What Causes Rectal Bleeding In Person With Liver Failure?

please help my sister has Liver Failure,she has said she has started bleeding rectally no appetite,she weighs 80 pounds,She started liver Dyalisis and went 2 times she no longer wants Dyalysis.Is it true she may Die a lot sooner without Dyalisis Treatment.Depression is setting in also and her teeth are loosening is that normal.