Dysentery is a disease that affects the digestive system and has many grotesque symptoms, such as diarrhea and vomiting. Dysentery is considered more of a set of symptoms instead of an actual organism, but it is almost always caused by a bacterium.
Malek, Rory and Hutchens, Zach, "What is Dysentery?" (2015). Infectious Diseases Project 2015. 5.