Treatment of Non-Watery Diarrhea (Dysentery/Bloody Diarrhea)
For non-watery diarrhea (dysentery with blood and mucus), antimicrobial therapy is the cornerstone of treatment, unlike watery diarrhea where antibiotics are generally avoided. 1
Immediate Assessment and Fluid Management
Assess hydration status first, as dehydration drives morbidity and mortality regardless of diarrhea type. 1
- Mild dehydration (3%-5% deficit): Administer 50 mL/kg of oral rehydration solution (ORS) over 2-4 hours 1
- Moderate dehydration (6%-9% deficit): Administer 100 mL/kg of ORS over 2-4 hours 1, 2
- Severe dehydration (≥10% deficit): This is a medical emergency requiring immediate IV boluses of 20 mL/kg Ringer's lactate or normal saline until pulse, perfusion, and mental status normalize 1
Clinical signs of severe dehydration include prolonged skin tenting (>2 seconds), cool poorly perfused extremities, decreased capillary refill, rapid deep breathing (acidosis), and altered consciousness 1
Antimicrobial Therapy Decision
Unlike watery diarrhea, bloody diarrhea (dysentery) requires stool cultures and empiric antimicrobial therapy while awaiting results. 1
When to Start Antibiotics:
- Dysentery (blood and mucus in stool): Start empiric antibiotics immediately 1, 3
- Fever with bloody diarrhea: Initiate antimicrobial therapy 4, 5
- Suspected shigellosis: Antibiotics are particularly beneficial and should be started 6, 3, 7
- Suspected amebiasis: Antiparasitic agents are indicated 6, 3
Critical Exception - NEVER Give Antibiotics If:
Shiga toxin-producing E. coli (STEC) O157 or STEC producing Shiga toxin 2 is suspected, as antimicrobials can precipitate hemolytic uremic syndrome. 1, 2
Antibiotic Selection for Dysentery
Azithromycin is the preferred first-line antibiotic for dysentery: 7
- Dosing: 1,000 mg single dose for febrile diarrhea/dysentery 7
- Alternative for Shigella in high-resistance areas: Levofloxacin 500 mg once daily for 3 days or ciprofloxacin 500 mg twice daily for 3 days 7
- Fluoroquinolones are becoming less effective due to increasing resistance, particularly among Campylobacter 7
Narrow antimicrobial therapy when culture and susceptibility results become available. 1
Nutritional Management
Continue breastfeeding throughout the illness in infants, and resume age-appropriate diet immediately after rehydration. 1, 2, 8
- Do not restrict diet during or after rehydration—early feeding improves outcomes 2, 8
- Small, light meals are preferable initially, avoiding fatty, heavy, spicy foods 4
What NOT to Do
Antimotility agents (loperamide) are absolutely contraindicated in dysentery/bloody diarrhea, as they risk toxic megacolon. 1, 4
- Never give loperamide to children <18 years of age under any circumstances 1, 2, 9
- Loperamide should only be used in immunocompetent adults with watery diarrhea without fever or blood 1, 4
Adjunctive Therapies
- Ondansetron: May be given to children >4 years with vomiting to facilitate ORS tolerance 2, 8
- Probiotics: May reduce symptom severity and duration in immunocompetent patients (weak recommendation) 2, 4
- Zinc supplementation: Reduces duration in children 6 months to 5 years in high zinc deficiency areas 2
Common Pitfalls to Avoid
- Never delay rehydration while awaiting diagnostic results—fluid replacement is the priority 8, 10
- Never neglect to obtain stool cultures before starting antibiotics in dysentery—this guides definitive therapy 1, 5
- Never use antibiotics empirically for watery diarrhea—this is the opposite approach from dysentery 1, 2
- Avoid overhydration in elderly patients with heart or kidney failure—frequent reassessment is essential 4