Having a stoma means there is no large intestine to hod digested food and remove liquid from it. From what I know, this presents 2 problems:
1. The need to eat highly digestible food.
2. The need for nutrient dense food because volume is a problem when there is limited space to hold it.
A mainly meat or animal based Low Carb way of eating, at least at first glance, appears the perfect diet for this situation because of it being quickly digested, low in fibre and nutrient dense.
Edited to add in animal based (must not forget fish and seafood).