Diarrhea is an increase in the frequency, fluidity, and volume of bowel movements. Although diarrhea is not a disease, it may be a symptom of a serious underlying disorder or infection. A temporary episode of diarrhea usually indicates a mild, self-limiting event, usually from an intestinal infection and may be due to factors such as; a stomach virus or food poisoning, traveler’s diarrhea (common in areas where there is poor water quality or sanitation), administration of antibiotics, a particular food allergy, or impaired digestive function.
Diarrhea that lasts more than 3-4 days, increases in severity, is bloody, or is present in a child under six years of age, usually indicates that there is an intestinal problem that requires immediate medical attention.
There are four types or classes of diarrhea:
- Osmotic diarrhea (due to laxatives, lactose intolerance, magnesium salt antacids, excess consumption of low-calorie sweeteners such as sorbitol, excessive vitamin C intake)
- Secretory diarrhea (due to toxin-producing bacteria, fat malabsorption, laxative abuse, hormone-producing tumors)
- Inadequate-contact diarrhea (due to intestinal surgery and short bowel syndrome).
It is essential that the type of diarrhea be identified through a complete diagnostic workup by a qualified health care professional, in order to render appropriate treatment.
The main symptom of diarrhea is an increase in the frequency, fluidity, and volume of bowel movements. Other symptoms that may accompany diarrhea include;
- abdominal pain
- loss of appetite
- severe, bloody diarrhea
Brief episodes of diarrhea with vomiting and loss of appetite are often due to gastroenteritis or food poisoning. Diarrhea accompanied with abdominal pain and bloating may be due to irritable bowel syndrome or diverticulosis. Diarrhea with headache, weakness, and lethargy is most often caused by dehydration.
According to the Centers for Disease Control (CDC) [1, 2]:
- Travelers’ diarrhea is the most common illness affecting travelers.
- Between 20%-50% of international travelers, approximately 10 million people, develop diarrhea.
- Diarrhea caused by parasites is still the single greatest worldwide cause of illness and death.
A temporary episode of diarrhea usually indicates a mild, self-limiting event, which frequently resolves within a day or two. If the condition gets progressively worse, it may be wise to call on a physician for assistance. Once the type of diarrhea is determined, the underlying causes can then be treated.
Because of the extreme loss of fluids, diarrhea is usually accompanied by dehydration. Lost fluids and electrolytes should be replaced by drinking juices, herbal teas, broths, or electrolyte-replacement drinks. An antidiarrheal drug, such as loperamide, may be prescribed. Antibiotics may also be prescribed to treat persistent diarrhea with a bacteria or parasitic cause.
Probiotics (lactobacillus acidophilus and bifidobacteria) Probiotics including lactobacillus acidophilus (small bowel friendly bacteria) and bifidobacteria (large bowel friendly bacteria) are nutritional supplements containing the same beneficial bacteria that are found in the digestive tract. Probiotics supplementation is important for the treatment of diarrhea of any kind, and is shown to enhance intestinal tract immunity, improve digestive health, relieve food allergy symptoms, and insure healthy intestinal microflora. Since antibiotics are used to treat persistent diarrhea with a bacteria or parasitic cause and often destroy friendly bacteria in the intestinal tract, probiotic supplementation is particularly helpful. [2-5]
Pancreatic Digestive Enzymes Digestive enzymes containing pancreatic enzymes (protease, lipase, and amylase) aid digestion and help the body to absorb and completely utilize the food. Digestive enzymes supplementation is particularly helpful for diarrhea caused by food allergy and nutritional malabsorption problems as well as a parasitic infection.[6-8]
Lactase Digestive Enzymes Deficiency in the digestive enzyme, lactase, is common worldwide. This enzyme is solely responsible for digesting milk and dairy products. Lactose-intolerant people don’t produce enough lactase to properly digest milk and dairy products, and often suffer from symptoms ranging from minor bloating and abdominal pain, to severe diarrhea. Lactase-containing enzyme supplements can aid in the digestion of lactose-containing foods and reduce the symptoms associated with this condition. 
Berberine Standardized berberine, extracted from berberine-containing plants such as goldenseal, barberry, Oregon grape, and goldthread, may be effective in treating gastrointestinal infections such as traveler’s diarrhea, shigellosis, food poisoning, giardiasis, amebiasis, and cholera. Studies have show that diarrhea caused by E. coli, Shigella, Salmonella, Klebsiella, Faecalis aerogenes, or the parasite Giardia, is effectively treated by berberine supplementation. [10-12] Another study reports that traveler’s diarrhea can be helped with the dietary supplementation of berberine. 
Carob Carob powder has been shown to be an effective treatment of acute diarrhea. One study indicates that young children hospitalized with acute diarrhea of bacterial and viral origin benefited from carob powder supplementation. 
Pectin and Kaolin The use of pectin (fruit fiber) alone, or in combination with Kaolin (clay), is an effective natural treatment for diarrhea.  Pectin and kaolin have been traditionally used as bulking agents to improve stool consistency, and are found in popular antidiarrheal drugs, like Kaopectate, Donnagel, and Kaodene.
1. CDC: Diarrhea
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13. Rabbani GH et al. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic escherichia coli and vibrio cholerae. J Infect Dis 1987 (155): 979-84.
14. Loeb H et al. Tannin-rich carob pod for the treatment of acute-onset diarrhea. J Ped Gastroenterol Nutr 1989 (8): 480-5.
15. Pizzorno JE and Murray MT, eds. Encyclopedia of Natural Medicine, revised 2nd edition, CA: Prima Publishing, 1998: 435
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17. Stoppard M. Family Health Guide, New York: DK Publishing, 2002