Enterohemorrhagic E. coli typically presents with what type of diarrhea?

The typical presentation of enterohemorrhagic E. coli (EHEC), particularly serotype O157:H7, begins with watery diarrhea that can progress to bloody diarrhea. This progression occurs because the bacteria produce toxins that damage the intestinal lining, leading to inflammation and bleeding, which transforms the initially watery stool into bloody diarrhea. This characteristic symptom is a key feature of EHEC infections and helps differentiate it from other types of gastroenteritis.

While some individuals may experience abdominal pain accompanying the diarrhea, the hallmark is the shift from watery to bloody stool, making this presentation pivotal for diagnosis and management. Understanding this progression is crucial for identifying EHEC, especially in patients with recent exposure to undercooked meats or contaminated produce.