What is the cause of diarrhea after eating? Diarrhea after eating can cause various factors, including foodborne illnesses, infections, food intolerances, or gastrointestinal disorders. Contaminated food, viruses, or bacteria may lead to acute diarrhea, while chronic conditions like irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD) can cause persistent digestive issues. Identifying the specific cause is crucial for appropriate treatment and dietary adjustments. Seeking medical advice is recommended for persistent or severe symptoms.