“How long does a stomach infection last?”

Depending on which kind of infection you have, a typical viral stomach infection can sometimes last up to 2 weeks, especially in younger patients. The best thing to do is get a lot of rest, drink a lot of water and allow the body to fight off the infection on its own.

I need more information in order to answer. What infection? How was the diagnosis made? What were the symptoms? A common stomach infection is H pylori infection, which is a chronic, but your question seems to imply that you are referring to a more transient infection such as gastroenteritis, which might be from food poisoning lasting a few days.