I recently had what I am pretty sure was foodborne illness. It arrived in the middle of a friend's birthday party, a sudden onslaught of misery that lasted for the next 8 hours, reminding me, horribly, of a similar scene in The Mask of the Red Death. It was followed by two days of pretty much constant sleep. I don't recommend it.
But if a growing body of research is right, that 48-hours of grossness might not be the end of your body's interaction with a foodborne bug. In fact, some people seem to have otherwise unexplained symptoms persisting for years after they thought they'd recovered from food poisoning. This is best documented in people whose food poisoning experience was much worse than mine—folks who ended up in the hospital or the doctor's office and were, thus, accurately diagnosed, so we know they had a foodborne illness and not, say, a stomach flu. But it's an interesting hypothesis.
Maryn McKenna, my favorite Scary Disease Girl, has a story about this at Scientific American, plus some extra information at her Wired blog, where she explains why this phenomenon is so difficult to study.
I start the story with the tale of a Florida teen named Dana Dziadul, who 11 years ago was hospitalized with Salmonella and now at 14 has what is called "reactive" arthritis. Her mother Colette struggled for years to figure out why this was happening to her daughter, but didn't put the pieces together until she was asked to complete a survey of foodborne illness survivors, and spotted a list of possible after-effects — sequelae, technically — that the surveyors were curious about. That caused her to go back into Dana's medical chart, where she realized that her daughter's joint problems actually began while she was hospitalized as a 3-year-old.
The challenge of proving this connection is that our system for investigating foodborne illness is not set up for tracking victims long afterward. That's first because state health departments, which bear the burden of identifying outbreaks, are most concerned with finding people at the time, not keeping track of them; and second, because many outbreaks are spread across multiple states, with only a few victims in each state — so that maintaining contact with former victims would require a shared effort that no one is set up, or funded, to do. (That's not even to mention the complication of people moving from one jurisdiction to another. Myself, for instance, I've moved five times in the past 10 years.)