Tadayuki Oshima, and Hiroto Miwa. J Neurogastroenterol Motil 2018;24:334-44. https://doi.org/10.5056/jnm18029

Hye-Kyung Jung, Chung Hyun Tae, Kyung Ho Song, Seung Joo Kang, Jong Kyu Park, Eun Jeong Gong, Jeong Eun Shin, Hyun Chul Lim, Sang Kil Lee, Da Hyun Jung, Yoon Jin Choi, Seung In Seo, Joon Sung Kim, Jung Min Lee, Beom Jin Kim, Sun Hyung Kang, Chan Hyuk Park, Suck Chei Choi, Joong Goo Kwon, Kyung Sik Park, Moo In Park, Tae Hee Lee, Seung Young Kim, Young Sin Cho, Han Hong Lee, Kee Wook Jung, Do Hoon Kim, Hee Seok Moon, Hirota Miwa, Chien-Lin Chen, Sutep Gonlachanvit, Uday C Ghoshal, Justin C Y Wu, Kewin T H Siah, Xiaohua Hou, Tadayuki Oshima, Mi-Young Choi, and Kwang Jae Lee; The Korean Society of Neurogastroenterology and Motility. J Neurogastroenterol Motil 2021;27:453-81. https://doi.org/10.5056/jnm21077

Background: Functional dyspepsia (FD) is a disorder that presents with chronic dyspepsia, which is not only very common but also highly affects quality of life of the patients. In Japan, FD became a disease name for national insurance in 2013, and has been gradually recognized, though still not satisfactory. Following the revision policy of Japanese Society of Gastroenterology (JSGE), the first version of FD guideline was revised this time.Method: Like previously, the guideline was created by the GRADE (grading of recommendations assessment, development and evaluation) system, but this time, the questions were classified to background questions (BQs, 24 already clarified issues), future research questions (FRQs, 9 issues cannot be addressed with insufficient evidence), and 7 clinical questions that are mainly associated with treatment.Results and Conclusion: These revised guidelines have two major features. The first is the new position of endoscopy in the flow of FD diagnosis. While endoscopy was required to all cases for diagnosis of FD, the revised guidelines specify the necessity of endoscopy only in cases where organic disease is suspected. The second feature is that the drug treatment options have been changed to reflect the latest evidence. The first-line treatment includes gastric acid-secretion inhibitors, acetylcholinesterase (AChE) inhibitors (acotiamide, a prokinetic agent), and Japanese herbal medicine (rikkunshito). The second-line treatment includes anxiolytics /antidepressant, prokinetics other than acotiamide (dopamine receptor antagonists, 5-HT4 receptor agonists), and Japanese herbal medicines other than rikkunshito. The patients not responding to these treatment regimens are regarded as refractory FD.