Dysentery
Inflammation of the intestine, often with pain, diarrhea, bloody stools, etc.
It is usually caused by infestation of the bowel by an ameba.
Dysentery can be fatal, usually due to severe dehydration.
Treatment includes rapid rehydration, sometimes via IV, and medication.
From the Greek 'dys-' meaning 'abnormal or painful' + 'enteron' meaning 'intestine' = abnormal or painful intestine.