This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
A patient comes with hematemesis and melena. On the upper GI endoscopy there was no significant finding. 2 days later the patient rebleeds. Next line of investigation is: 
Select and explain. 
A. Emergency angiography, B. Repeat upper GI endoscopy, C. Enteroscopy, D. Laparotomy
B: Repeat upper GI endoscopy
Answer: B: Repeat upper GI endoscopy 
Explanation: Ans. (b) Repeat upper GI endoscopyRef: Sabiston 19th Edition, Page 1166* Endoscopy is advised even in cases in which previous endoscopy doesn't show any abnormality.