Two forms of dysentery are known, bacillary, or bacterial dysentery and amoebic dysentery. Both are widespread throughout the world and have been known since ancient times. An Egyptian manuscript from about 1550 B.C., for example, recounts a legend in which a dysentery-like disorder afflicts Horus, son of Isis and Osiris.

The disease has been particularly associated with warfare. During the Civil War, nearly as many soldiers died of dysentery as were killed in action. Improvements in sanitation methods in the twentieth century have changed the pattern of the disease. It is now much less common in industrialized nations while still remaining a major health problem in many parts of Africa, Asia, and Central America.

Dysentery is characterized by loose and frequent stools that often contain blood, inflammation of the intestine, abdominal pain, and intestinal ulceration. Left untreated, either form of dysentery may result in death as a result...