Which organism is the most common cause of diarrhea?

The most common cause of diarrhea among the choices listed is associated with infectious agents like certain types of bacteria. Campylobacter is recognized as one of the leading causes of bacterial gastroenteritis worldwide, particularly in developed countries. It is usually transmitted through contaminated food or water, frequently associated with undercooked poultry, unpasteurized milk, or contaminated water supplies.

Infections caused by Campylobacter often result in diarrhea, which may be bloody, accompanied by abdominal pain, fever, and may sometimes lead to complications such as reactive arthritis or Guillain-Barré syndrome.

The other organisms and factors listed contribute to diarrhea; however, Campylobacter consistently ranks as the most common bacterial cause of gastroenteritis in many epidemiological studies. This distinction is significant in understanding the public health impact of foodborne illnesses and underscores the importance of proper food handling and sanitation practices in reducing the incidence of infections.