I kinda think you took it the wrong way tbh. I think they were just trying to add in some useful info, and not even in a rude way. Just as a literal “fyi” in case you or the people who saw your post didn’t know. I also think it’s super odd that you specified that it was a “major, invasive surgery” that fixed your issue. Just in general I think you added wayyy too much info, and like, why..? I’m not trying to be rude or mean, and I am glad that your surgery helped you so much! But it’s a bit strange that you included so much personal info with such descriptive language when you could’ve just said something like, “I’ve got a nearly full bottle of flinstones vitamins with extra iron that I no longer need. Would anyone like to have them?” and be done with it. Again, not at all trying to be rude, just wanted to point out that you don’t have to overshare like that. You’re not obligated to explain yourself, and if people are curious, they can either stay curious or you can just say you previously needed the extra iron but now you don’t. You don’t owe them an explanation, that’s all!