Definition & Facts

In this section:

• What is diarrhea?
• How common is diarrhea?
• Who is more likely to have diarrhea?
• What are the complications of diarrhea?

What is diarrhea?

Diarrhea is passing loose, watery stools three or more times a day, or more often than what is normal for you. Diarrhea may be acute, persistent, or chronic.

• Acute diarrhea is a common problem that typically lasts less than a week and goes away on its own.¹
• Persistent diarrhea lasts longer than 2 weeks and less than 4 weeks.¹
• Chronic diarrhea lasts at least 4 weeks.¹ Chronic diarrhea symptoms may be ongoing or may come and go.

How common is diarrhea?

Diarrhea is a common problem. Acute diarrhea is more common than persistent or chronic diarrhea. Research suggests that people in the United States have acute diarrhea about once a year.¹ However, the actual number may be higher since most people with diarrhea don’t seek medical care.

Research suggests that up to 5% of people in the United States have chronic diarrhea.²

Who is more likely to have diarrhea?

You’re more likely to have diarrhea if you

• have a viral or bacterial infection
• were exposed to untreated water, such as while camping or traveling to countries with limited sanitation
• work in a hospital, nursing home, or daycare facility
• have food allergies or digestive tract problems
• take certain medicines, such as antibiotics or medicines commonly used to treat cancer
• consume food or drinks with sugar alcohols, such as sorbitol, mannitol, or xylitol

What are the complications of diarrhea?

Diarrhea can lead to dehydration and malabsorption. These complications may cause serious symptoms and health problems. People who have diarrhea and are pregnant, are over age 65, are currently taking antibiotics, or have a weakened immune system are more likely to have complications from diarrhea and should keep in touch with their doctor.³

Dehydration

Dehydration means your body doesn’t have enough fluid and electrolytes. Diarrhea, especially acute diarrhea, may cause you to become dehydrated because loose stools remove more fluid and electrolytes from your body than solid stools. If you can’t drink enough liquids or oral rehydration solutions to rehydrate your body, becoming dehydrated can lead to serious health problems, such as organ damage, shock, coma, or even death. However, serious health problems from being dehydrated are rare.

Malabsorption

Malabsorption occurs when your body can’t absorb enough nutrients from the food you eat. Malabsorption may cause you to become malnourished. Chronic diarrhea can cause malabsorption. Certain conditions that cause chronic diarrhea—such as infections, food allergies and intolerances, and certain digestive tract problems—may also cause malabsorption.

References

Symptoms & Causes

In this section:

• What are the symptoms of diarrhea?
• What are the symptoms of dehydration and malabsorption?
• When should I seek a doctor’s help?
• What causes diarrhea?

What are the symptoms of diarrhea?

Diarrhea causes similar symptoms for adults and children, such as⁴

• loose, watery stools three or more times a day, or more often than what is normal for you
• an urgent need to use the bathroom
• cramping or pain in the abdomen
• loss of control of bowel movements
• nausea
• weight loss, if you have chronic diarrhea

Symptoms of diarrhea caused by some infections may also include

• bloody stools
• fever and chills
• lightheadedness and dizziness
• vomiting

Diarrhea may also cause dehydration and malabsorption.

You may have cramping or an urgent need to use the bathroom when you have diarrhea.

What are the symptoms of dehydration and malabsorption?

Dehydration and malabsorption can be serious health problems related to diarrhea.

Dehydration

Symptoms of dehydration may include

• extreme thirst or dry mouth
• urinating less than usual
• feeling tired, dizzy, or lightheaded
• dark-colored urine
• skin that, when pinched and released, does not flatten back to normal right away
• sunken eyes or cheeks

In addition to the symptoms above, infants, toddlers, and young children with dehydration may also have⁴

• no wet diapers for 3 hours or more
• no tears when crying
• sunken soft spot in the skull
• drowsiness

Malabsorption

Symptoms of malabsorption may include

• bloating
• changes in appetite
• gas
• loose, greasy, foul-smelling bowel movements
• weight loss or poor weight gain in children

When should I seek a doctor’s help?

Diarrhea can become dangerous if it leads to severe dehydration. Diarrhea may also be a sign of a more serious problem.

Talk with a doctor right away if you or an adult or child in your care has symptoms such as

• change in mental state, such as irritability or lack of energy
• frequent vomiting
• severe pain in the abdomen or rectum
• stools that are black and tarry or contain red blood or pus
• symptoms of dehydration

Additional symptoms for adults

You should also talk with a doctor right away if you or an adult in your care has symptoms such as⁵

• diarrhea lasting more than 2 days
• high fever
• six or more loose stools per day

People who have diarrhea and are pregnant, are over age 65, are currently taking antibiotics, or have a weakened immune system are more likely to have health problems from diarrhea and should keep in touch with their doctor.⁵

Additional symptoms for infants and children

You should also talk with a doctor right away if an infant or child has symptoms such as

• diarrhea lasting more than a day
• any fever in infants or high fever in older children
• refusing to eat or drink anything for longer than a few hours in infants
• frequent loose stools

If an infant or child has diarrhea, don’t hesitate to call a doctor for advice. Diarrhea is especially dangerous in newborns and infants and can lead to severe dehydration in just a day or two. A child with symptoms of dehydration can die within a day if left untreated.

Seek a doctor’s help right away if the child has diarrhea and is younger than 12 months, was born prematurely, or has a history of other medical conditions. Also, seek a doctor’s help right away if the child can’t drink enough liquids or oral rehydration solutions to prevent dehydration.

What causes diarrhea?

Acute diarrhea often has different causes than persistent and chronic diarrhea.

Acute diarrhea

The most common causes of acute diarrhea are viral gastroenteritis, food poisoning, and medicine side effects.

Viral gastroenteritis

Viral gastroenteritis is an infection of your intestines and a common cause of acute diarrhea. Many different viruses can cause viral gastroenteritis. The most common viruses include

• norovirus
• rotavirus
• adenovirus
• astrovirus

Food poisoning

Diarrhea can be a symptom of food poisoning. Food poisoning is an infection or irritation of your digestive tract that spreads through foods or drinks. Microbes—viruses, bacteria, and parasites—cause most food poisoning. Food poisoning usually goes away within a week, but some infections can last longer.

The most common microbes that cause food poisoning include

• certain types of Salmonella
• Clostridium perfringens, also called C. perfringens
• certain types of Campylobacter
• Staphylococcus aureus, also called staph
• Escherichia coli, also called E. coli

Any food or drink can contain microbes that cause food poisoning. However, some foods are more likely to lead to food poisoning than others, including

• undercooked meats, poultry, and seafood
• fruits and vegetables
• raw or untreated milk, eggs, and cheeses

Travelers’ diarrhea

Consuming contaminated food and water or other drinks while traveling may also cause diarrhea, a condition known as travelers’ diarrhea. Travelers’ diarrhea can occur anywhere. However, it’s more likely to affect people traveling to areas where sanitation and access to clean water are limited.

Medicine side effects

Medicines, such as antibiotics, antacids containing magnesium, and medicines commonly used to treat cancer, may cause acute diarrhea. Some liquid medicines contain sugar alcohols—such as sorbitol, mannitol, and xylitol—which may also cause diarrhea in some people.

Persistent and chronic diarrhea

Some infections, food allergies and intolerances, digestive tract problems, abdominal surgery, and long-term use of medicines can cause persistent and chronic diarrhea.

Infections

Some infections may cause ongoing diarrhea. After the infection goes away, you may have problems digesting certain carbohydrates, which can make diarrhea last longer.

Food allergies and intolerances

Allergies to foods such as cow’s milk, soy, cereal grains, eggs, and seafood may cause chronic diarrhea.

Some people have problems digesting certain carbohydrates, which can also cause chronic diarrhea.

• Lactose intolerance is a condition in which you may have diarrhea after you consume foods or drinks that contain lactose. Lactose is a sugar naturally found in milk and milk products.
• Dietary fructose intolerance is a condition in which you may have diarrhea after you consume foods or drinks that contain fructose. Fructose is a sugar found in fruits, fruit juices, and honey. Fructose is also added to many foods and soft drinks.
• Sucrose intolerance is a condition in which you may have diarrhea after you consume foods or drinks that contain sucrose. Sucrose is also known as table sugar or white sugar.
• Sugar alcohols commonly found in sugar-free candies and gum may also cause diarrhea in some people.

Digestive tract problems

Digestive tract problems that may cause chronic diarrhea include

• celiac disease
• Crohn’s disease
• diabetes problems, such as autonomic neuropathy
• problems with the pancreas
• small intestinal bacterial overgrowth
• ulcerative colitis

Disorders of gut-brain interaction

Disorders of gut-brain interaction, which used to be called functional gastrointestinal (GI) disorders, are related to problems with how the brain and gut work together. Disorders of gut-brain interaction aren’t diseases. They are groups of symptoms that occur together.

Two disorders of gut-brain interaction that cause chronic diarrhea are

• irritable bowel syndrome, in which you have repeated pain in your abdomen and changes in your bowel movements
• functional diarrhea, in which you have chronic diarrhea that isn’t due to another cause

Abdominal surgery

You may develop chronic diarrhea if you had surgery on your appendix, gallbladder, large intestine, liver, pancreas, or small intestine.

If you had surgery on your stomach or esophagus, you may develop a condition called dumping syndrome. Chronic diarrhea is a possible symptom of dumping syndrome.

Long-term use of certain medicines

Certain medicines that must be taken for a long time may cause chronic diarrhea. For example, antibiotics can change your gut flora and increase your chances of developing a Clostridioides difficile (C. difficile) infection. A C. difficile infection can cause chronic diarrhea.

References

Diagnosis

How do doctors find the cause of diarrhea?

If your doctor thinks it’s important to find the cause of your diarrhea, they may use your medical and family history, a physical exam, or tests.

Medical and family history

Your doctor may ask about your

• symptoms, including how long you’ve had diarrhea, what your stool looks like, and how often you have diarrhea
• eating and drinking habits
• prescription and over-the-counter medicines
• current and past medical conditions
• recent international travel

Your doctor may also ask whether anyone in your family has digestive tract problems, food allergies and intolerances, or conditions that cause chronic diarrhea. Some conditions that cause chronic diarrhea, include

• celiac disease
• Crohn’s disease
• diabetes
• irritable bowel syndrome
• lactose intolerance
• ulcerative colitis

Your doctor may use information from your medical and family history, a physical exam, or tests to find the cause of your diarrhea.

Physical exam

During a physical exam, your doctor may

• check for signs of fever or dehydration
• listen to sounds in your abdomen, or belly, using a stethoscope
• tap on your abdomen to check for tenderness or pain
• perform a digital rectal exam
• compare your current weight to past weights

What tests do doctors use to diagnose diarrhea?

If your doctor decides diagnostic tests would be helpful, they may use one or more of the following tests to help find the cause of diarrhea.

Stool test

Doctors may use stool tests to check for blood, bacteria, parasites, or signs of diseases. A health care professional will give you a container for catching and storing the stool. You will receive instructions on where to send or take the container for analysis.

Blood tests

Blood tests can show signs of certain causes of diarrhea or problems such as dehydration. For a blood test, a health care professional will take a sample of your blood and send it to a lab. Doctors may use blood tests to check for certain diseases or disorders that can cause diarrhea.

Hydrogen breath test

A hydrogen breath test can be used to diagnose

• lactose intolerance
• dietary fructose intolerance
• sucrose intolerance
• small intestinal bacterial overgrowth

Normally, a small amount of hydrogen is found in your breath. If you have problems digesting carbohydrates like lactose, fructose, and sucrose, you may have high levels of hydrogen in your breath.

For this test, you will drink a liquid containing a specific carbohydrate. Over a few hours, you will breathe into a container that measures how much hydrogen is in your breath. During this time, a health care professional will ask you about your symptoms. If your hydrogen levels go up and your symptoms get worse during the test, your doctor may diagnose one of the above conditions.

Changes in diet

Your doctor may ask you to avoid foods with certain ingredients to see whether your diarrhea responds to a change in diet.

Endoscopy

Your doctor may use endoscopy to view the inside of your digestive tract and help find your cause of diarrhea. Endoscopy tests may include

• colonoscopy
• flexible sigmoidoscopy
• upper gastrointestinal (GI) endoscopy

Treatment

In this section:

• How can I treat acute diarrhea at home?
• How can I treat my child’s acute diarrhea at home?
• How do doctors treat diarrhea?
• How can I prevent diarrhea?

How can I treat acute diarrhea at home?

In most cases, you can treat acute diarrhea at home, without medical treatment.

Hydrate and replace electrolytes

When you have diarrhea, you need to replace lost fluids and electrolytes to stay hydrated. Drink plenty of water and liquids that contain electrolytes, such as broths and sports drinks. You can also drink oral rehydration solutions, liquids that contain glucose and electrolytes. You can make rehydration solutions at home or buy them from a store that sells medicines or baby supplies.

Older adults; people with a weak immune system; and people who have diabetes, kidney disease, or other health conditions should talk with their doctor before drinking oral rehydration solutions. There may be specific solutions or amounts of liquid that would work best for you.

When you have diarrhea, you may lose your appetite for a short time. When your appetite returns, you can most often go back to eating your normal diet, even if you still have diarrhea.

Antidiarrheal medicine

In most cases, you can safely treat acute diarrhea with over-the-counter medicines such as loperamide and bismuth subsalicylate. Doctors typically recommend against over-the-counter medicines for infants, children, or people who have bloody stools or fever.

See a doctor if your diarrhea gets worse or lasts more than 2 days while taking over-the-counter medicine.

In most cases, you can treat acute diarrhea by staying hydrated.

How can I treat my child’s acute diarrhea at home?

If your child has diarrhea, talk with their doctor for advice.

It’s important for children to stay hydrated when they have diarrhea. They should drink plenty of water, as well as oral rehydration solutions, broths, and sports drinks. Infants should drink breast milk or formula as usual. Talk with a doctor before giving oral rehydration solutions to your infant.

Doctors typically recommend against giving infants, toddlers, and young children over-the-counter medicines to treat diarrhea.

How do doctors treat diarrhea?

Most cases of acute diarrhea go away on their own. However, doctors may use a combination of tools to treat diarrhea in some people.

Hydration

If you are severely dehydrated, your doctor may recommend you receive intravenous (IV) fluids. Doctors may need to treat people with severe dehydration in a hospital. If you aren’t severely dehydrated, your doctor may recommend staying hydrated and replacing electrolytes at home.

Medicines

Antibiotics or other medicines may help people with some digestive tract infections. Doctors may also prescribe medicines to treat conditions that cause chronic diarrhea, such as Crohn’s disease, irritable bowel syndrome, or ulcerative colitis.

Diet changes

Chronic diarrhea caused by a food allergy or intolerance can be treated by avoiding foods and drinks that trigger the reaction. Doctors may suggest tracking what you eat and drink, as well as your bowel habits, to find out what may be causing diarrhea.

Probiotic supplements

Probiotics are live microorganisms—most often bacteria—that are like the ones you have in your digestive tract. Researchers are still studying the use of probiotics to treat diarrhea. However, many doctors and professional societies don’t believe that the evidence supports their use in treating or preventing diarrhea.⁶

For safety reasons, talk with your doctor before using probiotics or any other complementary or alternative medicines or practices.

How can I prevent diarrhea?

You can take steps to lower your risk of getting diarrhea, such as washing your hands, avoiding contaminated foods and drinks, and getting vaccinated against certain viruses.

Wash your hands

Washing your hands can lower your chances of getting or spreading infections that can cause diarrhea. Wash your hands thoroughly with soap and water for at least 20 seconds⁷

• after using the bathroom
• after changing diapers
• before and after handling or preparing food
• before and after caring for someone with diarrhea
• after handling garbage

If you don’t have soap and water available, use a hand sanitizer that is at least 60% alcohol.⁷

Keep foods and drinks safe

Protect yourself against food poisoning by keeping foods and drinks safe. Properly storing, cooking, cleaning, and handling foods can help lower your chances of getting sick.

When traveling to areas with limited sanitation and water filtration systems, only

• drink bottled water and use it to make ice, prepare foods, and brush your teeth
• consume drinks that are in factory-sealed containers
• eat meat, fish, or shellfish if they’ve been cooked to a safe temperature and are served hot
• eat raw vegetables and raw fruits if they’ve been washed in clean water or are peeled

Vaccinate infants to prevent rotavirus infection

Two oral vaccines are approved to protect children from rotavirus, a virus that causes viral gastroenteritis. Doctors usually give infants the vaccines in either two or three doses.

For the rotavirus vaccine to be effective, infants should receive all doses by age 8 months. Infants age 15 weeks or older who have never received the rotavirus vaccine should not start the series.⁸

References

Eating, Diet, & Nutrition

What should I eat if I have diarrhea?

If you have acute diarrhea, you may not feel like eating. In most cases, when you feel like eating again, you can eat your normal diet. Children with acute diarrhea should have their usual age-appropriate diet, and infants should have breast milk or formula.

If you have chronic diarrhea, your doctor may recommend changing what you eat. People with food allergies or problems digesting certain carbohydrates or proteins should eat foods that improve symptoms and ensure good nutrition. Talk with your doctor about what foods are best for you.

What should I avoid eating if I have diarrhea?

If you have acute diarrhea, avoid foods and drinks that could make diarrhea worse, such as

• alcoholic beverages.
• drinks with caffeine, such as coffee, tea, and some soft drinks.
• foods and drinks containing large amounts of simple sugars, such as fructose and lactose. Sweetened beverages, some fruit juices, candy, and packaged desserts often have these sweeteners.
• foods and drinks containing sugar alcohols, such as sugarless gum and candies.
• foods that are high in fat, such as fried foods, pizza, and fast food.
• milk and milk products that contain lactose. Some people recovering from acute diarrhea have problems digesting lactose for up to a month or more afterward. Children and infants with acute diarrhea should continue their age-appropriate diet.

Most experts don’t recommend following a restricted diet, other than what is above, or fasting when you have acute diarrhea.

If you have chronic diarrhea, your doctor may suggest avoiding foods or drinks that make your symptoms worse.

Keeping a food journal could help you figure out which foods and drinks trigger your symptoms. Be sure to track

• what foods and drinks you consume
• what symptoms you have
• when symptoms occur
• which foods and drinks make symptoms worse

Take your notes to your doctor and talk about which foods and drinks seem to make your symptoms worse. You may need to avoid or limit these foods and drinks.

Clinical Trials

NIDDK conducts and supports clinical trials in many diseases and conditions, including digestive diseases. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.

What are clinical trials for diarrhea?

Clinical trials—and other types of clinical studies—are part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.

Researchers are studying many aspects of diarrhea, such as new ways to treat and prevent the condition.

Find out if clinical studies are right for you.

Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.

What clinical studies for diarrhea are looking for participants?

You can view a filtered list of clinical studies on diarrhea that are federally funded, open, and recruiting at ClinicalTrials.gov. You can expand or narrow the list to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health does not review these studies and cannot ensure they are safe for you. Always talk with your health care provider before you participate in a clinical study.