Polyglycolic acid sheets and fibrin glue are routinely used in surgical procedures. Their usefulness in gastrointestinal endoscopy is mainly to prevent complications (bleeding, delayed perforation, stenosis, etc.) associated with procedures such as endoscopic submucosal dissection and endoscopic mucosal resection, with most reports on iatrogenic and secondary conditions. However, there are few reports on primary gastrointestinal diseases. Herein, we report three cases of gastrointestinal bleeding that were successfully treated with endoscopic hemostasis by sealing the lesions with polyglycolic acid sheets and fibrin glue. Case 1 was of an 83-year-old woman with a rare duodenal perforation that was treated with omental plugging who experienced subsequent bleeding from the greater omentum. Case 2 was of a 73-year-old woman with an acute hemorrhagic rectal ulcer that was difficult to treat even after performing standard endoscopic hemostasis techniques; however, surgery was avoided by sealing. Case 3 was that of an 89-year-old woman with a stercoral ulcer, treated curatively using a combination of sealing and argon plasma coagulation right from presentation based on the lessons learned from Cases 1 and 2. Endoscopic hemostasis using a polyglycolic acid sheet and fibrin glue may be a new treatment option for gastrointestinal bleeding particularly in refractory or rare causes.