~~~~SENSITIVE STOMACHS BE YE WARNED!!!~~~~
I have one, and it isn't pretty.
But it is good to know in case it happens to you, because despite what you think... IT CAN!!!!!!!!
I have a son who is Autistic. On a trip we pulled in after a 9.5 hour drive, and we rushed into the room, threw our stuff down, sprawled out on the bed and did our usual "We're HERE!!! Fall backwards on the bed, stretch our van curved bodies, and then UP and out the door for a dinner ressie at Boma.
Boma is of course a buffet. Now my son at the time was pretty good about not doing anything stupid at buffets. But thi0 time he did some really weird things. Like for instance, he came back from the buffet with 3" tall pile of shaved watermelon rind! (Yummy i will add) I explained to him that he would never be able to eat that much, and instructed him to separate a little and let the waitress take the rest back. Each return from the buffet yielded weirder and weirder selections, often in huge quantities. I tried my best to help him select tiny amounts of many items rather than huge amounts of items that may mess his system up. It just wasn't working this night. As we are stepping ONTO the bus to Magic Kingdom (EMH NIGHT) he informs me that he needs to go to the bathroom. Now we have probably ALL been there. Little Johnny or little Sally says they have to go potty. You say "We have waited in this line for 45 minutes!!! We're getting on the bus!!!"
We were a long walk from a bathroom when the bus pulled up, and I said NO, we're going to MK. There are bathrooms at the entrance. Just hold on a few.
As we all sit down on the bus the smell starts to fill the air, and we know WE are not going to have a magical night.


We endure the ride with the entire bus full of people; all looking as green as us, all smelling the same thing, and my son looking like he wants to cry.
OK HERE IS WHERE THE STORY TAKES A POSITIVE TURN!!!
But not quite yet actually. We proceed to the bathrooms slowly, and my son then makes the biggest mess in there that anyone has ever known. Remember he is Autistic. He's about 8 years old, but he's not prepared for something like this. He destroyed the place to put it nicely, and people are making jokes and such about the smell, and laughing loudly, and yelling things under the stall, you wouldn't believe how immature people can be. I grab a nearby CM, who deserves a HECK of a RAISE, and he very calmly handles the matter. As I help my son clean the stalls, floor, and himself, the CM hand washes my son's socks, underwear, shorts, and shirt. Yes, you read that right, the CM hand washed those things. He had a small arsonal of cleaning solvents and sterile stuff. He put each piece of clothing into a sanitary plastic bag, and twists it all up and ties it shut. He then escorts me into the MK to a gift shop where I bought my son a pair of really expensive, and rather plain looking pair of shorts. I would have preferred to spend the $50 on a nicer pair of shorts, but given the circumstances, I'll take the choices I'm given. Noted NEVER buy shorts at WDW. They aren't anything special, and are expensive.
We then get the next bus back to the POP where he takes a shower, gets all cleaned up, and we called it a night.
The story isn't over. This happened 2 more times. Once at Ohana, and once at a third place. It happened on 3 separate trips.
The moral of the story is if your going to eat unusual food (something we are all accustomed to at my home, because I cook spicy hot foods from all over the world) try to watch your children at a buffet bar. All 3 incidents happened at a buffet bar. The second (at Ohana) wasn't all his fault. We ALL got sick that night, and my wife told me later that the same exact thing almost happened to her immediately after the meal. I as well spent some time admiring the tilework on the floors in the Ohana restaurant. I think we all got bad food that night. All 4 of us went straight to the room and all 4 of us fought over the bathroom the remainder of the night.
At the Ohana incident, Disney escorted us in a Ford club wagon rather than making us brave a bus. All 3 times disney went out of their way to make things right and especially the first CM, was a real hero. The CM at Ohana told me that it happens a LOT, and it's often GROWN UPS!!! Its not always children with special needs, it's often perfectly healthy adults. And he went on to say its often far worse than our experience. He said it goes with working with the public.