Like Xerxes, almost every blockage I've had can be connected back to something "healthy" that I ate. At this point, I pretty much avoid fruit and veggies (with a few exceptions). I was never a big veggie eater, so nothing lost accept vitimins. To name a few items that have partially or fully blocked me: cantalop, coconut, chinese stir fry, apple, raisins, carrots, popcorn, macaroons (despite being shredded coconut), french fries.
When it comes to fruit, canned is best (as it has no skins) and veggies I just cook until really soft.
The other type of blockage I can get is narcotic induced. I use to be able to take large doses of codeine as means to slow my bowel movents down (before ileostomy I was 20 - 30 times a day). After my ostomy was installed, I couldn't take cough syrup with codeiene in it without my bowel coming to a virtual stop. I was also limited to 6mg of hydromorphine, which sucks as if you have a blockage you can't take morphine orally or you make the problem worse. The pain from taking too much narcotics is identical to a physical obstruction.
One contributing factor to the amount of obstructions you get is if you have any scar tissue from past surgeries that is restricting your passage. One thing that my G.I. doctor said she could do to try and reduce the occorance of these obstructions was:
Strictureplasty (also spelled Stricturoplasty) is a surgical procedure performed to alleviate bowel narrowing due to scar tissue that has built up in the intestinal wall from inflammatory bowel conditions such as Crohn's disease - details here: https://en.wikipedia.org/wiki/Strictureplasty
But, that is a surgical solution. What she did for me (I don't know what the procedure was called) was essentially stick her finger in my stoma, as the scar tissue was near the end, and carefully stretch the scars but not too far that they would puncture the bowel. In my mind it didn't sound like it would really do anything (like stretching an elastic it would just return to where it started when let go). That said, I don't question my G.I. doctors wisdom when it comes to things like this as she been at it for decades, so I had the procedure done. It's been 2 years and I have no had a blockage since (knock on wood). She said she may need to do it again in the future, but that is better than any surgery as I can't really lose any more bowel without running in to concerns of not obsorbing the necessities of life. In other words, I could end up having to go on TPN.
Last comment, when the blockages are really bad, I end up vommiting over and over (until its byle only). The body is naturally trying to reduce the pressure from the top by doing this. The hospital may also do it for you by putting in a stomach pump (goes through your nose to your stomach). For less severe blockages, my body could work them out but I needed the aid of IV pain medication to get through it. Once I better knew what was going on, I would make sure I told the ER doctor and to NOT start me on steroids as the issue was a blockage, not a flare-up. For the least severe blockages, I would stop eating and drinking (no pressure added from the top), then go to clear fluids after I felt some progress was being made. After every blockage cleared, I would be sore inside for the next day or two from all the cramping. I would keep my diet very gentle during that time (easy to digest foods with nothing rough about them)