This clinical trial will enroll patients at National Cheng Kung University Hospital. All patients who are hospitalized for lower gastrointestinal bleeding and undergo colonoscopy will be invited to participate. This study uses random allocation, with one Intervention group and one Standard group. Both groups will receive standard endoscopic hemostasis. Afterward, patients in the Intervention group will receive local administration of 1.5 g of tranexamic acid and 3 g of sucralfate. Following the endoscopic procedure, patients will be directly observed for 5 minutes to confirm successful hemostasis. All patients will be followed for 28 days to assess the occurrence of post-procedural rebleeding.