The Food Poisoning Incident

Pretty simple, really:

Someone eats bad food and doesn't know it. (Unless they are Homer Simpson).

Sometimes, they think they ate bad food and panic.

Occasionally, are horrified that they fed their family bad food.

Once in a while, it will be seemingly Ripped from the Headlines (the All in The Family example came not long after a botulism scare on the east coast).

May be considered a Sub-Trope to Amusing Injuries.

Compare to Cowboy Bebop: Mushroom Samba.

May overlap with Last Day to Live. May lead to a Vomit Chain Reaction, as with the 6teen example.

For some reason, often Played for Laughs.

It is suggested that this may be because the symptoms are usually of the distressing-cum-embarrassing sort (nausea, diarrhea, vomiting), and in part because of anxiety over E.Coli and the like. Either way, it's a pointed reminder of how much we rely upon our bodies. "For surely laughter masks a nervous soul."

Some shows seem to use this trope especially. It has been observed that The Simpsons use it to shift the Character Focus of the episode by eliminating not needed characters. Examples: the oysters eliminated everyone leaving only Bart and Skinner, on which the episode was focused. (They even acknowledged that it made no sense that Lisa got ill but they just Handwaved it.) The vegetables make the whole family sick so Lisa started her singing career.

Compare Water Source Tampering, Tampering with Food and Drink and Spitting in the Customer's Food.

Examples of The Food Poisoning Incident include:

Film

Monty Python's The Meaning of Life: The dinner party guests. All of them.
Please Give: It remains ambiguous if the elderly woman dies at the end from drinking tainted juice
In Bridesmaids there's a really gross food poisoning scene, although the protagonist claims it's a virus, as she's the one who suggested the restaurant.
Airplane!!. Anyone who had fish for their in-flight dinner got a life-threatening case of food poisoning. Guess what the entire flight crew had.
Living in Oblivion: In one of the sequences, the chief cinematographer is made violently ill from spoiled milk left out on the craft service table.

Literature

Aunt Dimity and the Family Tree has her father-in-law's housewarming party disrupted by eleventh-hour food poisoning at the caterer's firm; the narrator enlist help from the community to come up with the food.
A Billion for Boris: in this sequel to Freaky Friday, the reveal that the kid brother is in possession of a TV that sees 24 hours into the future is based on his knowing that a certain brand of soup has been recalled before anyone else does.

Live-Action TV

Seinfeld: the woman who gets sick when the silica pack gets into the salsa placed out at Putamayo. By a typical turn of events, Jerry's number is on speed dial under "Poison Control".
This is probably really obscure, but he mid-70s syndicated kids show Salty had an episode where they had to find someone who had eaten rancid food and didn't know it.
All in The Family: Archie may or may not have eaten toxic mushrooms after a recall due to botulism. He ends up going to the ER for a painful anti-toxin injection. Afterwards, Edith realizes that they weren't the recalled brand to begin with.
On the season 6 finale of How I Met Your Mother, Lily gets sick after eating soup and Marshall, who had eaten the same soup, prepares for the inevitable effects to kick in, just as he's interviewing for his dream job. In the end nothing happens to Marshall, and it turns out it wasn't the soup that made Lily sick; she was pregnant.
Happy Days: Chachi's mother has Howard and Marion Cunningham over for dinner, and inadvertently includes an ingredient in her pasta sauce that Marian is allergic to. Marian spends the rest of the evening in the bathroom.
The Stockard Channing Show: Susan's boss at the Consumer Affairs local tv show she works on gets ptomaine poisoning and thinks it's because of a bad fallafel he gets from a fast food joint. It turns out it's from a high priced fine dining restaurant.
The Adventures of Pete and Pete: Little Pete pretends to get food poisoning from spoiled tapioca so he can play hooky.
The Groundhog Day Loop episode of Supernatural where one of Dean's deaths is from a bad Taco.
Has happened to Bear Grylls on his show at least once. Not surprising, given all the dodgy stuff he eats.
A couple from M*A*S*H: Season 8, Episode 10, most of the camp has food poisoning. There is also an episode where Charles and Margaret eat a canned bird (pheasant?) and get ill.
In the Fawlty Towers episode "Basil the Rat", one of the catastrophes Basil Fawlty must deal with is the possibility that he has just served the health inspector a poisoned veal cutlet.
In The Nanny episode "Close Shave", C.C. Babcock is attending a cooking class and gets Maxwell Sheffield to try some of her cooking. He reluctantly does so, and ends up going to the hospital with food poisoning. Due to the food poison, he needs an appendectomy, and in preparation for surgery, the surgeon asks Fran Fine, disguised as a candy striper, to shave Maxwell...
What's Happening!! Rerun thinks he has gotten food poisoning from bad beef at Rob's. Dee explains later that it is actually appendicitis, and that Rerun had to get surgery
In an episode of Sex and the City ("The Ick Factor"), Charlotte and Harry go out for a romantic dinner, but they both end up sick shortly thereafter. Rather than being played for laughs, the incident is really sweet, as it shows the two of them accepting and comforting each other in their distress.

Professional Wrestling

One WWE Smackdown skit in 2004 revolved around Eddie Guerrero giving The Big Show a tainted Burrito and then the lucky people in the audience got to watch Big Show plead for toilet paper while a fairly nasty fart recording was played.

Recorded and Stand Up Comedy

Alluded to by Bill Engvall in his original "Here's Your Sign" routine:

If you bought a piece of stereo equipment, you know inside the box they put that little packet of drying agent. And on it in big bold letters, what does it say? Do not eat this! [Beat] Y'all ever bought a piece of stereo equipment thinking there might be somethin' to eat in there? But you know somebody opened that box and went, "Well, look! I got a receiver and a pack of Chiclets. I got music and gum!"

Western Animation

The Simpsons, "Homer and Apu". Apu marks down some expired ham. Homer eats it and gets sick. Upon Homer's complaint, Apu offers him ten pounds of "frozen" shrimp. Homer eats it and gets sick.
- In another Simpsons everyone thinks Homer has eaten poison sushi and only has 24 hours to live.
- Also inverted by The Simpsons when everyone except Lisa gets food poisoning from eating only vegetables (because their bodies are only used to junk food).
- All the kids on Martin's birthday party get sick from eating oysters except Bart. Lisa is just faking to be ill to have an excuse to leave the party.
- Homer becomes a victim of this trope again when he eats at a 33 cent discount store.
- Then there's the time he brought home some six feet of leftover party sub and continued to eat it for weeks afterward, well past its edible state.
- One episode has the entire town sick after eating vegetarian Krustyburgers made with contaminated barley from nearby Ogdenville. This is just a Lead In for the main plot, about Ogdenvillians migrating into Springfield.
  - A similar incident appears in a Halloween episode spoofing 28 Days Later, with "Double Meat" Krustyburgers turning people into "Munchers".
In one episode of 6teen, an accidentally unplugged fridge results in a Vomit Chain Reaction that wreaks havoc through the entire shopping mall.
In My Little Pony Friendship Is Magic, "Applebuck Season", a sleep-deprived Applejack tries to help Pinkie Pie with baking muffins, but gets the ingredients ridiculously wrong, replacing chocolate chips with potato chips, baking soda with soda pop, a cup of flour with "a cup of sour" (lemon juice), and wheat germ with "wheat worms" (earthworms from a mud puddle out back).
Inverted in an episode of SpongeBob SquarePants - the titular sponge is thought to have unknowingly eaten a deadly pie, which will end his life at sunset. Squidward, responsible for bringing a pie-shaped bomb to Spongebob, feels guilty enough to spend the rest of the day doing anything Spongebob wants. It's eventually revealed that Spongebob never ate the bomb-pie, but rather a different pie. He saved the bomb, which he promptly trips and thus throws into Squidward's face, producing a nuclear blast.
- A more straightforward example is when Mr. Krabs sells spoiled Krabby Patties that have turned yellow and spongy as an attempt to cash in on SpongeBob's popularity.
- Then there's "The Nasty Patty", in which Krabs and SpongeBob make the titular patty for what the think is a fake health inspector. Hilarity Ensues when they think the patty killed him.
- A milder example is "Pretty Patties", in which SpongeBob sells colored patties. The people who eat them don't get sick exactly, but they do turn the same color as the patties they ate.
King of the Hill has an episode where the supply of Alamo Beer delivered to Mexico has been tainted with some cleaning solution. Peggy finds out about it while taking on a temporary job as a call-center operator, and listens to complaints all day about vomiting and diarrhea caused by drinking the beer. Eventually she gets the executives at Alamo to admit their mistake and initiate a recall after sneaking some Mexican-market Alamo into a board meeting.