Treatment of Bloody Diarrhea
Bloody diarrhea should be treated as a medical emergency requiring prompt evaluation and management, with treatment focused on rehydration, antimicrobial therapy for specific pathogens, and supportive care.
Initial Assessment and Triage
- Evaluate for signs of dehydration: general appearance, eyes, mucous membranes, tears, capillary refill time, urine output, and vital signs (especially heart rate and blood pressure) 1
- Assess severity based on:
- Frequency and volume of stools
- Presence of fever, abdominal pain, or vomiting
- Signs of hypovolemic shock (tachycardia, hypotension)
- Mental status changes
Management Algorithm
1. Fluid Resuscitation and Rehydration
Mild to moderate dehydration:
Severe dehydration or shock:
- Initial fluid bolus of 20 ml/kg IV 2
- Continue rapid fluid replacement until clinical signs of hypovolemia improve 2
- Target adequate central venous pressure and urine output >0.5 ml/kg/h 2
- For oliguric acute kidney injury despite adequate volume resuscitation, seek nephrology or intensive care consultation 2
2. Microbiological Investigation
- Stool culture for bacterial pathogens (Salmonella, Shigella, Campylobacter, E. coli O157:H7) 3
- Specific testing for E. coli O157:H7 is critical due to risk of hemolytic uremic syndrome 3
- Consider parasitic causes (E. histolytica, Giardia) 4
3. Antimicrobial Therapy
For confirmed or strongly suspected bacterial pathogens:
| Pathogen | First-line Treatment | Alternative Treatment |
|---|---|---|
| Shigella | Azithromycin | TMP-SMX (if susceptible) |
| Campylobacter | Azithromycin | Erythromycin |
| Enterotoxigenic E. coli | TMP-SMX (if susceptible) or Azithromycin | |
| Bacterial gastroenteritis | Third-generation cephalosporin or Azithromycin |
Important: Avoid antimotility agents (loperamide) in bloody diarrhea as they may worsen outcomes 2, 1
4. Management of Neutropenic Enterocolitis (if applicable)
For cancer patients with neutropenia and bloody diarrhea:
- Broad-spectrum antibiotics covering gram-negative, gram-positive, and anaerobic organisms 2
- Recommended regimens:
- Consider amphotericin if no response to antibacterial agents 2
- Blood transfusions as needed 2
- Avoid anticholinergic, antidiarrheal, and opioid agents 2
5. Supportive Care
- Resume age-appropriate diet during or immediately after rehydration 1
- Offer food every 3-4 hours 1
- Avoid foods high in simple sugars and fats 1
- For immunotherapy-induced bloody diarrhea:
Indications for Hospitalization
- Severe dehydration
- Hemodynamic instability
- Severe abdominal pain
- Immunocompromised state
- Infants <3 months 4
- Persistent vomiting 4
- Suspected surgical abdomen 4
Prevention Measures
- Hand washing with soap and water after using toilet, changing diapers, before preparing food 1
- Contact precautions with gloves and gowns for C. difficile 1
- Vaccination against rotavirus to reduce incidence of gastroenteritis 1
Common Pitfalls to Avoid
- Delaying fluid resuscitation while awaiting diagnostic results
- Using antimotility agents in bloody diarrhea, which can worsen outcomes
- Failing to test specifically for E. coli O157:H7, which requires special culture media
- Overlooking surgical causes of bloody diarrhea (intussusception, appendicitis)
- Initiating antibiotics before obtaining stool cultures in non-severe cases
- Withholding nutrition during episodes of diarrhea, which can delay recovery 1
Special Considerations
- In children, cotrimoxazole may be effective for bloody diarrhea with faster resolution of symptoms 5
- For immunotherapy-induced diarrhea with bleeding, avoid loperamide and use corticosteroids 2
- For cancer patients with neutropenia, surgical intervention may be necessary for persistent bleeding, perforation, abscess formation, or clinical deterioration 2