We present a 19-year-old patient who was admitted for evaluation of prolonged watery diarrhea. Previous study showed one stool culture positive for Campylobacter jejuni, which was treated with appropriate antibiotics with no response. She underwent colonoscopy with multiple biopsies, which led to a diagnosis of lymphocytic colitis. We believe that the patient's disease was due to the infectious process, which triggered an autoimmune response and caused the lymphocytic colitis.