Acute diarrhea is three or more loose stools a day for less than 14 days, most often caused by viruses such as norovirus. The main danger is dehydration, especially in young children and older adults.
Key symptoms
- Frequent loose or watery stools
- Abdominal cramps
- Nausea and vomiting
- Fever in some cases
- Blood in the stool with invasive bacteria
What you find on exam
- Hydration: mucous membranes, skin turgor, heart rate, orthostatic vital signs
- Temperature
- Abdominal tenderness, usually mild and diffuse
- Mental status
- Weight in children
Tests
- Most patients need no tests
- Stool PCR panel or culture if bloody stools, fever, severe illness or immune suppression
- C. difficile test after recent antibiotics or a hospital stay
- Electrolytes and kidney function if dehydrated
- Stool ova and parasites after travel or if it lasts longer
Treatment basics
- Oral rehydration solution as first line
- IV fluids for severe dehydration or ongoing vomiting
- Loperamide for adults without fever or bloody stools
- Antibiotics only for selected cases, such as azithromycin for severe traveler's diarrhea
- Hand hygiene to prevent spread
Red flags
- Severe dehydration: confusion, low blood pressure, no urine
- Bloody diarrhea with fever or severe pain
- Diarrhea in an infant, a frail older adult or an immunosuppressed patient
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.