Diagnosis and treatment of functional gastrointestinal disorders in the Asia-Pacific region: a survey of current practices

Evidence-Based and Emerging Dietary Approaches to Upper Disorders of Gut-Brain Interaction

Food ingestion is a major symptom trigger in functional esophageal and gastroduodenal disorders and gastroparesis. This review summarizes current knowledge and identifies areas of research on the role of food factors and the opportunities for dietary intervention in these disorders. While many patients experiencing functional esophageal and gastroduodenal disorders identify specific food items as symptom triggers, available data do not allow the identification of specific nutrient groups that are more likely to induce symptoms. In functional dyspepsia (FD), recent studies have shown the potential efficacy of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, although the underlying mechanism of action is unclear. Reports of favorable responses to gluten elimination in patients with FD are confounded by the concomitant benefit of reduced intake of fructans, fermentable oligosaccharides, disaccharides, monosaccharides, and polyols present in wheat. Emerging data based on a 6-food elimination diet and confocal laser endomicroscopic evaluation of mucosal responses to food proteins suggest a role for duodenal allergic reactions in FD symptom generation. In patients with gastroparesis, a low-residue diet has been shown to improve symptoms. Novel dietary approaches under evaluation are the Mediterranean diet and the heating/cooling diet approach.

Gluten-Free Diet and Its 'Cousins' in Irritable Bowel Syndrome

Functional disorders are common, with irritable bowel syndrome (IBS) being the commonest and most extensively evaluated functional bowel disorder. It is therefore paramount that effective therapies are available to treat this common condition. Diet appears to play a pivotal role in symptom generation in IBS, with a recent interest in the role of dietary therapies in IBS. Over the last decade, there has been a substantial increase in awareness of the gluten-free diet (GFD), with a recent focus of the role of a GFD in IBS. There appears to be emerging evidence for the use of a GFD in IBS, with studies demonstrating the induction of symptoms following gluten in patients with IBS. However, there are questions with regards to which components of wheat lead to symptom generation, as well as the effect of a GFD on nutritional status, gut microbiota and long-term outcomes. Further studies are required, although the design of dietary studies remain challenging. The implementation of a GFD should be performed by a dietitian with a specialist interest in IBS, which could be achieved via the delivery of group sessions.

Breath Hydrogen Testing in East and Southeast Asia

Breath hydrogen tests are popular, noninvasive tests for the assessment of carbohydrate fermentation in patients with irritable bowel syndrome (IBS) and functional dyspepsia (FD). There is limited information regarding the utility of breath hydrogen and methane tests in IBS and FD patients in East and Southeast Asia. This review aims to summarize current literature about common indications of breath testing in this region, the genesis of functional gastrointestinal symptoms by provocative breath testing and provide suggestions for correct use. The most common testing indication is the assessment of lactose intolerance, followed by small intestinal bacterial overgrowth (SIBO) and differentiation of intestinal gas profiles in research setting. Studies in this region not only documented a high prevalence of lactose malabsorption but a population, both healthy and IBS, that is highly symptomatic to typical lactose intakes. Breath hydrogen assessment of other fermentable carbohydrates (FODMAPs) are fairly uncommon, whereas methane breath testing is almost nonexistent. Cumulative hydrogen production following lactulose was also not excessive in IBS patients compared with controls. The evidence however, for the detection of SIBO suggests limited reliability in the use of lactulose or glucose breath testing alone and inconclusive data on its correlation with symptoms. Conversely, little has been carried out in FD. In conclusion, breath testing should be limited in the predicting patients with SIBO for directing clinical management but can be considered in the objective assessment of lactose malabsorption within a low FODMAP diet. Recommendations to improve the interpretation of breath testing in research were also provided.

Food Therapy in Sinosphere Asia

Traditional Chinese Food Therapy has long been an integral part of dietary practices in Sinosphere Asia. This therapy is defined by the classification of foods into cooling (Yin) and heaty (Yang) and the manipulation of dietary intake of these foods as a therapeutic strategy for chronic diseases. Both functional dyspepsia (FD) and irritable bowel syndrome (IBS) are chronic, functional gut disorders widely prevalent in Sinosphere Asia. Diet is increasingly recognized as a symptom trigger in FD and IBS, and the evidence suggesting the utility of diet therapies as front-line management is growing, particularly in the West. Specifically, a diet low in Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols is an efficacious therapy for patients with IBS. In contrast, a proportion of patients with IBS in Sinosphere Asia utilize Chinese Food Therapy for symptom management. Chinese Food Therapy provides an attractive target for integration with evidence-based Western dietary therapies as a management strategy in FD and IBS. However, significant gaps in research exist with the utility of Chinese Food Therapy that first need to be addressed. This includes a lack of standardization for heaty and cooling classification, limited mechanistic rationale or clinical studies supporting its efficacy in FD and IBS, and the lack of an ideal practitioner for implementation of Chinese Food Therapy. Hence, the review provides a summary of the role of diet and nutrition in Sinosphere Asia with an emphasis on FD and IBS, and an examination of how modern dietary practices may be able to be integrated into practices in this region.

Irritable bowel syndrome in Asia: Pathogenesis, natural history, epidemiology, and management

Historically, the epidemiology of gastrointestinal diseases in Asia was different from that in Western countries. Early studies suggested a low prevalence of irritable bowel syndrome (IBS) in Asia. As the diagnosis of IBS is symptom-based and as symptom perception, expression, and interpretation are influenced by sociocultural perspectives including language, the presentation of IBS is expected to vary in different communities. Furthermore, the pathogenesis is multifactorial with psychosocial (stress, illness, behavior, and diet) and biological (infection, gut microbiota, and immune activation) variables interacting, and so, the present study can anticipate that the development of IBS will vary in different environments. In recognition of this aspect of functional gastrointestinal disorders, the recently published Rome IV documents have provided greater focus on cross-cultural factors. In this review, the present study seeks to highlight Asian perspectives by identifying historical trends and recent publications from the region and comparing these with the observations from Western societies.

Rome foundation Asian working team report: Real world treatment experience of Asian patients with functional bowel disorders

BACKGROUND AND AIM

Information on real world treatment experiences of patients with functional bowel disorders is lacking from Asia. This study aimed to describe the medication exposure and treatment satisfaction of patients presenting to gastroenterology clinics across a sampling of Asian cities.

METHODS

From March 2011 to October 2013, adult patients presenting to hospital-based gastroenterology outpatient clinics in 11 cities across Asia, who fulfilled screening criteria for any functional gastrointestinal disorder, were asked to complete a validated culturally adapted translation of the Rome III diagnostic questionnaire, a checklist of medications received in the preceding 3 months and questions on treatment satisfaction.

RESULTS

A total of 1376 patients (female 755, male 621, 41.36 ± 13.25 years) comprising irritable bowel (621, 45.1%), unspecified functional bowel disorder (372, 27.8%), functional constipation (202, 14.7%), functional bloating (144, 10.5%), and functional diarrhea (56, 4.1%) completed the study. Of 1105 patients with a previous consultation, 509 (46.1%) were dissatisfied with their treatment, with ineffective treatment being the commonest reason. Satisfaction with previous consultation was lowest by diagnosis for functional constipation (29.2%), and the most bothersome symptom was straining (37.5%). Of 1046 patients who had taken medications for their gastrointestinal symptoms in the last 3 months, 793 (75.8%) had received two or more drugs. For irritable bowel syndrome patients, treatment with proton pump inhibitors and antispasmodics was recorded in 57% and 31%, with overlapping epigastric pain and heartburn predicting proton pump inhibitors use.

CONCLUSIONS

More attention should be given to treatment gaps with regards to possible under-treatment with antispasmodics in irritable bowel syndrome and to critically evaluating the efficacy of constipation management.

Management of the clinical issue of constipation with abdominal complaints in adults. A national survey of Primary Care physicians and gastroenterologists

Irritable bowel syndrome and functional constipation represent a relevant and common health issue. However, real-world clinical practice includes patients with constipation who may or may not have other abdominal complaints (pain, bloating, abdominal discomfort) with variable frequency. The goal of the present study was to obtain information on the workload entailed by patients with constipation and associated abdominal complaints, predominant clinical behaviors, education needs, and potential daily practice aids both in Primary Care and gastroenterology settings. The clinical behavior of doctors is generally similar at both levels, despite differences in healthcare approach: use of empiric therapies and clinically guided diagnostic tests, with some differences in colonoscopy use (not always directly accessible from Primary Care). Regarding perceptions, general support and osmotic laxatives are most valued by PC doctors, whereas osmotic laxatives, combined laxatives, and linaclotide are most valued by GE specialists. Furthermore, over half of respondents considered differentiating both diagnoses as challenging. Finally, considerable education needs are self-acknowledged at both levels, as is a demand for guidelines and protocols to help in managing this issue in clinical practice. A strength of this study is its providing a joint photograph of the medical approach and the perceptions of constipation with abdominal discomfort from a medical standpoint. Weaknesses include self-declaration (no formal validation) and a response rate potentially biased by professional motivation.

The low-FODMAP diet in the management of functional dyspepsia in East and Southeast Asia

Functional dyspepsia (FD) is a common disorder in East and Southeast Asia where subjects experience post prandial fullness/bloating, early satiety, belching, epigastric pain, and/or burning. A subset of patients with FD experience triggers exclusively related to meals, defined as the post prandial distress syndrome in the Rome IV guidelines. There is significant overlap of symptoms and implicated pathogenic factors with another common functional gastrointestinal disorder, irritable bowel syndrome (IBS) and in fact, a significant proportion of subjects have FD/IBS overlap. The introduction of the low-FODMAP diet has changed the paradigm of treatment for IBS. Like IBS, dietary management appears to be important to patients with FD and clinicians treating the condition. This review aims to examine the current role of diet in the management of FD in East and Southeast Asia, with an exploration of the likely efficacy and mechanisms of action of the low-FODMAP diet in this region.

Who should deliver the low FODMAP diet and what educational methods are optimal: a review

Dietary management is being hailed as an effective strategy for the management of irritable bowel syndrome. Specifically, a diet low in fermentable carbohydrates (FODMAPs) has demonstrated efficacy in approximately 70% of patients. As evidence in support of the low FODMAP diet continues to emerge, there is increasing debate regarding implementation of the diet particularly concerning who should educate patients and how to educate them. Registered dieticians have largely pioneered the evidence that supports the effectiveness of the low FODMAP diet in irritable bowel syndrome, and the diet is recognized as a dietician-led therapy. However, there is an increasing trend for non-dietician-led implementation of the diet despite an absence of evidence on both the clinical or cost-effectiveness of such. Additionally, there is a growing requirement for dietetic services to increase capacity in response to increasing referrals, and consequently, there is a need to investigate innovative ways to educate patients whilst maintaining dietician-led intervention. Herein, we review the evidence for delivery of the low FODMAP diet and discuss potentially effective methods for service delivery.

Helicobacter pylori and Nonmalignant Diseases

Helicobacter pylori is responsible for most peptic ulcers, plays a role in functional dyspepsia and is thought by some to influence the course of gastroesophageal reflux disease. This article addresses recent studies that have been published in connection with these diseases. H. pylori-associated peptic ulcer is declining in prevalence but the incidence of perforation and bleeding remains high especially in the elderly. All H. pylori associated peptic ulcers should be treated by eradication of the infection. Dyspepsia is a common disorder that affects up to 25% of the population. About 8% of cases that are infected with H. pylori will respond to treatment of the infection. The association between H. pylori and gastroesophageal reflux disease continues to be debated, a number of studies have shown that there is a negative association between H. pylori infection and Gastroesophageal reflux disease but treatment of H. pylori has not been shown to induce reflux or to affect the response to medication. Gastric atrophy is known to extend when acid suppression is used in infected patients implying that H. pylori treatment should be used in infected patients who are to undergo long-term Proton Pump Inhibitor therapy.

Survey of clinical practice for irritable bowel syndrome in East asian countries

AIM

Sociocultural factors are important because their different effects on the features of irritable bowel syndrome (IBS) between countries will provide clues towards solving this problem. The aims of this study were to depict the clinical realities of IBS in East Asian countries and test the hypothesis that the diagnosis and treatment of IBS differ between countries.

SUBJECTS AND METHODS

Study participants were 251 physicians involved in the clinical practice of IBS at major institutions in Japan, South Korea, China, the Philippines, Indonesia and Singapore. The questionnaire contained 45 questions focused on the clinical practice of IBS.

RESULTS

Subjects in Japan, South Korea, China, Indonesia, the Philippines and Singapore accounted for 55.4, 17.9, 8.8, 8.0, 6.4 and 3.6% of the study cohort, respectively. Amongst East Asian physicians, the most important symptom was considered to be abdominal pain by 33.4%, whilst 24.3% regarded alternating diarrhea and constipation to be the most important symptoms. Total colonoscopy and histopathology use showed no difference among countries. Prescriptions given for mild (p < 0.0001), moderate (p < 0.0001), severe (p < 0.0001), intractable (p = 0.002), diarrheal (p < 0.0001) and constipating (p < 0.0001) patients with IBS significantly differed between the countries. Except for several minor points, IBS specialists showed no significant difference in their diagnosis and treatment of IBS when compared to nonspecialists.

CONCLUSION

This survey provided data on the clinical treatment of IBS among East Asian countries. The results supported the hypothesis that the diagnosis and treatment of IBS differs between countries.

A Rome III survey of functional dyspepsia among the ethnic Malays in a primary care setting

Backgrounds

The study aimed to survey for FD in a primary care setting in a population known to have an extremely low prevalence of Helicobacter pylori (H. pylori) infection, with the hypothesis that in such a population, dyspepsia should have been relatively less common.

Methods

The Rome III FD Diagnostic Questionnaire was translated into the Malay language and later tested for reliability. A prospective cross-sectional survey was then performed involving 160 Malay patients attending primary care clinic after informed consent. Patients positive for symptoms of FD were subjected to upper endoscopy and exclusion of H. pylori infection. Univariable and multivariable analyses were used to test for associated risk factors.

Results

The back-translated questionnaire was similar to the original English version and was reliable (Cronbach Alpha-coefficient 0.85). Of the 160 surveyed subjects, 19 of them (11.9%) had symptoms of FD. With exclusion of erosive diseases (3/160 or 1.9%) from endoscopy, 16 subjects or 10% had FD. None of the 19 subjects were positive for H. pylori infection. Epigastric pain syndrome was present in 11/16 (68.8%) and the rest, overlap with postprandial distress syndrome. With multivariable analysis, a married status (OR = 8.1; 95% CI 1.0-36.5) and positive psychosocial alarm symptoms (OR = 3.8; 95% CI 1.0-14.0) were associated with FD. Of those married subjects, females were more likely to have FD and psychosocial symptoms than men (6.3% vs. 1.9%), P = 0.04.

Conclusions

FD was more common than one had expected among Malays attending primary care clinic in an area with low prevalence of H. pylori.

Treatment of functional dyspepsia with sertraline: A double-blind randomized placebo-controlled pilot study

AIM: To evaluate sertraline, a selective serotonin reuptake inhibitor in the treatment of patients with functional dyspepsia.

METHODS: Consecutive tertiary hospital patients with a clinical diagnosis of functional dyspepsia (FD) according to the Rome II criteria with a Hong Kong dyspepsia index (HKDI) of greater than 16 were recruited. Patients commenced enrolment prior to the inception of the Rome III criteria for functional dyspepsia. All patients were ethnic Chinese, had a normal upper endoscopy and were Helicobacter pylori negative prior to enrolment. Study patients were randomized to receive sertraline 50 mg or placebo daily for 8 wk. HKDI symptom scores, quality of life, hospital anxiety and depression (HAD) scale and global symptom relief were evaluated before, during and after treatment. Adverse effects were monitored during and after treatment.

RESULTS: A total of 193 patients were randomized in the intention to treat (ITT), and 150 patients were included in the per protocol (PP) analysis. In both the ITT and PP, there was no difference in the primary outcome of global dyspepsia symptoms between the sertraline and placebo groups at week 8. In the ITT analysis, 98 and 95 patients were randomized to the sertraline and placebo groups respectively. A total of 43 patients withdrew from the study (22.3%) by week 8, with 23 of the 24 drop-outs in the sertraline group occurring prior to week 4 (95.8%). In contrast, in the placebo arm, 11 of 19 patients dropped out by week 4 (57.9%). Utilizing the last response carried forward to account for the drop-outs, there were no differences between the sertraline and placebo groups at baseline in terms of the HKDI, HKDI 26.08 ± 6.19 vs 26.70 ± 5.89, P = 0.433; and at week 8, HKDI 22.41 ± 6.36 vs 23.25 ± 7.30, P = 0.352 respectively. In the PP analysis, 74 and 76 patients were randomized to the sertraline and placebo groups respectively. At baseline, there were no statistically significant differences between the sertraline and placebo groups, HKDI 25.83 ± 6.313 vs 27.19 ± 5.929 respectively, P = 0.233; however by week 8, patients in the sertraline group demonstrated a statistically significant difference in their Hong Kong Dyspepsia Index compared to placebo, HKDI 20.53 ± 6.917 vs 23.34 ± 7.199, P = 0.02, respectively). There was also no statistically significant difference in overall quality of life measures or the HAD scale related to treatment in either the ITT or PP analysis at week 8.

CONCLUSION: This pilot study, the first to examine sertraline, a selective serotonin reuptake inhibitor, for the management of FD, did not find that it was superior to placebo.

Investigating functional dyspepsia in Asia

The diagnosis of functional dyspepsia (FD) is challenging since it depends largely on symptoms which are often heterogeneous and overlapping. This is particularly so in Asia with many different cultures and languages. Symptom-based diagnosis of FD based on Rome III criteria has not been fully validated and it may not be suitable in some Asian populations. Clinicians often assume that investigations in FD are not rewarding and physiological tests are often not available unless in the research setting. Investigation of alarm features and role of Helicobacter pylori in FD remain controversial but experts agreed that both should be tested. Physiological tests including gastric accommodation and chemical hypersensitivity tests are underutilized in Asia and available studies were few. While experts do not recommend routine clinical use of gastric accommodation tests but they agree that these tests can be advocated if clinically indicated. Empiric therapeutic trial is not currently a diagnostic option. The pathogenesis of FD is still poorly understood and there is a substantial placebo response. As a conclusion, a diagnosis of FD is challenging especially so in the context of Asia and despite the limitations of available physiological tests experts agreed that these tests can be advocated if and when clinically indicated.

Helicobacter pylori and nonmalignant diseases

Research published over the past year has documented the continued decline of Helicobacter pylori-related peptic ulcer disease and increased recognition of non-H. pylori, non-steroidal anti-inflammatory drugs ulcer disease--idiopathic ulcers. Despite reduced prevalence of uncomplicated PUD, rates of ulcer complications and associated mortality remain stubbornly high. The role of H. pylori in functional dyspepsia is unclear, with some authors considering H. pylori-associated nonulcer dyspepsia a distinct organic entity. There is increasing acceptance of an inverse relationship between H. pylori and gastroesophageal reflux disease (GERD), but little understanding of how GERD might be more common/severe in H. pylori-negative subjects. Research has focused on factors such as different H. pylori phenotypes, weight gain after H. pylori eradication, and effects on hormones such as ghrelin that control appetite.