Sometimes the end of an intestinal infection is just the beginning of more misery. Of those who contract traveler's diarrhea, for example, an unlucky few go on to develop irritable bowel syndrome (IBS), a chronic inflammation of the intestinal tract.
source https://www.lifetechnology.com/blogs/life-technology-medical-news/scientists-examine-how-a-gut-infection-may-produce-chronic-symptoms