The in vitro analysis of intestinal epithelium has been hampered by a lack of suitable culture systems. Here we describe robust long-term methodology for small and large intestinal culture, incorporating an air-liquid interface and underlying stromal elements. These cultures showed prolonged intestinal epithelial expansion as sphere-like organoids with proliferation and multilineage differentiation. The Wnt growth factor family positively regulates proliferation of the intestinal epithelium in vivo. Accordingly, culture growth was inhibited by the Wnt antagonist Dickkopf-1 (Dkk1) and markedly stimulated by a fusion protein between the Wnt agonist R-spondin-1 and immunoglobulin Fc (RSpo1-Fc). Furthermore, treatment with the γ-secretase inhibitor dibenzazepine and neurogenin-3 overexpression induced goblet cell and enteroendocrine cell differentiation, respectively, consistent with endogenous Notch signaling and lineage plasticity. Epithelial cells derived from both leucine-rich repeat-containing G protein–coupled receptor-5–positive (Lgr5+) and B lymphoma moloney murine leukemia virus insertion region homolog-1–positive (Bmi1+) lineages, representing putative intestinal stem cell (ISC) populations, were present in vitro and were expanded by treatment with RSpo1-Fc; this increased number of Lgr5+ cells upon RSpo1-Fc treatment was subsequently confirmed in vivo. Our results indicate successful long-term intestinal culture within a microenvironment accurately recapitulating the Wnt- and Notch-dependent ISC niche.

Colorectal endoscopic submucosal dissection (ESD) has become common in recent years. Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also many types of precarcinomatous adenomas. It is important to establish practical guidelines in which the preoperative diagnosis of colorectal neoplasia and the selection of endoscopic treatment procedures are properly outlined, and to ensure that the actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with the guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society has recently compiled a set of colorectal ESD/endoscopic mucosal resection (EMR) guidelines using evidence-based methods. The guidelines focus on the diagnostic and therapeutic strategies and caveat before, during, and after ESD/EMR and, in this regard, exclude the specific procedures, types and proper use of instruments, devices, and drugs. Although eight areas, ranging from indication to pathology, were originally planned for inclusion in these guidelines, evidence was scarce in each area. Therefore, grades of recommendation were determined largely through expert consensus in these areas.

Guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment have been produced by the Japan Gastroenterological Endoscopy Society in collaboration with the Japan Circulation Society, the Japanese Society of Neurology, the Japan Stroke Society, the Japanese Society on Thrombosis and Hemostasis and the Japan Diabetes Society. Previous guidelines from the Japan Gastroenterological Endoscopy Society have focused primarily on prevention of hemorrhage after gastroenterological endoscopy as a result of continuation ofantithrombotic therapy, without considering the associated risk of thrombosis. The new edition of the guidelines includes discussions of gastroenterological hemorrhage associated with continuation of antithrombotic therapy, as well as thromboembolism associated with withdrawal of antithrombotic therapy.

The prevalence of NAFLD has increased in the general population, especially in males. There is a linear relationship between the prevalence of NAFLD and various metabolic parameters, even in nonobese subjects. The prevalence of NASH with advanced fibrosis is estimated to be considerably high in subjects with NAFLD.

Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also several types of precarcinomatous adenomas. It is important to establish practical guidelines wherein preoperative diagnosis of colorectal neoplasia and selection of endoscopic treatment procedures are appropriately outlined and to ensure that actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society compiled colorectal endoscopic submucosal dissection/endoscopic mucosal resection guidelines by using evidence‐based methods in 2014. The first edition of these guidelines was published 5 years ago. Accordingly, we have published the second edition of these guidelines based on recent new knowledge and evidence.