Diarrhea Causes and Effects

Study Notes

Diarrhea is defined as an increased frequency of bowel evacuation, with three or more loose or liquid stools per day.
Infectious causes are the most common source of diarrhea.
- Viral causes are the most prevalent.
- Bacterial causes are less common.
- Protozoan causes are even less common.
Rotavirus is the most common cause of diarrhea, especially in children under 2 years old, and is most prevalent during the winter months.
- The virus is highly contagious and spreads via the fecal-oral route.
- Oral vaccination against the virus has been available since 2006, and now significantly reduces the spread and effects of the virus
Common bacterial pathogens causing diarrhea include:
- Campylobacter, often associated with contaminated chicken and eggs rather than beef.
- Salmonella, commonly associated with recooked rice that has been kept warm or reheated.
- B. cereus spp.
Common Protozoan pathogens causing diarrhea include:
- Entamoeba histolytica (amoebic dysentery).
- Giardia lamblia (giardiasis).
- Stool samples are needed for diagnosis.
- Common treatments include metronidazole and tinidazole.

Drugs can contribute to diarrhea.
- Common culprits include laxatives, antacids containing magnesium, antineoplastic drugs such as:
  - Clindamycin
  - Tetracyclines
  - Sulfonamides
- Misoprostol (cytotec)
- PPIs
- Digoxin at toxic levels

Irritable bowel syndrome (IBS) is the most common cause of chronic diarrhea.
Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is another common cause.
Malabsorption syndromes, such as celiac disease or lactose intolerance, can also contribute.

Age: Young children and individuals over 65 are at higher risk of dehydration.
Duration: Diarrhea lasting more than 1 day in children and more than 2-3 days in adults should be evaluated.
Severity: Dehydration requires immediate medical attention.
Underlying Conditions: Individuals with current or prior conditions such as inflammatory diseases, diabetes, or cancer may require special considerations.

Oral Rehydration Solution (ORS): For dehydration, especially in children.
Loperamide: May be used for adults and children over 12 years old.
Zinc: Zinc supplementation with ORS can significantly improve the severity and duration of acute diarrhea in developing countries.

Adsorbents: Such as Pectokaolin® (pectin + kaolin). Effectiveness unproven and questionable.
Probiotics: Used to replace colonic microflora. Efficacy in preventing antibiotic-associated diarrhea (AAD) remains controversial.

Drink plenty of clear fluids: Water and rice water are effective remedies.
Avoid sugary drinks: Can prolong diarrhea.
Avoid milk and milky drinks: Temporary lactose intolerance may occur due to damage to the intestinal lining caused by organisms.