Everyone occasionally has diarrhea — loose, watery and more-frequent bowel movements. You might also have abdominal cramps and produce a greater volume of stool. The duration of diarrhea symptoms can provide a clue to the underlying cause.

Acute diarrhea lasts from 2 days to 2 weeks. Persistent diarrhea lasts 2 to 4 weeks. Acute and persistent diarrhea are typically caused by a bacterial, viral or parasitic infection of some sort.

Chronic diarrhea lasts longer than does acute or persistent diarrhea, generally more than four weeks. Chronic diarrhea can indicate a serious disorder, such as ulcerative colitis or Crohn's disease, or a less serious condition, such as irritable bowel syndrome.

Most cases of acute diarrhea go away without treatment. However, severe diarrhea (greater than 10 bowel movements a day or diarrhea where fluid losses are significantly greater than oral intake) can cause dehydration, which can be life-threatening if untreated. Dehydration is particularly dangerous in children, older adults and those with weakened immune systems.

Seek medical attention for a child with these symptoms:

  • Diarrhea that doesn't improve after 24 hours.
  • No wet diaper in three or more hours.
  • A fever of more than 102 F (39 C).
  • Bloody or black stools.
  • A dry mouth or tongue or cries without tears.
  • Unusually sleepy, drowsy, unresponsive or irritable.
  • A sunken appearance to the abdomen, eyes or cheeks.
  • Skin that doesn't flatten if pinched and released.

Schedule a doctor's visit for an adult with these symptoms:

  • Diarrhea lasts more than two days without improvement.
  • Excessive thirst, dry mouth or skin, little or no urination, severe weakness, dizziness or lightheadedness, or dark-colored urine, which could indicate dehydration.
  • Severe abdominal or rectal pain.
  • Bloody or black stools.
  • A fever of more than 102 F (39 C).
Aug. 11, 2023