The most common cause of diarrhea is viral gastroenteritis, a mild viral infection that goes away on its own within a few days. This condition is often called the stomach flu. Viral gastroenteritis often occurs in mini-epidemics in schools, neighborhoods, or families. Food poisoning and traveler's diarrhea are two other common causes of diarrhea. They occur as a result of eating food or drinking water contaminated with bacteria or parasites. Medications, especially antibiotics, laxatives containing magnesium, and chemotherapy for cancer treatment, can also cause diarrhea.
The following medical conditions can also lead to diarrhea:
Other less common causes of diarrhea include:
| 
