Hemilectomy (partial colon removal) for Cancer

[Rahksan]

Hi, my mother had part of her colon removed 5 weeks ago, at the same time they diagnosed her with colon cancer which was spread to her lymphnodes and to a main artery in her stomach.  The surgeon she would have 2 years to live if she could tolerate chemo.  She was released from hospital after 10 days.  Since that time she has been in constant pain, she has been back and forth to hospital 7 times.  She has had major pain in her upper stomach which she says it is like gas but worse and most recently she had started vomiting and cannot keep any food down.  The doctors have done numerous x-rays and CT scans and say there is nothing showing for her pain, her blood work all comes back normal, and they just want to send her home.  

Me and my family are exhausted with staying up nights and rushing her to hospital, only to have doctors say nothing is wrong.  Can anyone shed some light on this for me, is this the normal process after colon surgery?