Campylobacter jejuni infection causes cramping, diarrhea, abdominal pain and fever within 2 to 5 days after a person has been exposed to the organism. Campylobacter jejuni is one of the most common bacterial causes of diarrhea. Most cases of Campylobacter jejuni come from handling or ingesting raw or undercooked poultry meat. Although poultry and other birds are not affected by the bacterium, other animals can be. Therefore it is possible for a person to aquire the infection from contact with infected stool of an ill cat or dog. This is what Campylobacter organisms look like through a microscope. (Image courtesy of the Centers for Disease Control and Prevention.)