The symptom of diffuse, watery diarrhea that produces a relatively clear stool containing mucus flecks is suggestive of infection caused by which organism?

The symptom of diffuse, watery diarrhea that produces a relatively clear stool containing mucus flecks is suggestive of infection caused by which organism?

• A. Enterohemorrhagic E. coli
• B. Shigella dysenteriae
• C. Vibrio cholerae
• D. Yersinia enterocolitica

Answer: (C)

The key idea is secretory, non-inflammatory diarrhea produced by a toxin that drives massive water and electrolyte loss in the gut. Vibrio cholerae causes this exact pattern: cholera toxin stimulates chloride secretion and water loss in the small intestine, leading to very large volumes of watery stool. The stool can be pale or clear and may contain mucus flecks, but it typically lacks blood or visible pus, which fits the description of diffuse, watery diarrhea with a relatively clear stool and mucus strands. In contrast, the other organisms listed generally cause inflammatory diarrhea. Enterohemorrhagic E. coli often leads to bloody diarrhea and sometimes severe complications like HUS. Shigella dysenteriae produces dysentery with bloody, mucus-laden stools and fever. Yersinia enterocolitica tends to cause inflammatory diarrhea that can mimic appendicitis, sometimes with fever and abdominal pain, not the classic large-volume, clear, mucus-containing stool of cholera. So the combination of very watery, large-volume stools with a clear, mucus-containing appearance is most characteristic of cholera caused by Vibrio cholerae.

The key idea is secretory, non-inflammatory diarrhea produced by a toxin that drives massive water and electrolyte loss in the gut. Vibrio cholerae causes this exact pattern: cholera toxin stimulates chloride secretion and water loss in the small intestine, leading to very large volumes of watery stool. The stool can be pale or clear and may contain mucus flecks, but it typically lacks blood or visible pus, which fits the description of diffuse, watery diarrhea with a relatively clear stool and mucus strands.

In contrast, the other organisms listed generally cause inflammatory diarrhea. Enterohemorrhagic E. coli often leads to bloody diarrhea and sometimes severe complications like HUS. Shigella dysenteriae produces dysentery with bloody, mucus-laden stools and fever. Yersinia enterocolitica tends to cause inflammatory diarrhea that can mimic appendicitis, sometimes with fever and abdominal pain, not the classic large-volume, clear, mucus-containing stool of cholera.

So the combination of very watery, large-volume stools with a clear, mucus-containing appearance is most characteristic of cholera caused by Vibrio cholerae.