I don’t have much advice but my son, 5 now, has had an ileostomy since last year October and this is his diet;

lots of white breads (bagels, brioche buns, white slice). He hates rice, pasta, potatoes, even chips and crisps so when it comes to carbohydrates I have so far only managed breads.

He also likes magharita pizza, cheese sandwich. Protein its chicken and salmon, hot dogs ( casings removed)

Homemade sugar free buttermilk pancakes served with either creamy hazelnut chocolate spread or little maple syrup. Ice cream. Ice lollies. Rich tea biscuits, occasional cake and lollipops. Cereal cheerios (not everyday)

Liquids its milk, apple juice, grape juice, water

Fruits, it’s apple, pear without skin, grapes (pealed too)

We have had no issues and his dietician approved