My two year old has had 4 watery diarrhea in the past 24 hours. he has no other symptoms, in fact he is playful and running around. what could this be?

Viral diarrhea: Vast majority of diarrhea episodes in children are due to intestinal viral infections which are self limited. Meaning, it should go away on its own. The danger is always dehydration from the diarrhea. Helpful at home treatments: first small amounts of water or mild electrolyte solutions like pedialyte frequently, avoid gatorage and other adult sports drinks. Second, acidophilus rich yogurt.

Diarrhea: It could be a few things. One of the more common things is drinking too much juice - keep it to 6-8 ounces a day max. He could also have a minor virus - commonly known as stomach flu. If he is having bad abdominal pain, fever, or blood in stool, these are more serious things. The final thing for benign diarrhea is teething. Even at his age kids can get loose stool with teething.