Final answer:
The most common cause of bacterial diarrhea in the United States is Campylobacter jejuni.
Step-by-step explanation:
The most common cause of bacterial diarrhea in the United States is Campylobacter jejuni. It is a bacterium that is commonly found in poultry, raw milk, and untreated water.
Ingesting contaminated food or water containing Campylobacter can lead to gastroenteritis, which is characterized by symptoms such as diarrhea, abdominal pain, and fever.