A 49-year-old man visited the emergency room of Korea University Ansan Hospital with hematochezia starting the day before the visit. Recently, he was on anti-platelet medication due to hypertension. The patient had no definite symptoms other than hematochezia. Digital rectal exam was positive and laboratory tests showed severe anemia. Sigmoidoscopy was initiated and almost no fecal material was observed in the intestinal tract, allowing insertion into the cecum. Active bleeding from the appendiceal opening was noted. On abdominal CT, contrast enhancement was observed at the tip of the appendix. Under suspicion of acute appendicitis, we consulted with a surgeon. The patient underwent appendectomy with partial cecal resection. Pathologic examination revealed a diagnosis of appendix bleeding due to acute suppurative appendicitis. The patient had no further bleeding after surgery and was discharged in a stable state. Careful observation by the endoscopist is necessary for accurate diagnosis of lower gastrointestinal hemorrhage. Appendiceal hemorrhage is very rarely reported, but it has various pathophysiologies. CT scan is useful when appendiceal hemorrhage is confirmed by endoscopic findings. Surgical treatment was needed in almost all cases reported worldwide. If bleeding from the appendix is confirmed, surgical treatment should be considered for both therapeutic and diagnostic purposes.