Mechanism

Location

Illness

Stool Findings

Examples of Pathogens Involved

Noninflammatory (enterotoxin)

Proximal small bowel

Watery diarrhea

No fecal leukocytes; mild or no increase in fecal lactoferrin

Vibrio cholerae, enterotoxigenic Escherichia coli (LT and/or ST), enteroaggregative E. coli, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Aeromonas hydrophila, Plesiomonas shigelloides, rotavirus, norovirus, enteric adenoviruses, Giardia lamblia, Cryptosporidium spp., Cyclospora spp., microsporidia

Inflammatory (invasion or cytotoxin)

Colon or distal small bowel

Dysentery or inflammatory diarrhea

Fecal polymorphonuclear leukocytes; substantial increase in fecal lactoferrin

Shigella spp., Salmonella spp., Campylobacter jejuni, enterohemorrhagic E. coli, enteroinvasive E. coli, Yersinia enterocolitica, Vibrio parahaemolyticus, Clostridium difficile, ?A. hydrophila, ?P. shigelloides, Entamoeba histolytica

Penetrating

Distal small bowel

Enteric fever

Fecal mononuclear leukocytes

Salmonella typhi, Y. enterocolitica, ?Campylobacter fetus