Abnormalities of the electrogastrogram in functional gastrointestinal disorders

OBJECTIVE: Cutaneous electrogastrography records gastric electrical activity and detects gastric arrhythmias. Abnormalities of the electrogastrogram have been described in a variety of disorders, but their specificity and their prevalence in patients with functional gastrointestinal disorders has not been reported. The aim of this study was to assess the specificity of electrogastrography as well as the prevalence and pattern of abnormalities in functional dyspepsia and irritable bowel syndrome. METHODS: Electrogastrography was performed in 170 patients with functional dyspepsia, 70 patients with irritable bowel syndrome, 20 patients with gastroesophageal reflux disease, and 30 asymptomatic controls. The abnormal electrogastrogram was defined as <70% normal electrical activity either before or after a test meal. RESULTS: The electrogastrogram was abnormal in 36% of patients with functional dyspepsia and in 25% with irritable bowel syndrome who complained of concurrent dyspepsia. The electrogastrogram was normal in 93% of asymptomatic controls, 90% of patients with gastroesophageal reflux, and 92% of patients with irritable bowel syndrome who did not complain of dyspepsia. As a group, functional dyspepsia patients had a greater degree of tachygastrias both before (p < 0.02) and after (p < 0.01) a test meal. The electrical frequency after the test meal was also more unstable (p < 0.003). CONCLUSIONS: The electrogastrogram is abnormal in approximately 36% of functional dyspepsia patients and has a specificity of approximately 93%. Electrogastrography defines a subgroup of patients with functional dyspepsia and electrical rhythm disturbance. In irritable bowel syndrome, the electrogastrogram is usually abnormal only if concurrent dyspepsia is present.     

3 Is functional dyspepsia just a subset of the irritable bowel syndrome?

To determine whether functional dyspepsia and irritable bowel syndrome are different entities, epidemiological data, factor analysis studies, physiological data and associated psychological symptoms were reviewed. Between 30% and 60% of patients with either diagnosis also meet the criteria for the other diagnosis, a level greater than expected to occur by chance but not sufficient to infer an identity. Most factor analysis studies identify independent clusters of symptoms corresponding to functional dyspepsia and irritable bowel syndrome. Visceral hypersensitivity is seen throughout the gastrointestinal tract in both disorders, but the motility patterns seen in association with functional dyspepsia (principally antral hypomotility and delayed gastric emptying) differ from the motility patterns seen in irritable bowel syndrome. Psychological symptoms are similar in these two disorders but are not believed to be aetiological for either of them. Thus, based on a factor analysis of gastrointestinal symptoms and differences in intestinal motility, functional dyspepsia and irritable bowel syndrome appear to be different entities.     

Effects on gastrointestinal functions and symptoms of serotonergic psychoactive agents used in functional gastrointestinal diseases

The effects of antidepressants on the gastrointestinal tract may contribute to their potential efficacy in functional dyspepsia and irritable bowel syndrome; buspirone, a prototype 5-HT1A agonist, enhances gastric accommodation and reduces postprandial symptoms in response to a challenge meal. Paroxetine, a selective serotonin reuptake inhibitor, accelerates small bowel but not colonic transit, and this property may not be relevant to improve gut function in functional gastrointestinal disorders. Venlafaxine, a prototype serotonin norepinephrine reuptake inhibitor, enhances gastric accommodation, increases colonic compliance and reduces sensations to distension; however, it is associated with adverse effects that reduce its applicability in treatment of functional gastrointestinal disorders. Tricyclic antidepressants reduce sensations in response to food, including nausea, and delay gastric emptying, especially in females. Buspirone appears efficacious in functional dyspepsia; amitriptyline was not efficacious in a large trial of children with functional gastrointestinal disorders. Clinical trials of antidepressants for treatment of irritable bowel syndrome are generally small. The recommendations of efficacy and number needed to treat from meta-analyses are suspect, and more prospective trials are needed in patients without diagnosed psychiatric diseases. Antidepressants appear to be more effective in the treatment of patients with anxiety or depression, but larger prospective trials assessing both clinical and pharmacodynamic effects on gut sensorimotor function are needed.     

Sobreposición entre los trastornos funcionales de dolor abdominal y enfermedades orgánicas en niños

Functional abdominal pain disorders are highly prevalent in children. These disorders can be present in isolation or combined with organic diseases, such as celiac disease and inflammatory bowel diseases. Intestinal inflammation (infectious and non-infectious) predisposes children to the development of visceral hypersensitivity that can manifest as functional abdominal pain disorders, including irritable bowel syndrome. The new onset of irritable bowel syndrome symptoms in a patient with an underlying organic disease, such as inflammatory bowel disease, is clinically challenging, given that the same symptomatology may represent a flare-up of the inflammatory bowel disease or an overlapping functional abdominal pain disorder. Similarly, irritable bowel syndrome symptoms in a child previously diagnosed with celiac disease may occur due to poorly controlled celiac disease or the overlap with a functional abdominal pain disorder. There is little research on the overlap of functional abdominal disorders with organic diseases in children. Studies suggest that the overlap between functional abdominal pain disorders and inflammatory bowel disease is more common in adults than in children. The causes for these differences in prevalence are unknown. Only a handful of studies have been published on the overlap between celiac disease and functional abdominal pain disorders in children. The present article provides a review of the literature on the overlap between celiac disease, inflammatory bowel disease, and functional abdominal pain disorders in children and establish comparisons with studies conducted on adults.     

10 Are psychosocial factors of aetiological importance in functional dyspepsia?

The causes of functional dyspepsia remain unclear. Research has linked other functional gastrointestinal disorders, particularly irritable bowel syndrome, to a history of physical or sexual abuse, psychosocial distress and certain psychiatric disorders. In functional dyspepsia, there is a possibility of certain psychiatric disorders, particularly alcohol abuse and eating disorders, indirectly influencing the development of functional dyspepsia-like symptoms. However, the literature on possible psychosocial correlates in functional dyspepsia is not as mature as the literature on irritable bowel syndrome. This paper critically reviews the psychosocial dimensions and implications for the psychotherapeutic treatment of functional dyspepsia.     

A unifying hypothesis for the functional gastrointestinal disorders: really multiple diseases or one irritable gut?

The functional gastrointestinal disorders are defined by the Rome criteria as a heterogeneous group of symptom-based conditions that have no structural or biochemical explanation. However, this definition now seems outdated, because structural and molecular abnormalities have begun to be recognized in subsets of patients with the irritable bowel syndrome (IBS), the prototypic functional bowel disease. A complex classification system based arbitrarily on symptom criteria does not fit in with a number of emerging facts. For example, the symptom overlap of IBS with gastroesophageal reflux disease is not due to chance, and the emergence of post-infectious IBS, dyspepsia, or both after Salmonella gastroenteritis fits better with a 1-disease model. A new paradigm seems to be needed. All of these disorders may arise after infection or gut inflammation, but the phenotype depends on localized neuromuscular dysfunction in the predisposed human host (the "irritable gut").     

Relation among personality and symptoms in nonulcer dyspepsia and the irritable bowel syndrome

The importance of personality traits in nonulcer dyspepsia and irritable bowel syndrome is a controversial issue. We wished to assess the distribution of abnormal personality traits in nonulcer dyspepsia and the irritable bowel syndrome, define any relation among personality and symptoms, and determine whether personality factors discriminate among patients with functional, psychiatric, or organic gastrointestinal diseases. Patients with nonulcer dyspepsia (n = 31), irritable bowel syndrome (n = 67), organic gastrointestinal disease (n = 64), somatoform disorder (n = 36) and healthy controls (n = 128) were studied. Before diagnostic evaluation by an independent physician, all patients completed the Minnesota Multiphasic Personality Inventory and a symptom questionnaire. Symptom scores for abdominal pain and the Manning criteria, which is considered to be diagnostic for the irritable bowel syndrome, were evaluated. Personality scales in patients with nonulcer dyspepsia, irritable bowel syndrome, and organic disease were very similar. However, patients in the other groups differed from somatoform disorder on nearly all scales. In nonulcer dyspepsia, irritable bowel syndrome, and organic disease, hypochondriasis weakly correlated with pain. Subgroups of irritable bowel syndrome patients with predominant constipation and those with predominant diarrhea had similar personality traits, although hypomania was minimally increased in constipation. Patients who fulfilled the Manning criteria for irritable bowel syndrome had more psychological distress than those who did not. The Minnesota Multiphasic Personality Inventory correctly classified somatoform disorder and health 81% and 75% of the time, respectively, but it classified nonulcer dyspepsia and irritable bowel syndrome correctly in only 32% and 34% of cases. Our results suggest that psychopathology may not be the major explanation for functional gastrointestinal disorders.     

Placebo responses and placebo effects in functional bowel disorders

The nature and determinants of the placebo response are widely unknown, as are the underlying psychological and biological mechanisms. Placebo response rates in functional bowel disorders (functional dyspepsia, irritable bowel syndrome) trials are similar to those in nonintestinal pain conditions and are comparable with other organic gastrointestinal diseases (duodenal ulcer, inflammatory bowel diseases). In this narrative review, different methodologies (meta-analyses, reanalyses, and experimental setups) are discussed that have been applied to the study of the placebo response in functional dyspepsia and the irritable bowel syndrome.     

9 Gastrointestinal sensory abnormalities in functional dyspepsia

Symptoms of functional dyspepsia, such as epigastric pain, bloating or early satiety and nausea, are non-specific and are likely to arise from different mechanisms. Current evidence suggests the presence of at least two subgroups: patients who respond to a prolonged course of acid suppression and patients who show a significant overlap of symptoms with other functional gastrointestinal disorders such as irritable bowel syndrome. An enhanced sensitivity of visceral afferent pathways with or without associated autonomic dysregulation appears to play an important role in the aetiology of symptoms in the second group. In the absence of visceral hypersensitivity, neither the slowing of gastric emptying nor the presence of chronic gastritis appears to be sufficient to cause symptoms of functional dyspepsia. The mechanisms and aetiology of visceral hypersensitivity are incompletely understood. An alteration in the interplay between vagal and spinal afferents, and the inadequate activation of antinociceptive systems in response to tissue irritation, may play a role in symptom generation.     

Functional dyspepsia: subgroups, history and outcomes

Dyspepsia is a symptom complex common both in the population and in clinical practice. Persons with dyspeptic symptoms who have not been evaluated are considered to have uninvestigated dyspepsia. If, after investigation, no structural or biochemical explanation is identified to explain the person's symptoms, the diagnosis of functional dyspepsia is made. While substantial efforts have been made to provide symptom-based criteria for the diagnosis of functional dyspepsia, the etiology and natural history of the disorder remains elusive. Population-based studies have often had difficulty distinguishing functional dyspepsia from irritable bowel syndrome. Clinically, there is clearly substantial overlap and many persons with functional dyspepsia either present with symptoms consistent with the irritable bowel syndrome or will develop such symptoms at a later date. Even if one can accept functional dyspepsia as an entity separate from irritable bowel syndrome, it is clearly a heterogeneous disorder. Unfortunately attempts using different strategies to subcategorize functional dyspepsia have not made progress with respect to elucidating pathophysiology or directing therapy. Importantly, most persons with functional dyspepsia experience symptom variability resulting in subgroup reassignment over time. Persons presenting with functional dyspepsia will likely remain symptomatic over time. Sadly, at the present time, gastroenterologists have little ability to predict what those symptoms will be, to understand the mechanism for their existence or to offer therapies that offer a reasonable likelihood of success based on a pathophysiologic rationale.     

Modern myths of clinical gastroenterology]

The appropriateness of further wide prevalence of diagnostics of gastroesophageal reflux disease, functional non-ulcer dyspepsia and irritable bowel syndrome is discussed. All these diseases are believed to be found in 30-50% of adults. It is very difficult to find a healthy person taking into account such an approach to the problem. As a matter of fact, gastroesophageal disease was invented by merging two different diseases: esophagitis and reflux esophagitis plus such a prevalent symptom as heartburn. All this leads to the hyperdiagnosis of this disease. The irritable bowel syndrome also includes two conditions: that of the irritable large intestine and dyskinesia of the small one. They are very different. The application of the diagnosis of functional dyspepsia leads to the practical disappearance of the diagnosis of chronic gastritis. At that symptoms of the dyskinetic form of functional dyspepsia coincide with minor symptoms of gastric carcinoma, which can lead to late diagnostics of this oncological disease. In this connection, it is necessary to narrow the limits of these diseases because their actual prevalence is much lower than that found in medical literature.     

Gender difference in the overlap of irritable bowel syndrome and functional dyspepsia: a prospective nationwide multicenter study in Korea

Journal of Gastroenterology - The overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS) is associated with more severe gastrointestinal (GI) symptoms and lower quality of...     

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.     

Predominant symptoms identify different subgroups in functional dyspepsia

OBJECTIVE: Dyspepsia is a common syndrome that often defies diagnosis. Whether the unexplained (or "functional") dyspepsia represents a homogeneous syndrome or includes different subgroups with specific clinical features has not been clarified. The aim of this study was to investigate the relationship between symptom severity, demographic features, and gastric dysmotility in a large series of patients with functional dyspepsia. METHODS: Severity of individual digestive symptoms, demographic features, and scintigraphic gastric emptying of solids were evaluated in 483 patients with chronic unexplained dyspepsia. RESULTS: Two main subgroups were identified. The first was characterized by predominant epigastric pain, male gender (61%), and normal gastric emptying. The second subgroup was characterized by predominant nonpainful symptoms, female gender (60%), a high frequency of associated irritable bowel syndrome (30%), and delayed gastric emptying (42%). A third group included approximately one-third of patients who did not present with any predominant symptom, and was characterized by a high frequency of delayed gastric emptying (30%), overlapping irritable bowel syndrome (28%), and gastroesophageal reflux disease (41%). CONCLUSIONS: Different subgroups exist among patients with functional dyspepsia seen in a referral center. They can be identified by the predominant symptom and are characterized by different demographic, clinical, and pathophysiological features.     

Diagnosis and treatment of chronic gastroparesis and chronic intestinal pseudo-obstruction

Chronic gastroparesis and CIP are debilitating disorders that are difficult to treat with currently available therapies. Failure of proper migration and differentiation of enteric neurons or ICC can result from specific genetic mutations and lead to phenotypes of CIP with or without concomitant gastroparesis. Intestinal dysfunction in diabetes may reflect a depletion of NO production (and perhaps other neurotransmitters or modulators), which is manifest as a syndrome of gastroparesis, diarrhea, or constipation in individual patients. As the key molecular changes underlying these disorders are defined, clinicians will begin to understand their precise etiology and rational medical therapy may become possible. In the future, testable hypotheses regarding the etiology of other functional bowel disorders (e.g., functional dyspepsia, irritable bowel syndrome, and so forth) may be developed.     

Functional chest pain: esophageal or overlapping functional disorder

BACKGROUND: Whether patients with functional chest pain have an esophageal or overlapping functional disorder of the gut is unclear. We investigated the prevalence of functional gastrointestinal disorders in patients with functional chest pain. METHODS: One hundred patients with functional chest pain and normal cardiac, endoscopic, and manometric studies were evaluated for esophageal hypersensitivity with a balloon distension test. Subsequently, a modified Rome II functional bowel disorder questionnaire was mailed to these subjects. Prevalence of irritable bowel syndrome (IBS) and other functional disorder were determined using the Rome II criteria. In addition, we assessed the prevalence of chest pain in 81 patients with functional constipation. RESULTS: There were 69 responders (54 women); 2 were excluded. Fifty-five patients (82%) fulfilled criteria for other functional disorders besides chest pain. Although there was an overlap, IBS (27%) and abdominal bloating (22%) were most common; dyspepsia (7%), dysphagia (7%), nonspecific bowel disorder (7%), constipation (4%), abdominal pain (3%), and diarrhea (1%) were less common. Among responders, 52 (78%) had esophageal hypersensitivity and 15 (22%) had normosensitivity, with similar prevalence of functional disorders. Thirty-two (39%) of the subjects with functional constipation reported chest pain occasionally, and 5 (6%) frequently. CONCLUSIONS: Approximately 80% of patients with functional chest pain exhibit features of other functional disorders including IBS suggesting an overlap. This association is independent of esophageal hypersensitivity. Recognition of this overlap may facilitate better management of these patients.     

Functional dyspepsia and duodenal eosinophilia: A new model

Functional dyspepsia (FD) is a highly prevalent disorder that affects more than 10% of the population. In the past decade, the theoretical underpinning of the concept of FD has begun to change, in light of new data on the underlying pathophysiological mechanisms of this disorder, with a focus on the duodenum. The Rome IV criteria, published in 2016, note that gastroesophageal reflux disease and irritable bowel syndrome overlap with FD more than expected by chance, suggesting that they may be part of the same disease spectrum. Infection by Helicobacter pylori (H. pylori) may explain a minority of cases of FD and in the Rome IV criteria H. pylori‐associated dyspepsia (defined as symptom relief after eradication therapy) is considered a separate entity. Duodenal inflammation characterized by increased eosinophils and in some cases mast cells, may impair the intestinal barrier. Post‐infectious gastroenteritis is now an established risk factor for FD. Other risk factors may include atopy, owning herbivore pets and exposure to antibiotics, together with gastroduodenal microbiome disturbances. Small bowel homing T cells and increased cytokines in the circulation occur in FD, correlating with slow gastric emptying, and a possible association with autoimmune rheumatological disease supports background immune system activation. A genetic predisposition is possible. FD has been linked to psychological disorders, but in some cases psychological distress may be driven by gut mechanisms. Therapeutic options are limited and, aside from responders to H. pylori eradication, provide only modest and temporary relief. Advances in understanding FD may alter clinical practice, and the treatment of duodenal inflammation or microbiome alterations may lead to a cure for a subset of these patients in the future.     

Delayed gastric emptying in functional dyspepsia

Opinion statement Functional dyspepsia is a complex syndrome with a poorly defined pathophysiology, resulting in uncertainties in its therapeutic approach. Abnormalities in gastrointestinal motility and sensitivity alone or combined seem to play a role in a substantial subgroup of patients. Drugs capable of prokinetic effects, such as antidopaminergics (eg, metoclopramide, domperidone, levosulpiride) and serotonin 5-HT4 receptor agonists (eg, tegaserod) can be potentially used in the treatment of dyspeptic patients. Furthermore, 5-HT4 receptor agonists do not appear to increase the gastric fundus tone which may also contribute to improved symptoms in subsets of patients. Alosetron, a 5-HT3 receptor antagonist, has been investigated mainly in irritable bowel syndrome, and the few studies performed in functional dyspepsia have provided conflicting results. Erythromycin and related derivatives, the motilides, represent another class of prokinetic compounds able to accelerate gastric emptying and potentially indicated in functional dyspepsia. The stimulatory effect on fundic tone and the occurrence of tachyphilaxis hamper the efficacy of these drugs in the long-term treatment. к-opioid receptor agonists might be useful for functional digestive syndromes because of their antinociceptive effects, but there are few available results and most are inconclusive. Results are also needed to prove efficacy of antidepressants (tricyclic agents and 5-HT reuptake inhibitors). Future clinical trials should be performed so that the formal structure required by good clinical practice can be adapted to detect significant effects in subgroups of patients with functional dyspepsia. Therapy should be ideally targeted to the different pathophysiologic abnormalities of these subgroups. The identification of the mechanisms leading to symptom generation should facilitate the development of newer and more effective therapeutic strategies in functional dyspepsia.     

Pain/Depression Dyad: A Key to a Better Understanding and Treatment of Functional Somatic Syndromes

Functional somatic syndromes include some of the most common and frustrating illnesses seen by primary care physicians and medical specialists. An extensive literature search of the 2 best characterized functional somatic syndromes, fibromyalgia and irritable bowel syndrome, reveals the overlap of these 2 disorders and their close relationship to depression. New pathophysiologic studies have shown that there are similar central nervous system changes in fibromyalgia, irritable bowel syndrome, and depression. These clinical and biologic similarities are consistent with the observations that the effective management of fibromyalgia and irritable bowel syndrome is comparable to that of depression.     

A patient questionnaire to identify bowel disease

Although functional gastrointestinal symptoms are seen frequently by internists and are the commonest reason for patients to be referred to gastroenterologists, no validated self-report questionnaire is available for their diagnosis. To differentiate among non-ulcer dyspepsia, the irritable bowel syndrome, organic gastrointestinal disease, and health, we developed a self-report questionnaire. Our bowel disease questionnaire, which evaluated 46 symptom-related items was completed prospectively by 361 subjects before their clinical evaluation as outpatients. Of these subjects, 115 were categorized ultimately as having functional bowel disease (non-ulcer dyspepsia or the irritable bowel syndrome), 101 were categorized ultimately as having organic gastrointestinal disease, and 145 were healthy persons having routine periodic examinations for whom no additional diagnoses were made. All diagnoses were based on independent clinical evaluations, not on the patients' responses to the questionnaire. The bowel disease questionnaire was acceptable and easily completed; it elicited symptoms in a highly reliable manner and was shown to be a valid measure of functional bowel complaints. Our questionnaire discriminated non-ulcer dyspepsia from irritable bowel syndrome with a sensitivity of 75% and a specificity of 72%, and it discriminated functional bowel disease from organic disease and health with sensitivities of 85% and 83%, and specificities of 60% and 76%, respectively. We believe that this questionnaire is an additional and useful diagnostic tool for identifying patients with functional gastrointestinal symptoms.