unable to keep anything in stomach

My friend has cancer.  She has cancer of the mucus lining inside of the skin.  She also had cancer in her apendix and gall bladder.  She is in the hospital getting hydrated, anitbiotics, potassium, magnesium, and nutrients.  They have put a tube down her nose and into the stomach to pump out this horrible green looking bile.  She is unable to keep anything on her stomach.  She is down to 80 + lbs.  They don't want to start chemotherapy on her until she gains some strength back and is able to keep food down.  When she had the surgery to remove the gall bladder and apendix they also did some "looking".   OK.....now for the question....

Why would she not be able to keep the simplest foods down, like chicken broth?  Her stomach rejects everything.
Is the stomach in shock?   She needs the chemo.  And, it will also make her sick.  I don't understand why the doctors at her hospital (Medical City, Dallas TX) cannot find out why she isn't able to retain nourishment in her stomach and fix it!  Please help.  We are co-mothers-in-law.  The kids are devastated.  She gets weaker every day.  
And, she says, "I can't do this anymore".  I don't know what else to do, but, keep her walking to get the muscles working and the circulation going strong.  

My sincere appreciation to anyone who cares to take this on.  Hugs to you and God Bless.  Melinda Potosky
                                                                                                                                      Keller, TX