Key takeaways

  • Diarrhea is when you experience frequent, loose, watery stools. You may also feel an urgent need to pass these stools. Causes range from food intolerances and medication reactions to infections and bowel diseases.
  • Dehydration is a significant risk of diarrhea, especially for babies and young children. Symptoms of dehydration need prompt attention and fluid replacement.
  • Treatment will depend on the underlying cause of your diarrhea. Preventive measures, such as frequent handwashing, proper food handling, and safe travel practices, may also reduce your risk of getting infections that can cause diarrhea.

Diarrhea can range in severity, from mild and temporary to severe or long-term.

Often, you can manage mild diarrhea at home, such as with rest, staying hydrated, and asking a pharmacist about over-the-counter remedies. However, severe or subacute diarrhea, or diarrhea with other symptoms, needs care from a medical professional.

Diarrhea can occur due to several different conditions or circumstances. Potential causes of diarrhea include:

  • viral stomach infections, such as rotavirus, norovirus, and viral gastroenteritis
  • bacterial stomach infections, such as Salmonella and E. coli
  • parasitic infections
  • food intolerances, such as lactose intolerance
  • side effects from some medications, like some antibiotics, medications containing magnesium, and cancer-treating medications
  • consuming sugar alcohols, such as sorbitol, mannitol, and xylitol
  • stomach surgery
  • gastrointestinal conditions, such as:
    • irritable bowel syndrome (IBS)
    • inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis
    • functional bowel disorders
    • gastroenteritis or “stomach flu,” inflammation caused by infection or other irritation
    • celiac disease

Rotavirus infection is the most common cause of severe diarrhea in infants and young children globally.

Common ways that rotavirus and other stomach infections spread include include poor handwashing, eating contaminated food, or exposure to waste or contaminated water.

Chronic diarrhea may be a symptom of a more severe condition such as irritable bowel syndrome or inflammatory bowel disease. Frequent and severe diarrhea could be a sign of intestinal disease or a functional bowel disorder.

Acute vs. chronic diarrhea

Diarrhea can be acute, subacute, or chronic:

  • Acute diarrhea lasts less than 2 weeks and is often caused by stomach infections.
  • Subacute diarrhea lasts between 2 and 4 weeks.
  • Chronic diarrhea is when you have diarrhea on most days for longer than 4 weeks. Common causes of chronic diarrhea include IBS, IBD, and other chronic gastrointestinal conditions.

The main symptoms of diarrhea are having frequent loose, watery stools and a feeling of urgently needing to pass stool.

However, many other symptoms can accompany diarrhea. The exact symptoms you experience may depend slightly on the diarrhea’s cause and severity. Examples of additional diarrhea symptoms include:

You may have only a few diarrhea symptoms to a combination of all of them.

Dehydration and diarrhea

Diarrhea can cause you to lose fluids quickly. If you don’t receive treatment for diarrhea, it may cause dehydration and other severe effects.

Symptoms of dehydration include:

Contact your doctor as soon as possible if you think your diarrhea is causing dehydration.

Diarrhea in babies and young children

Children are particularly susceptible to diarrhea, dehydration, and their complications. According to experts, diarrhea is the second most common cause of death in children under the age of 5 around the world.

Call a doctor or seek emergency care immediately if you notice symptoms of dehydration in a child or infant, such as:

  • not peeing as often as usual, such as not wetting diapers as often
  • dark yellow or strong-smelling pee
  • dizziness, lightheadedness, or headache
  • dry mouth, lips, or skin
  • fatigue
  • few to no tears when crying
  • sunken eyes
  • sunken fontanel
  • sleepiness, irritability, or other changes in mental status

You may be able to treat mild cases of acute diarrhea at home, with steps like:

  • drinking more water or rehydration drinks, including oral rehydration solutions or sports drinks
  • asking a pharmacist or doctor whether you can take any over-the-counter antidiarrhea medications
  • resting
  • avoiding irritating foods, eating bland foods instead

Talk with a pharmacist or doctor for their recommendations before using oral rehydration solutions if you are an older adult or have other health conditions, such as a weak immune system, diabetes, or kidney disease. Also, doctors often recommend against giving children and infants over-the-counter diarrhea medications.

In more severe cases, you may need fluids through intravenous (IV) therapy, such as in a healthcare center or hospital. If a bacterial infection is the cause of your diarrhea, a doctor may also prescribe antibiotics.

Your medical team will decide your treatment based on:

  • the severity of the diarrhea and related condition
  • the frequency of the diarrhea and related condition
  • the degree of your dehydration status
  • your health and medical history
  • your age
  • your ability to tolerate different procedures or medications
  • expectations for improvement of your condition

A doctor will complete a physical examination and consider your medical history when diagnosing the cause of your diarrhea. They may also request laboratory tests to examine urine and blood samples.

Additional tests your doctor may order to determine the cause of your diarrhea include:

  • a stool culture, to check for bacteria, viruses, parasites, or other signs of disease
  • diet elimination tests, to determine whether a food intolerance or allergy is the cause
  • ultrasound, CT scan, or other imaging scans to check for inflammation or structural problems in your digestive system
  • colonoscopy, to check your colon for signs of intestinal disease
  • sigmoidoscopy, to check your rectum and lower colon for signs of intestinal disease

Diarrhea can occur for various reasons, and isn’t always preventable.

However, some steps can help reduce your chances of food poisoning, traveler’s diarrhea, and other cases of stomach infections:

  • Avoid developing diarrhea from food poisoning by sanitizing your food preparation areas and cooking tools thoroughly after each use.
  • Cooking food to safe temperatures, which you can check with a food thermometer.
  • Serve food immediately after preparing it.
  • Refrigerate leftovers promptly.
  • Always thaw frozen food in a refrigerator.
  • Avoid tap water, ice cubes, and fresh produce that has likely been washed with tap water while you’re on vacation.
  • Drink bottled water only while on vacation.
  • Eat only cooked, and no raw, food while on vacation.
  • Ask your doctor if you can begin an antibiotic treatment before you travel.
  • Ask a doctor about available vaccines, such as the rotavirus vaccine.

The steps below may also help prevent stomach infections from spreading between people:

  • washing your hands with soap and water frequently, for at least 20 seconds each time
  • using hand sanitizer if soap and clean water aren’t available
  • avoiding sharing personal items, such as silverware, drinking glasses, and towels
  • frequently sanitizing household surfaces when someone you live with has diarrhea

Most cases of acute diarrhea improve on their own, with symptoms typically improving within a few days.

However, the National Institute of Diabetes and Digestive and Kidney Diseases recommends getting medical care if your symptoms last for longer than 2 days. This is because you may be getting dehydrated and need IV fluids or other treatment.

Diarrhea can also be a symptom of some medical emergencies. Get immediate help if you experience loose, watery stools alongside any of the following symptoms:

  • fever
  • bloody stools
  • frequent vomiting

Also, get immediate treatment for a child that has any of the following symptoms:

  • diarrhea for 24 hours or more
  • fever of 102°F (39°C) or higher
  • passing stools that contain blood
  • passing stools that contain pus
  • passing stools that are black and tarry

These are all symptoms that indicate an emergency.

Call 911

If you or someone around you experiences symptoms of severe diarrhea and dehydration or any of the symptoms above, call 911 or your local emergency number, or go to the nearest emergency department.

If you have diarrhea, you experience loose, watery stools multiple times a day. You may also experience sudden urges to empty your bowels.

Diarrhea is often the result of a stomach infection, typically from bacteria or viruses. Food intolerances, the side effects of medications, and underlying chronic conditions can also cause diarrhea.

Sometimes, diarrhea can lead to complications, such as dehydration, which can be severe in some cases. Diarrhea can also be subacute or chronic, lasting for 2 weeks or more, although this is less common.

Contact a doctor if you have diarrhea symptoms for more than 2 days. If a child you care for has symptoms of diarrhea or dehydration, seek medical care immediately. Children under 5 years old are particularly susceptible to diarrhea and dehydration, and they are often a medical emergency.