There's no reason for the doctor not to refer MIL to hospice, since the requirement is 6 mos. or less to live...and I certainly don't think she will last that long.
David is right. For a normal person, BRB (bright red blood) in stool is usually from hemorrhoids or diet (tomatoes, beets), but in someone with advanced liver disease and clotting problems, it can be a big deal.
Let us know what the doctor says.
Hugs,
Connie