Achalasia cardia is one of the common causes of motor dysphagia.Though the disease was first described more than 300 years ago,exact pathogenesis of this condition still remains enigmatic.Pathophysiologically,achalasi...Achalasia cardia is one of the common causes of motor dysphagia.Though the disease was first described more than 300 years ago,exact pathogenesis of this condition still remains enigmatic.Pathophysiologically,achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the esophagus.In the initial stage,degeneration of inhibitory nerves in the esophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine,resulting in high amplitude non-peristaltic contractions(vigorous achalasia);progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the esophageal body(classic achalasia).Since the initial description,several studies have attempted to explore initiating agents that may cause the disease,such as viral infection,other environmental factors,autoimmunity,and genetic factors.Though Chagas disease,which mimics achalasia,is caused by an infective agent,available evidence suggests that infection may not be an independent cause of primary achalasia.A genetic basis for achalasia is supported by reports showing occurrence of disease in monozygotic twins,siblings and other first-degree relatives and occurrence in association with other genetic diseases such as Down's syndrome and Parkinson's disease.Polymorphisms in genes encoding for nitric oxide synthase,receptors for vasoactive intestinal peptide,interleukin 23 and the ALADIN gene have been reported.However,studies on larger numbers of patients and controls from different ethnic groups are needed before definite conclusions can be obtained.Currently,the disease is believed to be multi-factorial,with autoimmune mechanisms triggered by infection in a genetically predisposed individual leading to degeneration of inhibitory ganglia in the wall of the esophagus.展开更多
Irritable bowel syndrome(IBS)is a common condition characterized by abdominal pain or discomfort,bloating,and altered stool form and passage.Small intestinal bacterial overgrowth(SIBO)is a condition in which there is ...Irritable bowel syndrome(IBS)is a common condition characterized by abdominal pain or discomfort,bloating,and altered stool form and passage.Small intestinal bacterial overgrowth(SIBO)is a condition in which there is overgrowth of bacteria in small bowel in excess of 105colony forming units per milliliter on culture of the upper gut aspirate.Frequency of SIBO varied from 4%-78%among patients with IBS and from 1%-40%among controls.Higher frequency in some studies might be due to fallacious criteria[postlactulose breath-hydrogen rise 20 PPM above basal within 90 min(early-peak)].Glucose hydrogen breath test(GHBT)has a low sensitivity to diagnose SIBO.Hence,studies based on GHBT might have under-estimated frequency of SIBO.Therefore,it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected.This review evaluates studies on association between SIBO and IBS,discordance between different studies,their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS.展开更多
Irritable bowel syndrome(IBS) is a chronic gastrointestinal disorder, common in clinic and in the community. It has a significant impact on both society and patients' quality of life. The epidemiology, clinical pr...Irritable bowel syndrome(IBS) is a chronic gastrointestinal disorder, common in clinic and in the community. It has a significant impact on both society and patients' quality of life. The epidemiology, clinical presentation, and management of IBS may vary in different geographical regions due to differences in diet, gastrointestinal infection, socio-cultural and psychosocial factors, religious and illness beliefs, symptom perception and reporting. Although previous reviews and consensus reports on IBS in Asia have been published, Asia is quite diverse socio-demographically. In this context, India, Bangladesh and Malaysia share some similarities, including:(1) large proportion of the population living in rural areas;(2) rapid development and associated lifestyle changes in urban areas; and(3) dietary, cultural and religious practices. The present review explores the clinical and epidemiological data on IBS from these three major nations in South and South-East Asia. In-depth review of the literature revealed important differences between IBS in the East, as revealed by studies from these three countries, and the West; these include a predominantly rural profile, differences in bowel habit and symptom profile, raising concern with regards to diagnostic criteria and subtyping of IBS, higher dietary fiber consumption, frequent lactose malabsorption, parasitosis, and possible overlap between post-infectious IBS and tropical sprue. Moreover, the current perception on difference in prevalence of the disorder in these countries, as compared to the West, might be related to variation in survey methods.展开更多
文摘Achalasia cardia is one of the common causes of motor dysphagia.Though the disease was first described more than 300 years ago,exact pathogenesis of this condition still remains enigmatic.Pathophysiologically,achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the esophagus.In the initial stage,degeneration of inhibitory nerves in the esophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine,resulting in high amplitude non-peristaltic contractions(vigorous achalasia);progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the esophageal body(classic achalasia).Since the initial description,several studies have attempted to explore initiating agents that may cause the disease,such as viral infection,other environmental factors,autoimmunity,and genetic factors.Though Chagas disease,which mimics achalasia,is caused by an infective agent,available evidence suggests that infection may not be an independent cause of primary achalasia.A genetic basis for achalasia is supported by reports showing occurrence of disease in monozygotic twins,siblings and other first-degree relatives and occurrence in association with other genetic diseases such as Down's syndrome and Parkinson's disease.Polymorphisms in genes encoding for nitric oxide synthase,receptors for vasoactive intestinal peptide,interleukin 23 and the ALADIN gene have been reported.However,studies on larger numbers of patients and controls from different ethnic groups are needed before definite conclusions can be obtained.Currently,the disease is believed to be multi-factorial,with autoimmune mechanisms triggered by infection in a genetically predisposed individual leading to degeneration of inhibitory ganglia in the wall of the esophagus.
文摘Irritable bowel syndrome(IBS)is a common condition characterized by abdominal pain or discomfort,bloating,and altered stool form and passage.Small intestinal bacterial overgrowth(SIBO)is a condition in which there is overgrowth of bacteria in small bowel in excess of 105colony forming units per milliliter on culture of the upper gut aspirate.Frequency of SIBO varied from 4%-78%among patients with IBS and from 1%-40%among controls.Higher frequency in some studies might be due to fallacious criteria[postlactulose breath-hydrogen rise 20 PPM above basal within 90 min(early-peak)].Glucose hydrogen breath test(GHBT)has a low sensitivity to diagnose SIBO.Hence,studies based on GHBT might have under-estimated frequency of SIBO.Therefore,it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected.This review evaluates studies on association between SIBO and IBS,discordance between different studies,their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS.
文摘Irritable bowel syndrome(IBS) is a chronic gastrointestinal disorder, common in clinic and in the community. It has a significant impact on both society and patients' quality of life. The epidemiology, clinical presentation, and management of IBS may vary in different geographical regions due to differences in diet, gastrointestinal infection, socio-cultural and psychosocial factors, religious and illness beliefs, symptom perception and reporting. Although previous reviews and consensus reports on IBS in Asia have been published, Asia is quite diverse socio-demographically. In this context, India, Bangladesh and Malaysia share some similarities, including:(1) large proportion of the population living in rural areas;(2) rapid development and associated lifestyle changes in urban areas; and(3) dietary, cultural and religious practices. The present review explores the clinical and epidemiological data on IBS from these three major nations in South and South-East Asia. In-depth review of the literature revealed important differences between IBS in the East, as revealed by studies from these three countries, and the West; these include a predominantly rural profile, differences in bowel habit and symptom profile, raising concern with regards to diagnostic criteria and subtyping of IBS, higher dietary fiber consumption, frequent lactose malabsorption, parasitosis, and possible overlap between post-infectious IBS and tropical sprue. Moreover, the current perception on difference in prevalence of the disorder in these countries, as compared to the West, might be related to variation in survey methods.