Campylobacter is the leading cause of bacterial diarrhea in humans. It is commonly transmitted through contaminated or undercooked poultry, raw milk, or untreated water. Symptoms usually appear within 2 to 10 days and include diarrhea, fever, nausea, and abdominal pain. While most cases resolve on their own within a week, complications can occasionally occur such as Guillain-Barré syndrome. Proper food handling and cooking can help prevent Campylobacter infections.