what else could be going on with my patient?

So, I work in a rehab/sub acute unit and was covering a 3 hour stretch (after working 9 hours previously in a different location). this woman had just been admitted, and I got a brief report about her history. (I didn't do the admission) This little lady was 83y/o and went to the ER with epistaxis that wouldn't stop. They noted her H&H to be critically low and PT/INR to be critically high (coumadin for a-fib) and so gave 2 units of FFP. That caused flash pulmonary edema and at some point she was also in acute renal failure? Then they discovered a DVT in her right leg. She was transferred out of the ICU and to our facility the same day. Her H&H was stable. PT/INR was still high (around 3) but she did have that DVT. Around 645 I go into the room because she's saying she feels like she was just incontinet of BM. What she thought was BM was frank, dark red blood with clots. About 1.5 cups. It obviously came from her rectum and she wasn't actively bleeding. Vitals were all stable and she was absolutely asymptomatic, pulse ox was ok but I turned up her O2 anyway. So we sent her back to the hospital, but I'm thinking there's more going on than just hypercoagulation. I mean, if her PT/INR was high in the first place, how'd she develop the DVT? And why were there multiple clots in the rectal blood? I'm thinking there could be some sort of hematology/onc problem, or DIC. But I'm sure they would have caught DIC at the hospital, and she'd be alot sicker, right? Does anyone know what else could be going on? thanks!