Many people have spent a tropical vacation with a bad stomach bug. They might have had dysentery, a painful intestinal infection that is usually caused by bacteria and rarely by parasites. Dysentery is defined as diarrhea in which there is blood and pus.

There are two main types of dysentery. The first type, amoebic dysentery or intestinal amebiasis, is caused by a single-celled, microscopic parasite living in the large bowel . The second type, bacilliary dysentery, is caused by invasive bacteria. Both kinds of dysentery occur mostly in hot countries. Poor hygiene and sanitation increase the risk of dysentery by spreading the protozoa or bacteria that cause it through food or water contaminated by infected human feces.

Causes
Bacterial infections are by far the most common causes of dysentery. These infections include Shigella, Campylobacter, E. coli, and Salmonella species of bacteria. The frequency of each pathogen varies considerably in different regions of the world. For example, shigellosis is most common in Latin America while Campylobacter is the dominant bacteria in Southeast Asia. Dysentery can have a number of causes. Dysentery is rarely caused by chemical irritants or by intestinal worms.
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