Ok,,keep in mind im not a doc. I do have kidney disease though and do understand the pain and the levels.
My concern is that she is bleeding somewhere. Low platelet count is norm with dialysis patients,,and anemia.Butttttttttttttt transfusions of blood with black stool tells me there is some internal bleeding going on!!!!!!!!!
As soon as possilbe directly ask for her to be checked for internal bleeding.....Stomach, colon,,etc.
Remember,,,,,,,,,they can treat diff issues,,but if they do not find underlying problem,,its all in vain!
God bless you and ur mum.
Kimmyk