This document discusses the causes, treatment, and management of diarrhea. It begins by defining diarrhea as three or more loose stools in a 24 hour period. The causes of diarrhea include osmotic, secretory, motility issues, altered morphology, allergies, drugs, and certain cancers. Treatment involves rehydration either orally or intravenously. Oral rehydration solutions contain sodium, potassium, citrate, and glucose. Antimicrobial therapy may be used for certain infectious causes. Probiotics can help with antibiotic-associated diarrhea. Management of inflammatory bowel disease is also discussed.