I’m sorry, you are going through this. My lovely mum is 83 next month and has bowel cancer. She had an ileostomy bag fitted 3 months ago. Before the surgery, she fell and hit her head. They were reluctant to put her under anaesthetic but we more or less begged them to operate. They didn’t take a biopsy or remove any of the cancer. She has got slowly better and is walking up and down her street and doing her exercises. We don’t really know what we are dealing with, which is unnerving. She was very weak after surgery to the point we thought we were going to lose her. She is in pain but not as bad as before the surgery with the part bliockage. Now she is stronger, we have asked if there are any meds she can take to suppress it. 
We are so close and it’s horrible to see her so tired and not eating much - this has slightly improved. She’s lost lots of weight. No advice but just wanted to let you know I’m.in a similar position and also lost with how to help her. She is stubborn too! I’m helping Dad look after her however this is not so intense now she’s improved from surgery.