Prevalence of Irritable Bowel Syndrome in Japan, China, and South Korea: An International Cross-sectional Study

Background/Aims@#Symptoms of irritable bowel syndrome (IBS), a common gut-brain interaction disorder, deteriorate patients’ quality of life and increase medical needs; therefore, IBS represents a significant global burden. The estimated global prevalence is approximately 10%; however, accumulated evidence shows international heterogeneity. In this study, we have described and compared the prevalence of IBS in 3 East Asian countries: Japan (Tokyo and Fukuoka), China (Beijing), and South Korea (Seoul). @*Methods@#We conducted an internet-based cross-sectional survey of the urban population aged > 20 years in the abovementioned countries. We recruited equal numbers of age- (20s-60s) and sex-matched participants (3910 residents). IBS was diagnosed according to the Rome III criteria, and the subtypes were analyzed. @*Results@#The overall prevalence of IBS with 95% CI was 12.6% (11.6-13.7); the prevalence was significantly different across Japan, China, and South Korea (14.9% [13.4-16.5], 5.5% [4.3-7.1], and 15.6% [13.3-18.3], respectively) (P < 0.001). Furthermore, 54.9% of patients were male. IBS-mixed was the most prevalent subtype; the prevalence of other subtypes varied. @*Conclusions@#The overall prevalence of IBS in the 3 countries was slightly higher than the global prevalence, and it was significantly lower in China than in Japan and South Korea. IBS prevalence was the highest and lowest among individuals in their 40s and 60s, respectively. Male individuals had a higher prevalence of IBS with diarrhea. Further studies are needed to elucidate the factors associated with this regional heterogeneity.

Second Asian Consensus on Irritable Bowel Syndrome

BACKGROUND/AIMS: There has been major progress in our understanding of the irritable bowel syndrome (IBS), and novel treatment classes have emerged. The Rome IV guidelines were published in 2016 and together with the growing body of Asian data on IBS, we felt it is timely to update the Asian IBS Consensus. METHODS: Key opinion leaders from Asian countries were organized into 4 teams to review 4 themes: symptoms and epidemiology, pathophysiology, diagnosis and investigations, and lifestyle modifications and treatments. The consensus development process was carried out by using a modified Delphi method. RESULTS: Thirty-seven statements were developed. Asian data substantiate the current global viewpoint that IBS is a disorder of gut-brain interaction. Socio-cultural and environmental factors in Asia appear to influence the greater overlap between IBS and upper gastrointestinal symptoms. New classes of treatments comprising low fermentable oligo-, di-, monosacharides, and polyols diet, probiotics, non-absorbable antibiotics, and secretagogues have good evidence base for their efficacy. CONCLUSIONS: Our consensus is that all patients with functional gastrointestinal disorders should be evaluated comprehensively with a view to holistic management. Physicians should be encouraged to take a positive attitude to the treatment outcomes for IBS patients.

Effect of Mizagliflozin on Postprandial Plasma Glucose in Patients With Functional Constipation

No abstract available.

Increased Postprandial Colonic Motility and Autonomic Nervous System Activity in Patients With Irritable Bowel Syndrome: A Prospective Study

BACKGROUND/AIMS: The prevalence and severity of irritable bowel syndrome (IBS) declines with age, but the cause of this is unknown. This study tested 2 hypotheses: (1) autonomic nervous system responses to eating and bowel distention, measured by heart rate variability (HRV), differs by age in IBS patients and (2) HRV is correlated with colonic motility and IBS symptoms. METHODS: One hundred and fifty-six Rome III positive IBS patients and 31 healthy controls underwent colonic manometry with bag distention in the descending colon, followed by ingestion of an 810-kcal meal. HRV, evaluated by low frequency (%LF; 0.04–0.15 Hz) component, high frequency (%HF; 0.15–0.40 Hz) component, and the LF/HF ratio, was measured during colonic distention and after the meal. Motility index and subjective symptom scores were simultaneously quantified. RESULTS: Both colonic distention and eating decreased %HF and increased the LF/HF ratio, and both indices of autonomic nervous system correlated with age. In IBS patients, %HF negatively correlated with the postprandial motility index after adjusting for age. The %HF and LF/HF ratios also correlated with psychological symptoms but not bowel symptoms in IBS patients. CONCLUSION: Decreased vagal activity is associated with increase in age and greater postprandial colonic motility in patients with IBS, which may contribute to postprandial symptoms.

Dai-Kenchu-To, a Herbal Medicine, Attenuates Colorectal Distention-induced Visceromotor Responses in Rats

BACKGROUND/AIMS: Dai-kenchu-to (DKT), a traditional Japanese herbal medicine, is known to increase gastrointestinal motility and improve ileal function. We tested our hypotheses that (1) pretreatment with DKT would block the colorectal distention-induced visceromotor response in rats, and (2) pretreatment with DKT would attenuate colorectal distention-induced adrenocorticotropic hormone (ACTH) release and anxiety-related behavior. METHODS: Rats were pretreated with vehicle or DKT (300 mg/kg/5 mL, per os). Visceromotor responses were analyzed using electromyography in response to colorectal distention (10, 20, 40, 60, and 80 mmHg for 20 seconds at 3-minutes intervals). Anxiety-related behavior was measured during exposure to an elevated-plus maze after colorectal distention. Plasma ACTH and serum corticosterone levels were measured after exposure to the elevated-plus maze. RESULTS: Colorectal distention produced robust contractions of the abdominal musculature, graded according to stimulus intensity, in vehicle-treated rats. At 40, 60, and 80 mmHg of colorectal distention, the visceromotor responses of DKT-treated rats was significantly lower than that of vehicle-treated rats. At 80 mmHg, the amplitude was suppressed to approximately one-third in DKT-treated rats, compared with that in vehicle-treated rats. Smooth muscle compliance and the velocity of accommodation to 60 mmHg of stretching did not significantly differ between the vehicle-treated and DKT-treated rats. Similarly, the DKT did not influence colorectal distention-induced ACTH release, corticosterone levels, or anxiety-related behavior in rats. CONCLUSIONS: Our results suggest that DKT attenuates the colorectal distention-induced visceromotor responses, without increasing smooth muscle compliance, ACTH release or anxiety-related behavior in rats.

Relationship between Job Stress and Hypo-high-density Lipoproteinemia of Chinese Workers in Shanghai: The Rosai Karoshi Study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Karoshi, or death due to overwork, has now become a serious social problem in China. Worsening of cardiovascular risks by stress might initiate karoshi. Many studies have examined the relationship between job stress and obesity, hypertension, and type 2 diabetes mellitus, but less evidence exists for dyslipidemia like hypo-high-density lipoproteinemia (hypo-HDL). The aim of this study was to investigate the relationship between job stress and hypo-HDL of Chinese workers in Shanghai.</p><p><b>METHODS</b>We studied 2219 Chinese workers in Shanghai, who participated in the Japan-China cooperative study for the prevention of karoshi. A questionnaire was administered to examine the lifestyle characteristics, job category, weekly working hours, and job stress. Job demand and job control were quantified using the National Institute for Occupational Safety and Health questionnaire. Modified job strain measure was defined by the combination of low job control and high demand. Hypo-HDL was defined as plasma high-density lipoprotein cholesterol concentration of <1.04 mmol/L (40 mg/dl). Multivariate logistic regression analysis was performed for hypo-HDL as a dependent variable.</p><p><b>RESULTS</b>Modified job strain was not related to hypo-HDL either in men or women. In men, multivariate adjusted odds ratio (OR) for having hypo-HDL was significantly higher in the lowest job control tertile compared with the highest job control tertile (OR = 1.39, 95% confidence interval [CI] 1.03-1.87, P = 0.034). In the same model, a similar trend was observed for women, but it did not reach a statistically significant level (OR = 1.51, 95% CI, 0.88-2.56, P = 0.132).</p><p><b>CONCLUSION</b>A low level of job control but not modified job strain was significantly related to higher prevalence of hypo-HDL of Chinese workers in Shanghai.</p>

Validity and Reliability of the Japanese Version of the Rome III Diagnostic Questionnaire for Irritable Bowel Syndrome and Functional Dyspepsia

BACKGROUND/AIMS: Reliable diagnostic instruments for measuring the presence of functional gastrointestinal disorders based on the Rome III criteria have been lacking in Japan. The aims of the present study were to translate and validate the Rome III diagnostic questionnaire which was widely used in Western countries. METHODS: The original version of Rome III diagnostic questionnaire was translated from English into Japanese through 3 independent forward translations, resolution, back translation and reconciliation of the differences. Forty-nine patients with irritable bowel syndrome (IBS), 32 patients with functional dyspepsia (FD) and 56 subjects without any current GI symptoms as controls were recruited from three hospitals located in different regions of Japan and completed the IBS and FD diagnostic modules twice within 14 days. Kappa statistic was used to assess test-retest reliability. The sensitivity and specificity of each diagnostic module for distinguishing IBS or FD patients from controls was tested. RESULTS: Median kappa statistics were 0.63 for the translated IBS diagnostic module and 0.68 for the FD module. The sensitivity, specificity, and positive predict value of the IBS module against physician diagnosis was 61.2%, 100%, and 100% and those of the FD module was 53.2%, 98.2%, and 94.4%, respectively. Meanwhile, IBS patients were significantly more likely to report blood in stools compared to controls (18.4% vs 1.8%, P < 0.01). CONCLUSIONS: The IBS and FD diagnostic modules on the Japanese version of the Rome III diagnostic questionnaire are valid and reliable. Further studies are warranted to elucidate the diagnostic utility of the red flag questionnaire.

Biopsychosocial Model of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common chronic disorder seen in gastroenterology and primary care practice. It is characterized by recurrent abdominal pain or discomfort associated with disturbed bowel function. It is a heterogeneous disorder with varying treatments, and in this regard physicians sometimes struggle with finding the optimal approach to management of patients with IBS. This disorder induces high health care costs and variably reduces health-related quality of life. IBS is in the class of functional gastrointestinal disorders, and results from dysregulation of central and enteric nervous system interactions. Psychosocial factors are closely related to their gut physiology, associated cognitions, symptom manifestations and illness behavior. Therefore, it is important for the physician to recognize the psychosocial issues of patients with IBS and in addition to build a good patient-physician relationship in order to optimize treatment. This review focuses on the interaction between psychological and physiological factors associated with IBS by using a biopsychosocial model. In this article, we describe (1) the predisposing psychological features seen in early life; (2) the psychological factors associated with life stress, the symptom presentation, and their associated coping patterns; (3) gut pathophysiology with emphasis on disturbances in motility, visceral hypersensitivity and brain-gut interactions; and finally (4) the clinical outcomes and effective treatments including psychotherapeutic methods.