What happens if both of your kidney is only working at 20%and can it be fix?

Well my dad just fainted because his blood was too low and he has high blood pressure, and high cholesterol and both of his kidney is only working at 20% which causes his body to not function right well we rushed him to the emergency room and they found out that he was bleeding from the intestine which is called a hamaroid but inside of the intestine which was caused by the kidney failure is there a way to make his kidney work again without a kidney transplant? they said they are going to removed the hamaroid so that is ok, but i am worried about the kidney i want him to live no one wants there dad died so can you guys please help? is there a way to make the kidney better and working again? or they said they will place a machine that will help clean out his kidney but this lady next door to me had the same machine placed in her kidney and she died 5 hours later after she came home she was in her 60s though my dad is only 30 something so i would be happy if some one can help or tell me if you are suffering from the same thing or had the same thing before and what did you do?