Blood transfusions 4x n a year, 5-6 units each time what could cause server anemia like this when no bleedouts can b found etc. Taking Coumadin (warfarin) 4 clots?

Hemolysis. There are multiple possibilities. Blood loss can be present without visible bleeding. Your severe anemia sounds like you are not producing enough red cells, regardless of whether you are bleeding or not. You should see a hemotologist for a full workup, including a bone marrow biopsy.