Had my permanent ileostomy back in 1990. So loads of experience.
I have a very substantial salad as my man most days. including tomatoes, etc. They have never caused me any problems. You really do need to experiment carefully with different foods. I cannot eat the skin of a baked potatoes and always peel apples.
Your operation has given you your life back, do not be afraid to live it to the full. Like with anything else, so people react more to some foods than other do. Only careful experimentation will show which you are able to eat.
If you do feel that a blockage is occurring, then learn the very early symptoms (mine, strangely enough is feeling hungry when I have just eaten.). Very quickly that will lead into a lump I can feel, and then what can only described as something like labour pains. Very debilitating. I find that heat is what sorts this out, a hot water bottle on my tummy, drinking a mug of the hottest water I can manage. Sitting in a hot bath. Usually, that sorts itself out within a couple of hours.