Infectious intestinal disorder. It is characterized by inflammation, abdominal pain and straining, and diarrhea, often containing blood and mucus. Dysentery is spread in food or water contaminated by feces, often by infected individuals with unwashed hands. Bacillary dysentery (shigellosis), caused by Shigella bacteria, may be mild or may be sudden, severe, and fatal. Fluid loss causes dehydration. Advanced stages include chronic large-intestine ulceration. It is treated with antibiotics, fluid replacement, and sometimes blood transfusion. Amoebic (or amebic) dysentery, caused by the amoebaEntamoeba histolytica, has two forms, one much like bacillary dysentery and the other chronic and intermittent, sometimes with large-intestine ulcerations. It is treated with drugs that kill the amoeba.