Diarrhea is a symptom, not a disease. It is defined as passing frequent (3 or more per day) loose or watery stools. The acute form lasts less than 14 days (usually only a few days), goes away on its own, and usually isn't serious, but it can be linked with some other problems. It affects people of all ages, and some types are infectious. The average adult may get acute diarrhea 4 times a year, and long-term effects are rare.
Chronic diarrhea lasts longer than 4 weeks. An inflammatory bowel condition such as ulcerative colitis or Crohn's disease may be to blame.
Children and infants with diarrhea should be seen by a doctor.