Diarrhea is one of the most common health complaints. It can range from a mild, temporary condition, to a potentially life-threatening one.
Globally, an estimated 2 billion cases of diarrheal disease occur each year, and 1.9 million children under the age of 5 years, mostly in developing countries, die from diarrhea.
Diarrhea is characterized by abnormally loose or watery stools.
Some people frequently pass stools, but they are of normal consistency. This is not diarrhea. Similarly, breastfed babies often pass loose, pasty stools. This is normal. It is not diarrhea.
Fast facts on diarrhea
Here are some key points about diarrhea. More detail and supporting information is in the body of this article.
Most cases of diarrhea are caused by bacteria, viruses, or parasites
Inflammatory bowel diseases (IBD) including Crohn’s disease and ulcerative colitis can cause chronic diarrhea
Antidiarrheal medications can reduce diarrheal output and zinc supplement is effective in children
Some nutritional and probiotic interventions may help prevent diarrhea
Correcting dehydration is the priority of diarrhea treatment.
Most cases of diarrhea are caused by an infection in the gastrointestinal tract. The microbes responsible for this infection include:
The most commonly identified causes of acute diarrhea in the United States are the bacteria Salmonella, Campylobacter, Shigella, and Shiga-toxin-producing Escherichia coli.
Some cases of chronic diarrhea are called “functional” because a clear cause cannot be found. In the developed world, irritable bowel syndrome (IBS) is the most common cause of functional diarrhea.
IBS is a complex of symptoms. There is cramping abdominal pain and altered bowel habits, including diarrhea, constipation, or both.
Inflammatory bowel disease (IBD) is another cause of chronic diarrhea. It is a term used to describe either ulcerative colitis or Crohn’s disease. There is often blood in the stool in both conditions.
Other major causes of chronic diarrhea include:
Microscopic colitis: This is a persistent diarrhea that usually affects older adults, often during the night.
Malabsorptive and maldigestive diarrhea: The first is caused by impaired nutrient absorption, the second by impaired digestive function. Celiac disease is one example.
Chronic infections: A history of travel or antibiotic use can be clues to chronic diarrhea. Various bacteria and parasites can be the cause.
Drug-induced diarrhea: Laxatives and other drugs, including antibiotics, can trigger diarrhea.
Endocrine causes: Sometimes hormonal factors cause diarrhea, for example, in the case of Addison disease and carcinoid tumors.
Cancer causes: Neoplastic diarrhea is associated with a number of gut cancers.
Mild cases of acute diarrhea may resolve without treatment. Persistent or chronic diarrhea will be diagnosed and any underlying causes will be treated in addition to the symptoms of diarrhea.
For all cases of diarrhea, rehydration is key:
Fluids can be replaced by simply drinking more fluids, or they can be received intravenously in severe cases. Children and older people are more vulnerable to dehydration.
Oral rehydration solution or salts (ORS) refers to water that contains salt and glucose. It is absorbed by the small intestine to replace the water and electrolytes lost in the stool. In developing countries, ORS costs just a few cents. The World Health Organization (WHO) says ORS can safely and effectively treat over 90 percent of non-severe diarrhea cases.
Oral rehydration products, such as Oralyte and Rehydralyte, are available commercially.
Zinc supplementation may reduce the severity and duration of diarrhea in children. Various products are available to purchase online.
Over-the-counter (OTC) antidiarrheal medicines are also available:
Loperamide, or Imodium, is an antimotility drug that reduces stool passage. Loperamide and Imodium are both available to purchase over-the-counter or online.
Bismuth subsalicylate, for example, Pepto-Bismol, reduces diarrheal stool output in adults and children. It can also be used to prevent traveler’s diarrhea. The can be bought online as well as over-the-counter.
There is some concern that antidiarrheal medications could prolong bacterial infection by reducing the removal of pathogens through stools.
Antibiotics are only used to treat diarrhea caused by a bacterial infection. If the cause is a certain medication, switching to another drug might be possible.
Nutritionists from Stanford Health Care offer some nutritional tips for diarrhea:
Sip on clear, still liquids such as fruit juice without added sugar.
After each loose stool, replace lost fluids with at least one cup of liquid.
Do most of the drinking between, not during meals.
Consume high-potassium foods and liquids, such as diluted fruit juices, potatoes without the skin, and bananas.
Consume high-sodium foods and liquids, such as broths, soups, sports drinks, and salted crackers.
Other advice from the nutritionists is to:
eat foods high in soluble fiber, such as banana, oatmeal and rice, as these help thicken the stool
limit foods that may make diarrhea worse, such as creamy, fried, and sugary foods
Foods and drinks that might make the diarrhea worse include:
sugar-free gum, mints, sweet cherries, and prunes
caffeinated drinks and medication
fructose in high amounts, from fruit juices, grapes, honey, dates, nuts, figs, soft drinks, and prunes
lactose in dairy products
olestra, or Olean, a fat substitute
There is mixed evidence for the role of probiotics in diarrhea. They may help prevent traveler’s diarrhea. In children, there is evidence that they might reduce diarrheal illness by 1 day.
Antibiotic-associated diarrhea might be reduced by the use of probiotics, as may diarrhea related to Clostridium difficile, although the evidence is mixed.
People should ask their doctor for advice, as there are numerous strains. The strain most studied for antibiotic-associated diarrhea are probiotics based on Lactobacillus rhamnosus and Saccharomyces boulardii.
Probiotics to help with Clostridium difficile and antibiotic diarrheas were investigated in a trial published in The Lancet. They found no evidence that a multi-strain preparation of bacteria was effective in preventing these conditions, calling for a better understanding of the development of antibiotic-associated diarrhea.
Probiotics are available in capsules, tablets, powders, and liquids, and may be purchase online.