What is Dysentery?
Dysentery is defined as the passage of stools containing gross blood visibly admixed with stool in the commode, often accompanied by severe constitutional symptoms including fever. 1
Clinical Definition and Key Distinguishing Features
Dysentery specifically refers to frequent, scant stools with visible blood and mucus, representing a severe form of inflammatory diarrhea that indicates colonic mucosal invasion by pathogens 1
Critical distinction: Normal-appearing stools with streaks of blood on toilet paper likely represent bleeding hemorrhoids, NOT dysentery 1
All dysentery is classified as severe diarrhea regardless of stool frequency, because it indicates invasive intestinal infection requiring more aggressive management 1
Common Etiologies
Bacterial Dysentery (Bacillary Dysentery)
Shigella species are the classic cause of bacillary dysentery, causing watery diarrhea that progresses to dysentery with frequent mucoid bloody stools, abdominal cramps, and tenesmus 2, 3
Shigella invades colonic mucosa, multiplies within epithelial cells, causes cell death, and spreads laterally to adjacent cells, resulting in mucosal ulceration, inflammation, and bleeding 3
Other bacterial causes include Salmonella (non-typhoidal), Campylobacter, and non-cholera Vibrio species 4
Amoebic Dysentery
Entamoeba histolytica causes amoebic dysentery, transmitted through fecal-oral contamination in areas with poor sanitation 5, 6
Amoebic dysentery is frequently misdiagnosed, and microscopic confirmation showing amebic trophozoites is essential before initiating specific treatment 5
Clinical Significance
Dysentery represents invasive intestinal infection with mucosal damage, distinguishing it from non-invasive watery diarrhea 1
The presence of dysentery warrants immediate diagnostic evaluation including stool culture for Salmonella, Shigella, Campylobacter, Yersinia, and Shiga toxin testing, plus parasitic examination for Entamoeba 4
Critical pitfall: Never use antimotility drugs (like loperamide) in patients with dysentery, as they can precipitate toxic megacolon or worsen outcomes 4