Diarrhea

Diarrhea

Diarrhea is characterized by frequent passage (≥ 3 times per day) of loose or watery stools. Causes include dietary changes, incomplete digestion (such as lactose intolerance), gastrointestinal inflammation, side effects from medications (antibiotics, magnesium-containing antacids), bacterial, amoebic, or viral infections. Although most cases resolve spontaneously, severe diarrhea may cause life-threatening dehydration and electrolyte loss, particularly in young children and older adults, requiring immediate medical attention.

When to See a Doctor

Seek medical attention if:

• Diarrhea persists longer than 3 days (2 days for elderly patients).
• Accompanied by fever or severe vomiting.
• Sudden changes in bowel habits.
• During pregnancy.

Prevention

• Wash hands with soap and clean water for at least 20 seconds or use alcohol-based hand sanitizer (≥ 60%).
• Exercise caution when consuming food and beverages in high-risk areas.
• Eat fruits and vegetables you have washed or peeled yourself.
• Ensure food is thoroughly cooked and clean.
• Avoidtap water and ice made from it.

Management

• Rehydrate adequately avoid alcohol and caffeinated beverages.
• Avoid fatty, heavy, hard-to-digest foods, and dairy products during episodes.

Treatment Options

1. Antidiarrheals

• Activated charcoal, attapulgite, kaolin, smectite absorb water, toxins, and reduce stool liquidity. Avoid use beyond 2 days and do not use in cases with fever.
• Kaolin often combined with pectin.

Antibiotics for Infectious Diarrhea

• Furazolidone, nifuroxazide, paromomycin may treat diarrhea caused by certain infections.
• Fluoroquinolones (ciprofloxacin, norfloxacin ) and tetracyclines (doxycycline) for severe cholera caused by Vibrio cholerae, characterized by severe watery diarrhea ("rice-water stools").
  • Doxycycline is contraindicated in children under 8 due to potential teeth discoloration.
  • Fluoroquinolones should be taken before meals, avoid concurrent intake with milk, calcium, or antacids. Not recommended for children under 6 years.

Antimuscarinics

• Dicycloverine reduces spasms and motility.

Combination Antidiarrheal Formulations

• Combinations (furazolidone, kaolin, diiodohydroxyquinoline, neomycin, rifaximin ) may treat infectious diarrhea.
• Diiodohydroxyquinoline has restricted use in Thailand due to neurotoxicity concerns. Kaolin may interfere with antibiotic effectiveness; thus, caution in combination use.

Bismuth salts

• mild astringent effects to relieve symptoms.

Probiotics

Live beneficial microorganisms to support treatment/prevention of diarrhea:

• Saccharomyces boulardii (CNCM I-745): infectious diarrhea, antibiotic-associated diarrhea, tube feeding-associated diarrhea, and adjunctive treatment for Clostridium difficile.
• Bacillus clausii: antibiotic-associated diarrhea.
• Lactobacillus acidophilus: uncomplicated diarrhea.
• Lactobacillus acidophilus + Bifidobacterium animalis ssp. lactis: reduces diarrhea post-H. pylori treatment.
• Bovine colostrum: reduces frequency and duration of diarrhea.

2. Antiamoebics

• Nitroimidazoles (metronidazole,tinidazole ): effective for amoebic diarrhea.

Patient Advice (During Antiamoebic Therapy)

• Avoid alcohol or products with propylene glycol during and for 3 days after treatment to prevent disulfiram-like reactions (nausea, flushing, etc.).
• Take tinidazole with food to reduce stomach upset.

3. Electrolytes and Hydration

• Oral rehydration solution (ORS) recommended by WHO:
  • Osmolality: 200–310 mOsm/L
  • Glucose: 20 g/L (111 mmol/L)
  • Sodium: 60–90 mEq/L
  • Potassium: 15–25 mEq/L
  • Citrate: 8–12 mmol/L
  • Chloride: 50–80 mEq/L

• Intravenous fluid replacement indicated for severe dehydration or inability to tolerate oral fluids.