What type of toxin does Bacillus cereus produce that leads to severe diarrhea?

Bacillus cereus is known to produce a diarrheal toxin that is responsible for causing severe diarrhea. This toxin is a cytotoxin known specifically as the "diarrheal enterotoxin," which disrupts the intestinal epithelium, leading to fluid accumulation and diarrhea. The mechanism involves stimulation of the intestinal lining that causes increased secretion of electrolytes and water, resulting in diarrhea.

The emetic toxin produced by Bacillus cereus is associated with a different clinical syndrome characterized by nausea and vomiting rather than diarrhea. Neurotoxins typically affect the nervous system, which is not relevant to the gastrointestinal symptoms caused by Bacillus cereus in this context. Hemolysins are associated with the destruction of red blood cells and are not relevant to the mechanism of diarrhea induced by Bacillus cereus.

Thus, the correct choice emphasizes the specific role of the diarrheal toxin in producing the gastrointestinal symptoms associated with Bacillus cereus infections.