The common causes of acute lower gastrointestinal bleeding include diverticulosis, colonic vascular ectasia, neoplasm and colitis. Acute lower gastrointestinal bleeding from the appendix is a very rare malady and the causes are reported as angiodysplasia, diverticulum, appendicitis and endometriosis. We report here on the case of a 47-year-old man, who was taking enteric coated aspirin, with severe lower gastrointestinal bleeding that was due to appendiceal ulcer. An active bleeding was identified as coming from the appendiceal orifice during colonoscopy. He was treated by simple appendectomy. Histologic evaluation showed ulceration with both acute and chronic inflammation, along with thickened vessel walls in the submucosa of the appendix.