The consensus reached during the meeting on complications associated with EMR entitled ‘The definition of bleeding that can be viewed as accidental’ was held at the third EMR Conference, December 20, 2003, in Tokyo is as follows. (1) The definition of complications associated with EMR as intraoperative bleeding is cases requiring special measures such as emergency surgery, intraoperative blood transfusion, or vasopressor therapy and cases where EMR has to be necessarily discontinued because of intraoperative bleeding; and (2) the definition of complications associated with EMR as postoperative bleeding is marked bleeding from the ulcer-affected area after EMR, requiring special measures for hemostasis. Bleeding during or after EMR may be deemed as accidental if the Hb level falls by 2 g/dL or more in comparison with the last preoperative level, or if any of apparent bleeding or massive melena, etc. is seen. Providing a clear definition for ‘apparent bleeding’ and ‘massive melena’ was left open to debate.