What type of diarrhea is characterized by high fever and the presence of blood or fecal leukocytes?

The type of diarrhea characterized by high fever and the presence of blood or fecal leukocytes is invasive diarrhea. This form of diarrhea typically arises from an infection where the pathogens invade the intestinal mucosa, causing inflammatory damage. This inflammation leads to a more severe clinical picture that includes systemic symptoms such as fever. The presence of blood in the stool, along with fecal leukocytes, indicates significant intestinal inflammation and damage, which is a hallmark of invasive bacterial infections, such as those caused by Shigella, Salmonella, or certain strains of E. coli.

Invasive diarrhea is distinct from noninvasive diarrhea, where pathogens do not invade the intestinal lining; instead, they remain in the intestinal lumen, often resulting in watery stools without the presence of blood or leukocytes. Osmotic diarrhea is caused by non-absorbable substances in the intestinal tract that draw water into the lumen, while secretory diarrhea is due to increased intestinal secretion of electrolytes and water without an accompanying increase in osmotic load. Neither osmotic nor secretory diarrhea typically presents with high fever or blood in the stool, which further emphasizes the unique characteristics of invasive diarrhea.