I haven't had any, but my mom and sister both have.
My mother had this weird eye thing where her eyes would close when it got dark for no reason, and she couldn't open them without physically using her fingers to do it. There were some other symptoms as well. I think they were watering badly and irritated also. She could not figure out what was going on and neither could the eye doctor. It ended up being this weird skin disease that the dermatologist diagnosed that somehow affected her eyelids. This was why the eye dr couldn’t come up with anything; her eyes were fine.
Then, my sister has Crohn's. It took about 6 months to get a diagnosis for her. The whole thing was very scary because she just kept getting sicker and sicker, and we didn't know what was going on or how to help her. As bad as the diagnosis was, by the time they gave it, we were at the children’s hospital and just happy to have an answer. Little did we know that was just the beginning as it took almost four years to find a doctor who knew how to treat her.