How long does diarrhea last for till it clears up?

Depends on cause: Diarrhea can have many causes - for example, it can be infectious or inflammatory. For run of the mill viral gastroenteritis, usually symptoms last 5-7 days. If diarrhea is lasting longer than that, especially if associated with blood, fevers, or abdominal cramping, then i like to suggest to my patients to have a more thorough workup done, including possibly stool studies. Hope this helps!