Obscure gastrointestinal bleeding is an uncommonly encountered and difficult-to-treat clinical problem in gastroenterology,but advancements in endoscopic and radiologic imaging modalities allow for greater accuracyin diagnosing obscure gastrointestinal bleeding.Ectopic varices account for less than 5% of all variceal bleeding cases,and jejunal variceal bleeding due to extrahepatic portal hypertension is rare.We present a 47-year-old man suffering from obscure gastrointestinal bleeding.Computed tomography of the abdomen revealed multiple vascular tufts around the proximal jejunum but no evidence of cirrhosis,and a visible hypodense filling defect suggestive of thrombus was visible in the superior mesenteric vein.Enteroscopy revealed several serpiginous varices in the proximal jejunum.Serologic data disclosed protein C deficiency(33.6%).The patient was successfully treated by therapeutic balloonassisted enteroscopy and long-term anticoagulant therapy,which is normally contraindicated in patients with gastrointestinal bleeding.Diagnostic modalities for obscure gastrointestinal bleeding,such as capsule endoscopy,computed tomography enterography,magnetic resonance enterography,and enteroscopy,were also reviewed in this article. Obscure gastrointestinal bleeding is an uncommonly encountered and difficult-to-treat clinical problem in gastroenterology, but advancements in endoscopic and radiologic imaging modalities allow for greater accuracy in diagnosed obscure gastrointestinal bleeding. Ectopic varices account for less than 5% of all variceal bleeding cases, and jejunal variceal bleeding due to extrahepatic portal hypertension is rare. We present a 47-year-old man suffering from obscure gastrointestinal bleeding. Computed tomography of the abdomen revealed multiple vascular tufts around the proximal jejunum but no evidence of cirrhosis, and a visible hypodense filling defect suggestive of thrombus was visible in the superior mesenteric vein. Enteroscopy revealed several serpiginous varices in the proximal jejunum. Serologic data disclosed protein C deficiency (33.6%). The patient was successfully treated by therapeutic balloonassisted enteroscopy and long-term anticoagulant therapy, which is normally contraindicated in patients with gastrointestinal bleeding. Diagnostic modalities for obscure gastrointestinal bleeding, such as capsule endoscopy, computed tomography enterography, magnetic resonance enterography, and enteroscopy, were also reviewed in this article.