Overview of neurogastroenterology-gastrointestinal motility and functional GI disorders: classification, prevalence, and epidemiology

The mechanisms of nerve injury caused by viral infection in the occurrence of gastrointestinal motility disorder-related diseases

Gastrointestinal motility refers to the peristalsis and contractility of gastrointestinal muscles, including the force and frequency of gastrointestinal muscle contraction. Gastrointestinal motility maintains the normal digestive function of the human body and is a critical component of the physiological function of the digestive tract. At present, gastrointestinal motility disorder-related diseases are gradually affecting human production and life. In recent years, it has been consistently reported that the enteric nervous system has a coordinating and controlling role in gastrointestinal motility. Motility disorders are closely related to functional or anatomical changes in the gastrointestinal nervous system. At the same time, some viral infections, such as herpes simplex virus and varicella-zoster virus infections, can cause damage to the gastrointestinal nervous system. Therefore, this paper describes the mechanisms of viral infection in the gastrointestinal nervous system and the associated clinical manifestations. Studies have indicated that the means by which viruses can cause the infection of the enteric nervous system are various, including retrograde transport, hematogenous transmission and centrifugal transmission from the central nervous system. When viruses infect the enteric nervous system, they can cause clinical symptoms, such as abdominal pain, abdominal distension, early satiation, belching, diarrhea, and constipation, by recruiting macrophages, lymphocytes and neutrophils and regulating intestinal microbes. The findings of several case‒control studies suggest that viruses are the cause of some gastrointestinal motility disorders. It is concluded that one of the causes of gastrointestinal motility disorders is viral infection of the enteric nervous system. In such disorders, the relationships between viruses and nerves remain to be studied more deeply. Further studies are necessary to evaluate whether prophylactic antiviral therapy is feasible in gastrointestinal motility disorders.

Psychiatric comorbidities among adult patients with disorders of gut-brain interaction: Prevalence and relationships to treatment outcomes

BACKGROUND

Little is known about the impact of psychiatric comorbidity on pharmacologic treatment outcomes, including neuromodulators (medications targeting the gut-brain axis), among adult patients with disorders of gut-brain interaction (DGBI). Accordingly, we aimed to examine associations between psychiatric comorbidity and DGBI pharmacologic treatment outcomes.

METHODS

In a retrospective study of consecutively referred new patients (N = 410; ages 18-90; 73% female) to a tertiary neurogastroenterology clinic in 2016 with follow-up through 2018, relationships between psychiatric illness (any psychiatric illness, anxiety disorders, depressive disorders) and pharmacologic treatment selection (any medication, neuromodulating medication) and treatment outcomes, respectively, were examined using multivariable logistic regression, adjusting for demographics, gastrointestinal (GI) diagnoses, and pre-existing neuromodulator use.

KEY RESULTS

Anxiety disorders (35%) were the most common psychiatric comorbidity, followed by depressive disorders (29%). Patients with anxiety disorders were more likely to be prescribed a neuromodulator by their gastroenterologist (OR = 1.72 [95% CI 1.10-2.75]) yet less likely to respond to neuromodulators (OR = 0.43 [0.21-0.90]) or any GI medication (OR = 0.24 [0.12-0.50]) in fully adjusted analyses. In contrast, depressive disorders were not associated with neuromodulator prescription or response.

CONCLUSIONS AND INFERENCES

Anxiety disorders are common among patients with DGBI and significantly reduce the likelihood of GI pharmacologic treatment response to any medication prescribed, including neuromodulators.

Abdominal massage: A review of clinical and experimental studies from 1990 to 2021

OBJECTIVE

To systematically review the current state and holistic application of abdominal massage (AM).

DESIGN

A systematic review of qualitative evidence was conducted. All English articles exploring the topic of AM that had been published until the end of June 2021 were retrieved.

DATA SOURCES

The PubMed, Cochrane library, and Embase databases were accessed. Some original texts were obtained from Google Scholar.

DATA EXTRACTION AND SYNTHESIS

Two authors independently evaluated all search data to identify relevant studies. Disagreements were settled by discussion with a third author. Results were independently extracted into standardized sheets and checked for accuracy.

MAIN RESULTS

A total of 107 full-text reports were eligible for inclusion. Adult digestive disorders, pediatric disorders, gynecological disorders, obstetric disorders, metabolic disorders, psychological disorders, the side effects of AM, and animal experiments accounted for 49.53%, 14.02%, 7.48%, 7.48%, 4.67%, 4.67%, 5.61%, and 6.54% of all these papers, respectively, with most reports focusing on clinical studies.

CONCLUSION

The variety of diseases treated with AM is gradually increasing, and the treatment programs of AM for many diseases are being gradually optimized. Different forms of AM, especially mechanical AM, have been widely studied; the side effects of AM have also been considered; and the possible mechanisms of AM therapy continue to be discovered. In general, AM is an effective and safe therapy and can be widely used in various diseases, but further studies are necessary to clarify the mechanism of AM for different diseases. In the future, AM could become an even safer, more popular, and more modern therapy.

Whole Body Pain Distribution and Risk Factors for Widespread Pain Among Patients Presenting with Abdominal Pain: A Retrospective Cohort Study

Introduction

Abdominal pain frequently co-occurs with pain in other body sites. Chronic overlapping pain conditions (COPCs) represent a group of widespread pain diagnoses. Our study characterized how patterns of somatic pain distribution are associated with COPCs and aimed to characterize predictors of widespread pain among patients with chronic abdominal pain.

Methods

This retrospective cohort study included adults presenting to a tertiary pain clinic, reporting abdominal pain at their initial visit, and with a follow-up visit at 12 months. Body maps divided patients into localized, intermediate, and widespread pain distribution patterns. Diagnostic and psychosocial measures were assessed across groups at the initial and follow-up visits. We analyzed the association of baseline diagnoses and demographics and time-varying changes in psychosocial measures from initial to follow-up visit with changes in pain distribution over time with alternating logistic regression (ALR).

Results

Among 258 patients, most were female (91.5%) and reported widespread pain (61.5%). Those with widespread pain at baseline reported elevated anger and 60.0% of patients remained in the same pain category at follow-up. Multivariable ALR demonstrated higher pain interference (AOR 1.06, 95% CI 1.02–1.10, P = 0.002), higher anxiety (AOR 1.05, 95% CI 1.01–1.09, P = 0.01), more than one COPC at initial visit (AOR 2.85, 95% CI 1.59–5.11, P = 0.0005), and initial visit widespread pain categorization (AOR 4.18, 95% CI 2.20–8.00, P < 0.0001) were associated with an increased risk of widespread pain at the follow-up visit.

Conclusion

Most patients with abdominal pain report additional pain locations at multiple other body sites, and non-localized pain persists 12 months after pain treatment. Screening for widespread pain and COPC at the initial visit may identify patients at higher risk for persistent or new-onset widespread pain, and interventions to reduce pain interference and anxiety may promote reversal of widespread pain.

Belching: Pathogenesis, Clinical Characteristics, and Treatment Strategies

PURPOSE

Belching is a common condition that frequently overlaps with other functional gastrointestinal disorders. While not associated with any increase in mortality, it is associated with impaired health-related quality of life. Management is challenging, as there are no pharmacologic therapies specifically targeted towards this disorder. This review covers pathogenesis, prevalence, and treatments for this condition, with specific emphasis on the evolving role of behavioral treatments in management.

KEY FINDINGS

The diagnosis of gastric and supragastric belching can usually be made clinically, without the need for invasive testing. If necessary, multichannel intraluminal impedance and pH testing can provide a more definitive diagnosis and can also be used to estimate the frequency of gastric and supragastric belching episodes, which each have a distinct appearance on impedance tracing. Belching disorders are commonly associated with gastroesophageal reflux disease and functional disorders of the gastrointestinal tract. Supragastric belching is also associated with behavioral disorders like anxiety and obsessive-compulsive disorder. Speech therapy, cognitive-behavioral therapy, and diaphragmatic breathing are all interventions that have recently shown promise in the management of this challenging disorder.

Nutrition Management in Patients With Chronic Gastrointestinal Motility Disorders: A Systematic Literature Review

BACKGROUND

The aim of this study was to systematically review effects of nutrition interventions on outcomes in patients with chronic gastrointestinal (GI) motility disorders. There is currently a lack of evidence-based guidelines for nutrition management in this group, likely a result of the rarity of the conditions.

METHODS

A systematic review of all study types to evaluate current evidence-based nutrition interventions was performed using Medline, Embase, and CINAHL databases. Two independent reviewers participated in the process of this systematic review. A total of 15 studies and a total of 524 subjects were included.

RESULTS

Best treatment of this population group was found to include a stepwise process, progressing from oral nutrition to jejunal nutrition and lastly to parenteral nutrition. Small particle, low-fat diets were significantly better tolerated than the converse, with jejunal nutrition prior to consuming oral food significantly improving oral intake and motility. In more progressive cases, percutaneous endoscopic gastrostomy with jejunal extension nutrition had lower reported symptoms than other enteral routes. Exclusive long-term parenteral nutrition is a feasible option for advanced cases, with a 68% survival rate at 15 years duration, though oral intake with parenteral nutrition is associated with higher survival rates.

CONCLUSION

Treatment of patients with GI motility disorders should first trial oral nutrition. For patients who progress to jejunal or parenteral feeds, the primary aim should be to maintain or reinstate oral intake to reduce morbidity and mortality risk. Higher-quality studies are still required in this area, particularly in the areas of chronic intestinal pseudo-obstruction and systemic sclerosis.

Naringenin induces laxative effects by upregulating the expression levels of c-Kit and SCF, as well as those of aquaporin 3 in mice with loperamide-induced constipation

Constipation is a common affliction which causes discomfort and affects the quality of life of affected individuals. Naringenin (NAR), a natural flavonoid widely found in citrus fruits and tomatoes, has been reported to exhibit various pharmacological effects, such as anti-inflammatory, anti-atherogenic, anti-mutagenic, hepatoprotective and anticancer effects. Increasing evidence has indicated that NAR has potential for use in the treatment of constipation. Thus, the aim of this study was to evaluate the laxative effects of NAR in mice with loperamide-induced (Lop-induced) constipation. The data indicated that NAR relieved Lop-induced constipation in mice based on the changes of fecal parameters (numbers, weight and water content), the intestinal charcoal transit ratio and the histological alteration. ELISA revealed that NAR regulated the production levels of gastrointestinal metabolic components, such as motilin (MTL), gastrin (Gas), endothelin (ET), substance P (SP), acetylcholinesterase (AChE) and vasoactive intestinal peptide (VIP) in serum. The expression levels of enteric nerve-related factors, glial cell line-derived neurotrophic factor (GDNF), transient receptor potential vanilloid 1 (TRPV1), nitric oxide synthase (NOS), c-Kit, stem cell factor (SCF) and aquaporin 3 (AQP3) were examined by western blot analysis and RT-PCR analysis. The results of this study suggest that NAR relieves Lop-induced constipation by increasing the levels of interstitial cells of Cajal markers (c-Kit and SCF), as well as AQP3. Thus, NAR may be effective as a candidate in patients suffering from lifestyle-induced constipation.

Adult enteric nervous system in health is maintained by a dynamic balance between neuronal apoptosis and neurogenesis

According to current dogma, there is little or no ongoing neurogenesis in the fully developed adult enteric nervous system. This lack of neurogenesis leaves unanswered the question of how enteric neuronal populations are maintained in adult guts, given previous reports of ongoing neuronal death. Here, we confirm that despite ongoing neuronal cell loss because of apoptosis in the myenteric ganglia of the adult small intestine, total myenteric neuronal numbers remain constant. This observed neuronal homeostasis is maintained by new neurons formed in vivo from dividing precursor cells that are located within myenteric ganglia and express both Nestin and p75NTR, but not the pan-glial marker Sox10. Mutation of the phosphatase and tensin homolog gene in this pool of adult precursors leads to an increase in enteric neuronal number, resulting in ganglioneuromatosis, modeling the corresponding disorder in humans. Taken together, our results show significant turnover and neurogenesis of adult enteric neurons and provide a paradigm for understanding the enteric nervous system in health and disease.

The successful use of dronabinol for failure to thrive secondary to intestinal dysmotility

•

We describe the use of dronabinol in a patient with severe intestinal dysmotility.

•

Dronabinol was an effective treatment for nausea, vomiting, and anorexia.

•

Insurance coverage of dronabinol could improve care for many patients.

Introduction

Symptoms of severe intestinal dysmotility decrease patients’ quality of life and may prevent them from sustaining adequate oral intake. Dronabinol is a synthetic cannabinoid that is labeled for use in AIDS-related anorexia and chemotherapy-associated nausea and vomiting that has additional efficacy in patients with other etiologies of nausea, vomiting, and anorexia.

Presentation of case

We present a 58-year-old female with a history of nausea, vomiting, abdominal pain, and inability to maintain oral intake after multiple laparotomies for ectopic pregnancy, recurrent caecal volvulus, and cholecystitis. After eight years of unsuccessful trials of medicines, dietary modifications, and a partial colectomy, she began a trial of dronabinol, which caused almost complete remission of her symptoms. When this medication was discontinued by her payer, she was unable to maintain oral intake and therefore, was admitted to the hospital for fluid resuscitation and resumption of dronabinol.

Discussion

The use of dronabinol in this patient with severe intestinal dysmotility allowed her to maintain her nutritional status orally and obviated the need for enteral or parenteral feeding. Unfortunately, it was not covered by her insurance company for this indication.

Conclusion

Dronabinol has the potential to improve quality of life for patients beyond those undergoing chemotherapy or suffering from AIDS. Lack of access to this medicine for patients with intestinal dysmotility after all other modalities have been tried can lead to morbid and expensive complications, such as inpatient admission and surgery for enteral access.

Motility alterations in celiac disease and non-celiac gluten sensitivity

Regulation of gut motility is complex and involves neuromuscular, immune and environmental mechanisms. It is well established that patients with celiac disease (CD) often display gut dysmotility. Studies have shown the presence of disturbed esophageal motility, altered gastric emptying, and dysmotility of the small intestine, gallbladder and colon in untreated CD. Most of these motor abnormalities resolve after a strict gluten-free diet, suggesting that mechanisms related to the inflammatory condition and disease process are responsible for the motor dysfunction. Motility abnormalities are also a hallmark of functional bowel disorders such as irritable bowel syndrome (IBS), where it has been proposed as underlying mechanism for symptom generation (diarrhea, constipation, bloating). Non-celiac gluten sensitivity (NCGS) is a poorly defined entity, mostly self-diagnosed, that presents clinically with IBS symptoms in the absence of specific celiac markers. Patients with NCGS are believed to react symptomatically to wheat components, and some studies have proposed the presence of low-grade inflammation in these patients. There is little information regarding the functional characterization of these patients before and after a gluten-free diet. A study suggested the presence of altered gastrointestinal transit in NCGS patients who also have a high prevalence of nonspecific anti-gliadin antibodies. Results of an ongoing clinical study in NCGS patients with positive anti-gliadin antibodies before and after a gluten-free diet will be discussed. Elucidating the mechanisms for symptom generation in NCGS patients is important to find new therapeutic alternatives to the burden of imposing a strict gluten-free diet in patients who do not have CD.

Gastrointestinal motility revisited: The wireless motility capsule

INTRODUCTION

The wireless motility capsule (WMC) is a novel ambulatory technology that concurrently measures intraluminal pH, temperature, and pressure as it traverses the gastrointestinal tract.

OBJECTIVES

We aim to provide a concise summary of the WMC, detailing the procedure for its administration and the parameters it records. We also review the evidence that has validated the WMC against other methods currently regarded as 'gold standard'.

CONCLUSIONS

The WMC offers a number of advantages over and above current techniques, especially with respect to patient tolerability, safety, and standardization. The WMC represents a considerable enhancement of the researchers' and clinicians' investigatory armamentarium. If this technology becomes widely adopted, coupled with international consensus upon the interpretation of physiological data derived therein, it may herald a new and exciting era in gastrointestinal physiology.

Smoothelin expression in the gastrointestinal tract: implication in colonic inertia

Colonic inertia is a frustrating motility disorder to patients, clinicians, and pathologists. The pathogenesis is largely unknown. The aims of this study were to: (1) characterize the expression of smoothelin, a novel smooth muscle-specific contractile protein expressed only by terminally differentiated smooth muscle cells, in the normal gastrointestinal (GI) tract; and (2) determine whether smoothelin is aberrantly expressed in patients with colonic inertia. A total of 57 resections of the normal GI tract (distal esophagus to left colon) were obtained from patients without GI motor dysfunction. Sixty-one colon resections were obtained from patients with a clinical diagnosis of colonic inertia. Smoothelin immunostaining was conducted on full-thickness tissue sections. In the nondysmotile controls, strong and diffuse cytoplasmic staining for smoothelin was observed in both the inner circular and outer longitudinal layers of the muscularis propria (MP) throughout the entire GI tract. The muscularis mucosae (MM) and muscular vessel walls were either completely negative or only patchily and weakly stained. The 1 exception to this pattern was observed in the distal esophagus, in which the MM was also diffusely and strongly stained. In cases with colonic inertia, a moderate to marked reduction of smoothelin immunoreactivity was observed in 15 of 61 (24.6%) colon resections, selectively seen in the outer layer of the MP. The data demonstrate that smoothelin is differentially expressed in the MP and MM of the normal GI tract and suggest that defective smoothelin expression may play a role in the pathogenesis of colonic inertia in a subset of patients.

Pathophysiology of Greedy Colon and Diabetes: Role of Atropine in worsening of Diabetes

Greedy colon which is a synonym of constipation is a serious condition in the human body which may lead to complications, like damage of the rectal tissue, cellular dehydration and colorectal cancer. Diabetes mellitus, although a systemic disease with diverse clinical symptoms, is also related with cellular dehydration. Understanding the pathophysiological aspects of diabetes mellitus and greedy colon may shed light in the management of either of these conditions. The main purpose of this article is to demonstrate an association of tissue dehydration during diabetes mellitus and constipation. The adverse side effects of atropine will be discussed due to its M3 blockage effect and reduction in peristalsis keeping in mind the importance of these facts in the context of public health importance, especially in geriatric health. How to cite this article: Gundamaraju R, Vemuri R. Pathophysiology of Greedy Colon and Diabetes: Role of Atropine in worsening of Diabetes. Euroasian J Hepato-Gastroenterol 2014;4(1):51-54.

Effects of scleroderma antibodies and pooled human immunoglobulin on anal sphincter and colonic smooth muscle function

BACKGROUND & AIMS

Patients with systemic sclerosis (SSc) have impairments in gastrointestinal smooth muscle function. The disorder has been associated with circulating antibodies to cholinergic muscarinic the type-3 receptor (M(3)-R). We investigated whether it is possible to neutralize these antibodies with pooled human IgGs (pooledhIgG).

METHODS

We studied the effects of IgGs purified from patients with SSc (SScIgGs) on cholinergic nerve stimulation in rat colon tissues. We also examined the effects of SScIgGs on M(3)-R activation by bethanechol (BeCh), M(3)-R occupancy, and receptor binding using immunofluorescence, immunoblot, and enzyme-linked immunosorbent analyses of human internal anal sphincter (IAS) smooth muscle cells, before and after administration of pooledhIgG. Functional displacement of M(3)-R occupancy by the SScIgGs was compared with that of other IgGs during the sustained phase of BeCh-induced contraction of intact smooth muscles from rats.

RESULTS

SScIgG significantly attenuated neurally mediated contraction and acetylcholine release in rat colon as well as BeCh-induced sustained contraction of the IAS smooth muscle. In immunofluorescence analysis, SScIgG co-localized with M(3)-R. In immunoblot and enzyme-linked immunosorbent analyses, M(3)-R loop-2 peptide and human IAS SMC membrane lysates bound significant amounts of SScIgG, compared with IgGs from healthy individuals and pooledhIgG. Binding was attenuated significantly by application of pooledhIgG, which by itself had no significant effect. Incubation of samples with pooledhIgG, or mixing pooledhIgG with SScIgG before administration to tissues, significantly reduced binding of SScIgG, indicating that pooledhIgG prevents SScIgG blockade of M(3)-R.

CONCLUSIONS

In studies of rat and human tissues, pooled human IgG prevent and reverses the cholinergic dysfunction associated with the progressive gastrointestinal manifestations of SSc by neutralizing functional M(3)-R antibodies present in the circulation of patients with SSc.

Functional studies of the gastrointestinal tract in adult surgical clinics: when do they help?

Gut motility and visceral sensation are two important components of normal gastrointestinal (GI) tract function. Disordered gut motility and sensation can cause significant symptoms which not only pose a health burden to patients, but may also mimic structural diseases and may generate many surgical referrals from primary care. Unfortunately, diagnostic testing for disorders of function lags well behind that for structural disease. In this article we review common presentations of functional disorders in surgical clinics, and relevant testing modalities.

Investigating the relationships between peristaltic contraction and fluid transport in the human colon using Smoothed Particle Hydrodynamics

Complex relationships exist between gut contractility and the flow of digesta. We propose here a Smoothed Particle Hydrodynamics model coupling the flow of luminal content and wall flexure to help investigate these relationships. The model indicates that a zone of muscular relaxation preceding the contraction is an important element for transport. Low pressures in this zone generate positive thrust for low viscosity content. The viscosity of luminal content controls the localization of the flow and the magnitude of the radial pressure gradient and together with contraction amplitude they control the transport rate. For high viscosity content, high lumen occlusion is required for effective propulsion.

The rebirth of neuroscience in psychosomatic medicine, Part II: clinical applications and implications for research

During the second half of the last century, biopsychosocial research in psychosomatic medicine largely ignored the brain. Neuroscience has started to make a comeback in psychosomatic medicine research and promises to advance the field in important ways. In this paper we briefly review select brain imaging research findings in psychosomatic medicine in four key areas: cardiovascular regulation, visceral pain in the context of functional gastrointestinal disorders, acute and chronic somatic pain and placebo. In each area, there is a growing literature that is beginning to define a network of brain areas that participate in the functions in question. Evidence to date suggests that cortical and subcortical areas that are involved in emotion and emotion regulation play an important role in each domain. Neuroscientific research is therefore validating findings from previous psychosomatic research and has the potential to extend knowledge by delineating the biological mechanisms that link mind and body more completely and with greater specificity. We conclude with a discussion of the implications of this work for how research in psychosomatic medicine is conducted, the ways in which neuroscientific advances can lead to new clinical applications in psychosomatic contexts, the implications of this work for the field of medicine more generally, and the priorities for research in the next 5 to 10 years.

Regulation of enteric functions by adenosine: pathophysiological and pharmacological implications

The wide distribution of ATP and adenosine receptors as well as enzymes for purine metabolism in different gut regions suggests a complex role for these mediators in the regulation of gastrointestinal functions. Studies in rodents have shown a significant involvement of adenosine in the control of intestinal secretion, motility and sensation, via activation of A1, A2A, A2B or A3 purinergic receptors, as well as the participation of ATP in the regulation of enteric functions, through the recruitment of P2X and P2Y receptors. Increasing interest is being focused on the involvement of ATP and adenosine in the pathophysiology of intestinal disorders, with particular regard for inflammatory bowel diseases (IBDs), intestinal ischemia, post-operative ileus and related dysfunctions, such as gut dysmotility, diarrhoea and abdominal discomfort/pain. Current knowledge suggests that adenosine contributes to the modulation of enteric immune and inflammatory responses, leading to anti-inflammatory actions. There is evidence supporting a role of adenosine in the alterations of enteric motor and secretory activity associated with bowel inflammation. In particular, several studies have highlighted the importance of adenosine in diarrhoea, since this nucleoside participates actively in the cross-talk between immune and epithelial cells in the presence of diarrhoeogenic stimuli. In addition, adenosine exerts complex regulatory actions on pain transmission at peripheral and spinal sites. The present review illustrates current information on the role played by adenosine in the regulation of enteric functions, under normal or pathological conditions, and discusses pharmacological interventions on adenosine pathways as novel therapeutic options for the management of gut disorders and related abdominal symptoms.