I used to get blockages incredibly easily, so I couldn't eat whole grain cereals, nuts, seeds, or most fruits and vegetables (i.e. healthy food!). But since my last surgery I've been gradually introducing them to my diet and I don't seem to have problems anymore.
When I did need to be careful, I found some fruit and veg I could tolerate. Bananas, avocados, well cooked root veg, smooth vegetable soups, and tinned fruit (except tinned pineapple) are easy to digest, so they may be good things to start with.
White meat, fish, eggs, yoghurt (if ok with dairy) may be healthy protein options. I know some people believe refined grains to be unhealthy, but white bread, white rice, etc. are about the same in terms of calories as their brown counterparts. They lack the fibre, making them less healthy for most people, but with Crohn's and an ileostomy less fibre can be better. Though if you're managing granola ok, that may not be a problem for you. Porridge is another healthy cereal to try, it's not quite as difficult to digest as granola. Nut butters may also be something to try - crunchy if you're doing ok with fibre, or smooth if you need something easier to digest.