Bacillary dysentery. Artwork of the human descending colon, cut away to show the physical symptoms of acute bacillary (bacterial) dysentery. Also known as shigellosis, it is caused by Shigella sp. bacteria. It is spread by contact with a carrier or through food and water contaminated by their faeces. Symptoms seen include ulceration of the lining of the colon and oedema, which is the excessive accumulation of fluid in the tissues. Exudation of a liquid containing proteins and white cells is seen at lower centre and upper right. This often occurs as a result of inflammation.