CAMPYLOBACTER - A genus of bacteria that represents a number of different species that are pathogenic in man. Campylobacter jejuni is probably the second most common cause of waterborne diarrheal disease in the United States. Campylobacter pylori has been implicated as an etiologic factor in the development of gastritis and peptic ulcer disease. Common symptoms include abdominal pain, watery diarrhea (may be bloody) and fever.