Practical guide
When diarrhea needs medical care
Warning signs, dehydration clues, and situations that deserve faster evaluation.
Seek prompt medical care for blood or black stool, severe pain, confusion, fainting, signs of serious dehydration, or diarrhea in a very young infant. Higher-risk people should contact a clinician sooner.
Quick answer
Seek urgent care for severe dehydration, confusion, fainting, blood or black stool, severe abdominal pain, inability to keep fluids down, or serious illness. Contact a clinician sooner for infants, older adults, pregnancy, immunocompromise, recent antibiotics, or symptoms that persist.
Key takeaways
- Preventing dehydration is the first priority.
- Most short episodes improve with fluids, rest, and a return to normal food as tolerated.
- Medicines are not right for every person or every cause.
- Persistent or severe symptoms need medical evaluation.
Emergency warning signs
Call emergency services for collapse, severe confusion, signs of shock, extreme weakness with inability to stand, or severe rapidly worsening pain. Blood or black tarry stool also needs prompt assessment.
Signs of dehydration
Watch for very little urine, dark urine, intense thirst, dry mouth, dizziness, unusual sleepiness, sunken eyes, no tears in a child, or no wet diaper for several hours. Severe dehydration can be dangerous.
Duration matters
Adults should seek advice when diarrhea lasts more than about two days without improvement or sooner when symptoms are severe. Children—especially babies—need earlier assessment. Diarrhea lasting weeks requires evaluation for a persistent cause.
Higher-risk situations
Contact a clinician sooner after recent antibiotics, foreign travel, hospitalization, pregnancy, immune suppression, significant chronic disease, or if the person is very young or older.
Common questions
What temperature is concerning?
A high fever with diarrhea—especially around 39°C/102°F or higher—deserves medical advice, and lower fever may matter in infants or medically vulnerable people.
How little urine is too little?
Markedly reduced urination, very dark urine, or no wet diaper for several hours can indicate dehydration.
What if diarrhea wakes me at night?
Repeated nighttime diarrhea or ongoing symptoms should be discussed with a clinician because they may suggest more than a brief functional upset.
Sources
Editorial note
This page provides general education, not personalized medical advice. Content is written conservatively from public-health and clinical sources. Our planned medical-review program is described on the medical review page.