Which symptom differentiates Shigella infection from other gastrointestinal infections?

The symptom that differentiates Shigella infection from other gastrointestinal infections is the presence of bloody stools. Shigella, a genus of bacteria that causes shigellosis, is notably characterized by its ability to invade the intestinal lining, leading to inflammation and ulceration. This destruction of intestinal tissue results in bloody diarrhea, which is a hallmark sign of Shigella infections.

While other gastrointestinal infections can cause diarrhea, Shigella is particularly recognized for the severity and type of diarrhea it produces, often accompanied by pus and mucus, which points towards a more invasive process compared to conditions caused by non-invasive pathogens.

Other symptoms such as watery diarrhea, high fever, and seizures can be seen in various other infections, making them less specific. For instance, watery diarrhea is more commonly associated with infections caused by pathogens like Vibrio cholerae or certain strains of E. coli, while high fever can occur in a range of infections including viral gastroenteritis. Similarly, seizures are not a direct symptom of gastrointestinal infections and can result from a variety of causes unrelated to Shigella specifically. Therefore, the presence of bloody stools stands out as a defining feature of Shigella infections.