal dysmotility. Retrospectively, 126 consecutive patients with suspected functional abdominal symptoms who underwent upper gastrointestinal barium x-ray studies and gastrointestinal manometry were independently evaluated. Twenty-seven patients (21%) had an abnormally shaped duodenal loop (two proximal and 25 distal) by x-ray. An abnormal duodenal loop was associated with female gender but the presenting symptoms were similar in patients with normal and abnormal loops. Antral hypomotility was significantly more common in patients with distal duodenal malrotations compared to those with a normal x-ray (56% vs 27%, P < 0.01); intestinal dysmotility was not associated with the shape of the duodenal loop. The presence of an abnormally shaped duodenal loop in patients presenting with functional gastrointestinal symptoms may be a useful marker for idiopathic antral hypomotility.

Effect of octreotide on gastrointestinal pressure profiles in health and in functional and organic gastrointestinal disorders

The somatostatin analogue, octreotide, restores normal pressure profiles in disorders of upper gut motility. This study aimed to evaluate the acute effects of octreotide in five healthy subjects and in 50 consecutive patients with functional (n = 22) or organic (n = 28) dysmotility. Antroduodenojejunal manometry was performed during three hours' fasting, for two hours after a standard meal, and 30 minutes after subcutaneous injection of 50 micrograms octreotide. Antral motility, before and after octreotide, and characteristics of spontaneous migrating motor complexes and octreotide induced activity fronts were compared. Octreotide inhibited antral motility and induced a small intestinal activity front followed by motor quiescence in all healthy subjects and patients. The duration and propagation velocity of activity fronts were greater than those of spontaneous migrating motor complexes. Thirty per cent of activity fronts began simultaneously at different levels of small bowel, and in 20%, a second, normally propagated activity front developed within 30 minutes of octreotide injection. Octreotide induces rapidly propagated, long activity fronts, even in patients with neuropathology, and this may initially facilitate the intestinal propulsion of chyme. Propulsion may not occur, however, if octreotide induces simultaneous activity fronts or if the activity front is followed by prolonged quiescence. Inhibition of antral motility suggests that octreotide may not be effective in gastroparesis.

Response of gastric fundus to rectal distension in healthy persons

We aimed to record fundic motor activity in man using the barostat to ascertain if fundic motility is affected by rectal distension. The distal ends of two barostat tubes were placed in the gastric fundus and rectum in 10 healthy volunteers. The gastric bag was first inflated to a constant pressure level that recorded phasic motor activity as changes in volume of the air-filled bag. Baseline motor activity was recorded before, during, and after a 15-min period of constant rectal distension that was clearly perceived by all subjects but was not painful. In all subjects, continuous phasic volume changes, reflecting fundic motor activity, were recorded at a rate of 1-3/min. During rectal distension, a consistent change in mean contractile force of these phasic volume events was not detected; a decrease of more than 30% occurred in only three subjects. We conclude that fundic phasic volume changes are recordable by the barostat, but these are not substantially inhibited by rectal distension.