The one saving grace when it comes to a stomach bug is that it’s typically short-lived. The brutal nausea and vomiting of norovirus, for instance, subsides in one to three days; even the relentless diarrhea of cyclosporiasis can let up in a couple of days with an antibiotic. But after certain gut infections, once the most intense symptoms have resolved, GI troubles can linger, turning into chronic bowel issues and pain. That’s the usual course of post-infection irritable bowel syndrome (PI-IBS).