Overview

Diarrhea — loose, watery and possibly more-frequent passage of stool — is a common problem. Sometimes, it's the only symptom of a condition. At other times, it may be associated with other symptoms, such as nausea, vomiting, abdominal pain or weight loss.

Luckily, diarrhea is usually short-lived, lasting no more than a few days. But when diarrhea lasts beyond a few days, it is usually a clue to another problem — such as medicine side effects, changes in diet, irritable bowel syndrome (IBS), or a more serious disorder, including ongoing infection, celiac disease or inflammatory bowel disease (IBD).

Symptoms

Symptoms associated with loose, watery stools, also called diarrhea, may include:

  • Belly cramps or pain.
  • Bloating.
  • Nausea.
  • Vomiting.
  • Fever.
  • Blood in the stool.
  • Mucus in the stool.
  • Urgent need to pass stool.

When to see a doctor

If you're an adult, see your doctor if:

  • Your diarrhea doesn't get better or stop after two days.
  • You become dehydrated.
  • You have terrible abdominal or rectal pain.
  • You have bloody or black stools.
  • You have a fever above 101 degrees Fahrenheit (38 degrees Celsius).

In children, particularly young children, diarrhea can quickly lead to dehydration. Call your doctor if your child's diarrhea doesn't improve within 24 hours or if your child:

  • Becomes dehydrated.
  • Has a fever above 101 degrees Fahrenheit (38 degrees Celsius).
  • Has bloody or black stools.

Causes

A number of diseases and conditions can cause diarrhea, including:

  • Viruses. Viruses that can cause diarrhea include Norwalk virus, also known as norovirus, enteric adenoviruses, astrovirus, cytomegalovirus and viruses that cause hepatitis. Rotavirus is a common cause of sudden childhood diarrhea. The virus that causes coronavirus disease 2019 (COVID-19) also has been linked to gastrointestinal symptoms, including nausea, vomiting and diarrhea.
  • Bacteria and parasites. Exposure to certain bacteria, such as Escherichia coli, or parasites through contaminated food or water can lead to diarrhea. When traveling in developing countries, diarrhea caused by bacteria or parasites is often called traveler's diarrhea. Clostridioides difficile, also known as C. diff, is another bacterium that causes diarrhea, and it can occur after a course of antibiotics or during a hospital stay.
  • Medicines. Many medicines, such as antibiotics, can cause diarrhea. Antibiotics get rid of infections by killing bacteria that cause illness, but they also kill good bacteria that are helpful in the body. This disturbs the natural balance of bacteria in the intestines, leading to diarrhea or an infection such as C. diff. Other medicines that cause diarrhea are anticancer drugs and antacids with magnesium.
  • Lactose intolerance. Lactose is a sugar found in milk and other dairy products. People who have trouble digesting lactose often have diarrhea after eating dairy products. Lactose intolerance can increase with age because levels of the enzyme that helps digest lactose become lower as people get older.
  • Fructose. Fructose is a sugar found naturally in fruits and honey. It's sometimes added as a sweetener to certain beverages. Fructose can lead to diarrhea in people who have trouble digesting it.
  • Artificial sweeteners. Sorbitol, erythritol and mannitol — nonabsorbable sugars used as artificial sweeteners in chewing gum and other sugar-free products — can cause diarrhea in some otherwise healthy people.
  • Surgery. Partial intestine or gallbladder removal surgeries can sometimes cause diarrhea.
  • Other digestive disorders. Chronic diarrhea has a number of other causes, such as IBS, Crohn's disease, ulcerative colitis, celiac disease, microscopic colitis and small intestinal bacterial overgrowth (SIBO).

Risk factors

Some common risk factors for diarrhea include:

  • Exposure to viruses, bacteria or parasites. This is a major risk factor for sudden onset of diarrhea.
  • Diet. Certain foods or drinks, including coffee, tea, dairy products, or foods containing artificial sweeteners can cause diarrhea in some people.
  • Medicines. Some medicines, such as antibiotics, laxatives, magnesium supplements, antidepressants, NSAIDs, chemotherapy and immunotherapy, can cause diarrhea.

Complications

Diarrhea can cause dehydration, which can be life-threatening if not treated. Dehydration is particularly dangerous in children, older adults and those with weakened immune systems.

If you have symptoms of serious dehydration, seek medical help.

Symptoms of dehydration in adults

These include:

  • Excessive thirst.
  • Dry mouth or skin.
  • Little or no urination.
  • Weakness, dizziness or lightheadedness.
  • Fatigue.
  • Dark-colored urine.

Symptoms of dehydration in infants and young children

These include:

  • Not having a wet diaper in three or more hours.
  • Dry mouth and tongue.
  • Fever above 102 degrees Fahrenheit (39 degrees Celsius).
  • Crying without tears.
  • Drowsiness, unresponsiveness or irritability.
  • Sunken appearance to the belly, eyes or cheeks.

Prevention

Preventing infectious diarrhea

Wash your hands to prevent the spread of infectious diarrhea. To ensure adequate hand-washing:

  • Wash frequently. Wash your hands before and after preparing food. And wash your hands after handling uncooked meat, using the toilet, changing diapers, sneezing, coughing or blowing your nose.
  • Lather with soap for at least 20 seconds. After putting soap on your hands, rub your hands together for at least 20 seconds. This is about as long as it takes to sing "Happy Birthday" two times.
  • Use hand sanitizer when washing isn't possible. Use an alcohol-based hand sanitizer when you can't get to a sink. Apply the hand sanitizer as you would hand lotion, making sure to cover the front and back of both hands. Use a product that contains at least 60% alcohol.

Vaccination

You can help protect your infant from rotavirus, the most common cause of viral diarrhea in children, with one of two approved vaccines. Ask your baby's doctor about having your baby vaccinated.

Preventing traveler's diarrhea

Diarrhea commonly affects people who travel to countries with poor sanitation and contaminated food. To reduce your risk:

  • Watch what you eat. Eat hot, well-cooked foods. Don't eat raw fruits and vegetables unless you can peel them yourself. Don't eat raw or undercooked meats and dairy foods.

  • Watch what you drink. Drink bottled water, soda, beer or wine served in its original container. Don't drink tap water or use ice cubes. Use bottled water even for brushing your teeth. Keep your mouth closed while you shower.

    Beverages made with boiled water, such as coffee and tea, are probably safe. Remember that alcohol and caffeine can aggravate diarrhea and worsen dehydration.

  • Ask your health care team about antibiotics. If you're traveling to a developing country for an extended time, ask a member of your healthcare team about getting antibiotics before you go, especially if you have a weakened immune system.
  • Check for travel warnings. The Centers for Disease Control and Prevention maintains a travelers' health website where disease warnings are posted for various countries. If you're planning to travel outside of the United States, check there for warnings and tips for reducing your risk.
By Mayo Clinic Staff