You can say you have diarrhea if you pass stools of liquid consistency more than three times in one day. Diarrhea strikes all ages at one time or another. On average, adults can experience diarrhea as many as four times per year. Usually, when this condition presents it clears up on it's own after a day or two. This is considered acute or short-term diarrhea and usually will not last 3 weeks. (more…)