Acute diarrheal illness (<3 weeks)
Severe abdominal pain
Fever
Bloody/voluminous/purulent stools
Systemic illness/symptoms
Campylobacter jejuni
Infectious:
Salmonella
Yersinia enterocolitica
Shigella
Clostridium difficile 
Shiga toxin-producing E. coli
Clostridium difficile