My father is a survivor of colon cancer, liver cancer , prostate cancer and skin cancer. He now has terrible stomach pain, gas and diarhea after eating. The diarhea is quite severe. He also has quite a bit of gas after eating. He will not go to the doctor because he assumes it is not good, and he has already said, he will not go through any more cancer treatment. He is 83. Is there something he could do diet wise to mellow out his system? He tried clear liquids one day, and still had the diarhea.
Dear mister, unfortunately the first thing to think about are complications of previous diseases and surgical procedures. It is common to experience digestion disorders after colon and liver cancer especially if treated surgically or radio/behemoth. I understand your father knowing everything he went through, but you should definitely convince him to do some diagnostic test(Ct scan, colonoscopy and gastrostomy) to rule out receives of tumors but also any new abdominal pathology which can be treatable. If there is mechanical obstruction or colon mucosal damage, diet won't be helpful. You can only care that he doesn't lose too much weight or become deny Chat Doctor.  Wish you good health,