Dysentery is an infection of the colon that typically causes severe and bloody diarrhea, abdominal pain, fever and dehydration.

There are two main types of dysentery. The most common is bacillary dysentery, or shigellosis, which is caused by Shigella bacteria. The less common type is amebic dysentery, or amebiasis, which is caused by the parasite Entamoeba histolytica. Although the term “dysentery” has been used for years to refer to these two diseases, it actually refers to the specific type of bloody diarrhea that characterizes both conditions.

The main symptom of dysentery is mild to severe diarrhea that may contain blood or mucus. Other symptoms may include abdominal pain or cramping, fever and chills and unexplained weight loss. People with shigellosis experience symptoms within one to three days of exposure to the bacteria. Most people with amebiasis do not experience any symptoms and may carry the parasite for years.

The organisms that cause dysentery are spread through person-to-person contact, eating contaminated food and drinking or swimming in contaminated water. These microbes are passed through the stools, so contact with infected stool can transmit the disease to another person. Failure to wash the hands after going to the bathroom is a common form of transmission, either directly (from one person to another) or indirectly (from a person to food or water to another person).

Dysentery is common in developing countries where public hygiene is poor and food and water systems are contaminated. In developed countries, crowded conditions with the potential of poor hygiene, such as day care centers and other institutions, are the most likely locations for dysentery to spread. People also contract dysentery by traveling to areas with contaminated food and/or water supplies.

Dysentery may be diagnosed by a physician during a physical examination that includes a medical history. A stool test may be performed to detect the presence of an organism that may be causing symptoms. Because diarrhea can be caused by many diseases and conditions, other tests, such as blood tests, may be performed to rule these out.

Patients who experience mild symptoms may be treated with fluid replacement to avoid dehydration. Patients may be treated with antibiotic medication (in cases of shigellosis) or antiparasitic medication (in cases of amebiasis) to kill the organism causing the illness. In severe cases, patients may be hospitalized.