The logic doesn't hold up
While this claim could be responded to with one giant eye-roll emoji, let's break down why this myth is absolutely bananas. First of all, there's very little you can do to stop food poisoning once you have consumed contaminated food. Once your body becomes infected with pathogens, they're unlikely to be deterred by an express bus out of your system.
Additionally, no amount of cost-cutting would make up for the astronomical fees and damage awards in a potential lawsuit against a university. "The idea that any food service provider would serve anything that isn't food in their dining halls is simply ludicrous," says a dining services representative we spoke with. "It just makes no sense."
As for the real dining hall practices in place? "We take food safety very seriously," she says. "All our chefs and managers are certified by ServSafe, a nationally recognized food safety program. [We] meet regularly to discuss safety procedures, including ways to further improve sanitation through education around frequent hand washing, sanitizing workstations, avoiding cross-contamination, and ensuring proper food temperatures."
The short version, in other words, is that there are no laxatives in your dining hall food.