Just to add; the times I've had blockages it wasn't a particular food that was at issue, it was the overall amount of unbreakdownable foods over a few consecutive days. I always avoided the most likely suspects of blockages - sweetcorn, mushrooms, etc. - but had been eating things like fruits with skin and raw tomatoes. I'd tried them in small amounts, in isolation (i.e. testing one food at a time, then leaving it a couple of days to see if there was a reaction). Then I made the mistake of assuming that meant the foods that I'd tested were ok. But they weren't ok when eaten in larger quantities and/or when a few of these foods were all eaten within a short time of each other (a few days in my case).
That's what happened with my first, most major, blockage. The second was less major, but again resulted from me seeing what I could get away with by gradually increasing the amounts of fibrous foods - I thought I'd get some minor symptoms and know when I was reaching the amount I could tolerate. But I didn't, I went straight from feeling fine to (partial) blockage. The third was even more minor, same situation - I was trying it again because I had a new stoma. My second, current stoma can tolerate a lot more than my first, but again it seemed the only way to find out was the hard way, though because I was by now much more careful, the blockage was less painful and passed much easier than the first. I'm being extra careful at the moment because my weight's so low I can't afford another blockage that will interfere with eating, which may also be something you want to keep in mind - when you're recovering from surgery, you need energy to heal, so a blockage could really mess things up. You'll have time to experiment with other foods when you're all better.