65 yr old male. obese, diabetic and hypertensive.normal endo and colonoscopy repeatedly, blood loss requiring transfusion every 1 to 2 weeks. 1 kidney removed because of a large mass inside that turned out not to be malignant, other kidney substantially reduced function, currently on dialysis. has v fib, had a couple of cardiac oblation. do you have any thoughts on potential causes of unexplained blood loss? thank you Rob Rieder brother-in-law of the patient.