Detecting the source of obscure gastrointestinal bleeding can be difficult. Capsule endoscopy is a promising diagnostic tool for investigating patients with this condition, although identifying the source of intermittent or low-grade bleeding remains a diagnostic challenge. We present case reports of two patients with obscure gastrointestinal bleeding, in whom the source of recurrent bleeding episodes was diagnosed by capsule endoscopy while they were on anticoagulation therapy. The first patient, an 81-year-old white woman, was on long-term oral anticoagulation because she had chronic atrial fibrillation. Capsule endoscopy demonstrated a bleeding tumor in the region of the terminal ileum. The second patient, a 59-year-old white man, underwent an initial capsule endoscopy, which was negative. After initiation of anticoagulation with heparin, a second capsule endoscopy procedure in this patient revealed several small bleeding lesions in the proximal small bowel. In both cases a gastrointestinal stromal tumor was identified as the bleeding source and was resected. These two cases demonstrate that provocation of bleeding during capsule endoscopy may increase its sensitivity.