As an increase in gastroesophageal reflux disease (GERD) has been reported in Japan, and public interest in GERD has been increasing, the Japanese Society of Gastroenterology published the Evidence-based Clinical Practice Guidelines for GERD (1st edition) in 2009. Six years have passed since its publication, and there have been a large number of reports in Japan concerning the epidemiology, pathophysiology, treatment, and Barrett's esophagus during this period. By incorporating the contents of these reports, the guidelines were completely revised, and a new edition was published in October 2015. The revised edition consists of eight items: epidemiology, pathophysiology, diagnosis, internal treatment, surgical treatment, esophagitis after surgery of the upper gastrointestinal tract, extraesophageal symptoms, and Barrett's esophagus. This paper summarizes these guidelines, particularly the parts related to the treatment for GERD. In the present revision, aggressive proton pump inhibitor (PPI) maintenance therapy is recommended for severe erosive GERD, and on-demand therapy or continuous maintenance therapy is recommended for mild erosive GERD or PPI-responsive non-erosive GERD. Moreover, PPI-resistant GERD (insufficient symptomatic improvement and/or esophageal mucosal break persisting despite the administration of PPI at a standard dose for 8 weeks) is defined, and a standard-dose PPI twice a day, change in PPI, change in the PPI timing of dosing, addition of a prokinetic drug, addition of rikkunshito (traditional Japanese herbal medicine), and addition of histamine H2-receptor antagonist are recommended for its treatment. If no improvement is observed even after these treatments, pathophysiological evaluation with esophageal impedancepH monitoring or esophageal manometry at an expert facility for diseases of the esophagus is recommended.

Colonic diverticular disease has been increasing in prevalence in Japan due to the rapidly aging population. Colonic diverticular bleeding can result in hemorrhagic shock requiring blood transfusion, and it carries a high risk of recurrence within 1 year. Colonic diverticulitis can cause abscess, fistula formation, and perforation of the colon that may require surgery, and it often recurs. As a result, patients with colonic diverticular disease are often bothered by required frequent examinations, re-hospitalization, and a consequent decrease in quality of life. However, the management of diverticular disease differs between Japan and Western countries. For example, computed tomography (CT) is readily accessible at Japanese hospitals, so urgent CT may be selected as the first diagnostic procedure for suspected diverticular disease. Endoscopic clipping or band ligation may be preferred as the first endoscopic procedure for diverticular bleeding. Administration of antibiotics and complete bowel rest may be considered as first-line therapy for colonic diverticulitis. In addition, diverticula occur mainly in the sigmoid colon in Western countries, whereas the right side or bilateral of the colon is more commonly involved in Japan. As such, diverticular disease in the right-side colon is more prevalent in Japan than in Western countries. Against this background, concern is growing about the management of colonic diverticular disease in Japan and there is currently no practice guideline available. To address this situation, the Japanese Gastroenterological Association decided to create a clinical guideline for colonic diverticular bleeding and colonic diverticulitis in collaboration with the Japanese Society of Gastroenterology, Japan Gastroenterological Endoscopy Society, and Japanese Society of Interventional Radiology. The steps taken to establish this guideline involved incorporating the concept of the GRADE system for rating clinical guidelines, developing clinical questions (CQs), accumulating evidence through a literature search and review, and developing the Statement and Explanation sections. This guideline includes 2CQs for colonic diverticulosis, 24 CQs for colonic diverticular bleeding, and 17 CQs for diverticulitis.

General interest in functional gastrointestinal disorders is increasing among Japanese doctors as well as patients. This increase can be attributed to a number of factors, including recent increased interest in quality of life and advances in our understanding of the pathophysiology of gastrointestinal disease. Japan recently became the world's first country to list ''functional dyspepsia'' as a disease name for national insurance billing purposes. However, recognition and understanding of functional dyspepsia (FD) remain poor, and no standard treatment strategy has yet been established. Accordingly, the Japanese Society of Gastroenterology (JSGE) developed an evidence-based clinical practice guideline for FD, consisting of five sections: concept, definition, and epidemiology; pathophysiology; diagnosis; treatment; and prognosis and complications. This article summarizes the Japanese guideline, with particular focus on the treatment section. Once a patient is diagnosed with FD, the doctor should carefully explain the pathophysiology and benign nature of this condition, establish a good doctor-patient relationship, and then provide advice for daily living (diet and lifestyle modifications, explanations, and reassurance). The proposed pharmacological treatment is divided into two steps: initial treatment including an acid inhibitory drug (H2RA or PPI) or prokinetics, (strong recommendation); second-line treatment including anxiolytics, antidepressants, and Japanese traditional medicine (weak recommendation). H. pylori eradication, strongly recommended with a high evidence level, is positioned separately from other treatment flows. Conditions that do not respond to these treatment regimens are regarded as refractory FD. Patients will be further examined for other organic disorders or will be referred to specialists using other approaches such as psychosomatic treatment.

Acotiamide significantly enhances GAR and GER in FD patients. Acotiamide may have therapeutic potential for FD patients.

Background-Abnormalities of colonic motility were reported in relatively small studies of patients with lower functional gastrointestinal disorders (FGID) including irritable bowel syndrome (IBS). The influence of gender and body mass on the observed motor pathophysiology is unclear.

Daikenchuto (TU-100) is a traditional Japanese (Kampo) medicine used to treat postoperative ileus. TU-100 dose dependently increases gastrointestinal (GI) motility by modulating cholinergic and serotonergic mechanisms in animal studies. The aim of this study was to evaluate the effects of orally administered TU-100 on GI and colonic transit and bowel function in healthy humans. In a randomized, parallel-group, double-blind, placebo-controlled, dose-response study, 60 healthy subjects were randomly assigned to placebo or TU-100 2.5 g or 5 g tid ingested immediately before meals for 5 consecutive days. We measured GI and colonic transit by validated scintigraphy and stool frequency and consistency by daily diaries of bowel function. There were overall treatment effects on colonic filling at 6 h without any significant differences between each dose of TU-100 and placebo. There tended to be overall treatment effects on ascending colon (AC) emptying half-time; the TU-100 (7.5 g/day) treatment significantly accelerated AC emptying compared with placebo. There were numerically higher values of GC24 (which reflect overall colonic transit) with both doses of TU-100, but these changes were not statistically significant. There were no significant overall treatment effects on gastric emptying or stool frequency and consistency. One subject, who received 7.5 g/day of TU-100, had elevated creatine phosphokinase following the study. TU-100 (7.5 g/day) significantly accelerated AC emptying. Further randomized controlled trials in patients with functional constipation or irritable bowel syndrome with constipation are warranted to evaluate the clinical efficacy of TU-100 in these disorders.

There has been a progressive and rapid decline in the prevalence of H. pylori infection as well a fall in the rate of progression of gastric atrophy among H. pylori-infected Japanese coincident with the westernization and improvements in economic and hygienic conditions in Japan since World War II.

Background Rikkunshito, a traditional Japanese (Kampo) medicine, is widely prescribed as an oral preparation for the treatment of functional dyspepsia (FD). In our previous study, we reported that extracorporeal ultrasonography (US) is a useful technique for the assessment of the gastric accommodation reflex (AR) and duodenogastric motility. In this study, we examined the effects of Rikkunshito on the gastroduodenal function in patients with FD. Methods Sixteen FD patients (median age, 45 y) underwent US, before and after 14 days of treatment with Rikkunshito (7.5 g b.d.). For assessment of the AR, a cross-sectional area of the proximal stomach was measured after incremental ingestion of a liquid meal up to 400-mL. The expansion rate was used as the parameter to determine the AR. Then, the gastric emptying rate (GER), motility index (MI), and reflux index (RI) were evaluated using previously reported methods. Results Although no significant changes were observed in the total score of the Gastrointestinal Symptom Rating Scale (GSRS), the scores of 3 of the 15 symptoms of GSRS decreased significantly after treatment with Rikkunshito. The expansion rate of the proximal stomach was significantly greater after treatment with Rikkunshito than before the treatment. Although the GER and MI increased significantly, no significant differences in the RI were observed after treatment with Rikkunshito. Conclusion These observations suggested that Rikkunshito may be beneficial for the treatment of FD patients with impaired AR and gastric motility. These results also suggested that Rikkunshito has a therapeutic potential for FD and GERD.