Eligible volunteers will be enrolled in the study and admitted to the GCRC on Day -1. They will drink a measured dose of C. jejuni on Day 0, and followed for approximately 9 inpatient days, during which time the investigators expect at least 75% to develop a diarrheal illness, which will be promptly treated with replacement fluids (oral or IV, as indicated) and antibiotics. During the inpatient period, subjects will be assessed for any adverse events, and blood and stool specimens will be analyzed for markers of infection and markers of immune response. Subjects must have resolved or resolving symptoms and two negative stool cultures ≥12 hours apart to be eligible for discharge, and will be seen in outpatient follow-up at 21, 28, 35, 60, and 90 days for additional AE assessments and blood and stool analysis.