Loose, watery stools. Having diarrhea means passing loose stools three or more times a day. Diarrhea may be acute or chronic. Acute diarrhea is a common problem that usually lasts 1 or 2 days and goes away on its own. Diarrhea lasting more than 2 days may be a sign of a more serious problem. Bacterial, viral, or parasitic infections are usually the cause of acute diarrhea. Chronic diarrhea—diarrhea that lasts at least 4 weeks—may be a symptom of a chronic disease. Chronic diarrhea symptoms may be continual or they may come and go. Chronic diarrhea is usually related to a functional gastrointestinal disorder such as irritable bowel syndrome or an intestinal disease such as Crohn's disease.