Diarrhea Treatment: Medication Classes, Indications, and When to See a Doctor

Disclaimer: This information is educational, not medical advice. Consult a healthcare provider for diagnosis and treatment.

Medication Classes for Diarrhea

Class	Examples	Mechanism	Typical Use
Antimotility	Loperamide (Imodium), diphenoxylate/atropine (Lomotil)	Reduce gut motility, increase transit time	Acute non-bloody diarrhea; avoid if fever/blood
Antisecretory	Racecadotril	Inhibit enkephalinase → reduce intestinal secretion	Acute watery diarrhea (adjunct)
Bismuth compounds	Bismuth subsalicylate (Pepto-Bismol)	Antimicrobial, anti-inflammatory, absorptive	Traveler's diarrhea, H. pylori regimens
Antibiotics	Azithromycin, ciprofloxacin, rifaximin	Eradicate bacterial pathogens	Bloody diarrhea, fever, confirmed bacterial cause
Antiparasitics	Metronidazole, tinidazole, nitazoxanide	Kill protozoa (Giardia, Cryptosporidium, Entamoeba)	Parasitic diarrhea confirmed by stool O&P/antigen
Probiotics	Lactobacillus rhamnosus GG, Saccharomyces boulardii	Restore gut microbiota	Antibiotic-associated, viral, adjunct
Oral rehydration	ORS (WHO formula)	Replace fluid/electrolyte losses	All acute diarrhea—cornerstone of therapy

When to Seek Medical Care

• Diarrhoea >2 days (adults) or >24 hrs (children/elderly)
• Signs of dehydration (dry mouth, reduced urine, dizziness)
• High fever (>39°C / 102°F)
• Bloody or black/tarry stools
• Severe abdominal/rectal pain
• Recent antibiotics, hospitalization, travel, immunocompromise

Self-medication with antimotility agents can worsen invasive bacterial or C. difficile infections. Always identify the cause before targeted therapy.