Shigellosis is a bacterial infection that affects the intestines.
It is one of the more common causes of diarrhea. Most cases are seen in the summer and early fall and occur as single cases or outbreaks. Anyone can get shigellosis, but it is recognized more often in young children. Those who may be at greater risk include children in day-care centers, travelers to certain foreign countries, institutionalized people and men who have sex with other men. Shiga bacteria are found in the intestines of infected people, who, in turn, may contaminate food or water.