Diarrhea is loose, watery stools. Acute diarrhea is a common problem that usually lasts 1 or 2 days and goes away on its own.
Diarrhea lasting more than 2 days may be a sign of a more serious problem. Chronic diarrhea—diarrhea that lasts at least 4 weeks—may be a symptom of chronic disease. Chronic diarrhea symptoms may be continual or they may come and go. Diarrhea of any duration may cause dehydration, which means the body lacks enough fluid and electrolytes—chemicals in salts, including sodium, potassium, and chloride—to function properly. Loose stools contain more fluid and electrolytes and weigh more than solid stools.
Acute diarrhea is usually caused by a bacterial, viral, or parasitic infection. Chronic diarrhea is usually related to a functional disorder such as irritable bowel syndrome or other intestinal diseases. Some people develop diarrhea after stomach or gallbladder surgery, which may cause food to move through the digestive system more quickly. People who visit certain foreign countries are at risk for traveler’s diarrhea, which is caused by eating food or drinking water contaminated with bacteria, viruses, or parasites. Traveler’s diarrhea can be a problem for people traveling to developing countries in Africa, Asia, Latin America, and the Caribbean. Visitors to Canada, most European countries, Japan, Australia, and New Zealand do not face a high risk for traveler’s diarrhea. In many cases, the cause of diarrhea cannot be found. As long as diarrhea goes away on its own within 1 to 2 days, finding the cause is not usually necessary.
Adults with any of the following symptoms should see a health care provider:
- signs of dehydration
- diarrhea for more than 2 days
- severe pain in the abdomen or rectum
- a fever of 102 degrees or higher
- stools containing blood or pus
- stools that are black and tarry
Diarrhea is not usually harmful, but it can become dangerous or signal a more serious problem. If acute diarrhea lasts 2 days or less, diagnostic tests are usually not necessary. If diarrhea lasts longer or is accompanied by symptoms such as fever or bloody stools, a doctor may perform tests to determine the cause.
In most cases of diarrhea, the only treatment necessary is replacing lost fluids and electrolytes to prevent dehydration. Over-the-counter medicines such as loperamide (Imodium) and bismuth subsalicylate (Pepto-Bismol and Kaopectate) may help stop diarrhea in adults. However, people with recent antibiotic use, recent hospitalizations, bloody diarrhea, or fever—signs of bacterial or parasitic infection—should not use these medicines. If diarrhea is caused by bacteria or parasites, over-the-counter medicines may prolong the problem. Medications to treat diarrhea in adults can be dangerous for infants and children and should only be given with a doctor’s guidance.
Until diarrhea subsides, avoiding caffeine and foods that are greasy, high in fiber, or sweet may lessen symptoms. These foods can aggravate diarrhea. Some people also have problems digesting lactose during or after a bout of diarrhea. Yogurt, which has less lactose than milk, is often better tolerated. In some cases, yogurt with active, live bacterial cultures may even help people recover from diarrhea more quickly.
As symptoms improve, soft, bland foods can be added to the diet, including bananas, plain rice, boiled potatoes, toast, crackers, cooked carrots, and baked chicken without the skin or fat. For children, the health care provider may also recommend a bland diet. Once diarrhea stops, the health care provider will likely encourage children to return to a normal and healthy diet if it can be tolerated. Infants with diarrhea should be given breast milk or full-strength formula as usual, along with oral rehydration solutions. Some children recovering from viral diarrheas have problems digesting lactose for up to a month or more.
For more information on Diarrhea visit the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
*Information from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the Colon Cancer Alliance and 
