I will add my voice to the "broccoli is BAD for me" chorus. I can't figure out why either -- other FODMAPs are not an issue for me. And in the incredibly weird category, broccoli that is in Chinese food doesn't bother me in the slightest. Regular steamed broccoli, or broccoli I stir-fried at home? Oh the pain.
This has gotten somewhat better since I have been doing Whole30 stuff, and also since I learned that I am lactose intolerant. Very small amounts of broccoli are okay (they still give me a little gas, but not agony). That's really the only veggie that does it to me. I used to