We present a 19-year-old patient who was admitted for evaluation of prolong
ed watery diarrhea. Previous study showed one stool culture positive for Ca
mpylobacter 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.