Causes of Acute Diarrhea

Definition of Acute Diarrhea

• Diarrhea means having over three loose bowel movements a day.

• Acute (Latin acutus = sharp, pointed) diarrhea, by definition, lasts less than 3 weeks (1).

Causes of Acute Diarrhea

A) Acute INFECTIOUS Diarrhea

• Bacterial diarrhea usually occurs in food poisoningdue to infection with bacteria like E. coli or salmonella.
• Parasitic diarrhea may be due to intestinal worms, or one-cell parasiteslike Entamoeba hystolytica, or giardia.
• Viral diarrhea mainly affect small children in kinder-gartens due to stool-to-mouth infection from other children, or (in poor countries) due to infection by water, contaminated by rotavirus.

B) Acute NON-INFECTIOUS Diarrhea

• Food allergies may affect children or adults. Main causes are wheat, eggs, cow milk, soy, fish, shellfish, peanuts, and tree-nuts, but can be virtually any food.
• Fish poisoning. Both ciguatera poisoning by big tropical fish like barracuda or meckerel, and scombroid poisoning by non-properly stored fish are common.
• Psychic stress may cause sudden diarrhea.
• Antibiotic-associated diarrhea may appear few days or several weeks after start of treatment with antibiotics by mouth.
• Medications like laxatives or magnesium antacids stimulate bowel motility.
• Chemotherapy and irradiation damage cells in intestinal lining. 
• Mushrooms (even non-poisonous), and poisonous plants like foxglove or oleander may cause severe diarrhea.
• Pesticides, ingested or inhaled may cause severe diarrhea.
• Ingestion of heavy metals like arsenic or mercury may cause severe diarrhea.
• Runner's diarrhea often affects long-distance runners.
• Diarrhea may appear in women before child-birth.