It's hard to say if it was from Disney dining or something we picked up earlier in the parks or on the plane and happened to coincide after eating.
First off, we've been many times and have NEVER had an issue. Until this past trip over Easter.
We had been there two full days. We had eaten at the Outback (off site) our first night, Citricos the second night. On the third night we went to the Hoop Dee Doo review. We all ate everything there, ate out of the same buckets, and basically shared everything.
After the show as we were on our way back to the room, DD (15) was complaining that she overate. She did eat more than her usual so I wasn't concered. Two hours later, she was still complaining and going into a "moan." She then went to the bathroom and vomited 2-3 times in a one hour span. She went to bed, slept all night, felt like crap the next morning, but was better by noon. The rest of us were fine and we ate everything she did and even shared food with her.
After she got better, we went to 1900 Park Fare that next night for dinner. We all ate off the buffet. DS (12) ate predominantly off the kids buffet. About 6 hours after dinner (middle of the night), he comes into my room to tell me he has stomach pains. He tosses and turns for two hours, go to the bathroom, and vomits--one time. He went to bed, woke up the next day, and felt horrible the entire day and wouldn't eat a thing. The following day he was fine.
I really didn't know what to make of it. It didn't seem like food poisoning or a typical virus. It was just weird. I can't even say I blame it on the dining as we didn't all get sick but were eating the same things.