What to expect..they say nothing else they can do??

Hi,My father has been fighting cancer for a little over 4 years.  Started out as rectal/colon cancer.  My question is that everything that they have tried, he has had really bad reactions to.  The doctors just told him today that they don't have anything else that they can offer him.  They checked with the Mayo and another place in Madison Wis about if they had any trails going on.  They both said that they would not reccommend this for him!  They said that his enzymes have massive activity in his liver and lungs.  We also know that the cancer had already spread to his lungs, liver and spine, besides already being in his colon/rectum.   What should we expect for time line of time left?&n...