Diarrheal diseases are illnesses characterized by frequent, loose, or watery bowel movements. They can be caused by various factors, including infections from bacteria, viruses, or parasites, as well as contaminated food and water. Common pathogens include Escherichia coli, Norovirus, and Rotavirus. These diseases can lead to dehydration, especially in young children and the elderly, making prompt treatment essential. Preventing diarrheal diseases involves practicing good hygiene, such as washing hands with soap, drinking clean water, and ensuring food is properly cooked. Vaccines are available for some causes, like Rotavirus, which can help reduce the incidence of severe cases.