Altered gastric emptying in patients with irritable bowel syndrome

β-Endorphins are not responsible for delayed gastric emptying of digestible solids after exercise in professional cyclists. A preliminary study

OBJECTIVE

It has been reported that professional cyclists had an accelerated solid gastric emptying which decreased by increasing the exercise intensity. That could be explained by a predominance of stress-dependent motility inhibitors such gastrointestinal hormones, neurotransmitters and or the predominance of the gastric inhibitory vagal motor circuit. The aim of this preliminary study was to evaluate the role of β-endorphins, inhibitors of gastric motility, in these findings.

METHODS

Gastric emptying of solids marked with Tc⁹⁹ while resting and plasmatic levels of β-endorphins were evaluated in 27 healthy controls and 19 professional cyclists (day 1). Besides, gastric emptying of solids was also assessed in cyclists when they reached 50% (day 1) and 75% (day 2) of the maximum oxygen consumption (low and high, respectively), during exercise on the cycle-ergometer. The third day, naloxone was administered in cyclists in order to block the β-endorphins receptors and gastric emptying was measured when they reached 75% of the maximum oxygen consumption.

RESULTS

Basal β-endorphin levels were lower in cyclists vs controls (p<0.05) and they increased with the exercise intensity (p<0.001). There were no significant differences in gastric emptying of solids with or without naloxone when 75% of the maximum oxygen consumption was reached.

CONCLUSIONS

The inhibitory effect of the exercise in the gastric emptying of solids does not seem to be secondary to the action of β-endorphins, that leaves the gastric inhibitory vagal motor circuit a more likely predominant role.

Helicobacter pylori Infection—A Risk Factor for Irritable Bowel Syndrome? An Updated Systematic Review and Meta-Analysis

Nowadays, the relationship between Helicobacter pylori infection (HPI) and irritable bowel syndrome (IBS) remains controversial. Objective: The aim of this study is to investigate the relationship between HPI and IBS through a systematic review and meta-analysis based on the current evidence. Methods: We performed a systematic literature search in electronic databases (PubMed, EMBASE, and the Cochrane library) by computer to identify all reports published before 8 August 2021. The odds ratio (OR) and confidence interval (CI) were calculated to evaluate the association between HPI and IBS. Subgroup analyses were conducted for further assessment and exploration of heterogeneity sources. In addition, we assessed publication bias through funnel plots, Egger’s test, and Begg’s test. Finally, we conducted a sensitivity analysis to evaluate the robustness of the results. Results: Thirteen studies with 13,173 participants were included in the meta-analysis. The pooled OR of the association between HPI and IBS was 1.03 (95% CI [0.80,1.31]; p = 0.84). The adjusted OR of the association between HPI and IBS after excluding the studies with confounding factors defined by our team was 1.29 (95% CI [1.03,1.62]; p = 0.03). We found a positive association between HPI and IBS-D (diarrhea subtype) (OR: 1.54; 95% CI [1.22,1.95]; p = 0.0003). The OR of the relationship between cytotoxin-associated gene A (Cag A) positive HPI and IBS was 4.3 (95% CI [0.51,36.17]; p = 0.18). Conclusions: The likelihood of HPI in IBS patients is relatively higher than that of non-IBS participants but not statistically significant, implying that HPI is not significantly associated with IBS, albeit we may underestimate this association. Moreover, we found a positive association between HPI and IBS-D. We also observed an increased likelihood of Cag-A positive HPI in IBS patients than that of non-IBS participants but not statistically significant.

Association between Helicobacter pylori infection and irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori infection and irritable bowel syndrome (IBS) negatively affect the quality of life. Some previous studies found that H. pylori infection should be positively associated with the risk of IBS, but others did not. The present study aims to clarify this association, and to further analyse whether H. pylori treatment can improve IBS symptoms.

MATERIALS AND METHODS

The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure, China Science and Technology Journal and Wanfang databases were searched. Meta-analysis was performed using a random-effect model. The pooled odds ratios (ORs)/risk ratios (RRs) and their 95% CIs were calculated. Heterogeneity was evaluated using the Cochran's Q test and I² statistics. Meta-regression analysis was used to explore the sources of heterogeneity.

RESULTS

Thirty-one studies with 21 867 individuals were included. Meta-analysis of 27 studies found that patients with IBS had a significantly higher risk of H. pylori infection than those without (OR=1.68, 95% CI 1.29 to 2.18; p<0.001). The heterogeneity was statistically significant (I^²=85%; p<0.001). Meta-regression analyses indicated that study design and diagnostic criteria of IBS might be the potential sources of heterogeneity. Meta-analysis of eight studies demonstrated that H. pylori eradication treatment had a higher improvement rate of IBS symptoms (RR=1.24, 95% CI 1.10 to 1.39; p<0.001). The heterogeneity was not significant (I^²=32%; p=0.170). Meta-analysis of four studies also demonstrated that successful H. pylori eradication had a higher improvement rate of IBS symptoms (RR=1.25, 95% CI 1.01 to 1.53; p=0.040). The heterogeneity was not significant (I^²=1%; p=0.390).

CONCLUSION

H. pylori infection is associated with an increased risk of IBS. H. pylori eradication treatment can improve IBS symptoms.

The Impact of Gastrointestinal Symptoms on Patients' Well-Being: Best-Worst Scaling (BWS) to Prioritize Symptoms of the Gastrointestinal Symptom Score (GIS)

Background: The gastrointestinal symptom score (GIS) is used in a standardized form to ascertain dyspeptic symptoms in patients with functional dyspepsia in clinical practice. As a criterion for evaluating the effectiveness of a treatment, the change in the summed total point value is used. The total score ranges from 0 to 40 points, in which a higher score represents a more serious manifestation of the disease. Each symptom is included with equal importance in the overall evaluation. The objective of this study was to test this assumption from a patients’ perspective. Our aim was to measure the priorities of patients for the ten gastrointestinal symptoms by using best–worst scaling. Method: A best–worst scaling (BWS) object scaling (Case 1) was applied. Therefore, the symptoms of the GIS were included in a questionnaire using a fractional factorial design (BIBD—balanced incomplete block design). In each choice set, the patients selected the component that had the most and the least impact on their well-being. The BIB design generated a total of 15 choice sets, which each included four attributes. Results: In this study, 1096 affected patients were asked for their priorities regarding a treatment of functional dyspepsia and motility disorder. Based on the data analysis, the symptoms abdominal cramps (SQRT (B/W): −1.27), vomiting (SQRT (B/W): −1.07) and epigastric pain (SQRT (B/W): −0.76) were most important and thus have the greatest influence on the well-being of patients with functional dyspepsia and motility disorders. In the middle range are the symptoms nausea (SQRT (B/W): −0.69), acid reflux/indigestion (SQRT (B/W): −0.29), sickness (SQRT (B/W): −0.26) and retrosternal discomfort (SQRT (B/W): 0.26), whereas the symptoms causing the least impact are the feeling of fullness (SQRT (B/W): 0.80), early satiety (SQRT (B/W): 1.54) and loss of appetite (SQRT(B/W): 1.95). Discussion: Unlike the underlying assumption of the GIS, the BWS indicated that patients did not weight the 10 symptoms equally. The results of the survey show that the three symptoms of vomiting, abdominal cramps and epigastric pain are weighted considerably higher than symptoms such as early satiety, loss of appetite and the feeling of fullness. The evaluation of the BWS data has illustrated, however, that the restrictive assumption of GIS does not reflect the reality of dyspeptic patients. Conclusions: In conclusion, a preference-based GIS is necessary to make valid information about the real burden of illness and to improve the burden of symptoms in the indication of gastrointestinal conditions. The findings of the BWS demonstrate that the common GIS is not applicable to represent the real burden of disease. The results suggest the potential modification of the established GIS by future research using a stated preference study.

Quantification of mucosal EEC in jejunum. A comparative study of IBS patients and healthy controls

Background: Enteroendocrine cells (EEC) have been suggested to have a role in the pathogenesis of irritable bowel syndrome (IBS). Although many studies have analysed possible numeric changes of EEC in IBS, the results differ between different studies. One reason might be due to difficulties in standardising the morphometric method.Aim: The aim of this study was to compare two different methods for counting EEC in jejunum biopsies from patients with IBS and healthy controls.Method: Fifty-one patients with IBS and 35 healthy controls were included in the study. Jejunum mucosa was procured using a Watson capsule. Slides were immunostained for serotonin and chromogranin A and then scanned digitally. The morphometry was done by counting cells per high power field (hpf) and per mm² after defining area of the mucosa. The two methods were compared using Bland Altman analysis.Results: There was no difference in the number of EEC in patients with IBS compared to healthy controls. The number of cells detected by per mm² area of mucosa were higher than number of cells per hpf. Counting EEC per high power field systematically underestimated the number of cells in the mucosal area.Conclusions: Counting cells per mm² mucosal area gives a better representation of the number of EEC in small bowel mucosa. The finding of no difference in EEC numbers does not imply an equal function and further studies are needed to evaluate the role, if any of EEC, in IBS.

The Association between Helicobacter pylori Infection and Irritable Bowel Syndrome: A Meta-Analysis

The association of Helicobacter pylori (H. pylori) infection with functional dyspepsia has been well studied. However, the data on the relationship between H. pylori infection and irritable bowel syndrome (IBS) are conflicting. This study aims to elucidate the association between H. pylori infection and IBS. PubMed, Cochrane Library, CINAHL and SCOPUS databases were searched to identify eligible English articles published up to December 2019. Cross-sectional studies, case–control studies and cohort studies reporting both prevalence of H. pylori infection and IBS were selected for the detailed review. The pooled odds ratio (ORs) and their 95% confidence interval (CI) were calculated. A total of 7269 individuals in four cross-sectional studies and six case-control studies were included. The prevalence of H. pylori infection ranged from 12.8% to 73.4% in the control group, and 9.7% to 72.1% in the IBS group. The combined OR for H. pylori infection was 1.10 (95% CI: 0.93–1.29, I²: 37.5%). In a subgroup analysis of IBS defined according to Rome criteria, the OR for H. pylori infection was 1.10 (95% CI: 0.93–1.30, I² = 31.7%). In this meta-analysis, H. pylori infection was not significantly associated with IBS. Well-designed studies are needed to identify the relationship between H. pylori infection and IBS.

Recent advances in the diagnosis of irritable bowel syndrome

The symptom-based diagnosis of irritable bowel syndrome (IBS) has not been established in everyday clinical practice, and the diagnosis of this disorder remains one of exclusion. It has been demonstrated that the densities of duodenal chromogranin A, rectal peptide YY and somatostatin cells are good biomarkers for the diagnosis of sporadic IBS, and low-grade mucosal inflammation is a promising biomarker for the diagnosis of postinfectious IBS. Genetic markers are not useful as biomarkers for IBS since the potential risk genes have yet to be validated, and the intestinal microbiota cannot be used because of the lack of an association between a specific bacterial species and IBS. Furthermore, gastrointestinal dysmotility and visceral hypersensitivity tests produce results that are too nonconsistent and noncharacteristic to be used in the diagnosis of IBS. A combination of symptom-based assessment, exclusion of overlapping gastrointestinal diseases and positive biomarkers appears to be the best way to diagnose IBS.

Gastric Electrical Stimulation and Sacral Electrical Stimulation: A Long-Term Follow-Up Study of Dual-Device Treatment

AIMS

The objective of this study was to investigate sacral electrical stimulation (SES) and gastric electrical stimulation (GES) by comparing upper and lower gastrointestinal (GI) and genitourinary (GU) symptoms and quality of life, before treatment and in the long term after treatment. We hypothesized that dual-device treatment would greatly improve upper and lower gastrointestinal and genitourinary symptoms, as well as quality of life.

METHODS

Fifty-four patients who underwent dual-device treatment (GES and SES) were enrolled in this study. Patients who had surpassed 24 months since the second-device insertion were included. Patients were evaluated before and after both devices were implanted and given a symptom questionnaire regarding their upper GI, lower GI, and GU symptoms and their quality of life.

RESULTS

With combined treatment, a statistically significant improvement was seen in upper GI, lower GI, and GU symptoms and quality of life. However, fecal incontinence and fecal urgency improvements did not reach statistical significance, likely due to the small sample size.

CONCLUSION

The implantation of two stimulators appears to be safe and effective to improve patients' quality of life for those with upper GI symptoms, bowel problems, and bladder dysfunction.

Interaction between ingested nutrients and gut endocrine cells in patients with irritable bowel syndrome (review)

Several endocrine cell abnormalities have been reported in different segments of the gastrointestinal tract of patients with irritable bowel syndrome (IBS). These cells have specialized microvilli that project into the lumen; they function as sensors for the gut contents and respond to luminal stimuli (mostly ingested nutrients) by releasing hormones into the lamina propria, where they exert their effects via a paracrine/endocrine mode of action. Certain food items trigger the symptoms experienced by IBS patients, including those rich in fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs). In this review, we present the argument that the effects of both FODMAPs and the proportional intake of proteins, fats and carbohydrates on IBS symptoms may be caused by an interaction with the gut endocrine cells. Since the gut hormones control and regulate gastrointestinal motility and sensation, this interaction may be responsible for abnormal gastrointestinal motility and the visceral hypersensitivity observed in these patients. There is no consistent evidence that IBS patients suffer from food allergy. The role of gluten intolerance in the development of IBS symptoms in these patients remains a matter of controversy. Individual guidance on food management, which includes restrictions in the intake of FODMAP-rich foods and testing diets with different proportions of proteins, fats and carbohydrates has been found to reduce the symptoms, improve the quality of life, and make the habitual diet of IBS patients more healthy.

Ultrasonographic assessment of liquid gastric emptying and antral motility according to the subtypes of irritable bowel syndrome in children

OBJECTIVES

Gastric motor abnormalities have been reported in adults with irritable bowel syndrome (IBS), commonly in constipation-predominant IBS (IBS-C); however, such studies are uncommon in children. Furthermore, differences of gastric motility have not been studied in children with different IBS subtypes.

METHODS

Seventy-six children (33 [43%] boys, age 4-14 years, mean 7.9 years, SD 3.0 years) fulfilling Rome III criteria for IBS and 20 healthy controls (8 [40%] boys, age 4-14 years, mean 8.4 years, SD 3.0 years) were recruited (diarrhea-predominant IBS=21, IBS-C=31, mixed IBS=19, and unsubtyped IBS=5). Liquid gastric emptying rate (GER) and antral motility were assessed using an ultrasound method.

RESULTS

Average GER (43.8% vs 66.2% in controls), amplitude of antral contractions (56.4% vs 89%), and antral motility index (5.1 vs 8.3) were lower and fasting antral area (1.6 vs 0.6) was higher in patients with IBS (P<0.0001). Frequency of antral contractions F (8.9 vs 9.3) did not show a significant difference. Patients exposed to stressful events had a significantly lower GER, compared to those not exposed to such events (P=0.03). Gastric motility parameters had no correlation with severity of symptoms. GER (42.6%, 46.3%, 39.6%), fasting antral area (1.4 cm², 1.8 cm², 1.8 cm²), amplitude of antral contractions (53%, 58.9%, 51.8%), frequency of antral contractions (8.7, 8.9, 9.2), and antral motility index (4.7, 5.3, 4.8) were not different among diarrhea-predominant IBS, IBS-C, and mixed IBS (P>0.05).

CONCLUSIONS

GER and antral motility parameters were significantly impaired in children with IBS compared with controls. GER and antral motility parameters were not different between IBS subtypes.

Irritable bowel syndrome: Diagnosis and pathogenesis

Irritable bowel syndrome (IBS) is a common gastrointestinal (GI) disorder that considerably reduces the quality of life. It further represents an economic burden on society due to the high consumption of healthcare resources and the non-productivity of IBS patients. The diagnosis of IBS is based on symptom assessment and the Rome III criteria. A combination of the Rome III criteria, a physical examination, blood tests, gastroscopy and colonoscopy with biopsies is believed to be necessary for diagnosis. Duodenal chromogranin A cell density is a promising biomarker for the diagnosis of IBS. The pathogenesis of IBS seems to be multifactorial, with the following factors playing a central role in the pathogenesis of IBS: heritability and genetics, dietary/intestinal microbiota, low-grade inflammation, and disturbances in the neuroendocrine system (NES) of the gut. One hypothesis proposes that the cause of IBS is an altered NES, which would cause abnormal GI motility, secretions and sensation. All of these abnormalities are characteristic of IBS. Alterations in the NES could be the result of one or more of the following: genetic factors, dietary intake, intestinal flora, or low-grade inflammation. Post-infectious IBS (PI-IBS) and inflammatory bowel disease-associated IBS (IBD-IBS) represent a considerable subset of IBS cases. Patients with PI- and IBD-IBS exhibit low-grade mucosal inflammation, as well as abnormalities in the NES of the gut.

Low densities of serotonin and peptide YY cells in the colon of patients with irritable bowel syndrome

BACKGROUND

The gut hormones are important in regulating gastrointestinal motility. Disturbances in gastrointestinal motility have been reported in patients with irritable bowel syndrome (IBS). Reduced endocrine cell density, as revealed by chromogranin A, has been reported in the colon of IBS patients.

AIMS

To investigate a possible abnormality in the colonic endocrine cells of IBS patients.

METHODS

A total of 41 patients with IBS according to Rome Criteria III and 20 controls were included in the study. Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. The biopsies were immunostained for serotonin, peptide YY (PYY), pancreatic polypeptide (PP), entroglucagon, and somatostatin cells. Cell densities were quantified by computerized image analysis.

RESULTS

Serotonin and PYY cell densities were reduced in the colon of IBS patients. PP, entroglucagon, and somatostatin-immunoreactive cells were too few to enable reliable quantification.

CONCLUSION

The cause of these observations could be primary genetic defect(s), secondary to altered serotonin and/or PYY signaling systems and/or subclinical inflammation. Serotonin activates the submucosal sensory branch of the enteric nervous system and controls gastrointestinal motility and chloride secretion via interneurons and motor neurons. PYY stimulates absorption of water and electrolytes, and inhibits prostaglandin (PG) E2, and vasoactive intestinal peptide, which stimulates intestinal fluid secretion and is a major regulator of the "ileal brake". Although the cause and effect relationship of these findings is difficult to elucidate, the abnormalities reported here might contribute to the symptoms associated with IBS.

Classification of functional dyspepsia based on concomitant bowel symptoms

BACKGROUND

  Functional dyspepsia (FD) is a heterogeneous disease, and categorized into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). However, many FD patients have overlap of both PDS and EPS. The present study was designed to examine whether FD could be categorized based on the presence of concomitant gastrointestinal symptoms.

METHODS

  A web survey comprised of the Gastrointestinal Symptom Rating Scale (GSRS), Rome III criteria of FD, and demographic information was sent to public participants who have no history of severe illness. Factor and cluster analyses were conducted to identify sub-categories of FD based on GSRS.

KEY RESULTS

  A total of 8038 participants completed the survey. A total of 563 participants met the criteria for FD, whereas 6635 participants did not have dyspepsia symptoms. The remainder had either organic disease (377) or uninvestigated dyspepsia (463). The cluster analysis categorized participants as constipation predominant (cluster C), diarrhea predominant (cluster D), or having neither diarrhea nor constipation (cluster nCnD). Cluster C and D were significantly associated with the presence of FD [odds ratio (OR) 2.57, 95% confidence interval (CI) 2.06-3.21; OR 2.80; 95% CI 2.27-3.45, respectively]. In FD, especially in PDS cases, the scores of upper gastrointestinal symptoms were higher in cluster C or D than in cluster nCnD.

CONCLUSIONS & INFERENCES

  The severity of dyspepsia symptoms is associated with the presence of bowel symptoms especially in PDS. This novel categorization of FD based on concomitant constipation or diarrhea may improve classification of patients.

Pathophysiologic findings of irritable bowel syndrome in china

The mechanism of irritable bowel syndrome (IBS) is still incompletely understood in the world although large amount of investigations have been carried out on it. There are many studies on the pathophysiology of IBS in China, which has huge amount of population suffering from IBS with special ethnicity and culture, including Mainland China, Hong Kong and Taiwan. We collected the literatures to show the results and discuss whether there were any differences in the pathophysiologic findings between China and other countries, whether there were any differences among different subtypes and how the pathophysiology correlated with the manifestations of patients. Gene polymorphism, disturbances of gastrointestinal motility, visceral hypersensitivity, intestinal infection and inflammation, psychological disturbances, food hypersensitivity and intolerance, and altered gut microflora were reviewed in this paper. Some conflicting outcomes between China and other countries were noted although most of them were similar.

Abnormal small-intestinal endocrine cells in patients with irritable bowel syndrome

BACKGROUND

General disturbances in gastrointestinal motility have been reported in patients with irritable bowel syndrome (IBS). The gastrointestinal tract hormones play an important role in regulating gastrointestinal motility.

AIMS

To investigate a possible abnormality in the small intestinal endocrine cells of IBS patients.

METHODS

Included in the study were 41 patients with irritable bowel syndrome according to Rome Criteria III and 42 healthy controls. Duodenal biopsies were obtained from both patients and controls during gastroscopy. The biopsies were immunostained by avidin-biotin-complex method for secretin, CCK, GIP, somatostatin, and serotonin cells. The cell densities were quantified by computerized image analysis.

RESULTS

The density of secretin- and CCK-immunoreactive cells in patients with IBS was significantly reduced. The reduction in secretin and CCK cells occurred only in IBS-diarrhea patients, but not in IBS-constipation subtype. Both GIP and somatostatin cell densities were reduced in the duodenum of IBS patients. There was no statistical difference between the subtypes of IBS patients, regarding secretin, CCK, GIP, or somatostatin cell densities. Serotonin cell density was not affected in patients with IBS.

CONCLUSIONS

The low densities of secretin and CCK cells in IBS-diarrhea patients may cause a functional pancreatic insufficiency as well as inadequate gall emptying, as these hormones stimulate pancreatic bicarbonate and enzyme secretion and CCK stimulates as well gall bladder contraction. Low densities of secretin, GIP, and somatostatin cells in IBS patients might result in a high secretion of gastric acid, as secretin, GIP, and somatostatin inhibit gastric acid secretion.

Asian consensus on irritable bowel syndrome

BACKGROUND AND AIMS

Many of the ideas on irritable bowel syndrome (IBS) are derived from studies conducted in Western societies. Their relevance to Asian societies has not been critically examined. Our objectives were to bring to attention important data from Asian studies, articulate the experience and views of our Asian experts, and provide a relevant guide on this poorly understood condition for doctors and scientists working in Asia.

METHODS

A multinational group of physicians from Asia with special interest in IBS raised statements on IBS pertaining to symptoms, diagnosis, epidemiology, infection, pathophysiology, motility, management, and diet. A modified Delphi approach was employed to present and grade the quality of evidence, and determine the level of agreement.

RESULTS

We observed that bloating and symptoms associated with meals were prominent complaints among our IBS patients. In the majority of our countries, we did not observe a female predominance. In some Asian populations, the intestinal transit times in healthy and IBS patients appear to be faster than those reported in the West. High consultation rates were observed, particularly in the more affluent countries. There was only weak evidence to support the perception that psychological distress determines health-care seeking. Dietary factors, in particular, chili consumption and the high prevalence of lactose malabsorption, were perceived to be aggravating factors, but the evidence was weak.

CONCLUSIONS

This detailed compilation of studies from different parts of Asia, draws attention to Asian patients' experiences of IBS.

Mechanisms of burn-induced impairment in gastric slow waves and emptying in rats

Delayed gastric emptying is common following severe large cutaneous burns; however, the mechanisms of burn-induced delayed gastric emptying remain unknown. The aim of this study was to explore the possible involvement of hyperglycemia and cyclooxygenase-2 receptors in the burn-induced gastric dysrhythmias. Gastric slow waves and gastric emptying were assessed in rats 6 h following sham or burn injury. Animals were randomized to one sham-burn and seven burn groups: untreated; two groups of saline treated (control); insulin treated (5 IU/kg); cyclooxygenase-2 inhibitor treated (10 mg/kg); ghrelin treated (2 nmol/rat); and gastric electrical stimulation treated. It was found that 1) severe burn injury impaired gastric slow waves postprandially and delayed gastric emptying; 2) the impairment in gastric slow waves included a decrease in the slow-wave frequency and in the percentage of normal slow waves, and an increase in the percentage of bradygastria (P = 0.001, 0.01, and 0.01, respectively vs. preburn values). None of the gastric slow-wave parameters was significantly correlated with gastric emptying; 3) cyclooxygenase-2 inhibitor normalized burn-induced delayed gastric emptying (P = 0.3 vs. sham-burn), but not gastric dysrhythmias (P < 0.002 vs. sham), whereas insulin normalized both gastric emptying (P = 0.4 vs. sham-burn) and gastric dysrhythmias (P = 0.3 vs. sham-burn); 4) both gastric electrical stimulation and ghrelin accelerated burn-induced delayed gastric emptying (P = 0.002 and 0.04, respectively, vs. untreated burn). In conclusion, hyperglycemia alters gastric slow-wave activity and delayed gastric emptying, while cyclooxygenase-2 inhibition delays gastric emptying without altering gastric slow-wave activity.

Peripheral factors in the pathophysiology of irritable bowel syndrome

The pathophysiology of IBS is complex and still incompletely known. Both central and peripheral factors are thought to contribute to the symptoms of IBS, including psychosocial factors, abnormal GI motility and secretion, and visceral hypersensitivity. In this review the involvement of peripheral factors in the pathophysiology in IBS is reviewed. Altered GI motility is commonly found in this patient group, even though a specific motor pattern has been hard to find. Colonic transit has been found to be of relevance for the bowel habit of the patient. Abnormal gas handling within the gut is also commonly seen, and seems to be one, but not the only factor responsive for bloating. There is also limited evidence supporting the presence of abnormal GI secretion in IBS, but its relevance for symptoms remains unclear. Visceral hypersensitivity is currently considered to be one of the most important pathophysiological factors in IBS. It can be modulated by several external and internal factors and recent studies support an association between colorectal sensitivity and the symptoms reported by the patients, especially pain.

Gastric myoelectrical and motor abnormalities in children and adolescents with functional recurrent abdominal pain

BACKGROUND AND AIMS

Recurrent abdominal pain is common among children and adolescents. The majority of the affected patients have no apparent cause for their symptoms. This study evaluated gastric myoelectrical activity and motility abnormalities in children and adolescents with functional recurrent abdominal pain.

METHODS

Forty-two children with functional recurrent abdominal pain [19 (45.2%) males, mean 8 years, SD 3 years, 19 functional abdominal pain, 9 irritable bowel syndrome, 9 functional dyspepsia, 1 abdominal migraine, 1 aerophagia and 3 non-specific abdominal pain according to Rome III criteria] and 20 healthy children [10 (50%) males, mean 9 years, SD 2.7 years] from the same geographical area underwent electrogastrography (EGG), and ultrasonographic assessment of gastric emptying rate and antral motility.

RESULTS

Average gastric emptying rate, amplitude of antral contractions and antral motility index were lower in patients (46.5%, 74.3% and 6.5 respectively) compared to controls (66.17%, 89% and 8.3 respectively) (P < 0.001). Gastric emptying rate had a negative correlation with scores obtained for severity of symptoms (r = -0.63, P < 0.0001). Postprandial dominant frequency instability co-efficient (post-DFIC) was higher in patients than in controls (27.83% vs 18.3%, P = 0.0087), and correlated with the symptom score (r = 0.26, P = 0.045).

CONCLUSIONS

Gastric emptying and antral motility were significantly impaired in patients, indicating a possible role for gastric motility disturbances in the pathogenesis of childhood functional recurrent abdominal pain. Further studies, including therapeutic trials, are needed to confirm this association and for recommendation of prokinetic drugs in its management.

The clinical overlap between functional dyspepsia and irritable bowel syndrome based on Rome III criteria

BACKGROUND

Epidemiological studies suggest considerable overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS). To date, no surveys have been performed to investigate the clinical overlap between these two disorders using Rome III criteria. Our aim was to investigate the prevalence and risk factors for the overlap of FD and IBS based on Rome III criteria in a large clinical sample.

METHODS

Consecutive patients at the general gastroenterology outpatient clinic were requested to complete a self-report questionnaire. FD and IBS were defined by Rome III criteria.

RESULTS

Questionnaires were returned by 3014 patients (52.8% female, 89% response rate). FD-IBS overlap was observed in 5.0% of the patients, while 15.2% and 10.9% of the patients were classified as FD alone and IBS alone, respectively. Compared with non-IBS patients, the odds ratio of having FD among IBS patients was 2.09 (95% CI: 1.68-2.59). Patients with FD-IBS overlap had higher severity scores for the postprandial fullness symptom (2.35 +/- 1.49 vs. 1.72 +/- 1.59, P < 0.001) and overall FD symptom (6.65 +/- 2.88 vs. 5.82 +/- 2.76, P = 0.002) than those with FD alone. The only independent risk factor for FD-IBS overlap vs. FD alone was the presence of postprandial fullness symptom (OR 2.67, 95% CI: 1.34-5.31).

CONCLUSION

Clinical overlap of FD and IBS according to Rome III criteria is very common. One risk factor for FD-IBS overlap is the presence of postprandial fullness symptom. This study provides clues for future pathophysiological studies of FD and IBS.

The clinical overlap between functional dyspepsia and irritable bowel syndrome based on Rome III criteria

Background

Epidemiological studies suggest considerable overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS). To date, no surveys have been performed to investigate the clinical overlap between these two disorders using Rome III criteria. Our aim was to investigate the prevalence and risk factors for the overlap of FD and IBS based on Rome III criteria in a large clinical sample.

Methods

Consecutive patients at the general gastroenterology outpatient clinic were requested to complete a self-report questionnaire. FD and IBS were defined by Rome III criteria.

Results

Questionnaires were returned by 3014 patients (52.8% female, 89% response rate). FD-IBS overlap was observed in 5.0% of the patients, while 15.2% and 10.9% of the patients were classified as FD alone and IBS alone, respectively. Compared with non-IBS patients, the odds ratio of having FD among IBS patients was 2.09 (95% CI: 1.68–2.59). Patients with FD-IBS overlap had higher severity scores for the postprandial fullness symptom (2.35 ± 1.49 vs. 1.72 ± 1.59, P < 0.001) and overall FD symptom (6.65 ± 2.88 vs. 5.82 ± 2.76, P = 0.002) than those with FD alone. The only independent risk factor for FD-IBS overlap vs. FD alone was the presence of postprandial fullness symptom (OR 2.67, 95% CI: 1.34–5.31).

Conclusion

Clinical overlap of FD and IBS according to Rome III criteria is very common. One risk factor for FD-IBS overlap is the presence of postprandial fullness symptom. This study provides clues for future pathophysiological studies of FD and IBS.

Review article: gastroparesis

BACKGROUND

Gastroparesis is a chronic disorder caused by stomach pump failure and characterized by profound nausea, vomiting and epigastric pain. Most often, the cause is unapparent and of the known associations, diabetes is the most common. Diagnosis is usually made using an isotope-labelled test meal. Treatment is incremental and includes education, dietary support, prokinetic and antiemetic agents. There are novel approaches including gastric neurostimulation.

AIM

To review current concepts of gastric motor function, aetiology, investigation and treatment of gastroparesis.

METHODS

A systematic web-based review of the literature was undertaken using a lexicon of terms associated with gastroparesis.

RESULTS

There are few controlled studies of this condition. Little is known about causation or underlying nerve, muscle or pacemaker pathology. Idiopathic gastroparesis occurs most commonly in women and gastric emptying is often abnormal in diabetes. Isotopic gastric scintigraphy remains the gold standard investigation, but alternative tests are being developed. Treatment is multimodal and includes education, and nutritional support. There are no adequately powered controlled trials to support a particular drug regimen. In intractable gastroparesis, gastric neurostimulation appears to offer benefit.

CONCLUSION

Despite a significant progress in the past decade, further controlled trials are required into the therapeutic options available for treating this intriguing condition.

The physiology of gastric emptying

The gastric emptying rate is a carefully regulated process consisting of different mathematically defined phases. The gastric metabolic load, as well as neural regulatory mechanisms and hormonal influences, cooperate in order to achieve a well-balanced emptying of contents from the stomach into the duodenum for absorption in the small intestine. This finely tuned regulation is primarily regulated by the release of gastrointestinal peptide hormones which serve to counteract the emptying process in the fed state and to stimulate sweeping contractions in the fasted state, most likely in order to prepare the stomach for another meal. We have found that the two peptide hormones ghrelin and glucagon-like peptide- I (GLP- I) have a great impact on the regulation of gastric emptying: ghrelin is a most potent stimulator of gastric contractions and emptying, and GLP- I profoundly inhibits this emptying process. These data suggest possibilities for governing the rate of gastric emptying as a natural step in achieving metabolic balance and control.

Nutrient-dependent enhancement of rectal sensitivity in irritable bowel syndrome (IBS)

Food-related gastrointestinal symptoms are common in irritable bowel syndrome (IBS), but the mechanisms behind this are unclear. Enhanced colorectal sensitivity after duodenal lipid administration in IBS patients has been demonstrated. However, the effects of a regular meal on colorectal sensitivity in these patients and the importance of the composition of the meal are not known. On two separate days, 10 IBS patients and 11 controls randomly received a liquid meal (800 kcal), containing 60% calories from fat (fatty meal) or carbohydrate (carbohydrate meal). Using a barostat rectal sensitivity was assessed during four separate distension sequences before, immediately after and 30 and 60 min after the meal. In the patients, the discomfort (P = 0.04) and the pain thresholds (P = 0.007) were gradually reduced after the fatty meal, whereas only a tendency in the same direction was seen after the carbohydrate meal. In patients VAS ratings for pain increased after the fatty meal (P = 0.03), but not after carbohydrates. In the controls, sensory thresholds were not affected by the meals. In IBS, a liquid meal enhances rectal sensitivity, and this seems to be partly nutrient dependent as a fatty meal has more pronounced effects than a carbohydrate meal. This might be of relevance for their postprandial symptoms.

Impact of upper digestive symptoms in patients with irritable bowel syndrome

BACKGROUND

Functional digestive disorders constitute a sizable proportion of gastroenterology and primary healthcare consultations, and have a negative impact on health-related quality of life. Dyspepsia and heartburn are often associated with irritable bowel syndrome (IBS); however, the incidence of these symptoms and their effect on IBS patients have not been evaluated.

AIM

To investigate the clinical, psychological and health-related quality of life impact of upper digestive symptoms on IBS patients.

METHODS

A prospective, observational, multicentered study was conducted in Spain: 517 IBS patients (Rome II criteria), grouped according to predominant symptoms of constipation (IBS-C), diarrhea (IBS-D) or alternating bowel habit (IBS-A) and 84 controls without IBS were recruited. Upper digestive symptoms were recorded in a 30-day diary. Health-related quality of life was evaluated by Irritable Bowel Syndrome Quality of Life and Euro-Quality of Life Five-Dimension Questionnaires; psychological well-being was evaluated by the Psychological General Well-Being Index.

RESULTS

IBS patients had greater frequencies of upper digestive symptoms (72.3 vs. 6.0%), dyspepsia (21.1 vs. 4.8%) and heartburn (40.0 vs. 13.1%) (all P < 0.05) than controls. Prevalence of upper digestive symptoms was lower in patients with IBS-D than in those with IBS-C or IBS-A (P < 0.05). Health-related quality of life and psychological status were significantly worse in IBS patients with upper digestive symptoms than in those without.

CONCLUSIONS

Upper digestive symptoms, frequently present in IBS patients, impair health-related quality of life and psychological status. This effect is greater in patients with IBS-C and IBS-A than in those with IBS-D. These data emphasize the importance of evaluating the presence of upper digestive symptoms in IBS patients.

Disturbed bowel habits in patients with non-ulcer dyspepsia

BACKGROUND; Emerging medications for non-ulcer-dyspepsia, such as the serotonin-receptor modulators, also affect bowel habits by altering colonic transit. If drugs that alter colonic function were to prove useful in non-ulcer dyspepsia, knowledge of baseline bowel habit disturbances would be potentially critical.

AIM

To estimate the rate of non-ulcer dyspepsia patients with clinically relevant constipation or diarrhoea potentially precluding use of motility agents.

METHODS

Consecutive patients with non-ulcer dyspepsia (n = 79), gastro-oesophageal reflux disease (n = 135) and organic upper gastrointestinal disease (upper gastrointestinal disease; n = 36) completed a validated symptom questionnaire evaluating predominant bowel habits in the last year.

RESULTS

Prevalence of constipation was higher in non-ulcer dyspepsia (34%) than in gastro-oesophageal reflux disease (P = 0.01) and organic upper gastrointestinal disease (P = 0.01), prevalence of alternating diarrhoea/constipation (24%) and diarrhoea (22%) was similar, while prevalence of normal bowel habits was significantly less in non-ulcer dyspepsia (20%; P = 0.01 vs. gastro-oesophageal reflux disease and P < 0.01 vs. organic upper gastrointestinal disease). Constipation was particularly frequent in ulcer-like and dysmotility-like non-ulcer dyspepsia, while prevalence of diarrhoea was lowest in dysmotility-like non-ulcer dyspepsia. A normal bowel habit was equally uncommon in male (21%) and female non-ulcer dyspepsia patients (20%).

CONCLUSIONS

Only one of five non-ulcer dyspepsia patients had normal bowel habits based on clinical symptoms; constipation is particularly prevalent. Patients with functional dyspepsia who are prescribed motility altering drugs should be evaluated by taking a thorough bowel habit history.

Functional findings in irritable bowel syndrome

The pathophysiology of IBS is complex and still incompletely known. Both central and peripheral factors, including psychosocial factors, abnormal GI motility and secretion, and visceral hypersensitivity, are thought to contribute to the symptoms of IBS. Several studies have demonstrated altered GI motor function in IBS patients and the pattern differs between IBS subgroups based on the predominant bowel pattern. Few studies have so far addressed GI secretion in IBS, but there are some evidence supporting altered secretion in the small intestine of IBS patients. Visceral hypersensitivity is currently considered to be perhaps the most important pathophysiological factor in IBS. Importantly, several external and internal factors can modulate visceral sensitivity, as well as GI motility, and enhanced responsiveness within the GI tract to for instance stress and nutrients has been demonstrated in IBS patients. Today IBS is viewed upon as a disorder of dysregulation of the so-called brain-gut axis, involving abnormal function in the enteric, autonomic and/or central nervous systems, with peripheral alterations probably dominating in some patients and disturbed central processing of signals from the periphery in others.

Functional dyspepsia and irritable bowel syndrome, are they different entities and does it matter

A high prevalence of overlap between functional dyspepsia and irritable bowel syndrome has been consistently and universally reported. Recent studies demonstrating shared common pathophysiological disturbances including delayed gastric emptying and visceral hypersensitivity involving more than one region, suggest that these patients have a generalised rather than regional, disorder of the gut. Furthermore, a study of the natural history of dyspepsia suggests that with time, a substantial proportion will evolve into IBS. The recognition of IBS in dyspeptic patients has potentially profound therapeutic importance. It could help to reduce the risk of unnecessary cholecystectomy in IBS patients. The ability to appreciate the extent of involvement could allow us to address the disturbances more comprehensively, and thereby achieve greater patient satisfaction with their treatment.

Racial differences in epidemiology of irritable bowel syndrome alone, un-investigated dyspepsia alone, and "overlap syndrome" among african americans compared to Caucasians: a population-based study

There is A paucity of data on racial differences in epidemiology of irritable bowel syndrome (IBS) alone and un-investigated dyspepsia (UD) alone compared to "overlap syndrome" (OS). We conducted a random survey (n = 990). Subjects completed a questionnaire which included Rome II criteria for IBS and functional dyspepsia (FD). Among African Americans, the prevalence of IBS alone, UD alone, and OS was 0.6%, 17%, and 7.3%, respectively. It was 0%, 13%, and 13% among Caucasian Americans. All but four patients with IBS had UD. Among patients with UD, OS was seen in 30% of African Americans, compared to 50% among Caucasian Americans. Among African Americans, UD patients were younger compared to OS patients. African Americans with UD were more likely than OS patients to have children. Marital status, education, and household income were not a factor among Caucasians. African Americans patients below poverty level were more likely to have UD than OS (22% vs 10%). Considering patients with UD alone, race, age, sex, marital status, number of children, education, and income level were not different between African Americans and Caucasians. Compared to African Americans, Caucasians with OS were likely to be married and live in an urban area. There was a higher prevalence of OS among Caucasians with lower education. OS is 2.5 times more likely to occur among Caucasians compared to African Americans. We conclude that OS is more common among Caucasians than African Americans. IBS and OS are virtually synonymous.

Rectal distension modulates canine gastric tone and accommodation

Rectal distension affects upper GI myoelectrical activity and motility. The aim of this experiment was to investigate the effect of rectal distension on gastric tone, accommodation, and the underlying mechanism. Seven healthy dogs were surgically prepared and studied. Gastric tone and accommodation were assessed with a barostat. In Experiment 1, the effect of rectal distension on gastric tone and accommodation was evaluated; in Experiment 2, rectal distensions with various volumes were randomly applied and its effects on gastric tone were evaluated; and in Experiment 3, the role of the cholinergic pathway in distension-induced gastric relaxation was assessed. The results showed the following. (1) Rectal distension exerted an inhibitory effect on gastric tone, and this response was distension volume-dependent. (2) Postprandial gastric volume was similar in the control (468.6 +/- 24.7 ml) and the distension study (463.2 +/- 17.5 ml). However, rectal distension increased the preprandial gastric volume, and subsequently decreased the extent of gastric accommodation (139.3 +/- 34.7 ml), which was significantly lower than that of the control (383.2 +/- 26.3 ml; P < 0.001). (3) An intravenous bolus of atropine increased the astric volume from the baseline of 89.4 +/- 12.6 ml to 161.5 +/- 9.8 ml (P < 0.01), and subsequent rectal distension further increased this volume, but the overall change was comparable between the control (297.6 +/- 18.7 ml) and the atropine study (312.1 +/- 21.9 ml; P > 0.05). In conclusion, rectal distension inhibits gastric tone in a volume-dependent manner and impairs gastric accommodation. Atropine dose not block the effect of rectal distension on proximal gastric tone, suggesting that the observed effect may not be mediated by cholinergic pathway.

Gastric emptying is slow in chronic fatigue syndrome

BACKGROUND

Gastrointestinal symptoms are common in patients with Chronic Fatigue Syndrome (CFS). The objective of this study was to determine the frequency of these symptoms and explore their relationship with objective (radionuclide) studies of upper GI function.

METHODS

Thirty-two (32) patients with CFS and 45 control subjects completed a questionnaire on upper GI symptoms, and the 32 patients underwent oesophageal clearance, and simultaneous liquid and solid gastric emptying studies using radionuclide techniques compared with historical controls.

RESULTS

The questionnaires showed a significant difference in gastric (p > 0.01) symptoms and swallowing difficulty. Nocturnal diarrhoea was a significant symptom not previously reported.5/32 CFS subjects showed slightly delayed oesophageal clearance, but overall there was no significant difference from the control subjects, nor correlation of oesophageal clearance with symptoms. 23/32 patients showed a delay in liquid gastric emptying, and 12/32 a delay in solid gastric emptying with the delay significantly correlated with the mean symptom score (for each p < 0.001).

CONCLUSIONS

GI symptoms in patients with chronic fatigue syndrome are associated with objective changes of upper GI motility.

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.

Impact of coexisting irritable bowel syndrome on symptoms and pathophysiological mechanisms in functional dyspepsia

Epidemiological studies suggest considerable overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS).

AIM

The aim of the present study was to investigate whether coexisting IBS is also associated with symptom pattern or pathophysiology in FD.

METHODS

In 309 consecutive FD patients (207 women, age 42 +/- 0.8 yr), questionnaires were used to assess the dyspepsia symptom pattern and the Rome II criteria for IBS. The overall symptom severity was calculated adding the severity score (0-3, 0 = absent, 3 = severe) of eight dyspepsia symptoms. All patients underwent Helicobacter pylori testing, gastric barostat to determine sensitivity to distention and accommodation to a meal, and gastric emptying breath test.

RESULTS

Fifty-four percent of the patients had FD alone, whereas 46% had FD + IBS. FD + IBS patients were more likely to be female (75%vs 60%, p < 0.01) and to have a greater weight loss (5.4 +/- 0.6 vs 3.5 +/- 0.4 kg, p < 0.05). Coexisting IBS did not increase the risk of having any of the dyspeptic symptoms but the overall symptom severity was significantly higher in FD + IBS (12.4 +/- 0.4 vs 9.8 +/- 0.3, p < 0.01). FD + IBS patients had a lower threshold for first perception (2.9 +/- 0.3 vs 3.8 +/- 0.3 mmHg, p < 0.05) and for discomfort (7.9 +/- 0.4 vs 9.5 +/- 0.5 mmHg, p < 0.05) and a greater prevalence of hypersensitivity to gastric distention (44%vs 28%, p < 0.05). Gastric emptying, accommodation to a meal, and prevalence of H. pylori infection did not differ in the two groups.

CONCLUSION

About half of the FD patients fulfill the Rome II criteria for IBS. FD + IBS is more prevalent in female patients and is associated with a higher weight loss, with greater overall symptom severity, and with hypersensitivity to distention.

Are there alterations of neuroendocrine and cellular immune responses to nutrients in women with irritable bowel syndrome?

OBJECTIVES

The goal was to investigate the neuroimmune axis in irritable bowel syndrome (IBS) by analyzing the neuroendocrine and cellular immune responses to nutrient load.

METHODS

In the fasting state and 20, 40, 70, and 100 min following nutrient load, blood samples were collected and cardiovascular recordings were accomplished in 15 female IBS patients and 15 healthy women. Plasma norepinephrine, prolactin, cortisol, and growth hormone were analyzed, and blood pressure and heart rate responses were measured. The distribution of peripheral leukocytes and lymphocyte subpopulations and the in vitro production of tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) after whole blood stimulation with in lipopolysaccharide (LPS) were analyzed.

RESULTS

IBS patients demonstrated significantly greater postprandial increases in plasma norepinephrine and systolic blood pressure (p < 0.05), but no cortisol response. A postprandial redistribution of circulating leukocytes and lymphocyte subpopulations was observed in both groups, including significant increases in the numbers of leukocytes and granulocytes and significant decreases in the numbers of monocytes, T-cells, and natural killer (NK) cells (all p < 0.05). However, IBS patients demonstrated significantly greater postprandial increases in leukocytes and granulocytes, while changes in the numbers of monocytes and NK cells were significantly diminished (all p < 0.05). Patients also failed to show the postprandial decrease in the in vitro TNF-alpha production observed in controls. Postprandial norepinephrine concentrations were negatively correlated with NK cell numbers in IBS patients (r= 0.58, p < 0.05) but not controls.

CONCLUSIONS

IBS may involve an autonomic hyper-responsiveness to visceral stimuli, which occurs throughout the entire gut, is independent of acutely perceived GI symptoms, and does not necessarily involve HPA axis activation. Women with IBS show altered cellular immune responses to food intake, which may at least in part be mediated by adrenergic mechanisms. Thus, autonomic disturbances may have implications for cellular immune function along the neuroendocrine-immune axis in patients with IBS.

Overlapping upper and lower gastrointestinal symptoms in irritable bowel syndrome patients with constipation or diarrhea

OBJECTIVES

Distinguishing between irritable bowel syndrome (IBS) and functional dyspepsia can be challenging because of the variations in symptom patterns, which commonly overlap. However, the overlap is poorly quantified, and it is equally uncertain whether symptom patterns differ in subgroups of IBS arbitrarily defined by primary bowel patterns of constipation (IBS-C) and diarrhea (IBS-D). We aimed to determine and to compare the distribution of GI symptoms, both, upper and lower, among IBS-C and IBS-D patients.

METHODS

A total of 121 consecutive patients presenting with a diagnosis of IBS were grouped according to primary bowel symptoms as IBS-C (58 women and 18 men, mean age 47 +/- 17 yr) or IBS-D (26 women and 19 men, mean age 47 +/- 15 yr). The Hopkins Bowel Symptom Questionnaire, which includes a brief Quality of Life assessment, and the Hopkins Symptom Checklist 90-Revised were completed by all patients at intake.

RESULTS

IBS-C patients reported significantly more overall GI symptoms when compared to patients with IBS-D (6.67 vs 4.62, respectively, p<0.001). Abdominal pain patterns differed in patients with IBS-C versus IBS-D (lower abdominal pain: 40.8% vs 24.4% p=0.05 and upper abdominal pain: 36.8% vs 24.4%, respectively). Bloating was substantially more common in IBS-C patients (75%) than in IBS-D (40.9%). There were no significant differences in personality subscales by IBS subgroup; however, somatization was positively associated with multiple symptom reports and was negatively correlated with quality of life.

CONCLUSIONS

Upper GI symptoms consistent with functional dyspepsia were more frequent in IBS-C. Although there was considerable overlap of upper and lower GI symptoms in patients with IBS-C and IBS-D, the former had more frequent lower abdominal pain and bloating.

Full-thickness biopsy of the jejunum reveals inflammation and enteric neuropathy in irritable bowel syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is regarded as a functional bowel disorder. Few studies have looked for histopathologic changes in the gut and only then in biopsy specimens from intestinal mucosa. Because bowel function is governed mainly by nerve plexuses in the bowel wall, we have investigated full-thickness bowel biopsy specimens in patients with severe IBS.

METHODS

We used a laparoscopy-assisted technique to obtain full-thickness biopsy specimens from the proximal jejunum. Tissue specimens were investigated with light microscopy using routine stainings and immunohistochemical techniques. Horizontal sectioning was done to visualize large areas of the myenteric plexus. Fifteen autopsy specimens were used as controls regarding the myenteric plexus. Colorectal adenoma controls with terminal ileum biopsy specimens and full-thickness jejunal biopsy specimens from patients with degenerative enteric neuropathy were used as control groups for intraepithelial lymphocyte counts.

RESULTS

Ten patients (2 males, 8 females) were studied. In 9 patients, we found low-grade infiltration of lymphocytes in the myenteric plexus. Lymphocytes had peri- and intraganglionic location. The mean number of lymphocytes per ganglion ranged from 1.9 to 7.1 per patient, with an overall mean of 3.4. No intraganglionic lymphocytes were found in the control group and only a few periganglionic lymphocytes (mean, 0.2). Four patients had concomitant intraepithelial lymphocytosis. Neuron degeneration was evident in 6 of 9 patients with and 1 patient without ganglionic lymphocyte infiltration.

CONCLUSIONS

Our findings indicate that inflammation and neuronal degeneration in the myenteric plexus are involved in the pathogenesis of IBS.

Effect of 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced ileitis on the motor function of non-inflamed rat gastric fundus

During intestinal inflammation, motility disturbances are not restricted to inflamed regions, but may also occur in remote non-inflamed sites of the gastrointestinal tract. Our aim was to investigate the motor function of the gastric fundus after the induction of terminal ileitis in the rat. Ileal inflammation was induced by intraluminal installation of 2,4,6-trinitrobenzenesulphonic acid (TNBS) into the ileum. Inflammation was assessed both histologically and biochemically. Contractions and relaxations of longitudinal muscle strips from the gastric fundus were studied 36 h and 1 week later. During the acute phase of ileal inflammation (36 h), the non-inflamed stomach was distended. The contractility of longitudinal muscle strips of the gastric fundus was decreased due to a post-receptor defect. In addition, nonadrenergic noncholinergic (NANC) relaxations were inhibited due to neuronal dysfunction. Aortic contractility remained normal and the mere presence of food in the stomach did not account for the disturbed neuromuscular function in the gastric fundus. Ablation of extrinsic primary afferent neurones by capsaicin further impaired gastric fundus contractility. Transection and re-anastomosis of the jejunum reversed the effect of TNBS-induced ileitis on the neuromuscular function of the gastric fundus. One week after TNBS, cholinergic neurotransmission was increased in the gastric fundus. During acute ileitis, smooth muscle cell contractility and inhibitory NANC neurotransmission are inhibited in the non-inflamed gastric fundus. This phenomenon may be mediated by intrinsic connections within the enteric nervous system.

Irritable bowel syndrome

Patients with IBS need an integrated, individualized approach to treatment, with a foundation based on a successful patient-physician relationship. The emotional and psychologic needs of the patients need to be considered in a successful management plan. Further advances in the pathophysiology of disease are essential to develop suitable and more comprehensive treatment options.

Radioactivity in breast milk following 111In-octreotide

The concentration of 111In in breast milk in a 10 weeks postpartum woman was measured at daily intervals up to 72 h post-injection of 5.3 mCi (196 MBq) of 111In-octreotide (OctreoScan). Radiation surveys were also performed at the breast surface. The disappearance of 111In from the breast milk exhibited a bi-exponential pattern with a maximum concentration of 14.2 nCi (0.54 kBq) per 125 ml feeding at 4 h, with lower values thereafter. External surveys at the breast surface also showed a bi-exponential decrease with time. The maximum reading was 8.3 mrem x h(-1) (0.83 mSv x h(-1)) immediately after administration. This rapidly decreased due to 85% urinary excretion by 24 h. Breast milk tracer content and external surveys at the breast surface were determined at 3 h intervals for up to 10 days. If a newborn is nursed for the first 10 days, the internal and external dose equivalents would be 22.97 mrem (0.23 mSv) and 27.86 mrem (0.28 mSv), respectively, for a total of 50.83 mrem (0.5 mSv). The patient was instructed to resume breast-feeding on day 10, when the newborn received a total dose equivalent of 1.55 mrem (0.016 mSv). This dosimetry is based on a very conservative assumption, whereby 100% of the ingested 111In becomes systemic and follows adult bio-behaviour. Oral indium has been shown to be poorly absorbed from the gastrointestinal tract (approximately 0.15%), which suggests the infant's dose could be considerably less. Based on this case report, mathematical relationships are presented for determining the nursing infant's dose equivalent from internal and external exposures relative to time after the maternal administration of 111In-octreotide (OctreoScan).

Gastroduodenal motility

Several major themes emerged over the past year in the area of gastroduodenal motility. Mostly, these themes represented extensions of research areas discussed in prior reviews in this series rather than the emergence of completely new concepts. Thus, for example, considerable emphasis has again been placed on regional gastric motor function in dyspepsia and on the role of fundic relaxation and accommodation, in particular. Not surprisingly, basic physiologic research has also shown a keen interest in the regulation of fundic relaxation. One new and exciting development is the recognition of the stomach's role in satiety. The spectrum of gastric motor dysfunction in diabetes mellitus continues to be explored, and the important role of hyperglycemia in regulating gastric function has been further emphasized. More data have been provided on noninvasive alternatives to gastric motor function testing, and several studies have looked at factors that may influence variability in these various tests. There have been few innovations over the past year in the therapeutic arena; rather, the indications and limitations of current therapies have been further developed.