Compare VKA vs LMWH in Patients With Anticoagulation Criteria and Episode of Gastrointestinal Bleeding.

Warfarin in anticoagulant dose

"Group 2 (VKA oral anticoagulation: warfarin), which is the control group will receive VKA anticoagulation as before they had the bleeding episode, with regular monitoring by measurement of prothrombin time (INR). Patients taking acenocoumarol before bleeding episode will be treated with warfarin and the once who were receiving warfarin will continue with the same treatment. Treatment control is performed by measuring the INR periodically.~Randomization will be performed using sealed opaque envelopes that contain the treatment option that will be obtained through a list of random numbers generated by computer."