Which of the following is a common symptom of foodborne illness?

Diarrhea is a common symptom of foodborne illness, as it frequently occurs due to the ingestion of contaminated food or beverages. When pathogens such as bacteria, viruses, or parasites enter the gastrointestinal tract, they can disrupt normal digestive processes, leading to symptoms like diarrhea. This symptom is often the body's response to rid itself of the harmful substances or toxins, and it may accompany other signs such as abdominal cramping, nausea, and vomiting.

In contrast, while hives, headache, and fatigue can be associated with various illnesses or allergies, they are not specifically indicative of foodborne illness. Hives typically signify an allergic reaction rather than a direct consequence of foodborne pathogens. Headaches can arise from diverse factors, including dehydration, stress, or illness unrelated to food contamination. Similarly, fatigue is a vague and general symptom that can result from numerous conditions, but it does not specifically point to foodborne illness.