RESEARCH ARTICLE Effectiveness of CO2-insuff it d

occurrence of nausea due to abdominal distension after ESD indicated a significant difference (P=0.031). Mori et al. BMC Gastroenterology 2012, 12:37 http://www.biomedcentral.com/1471-230X/12/37abdominal distension. In addition, given recent issuesFull list of author information is available at the end of the articleConclusions: ESD using the duodenal balloon occlusion method is effective for reduction of post-ESD intestinal CO2 gas volume, resulting in a lower total amount of CO2 insufflation during ESD and reducing harmful influences on the human body to some extent. Background Endoscopic submucosal dissection (ESD) for gastrointes-tinal malignancy has been increasingly performed in Japan, and its technical basis is almost completely estab-lished [1-4]. The procedure is also covered by the health insurance system in Japan. However, ESD is technically complicated [5,6], requires a high level of endoscopic skill, and has been associated with serious complications [7,8]. Although insufflation of air has traditionally been used in ESD, there are many risks, such as air embolism. As an alternative to air, insufflation of CO2 has been used in regular colonoscopy and colorectal ESD which has been proven effective [9-17]. Insufflation of CO2 is also available to help maintain a stable respiratory and hemodynamic state during ESD by preventing pneumo-peritoneum when perforation occurs [18-21] and redu-cing post-ESD symptoms, such as nausea due t