Hi techie,
OK, lets see if this will help. Try using Boost, or carnation instant breakfast. You can also blend in a blender anything like soups and etc. So sorry to hear she is having problems. Make sure the Dr. knows about the diarrhea & get it stopped as soon as possible.
As far as pain, well she is lucky if she does not need anything. So lucky her.
Hope things will improve soon for her. It is a long journey.
Take Care,
Diane