In order to achieve these goals, the researchers propose to establish collaboration with the Minnesota Department of Health (MDH) which conducts active surveillance for bacterial and parasitic cases of acute IGE and other reportable illnesses in Minnesota, as part of the mandate to detecting outbreaks and prioritize control efforts. We plan to establish retrospective and prospective cohorts in this proposal. A randomly selected sub-set of these patients will be invited to Mayo Clinic for detailed investigations including assessment of GI motility, permeability, endoscopic examination for colon biopsies, and diverse blood and stool assays using techniques that are all validated to provide information about the mechanism of PI-IBS. The researchers will also investigate variations in the barrier function pathway genes in tissues of PI-IBS patients and to understand the contribution of these genetic variations in immune activation and control of barrier function to increased susceptibility to PI-IBS.