“…Although the short‐term prognosis of Fontan surgery is favorable, thromboembolism, heart failure, and sudden death are the three major causes of death 3 . Therefore, anticoagulant or antiplatelet drugs are commonly prescribed to prevent thromboembolism 4‐6 . However, gastromucosal injury, such as gastrointestinal bleeding associated with low‐dose aspirin (LDA), remains a problem 7,8 .…”