Diarrhea is loose, watery, and frequent stool. Diarrhea is considered chronic (long-term) when you have had loose or frequent stools for more than 4 weeks.

In most cases, diarrhea signs and symptoms usually last a couple of days. But sometimes diarrhea can last for weeks. In these situations, diarrhea can be a sign of a serious disorder, such as inflammatory bowel disease, or a less serious condition, such as irritable bowel syndrome.

Diarrhea may cause a loss of significant amounts of water and salts. Most cases of diarrhea go away without treatment. But see your doctor if diarrhea persists, if you become dehydrated or if you pass blood in your stool.

The most common cause of diarrhea is viral gastroenteritis which is a mild viral infection which goes away in a couple of days. Celiac disease, IBS, Chron's disease, and lactose intolerance can also be a cause of diarrhea.

When to see a doctor

If you're an adult, see your doctor if:

• Your diarrhea persists beyond three days
• You become dehydrated — as evidenced by excessive thirst, dry mouth or skin, little or no urination, severe weakness, dizziness or lightheadedness, or dark-colored urine
• You have severe abdominal or rectal pain
• You have bloody or black stools
• You have a temperature of more than 102 F (39 C)

In children, particularly young children, diarrhea can quickly lead to dehydration. Call your doctor if your child's diarrhea doesn't improve within 24 hours or if your baby:

• Hasn't had a wet diaper in three or more hours
• Has a fever of more than 102 F (39 C)
• Has bloody or black stools
• Has a dry mouth or cries without tears
• Is unusually sleepy, drowsy, unresponsive or irritable
• Has a sunken appearance to the abdomen, eyes or cheeks
• Has skin that doesn't flatten if pinched and released