Some individuals have minor cases and become carries who are a source of the disease. There are 3-4 carriers per 100,000 in the US Bacterial dysentery , Shigellosis is common and in the US we have 25 cases per 100,000 in infants. In a rural community of Guatemala 1965-1969, there were 200,000 cases per 100,000 population. Infants averaged two infections per year. There are several Shigella species that attack the intestines and cause ulcerous lesions.
Symptoms are bloody and mucous diarrhea.
Organisms passed via feces. There are also carriers. Cholera has produced pandemics over history. The individual suffers dehydration and dies of circulatory failure. Other Vibrio species are also pathological and live freely in soil especially salty soils.