Digestive Symptom

Diarrhea — Causes, Tests & When to See a Doctor

Why diarrhea happens, how to manage it safely at home, and the warning signs that need medical attention.

What Is Diarrhea?

Diarrhea is loose, watery stools occurring more than three times a day. Most cases are acute (lasting a few days) and caused by infection; chronic diarrhea lasting weeks needs further investigation.

Common Causes

See a doctor if: Diarrhea lasts more than 2 days, contains blood, is accompanied by high fever, severe abdominal pain, or signs of dehydration (dizziness, dry mouth, very little urine).

Tests Your Doctor May Order

TestPurpose
Stool cultureIdentifies bacterial or parasitic infection
CBCChecks for infection or inflammation
ElectrolytesChecks for dehydration-related imbalances
CRP / ESRScreens for inflammatory bowel disease

Managing Diarrhea at Home

Important: Severe, bloody, or persistent diarrhea — or diarrhea in young children and older adults — should be evaluated promptly by a doctor due to dehydration risk.