What Is Diarrhea?

Diarrhea is the unpleasant experience of having loose and watery stools three or more times in a day. It has a large number of causes, including food poisoning, infection, medications, food allergies or intolerances, inflammatory conditions, and malabsorption syndromes. The one causing your case will dictate appropriate treatment.

Diarrhea can lead to complications such as dehydration or even malnutrition. While loose stools usually improve after a day or two, you should see your doctor if symptoms are severe, or if diarrhea persists or is chronic. Likewise, any case of diarrhea in an infant or child should be evaluated by a pediatrician.

causes of diarrhea
Illustration by Brianna Gilmartin, Verywell 

Diarrhea Symptoms

Diarrhea can be characterized as acute, which is defined as sudden in onset and lasting less than two weeks; persistent, which lasts 14 to 28 days; or chronic, in which symptoms have been present for longer than four weeks.

The primary symptom of acute diarrhea is the presence of loose and watery stools. Other symptoms may include:

  • Increased frequency of bowel movements
  • Abdominal cramps
  • A sense of bowel urgency
  • Soiling accidents

If the reason behind diarrhea is an infection or toxin, you might also experience symptoms such as nausea, vomiting, fever, chills, or bloody stools.

People who have chronic diarrhea are also likely to experience other symptoms stemming from the underlying health problem. For example, people who have celiac disease may also experience weight loss and malnutrition.

Most of the time, people who experience a bout of acute diarrhea get better on their own. However, diarrhea can become a life-threatening situation for infants, older adults, and people who have a compromised immune system from an illness such as cancer or HIV.

If you see signs of diarrhea in a newborn or infant, call your doctor right away. You should also call your doctor if you or your child have any of the following symptoms:

  • Diarrhea that lasts longer than 24 hours in a child or 48 hours for an adult
  • Signs of dehydration
  • Stools that are bloody, pus-covered, black, or tarry


Diarrhea can have many causes. It can come simply from eating too much fruit or fiber or going on a mostly-liquid diet.

Acute diarrhea is often caused by food poisoning, when improper food handling leads to the spread of a bacteria that produces a toxin that causes diarrhea, nausea, and vomiting.

Stomach flu (viral gastroenteritis) also causes acute diarrhea. Examples of viral infections include rotavirus, the most common form to affect children, and norovirus, sometimes called "cruise ship diarrhea."

Bacterial infections causing acute diarrhea often come from consuming contaminated food or water. These include C. difficile, E. coli, Salmonella, Shigella, and Campylobacter. Parasites and amoeba such as Giardia and Entamoeba histolytica can also be contracted through contaminated food and water. "Travelers' diarrhea" can be caused by bacteria, viruses, or parasites in food or drinking water.

Diarrhea can be a side effect of certain types of medications, including antibiotics, antacids, heart medications, antidepressants, and others. Diarrhea may also be a post-surgery complication of bariatric surgery or gallbladder removal.

Health conditions that may have chronic diarrhea as a symptom include celiac disease, the inflammatory bowel diseases (Crohn's disease and ulcerative colitis), irritable bowel syndrome (IBS), and food intolerance (such as fructose or lactose malabsorption).

Less common causes of chronic diarrhea include colon cancer, ongoing parasitic infections, and radiation therapy.


Your doctor may not run any tests until your diarrhea has been present for longer than 48 hours, although this might not be the case depending on your medical history and other circumstances, such as recent travel.

If your doctor thinks that it is indicated, you may have stool tests for bacteria or parasites, particularly if you have traveled recently, are experiencing fever, or have bloody diarrhea. You may also have blood and urine tests to rule out other diseases, infections, dehydration, electrolyte imbalance, and to check your overall health.

If you are experiencing chronic diarrhea, your doctor may do more in-depth testing to try to figure out what may be underlying your symptoms. This testing may include an upper endoscopy, sigmoidoscopy, and/or colonoscopy.


The most important thing to do when you have acute diarrhea is to maintain adequate hydration, which requires taking in more fluids than normal given the fluid loss that occurs with the condition. Also, be sure to get plenty of rest to help your body to fight off the underlying infection.

During a bout of acute diarrhea, it's best to avoid food and drink that can make your diarrhea worse, such as alcoholic beverages, caffeine, dairy products, spicy foods, greasy or fatty foods, and fruits such as apples, peaches, and pears. Don't stay on a restricted diet any longer than necessary, especially if you have chronic diarrhea, as it may not provide proper nutrition.

Over-the-counter medications, like Imodium, Pepto-Bismol, and Kaopectate, should only be used by adults who have no signs of fever or bloody diarrhea. Such medications are generally not recommended for children and, thus, should only be used under direction of a doctor.

If you have signs of severe dehydration, you may be hospitalized. You will be given an IV to replace lost fluids and electrolytes. Antibiotics or anti-parasitic medications may be prescribed for bacterial infections or parasitic infections.

Treatment of chronic diarrhea will be primarily aimed at treating the underlying condition. The use of an over-the-counter medication like Imodium might be recommended to directly address the symptom of diarrhea.


The best way to deal with diarrhea is to not get it in the first place. Thorough hand-washing with soap and water can be very effective for preventing infection. This is especially crucial when cooking, after using the toilet, or when out in public.

People who are at higher risk for getting seriously sick if exposed to a disease-causing organism need to be extra vigilant. This includes infants, older adults, and people who have compromised immune systems.

Pregnant women should take extra precautions to avoid diarrhea, especially when caused by Listeria, which can cause miscarriage. Foods to avoid include:

  • Under-cooked meats and unheated deli meats
  • Raw (unpasteurized) dairy products, as well as soft cheeses
  • Raw shellfish

Everyone should maintain safe food and drink practices when traveling out of their home country so as to prevent travelers' diarrhea. This means to avoid any use or drinking of unfiltered tap water and avoiding all raw meats, fish, fruits, vegetables, and dairy products.

Cooked foods should only be eaten if they are served hot. You can eat raw fruit only if it has a peel that you have removed yourself. You can drink bottled water, hot drinks, and soft drinks. Before traveling, you may want to talk to your doctor about any possible need to take antibiotics before you leave or to have them on hand in case you do get sick.

A Word From Verywell

Diarrhea can be an annoyance, but sometimes it will ruin your plans or can even lead to serious complications. Simple prevention tactics such as hand-washing, safe food handling, and safe eating when traveling can help reduce bouts of acute diarrhea. If you have an ongoing problem with diarrhea, talk to your doctor so the underlying condition can get diagnosed and treated.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Barr W, Smith A. Acute diarrhea. Am Fam Physician. 2014;89(3):180-9.

  2. Schiller LR, Pardi DS, Sellin JH. Chronic Diarrhea: Diagnosis and Management. Clin Gastroenterol Hepatol. 2017;15(2):182-193.e3. doi:10.1016/j.cgh.2016.07.028

  3. National Institute of Diabetes and Digestive and Kidney Diseases. Eating, diet, and nutrition for diarrhea. Updated November, 2016.

Additional Reading
  • Diarrheal Diseases – Acute and Chronic. American College of Gastroenterology.

  • Minocha A, Adamec C. The Encyclopedia of the Digestive System and Digestive Disorders (2nd Ed.) New York:Facts on File. 2011.

  • National Institute of Diabetes & Digestive & Kidney Diseases. Diarrhea.