What is Diarrhea?
Diarrhea is characterized by the frequent passage of loose or watery stools, defined as three or more loose or liquid stools per day, or more frequently than normal for an individual. 1
Types of Diarrhea
Diarrhea can be classified based on duration:
- Acute diarrhea: Lasts less than 14 days 1
- Persistent diarrhea: Lasts 14 days to 4 weeks 1
- Chronic diarrhea: Lasts more than 4 weeks 1
Diarrhea can also be classified based on severity:
- Mild: Tolerable, not distressing, does not interfere with planned activities 1
- Moderate: Distressing or interferes with planned activities 1
- Severe: Incapacitating or completely prevents planned activities; all dysentery (bloody stools) is considered severe 1
Clinical Assessment
When evaluating diarrhea, important clinical features to assess include:
- Stool characteristics: Frequency, consistency, volume, presence of blood or mucus
- Duration of symptoms: Acute vs. persistent vs. chronic
- Associated symptoms: Fever, abdominal pain, vomiting, weight loss
- Hydration status: Signs of dehydration (dry mucous membranes, decreased skin turgor, tachycardia)
The Bristol stool chart can help identify true diarrhea (type 7, watery stool) versus loose stool (types 5-6) 1.
Causes of Diarrhea
Common causes include:
- Infectious: Viral, bacterial, parasitic
- Inflammatory: Inflammatory bowel disease
- Malabsorptive: Celiac disease, pancreatic insufficiency
- Functional: Irritable bowel syndrome
- Medication-induced: Antibiotics, laxatives
- Food-related: Food poisoning, food intolerances
Management Approach
1. Rehydration
- Oral rehydration is the cornerstone of treatment for all types of diarrhea 1, 2
- Replace fluids and electrolytes lost through diarrhea
2. Medication
For mild diarrhea:
- Antimotility agents like loperamide may be used for watery, non-bloody diarrhea 1, 2, 3
- Avoid antimotility agents in bloody diarrhea or suspected Shiga toxin-producing E. coli infection 1, 2
For moderate to severe diarrhea:
- Antibiotics may be considered for specific bacterial causes 1
- Use caution with loperamide in elderly patients or those taking medications that prolong QT interval 3
3. Diet
- Early oral refeeding is recommended rather than fasting 4
- Avoid foods that may exacerbate symptoms (high-fat, spicy, or dairy products)
When to Seek Medical Attention
Medical attention should be sought if:
- Diarrhea persists beyond 3 days
- Blood or mucus is present in stool
- Severe abdominal pain occurs
- Signs of dehydration develop
- Fever over 101.5°F (38.6°C) develops 2
- Patient is very young, elderly, or immunocompromised
Special Considerations
- Children: Higher risk for dehydration; loperamide is contraindicated in children under 2 years 3, 5
- Elderly: May experience more severe symptoms and complications 2
- Immunocompromised: May require more aggressive management 2
Common Pitfalls
- Failing to distinguish between functional and organic causes of diarrhea
- Using antimotility agents in cases of bloody diarrhea
- Not adequately assessing hydration status
- Unnecessary use of antibiotics in viral or self-limiting diarrhea
- Overlooking serious underlying conditions in chronic diarrhea
By understanding the definition, causes, and appropriate management strategies for diarrhea, clinicians can provide effective care while avoiding potential complications.