Intestinal arteriovenous malformations (AVMs) are an important cause of gastrointestinal bleeding. However, diagnosis is difficult depending on the timing of the examination. [Case] An 86-year-old man complained of bloody stool. Small intestinal capsule endoscopy (CE) revealed a submucosal tumor (SMT) -like elevation in the jejunum. Single-balloon enteroscopy (SBE) did not identify any lesions. Transfusion improved anemia, but gastrointestinal bleeding was observed again. Ninty-four days after the initial CE, small intestinal CE was performed again and revealed an SMT-like bulge with active bleeding in the jejunum. SBE revealed an SMT-like bump with redness in the jejunum, which was considered to be the source of hemorrhage. Small intestinal AVM was diagnosed. Partial resection of the small intestine was performed at a later date.
