That sounds really promising, KateK and I wish her well. As well as the NHS site serkeen quoted these seems to be no end of information on Dr Google, but perhaps a support group of people who have “been there” might be more helpful. Could Macmillan point you or her in the right direction?
Paw had a small bowel resection 9 years ago when a perforated bowel revealed a tumour and subsequent monoclonal antibody therapy for Lymphoma, but fortunately no stoma was needed.
Absorption of nutrients, dietary iron, vitamins etc etc are an ongoing problem for him and iron-deficiency anaemia means he needs regular blood transfusions, but there are other contributory issues there.
Your friend’s nutrition is going to be paramount to help with the healing process and maintain her strength, so do look at dietary supplement (Ensure Plus fruit juices as well as shakes) - you can get these on prescription, lots of high protein snacks, low fibre food, full fat yogurts, milk cheese etc and little but OFTEN meals. It is a challenge when a person has no appetite but every whim can be indulged!
Best of luck, she is fortunate indeed to have friends who are so concerned for her welfare!