What Is Watery Diarrhea?

Watery diarrhea means that you have liquid stools. Common causes include viral infections, such as norovirus, and bacterial infections, such as Clostridioides difficile (C. diff). Medical conditions like celiac disease and irritable bowel syndrome (IBS) also may cause it.

Some cases of watery diarrhea are easy to treat or don't require treatment at all. The symptoms can, however, lead to serious or even fatal complications, such as dehydration or malabsorption. This is a real cause for concern for infants and young children.

This article explains watery diarrhea causes and symptoms, as well as how this condition is diagnosed and treated.

Watery Diarrhea Symptoms

Usually, watery diarrhea occurs three or more times in one day. Diarrhea comes with a sudden and urgent need to use the restroom. Sometimes, there is a lack of control over your bowel movements.

When these symptoms appear and how long they last depends on what is causing them.

Diarrhea can sometimes coincide with other gastrointestinal (GI) issues. These may include:

• Nausea
• Vomiting
• Loss of appetite
• Cramping

In many cases, watery diarrhea will go away on its own without any treatment. However, this isn't always the case.

You should call a healthcare provider if watery diarrhea is accompanied by symptoms such as:

• Fever
• Severe abdominal or rectal pain
• Black or bloody stools
• Signs of complications like dehydration

Complications

Watery diarrhea is often harmless and fleeting. In some cases, though, it can lead to more serious conditions.

The two primary concerns related to watery diarrhea are dehydration and malabsorption.

Dehydration

The human body mostly consists of water. It needs water to function properly.

When it doesn’t have enough fluids, a condition known as dehydration, serious issues may arise. They include not having enough blood volume in the body, also known as hypovolemic shock. Kidney failure is possible, and fluid loss can even lead to death.

When you have watery diarrhea, it can be easy for your body to lose more fluids than it takes in. Dehydration can be especially dangerous for small children.

When babies lose fluids through watery diarrhea, it can be hard to replace them quickly enough to avoid dehydration. This concern is made worse when the illness causing the diarrhea also makes the baby vomit or reject feedings.

Signs and symptoms of dehydration can be different in children and adults. Generally speaking, they include:

• Thirst
• Dark-yellow or brown urine
• Needing to urinate less often than usual
• Fatigue or lack of energy
• Dry mouth
• Lack of tears when crying (in young kids and older infants)
• Decreased skin turgor (when you pinch the skin, it is slow to flatten and return to normal)
• Sunken eyes, cheeks, or a soft spot on an infant's skull
• Feeling lightheaded or fainting

Malabsorption

Malabsorption is when your body doesn’t absorb enough of the nutrients it needs after eating or drinking. This can lead to malnourishment.

The diarrhea itself doesn’t necessarily cause this problem. Some infections that cause diarrhea, such as parasites, can also disrupt the body’s ability to digest food properly and take in the nutrients it needs.

Signs and symptoms of malabsorption include:

• Bloating, abdominal discomfort, or gas
• Changes in appetite
• Weight loss or (in children) slowed weight gain

Causes

There are quite a few germs that can cause watery diarrhea. Many of them are spread through contaminated food, water, or objects. The vast majority of cases are caused by viral, bacterial, and parasitic infections.

However, some health conditions can also prompt diarrhea to occur.

Viruses

Viral gastroenteritis occurs when a virus infects the intestines. This leads to watery diarrhea along with other digestive symptoms, such as cramping and nausea.

There is no specific treatment for these viruses, and they often run their course without a person needing medication for their symptoms.

Rotavirus

Rotavirus is the most common cause of diarrhea in the world. It accounts for 40% of diarrhea-related hospitalizations in young children.

Experts estimate that in areas without rotavirus vaccination, nearly all kids will become infected with it at some point during early childhood. They will often become ill with rotavirus before their first birthday.

Norovirus

Norovirus is a highly contagious stomach bug. It accounts for roughly one in five cases of acute gastroenteritis worldwide. It is also the most common cause of foodborne disease in the United States.

The virus leads to roughly 400,000 emergency room visits every year in the U.S. Most of these cases occur in young children.

Astroviruses

Globally, astroviruses are one of the most common causes of watery diarrhea in young kids and adults with weakened immune systems.

Most cases clear up on their own within a few days.

Adenoviruses

Adenoviruses are often associated with the common cold or pink eye. However, this group of viruses can also cause mild diarrhea that can last up two weeks.

Bacteria

Bacterial infections are another common cause of watery diarrhea. There are several types of bacteria most often associated with watery diarrhea, though there impacts may change among people of different ages or even with the time of year.

Campylobacter

Campylobacter is a common cause of foodborne disease in the U.S. It leads to an estimated 1.3 million cases every year.

The bacteria are spread primarily through undercooked poultry, but can also be found in unpasteurized milk and contaminated water.

Most people with a campylobacter infection won’t need treatment or medical attention. The illness will eventually clear up on its own.

Escherichia coli (E. coli)

E. coli is a group of bacteria that can cause a wide range of symptoms. Some strains cause GI discomfort, while others cause respiratory illnesses, urinary tract infections, and other types of illnesses.

Shiga toxin-producing E. coli (STEC) is the kind of E. coli that causes watery (and sometimes bloody) diarrhea. It is spread through contaminated food or drinks. Common foods include raw or undercooked ground meat, raw vegetables, and sprouts.

Salmonella

Salmonella infections are predominantly linked to contaminated food. This bacteria is found in a range of raw and processed foods, including sprouts, nut butters, and chicken nuggets.

It also can be spread from animals to people. For example, in early 2019, the Centers for Disease Control and Prevention (CDC) reported a multi-state salmonella outbreak linked to pet hedgehogs.

Most of the time, the common symptoms of diarrhea, cramps, and fever go away on their own without treatment. But some salmonella cases can prompt diarrhea so severe they require hospitalization.

Salmonella causes an estimated 1.2 million illnesses and 450 deaths in the U.S. each year.

Shigella

Those with shigellosis usually start feeling sick about one to two days after they eat or drink something contaminated with the Shigella bacteria. This symptom of watery diarrhea after eating is associated with foods including salads, raw vegetables, milk, and dairy products.

It is also possible to be exposed through sexual contact with someone who is or recently was infected.

Shigellosis symptoms include watery diarrhea for a week, but it can sometimes take months for bowel movements to go back to normal.

Kids are the most likely to get shigellosis. Other groups at an increased risk of infection include travelers, men who have sex with men, and people with weakened immune systems.

Clostridioides Difficile

Most healthy people who come in contact with this bacteria, commonly referred to as C. diff or C. difficile, don't get sick. However, infection often occurs during or after a person takes antibiotics. In fact, the CDC notes that you are seven to 10 times more likely to be infected when taking these drugs or in the month after you finish them.

Given this and the contagious nature of this bacteria, it's no surprise that the risk of infection is greater in a medical setting. In particular, C. diff is common among people who have long stays in hospitals or long-term care facilities.

The CDC estimates that nearly half a million infections and roughly 15,000 deaths happen because of C. diff each year in the U.S. alone.

Cholera

Cholera is rarely spotted in developed countries like the U.S. Outbreaks of the bacteria are common in underdeveloped countries, though.

Most people infected with the bacteria won’t have any symptoms at all. However, they can spread the bacteria to other people through their feces. This is called fecal-oral route transmission, and it usually occurs because of poor hygiene. Washing your hands well after using the bathroom will help to limit it.

When symptoms do occur, watery diarrhea is the most characteristic sign of the disease. It is often called “rice water stools” because it looks like the water left after washing rice. Vomiting and cramps also are common symptoms.

In more serious cases, both kids and adults alike can die within a matter of hours due to severe dehydration.

The estimated 1.3 to 4 million cases of cholera that occur every year lead to between 21,000 and 143,000 deaths worldwide.

Parasites

Parasitic infections are a common cause of chronic diarrhea in areas with poor access to clean water and sanitation, although some do occur in developed nations. There are many different types of parasites that could lead to watery diarrhea.

Cryptosporidiosis

Cryptosporidiosis, or “crypto,” is caused by microscopic parasites that infect the intestines.

These parasites have a tough outer shell that protects them from disinfectants, including bleach. This is why cases are still fairly common in the U.S. despite the country’s improved sanitation and clean drinking water.

Crypto is particularly common in diaper-aged kids who attend daycare. It also is found in people who swim in or drink contaminated water (like streams or lakes), and those who travel abroad.

Cyclosporiasis

Cyclosporiasis is caused by another parasite. It is brought on by eating food and water contaminated with Cyclospora cayetanensis and is transmitted by feces or feces-contaminated water.

The parasite is too small to be seen with the naked eye. It makes its home in the small intestine, where it causes frequent (and sometimes explosive) watery diarrhea.

The diarrhea can last anywhere from a few days to more than a month. The symptoms can also go away and come back several times if the infection is left untreated.

Giardia

Giardia (also called giardiasis) is an infection in the small intestine.

It is caused by the parasite Giardia lamblia, which is most often transmitted through contaminated water sources and poor hygiene.

Cases don’t always result in symptoms, but even someone who doesn't show symptoms of infection can still have the parasite in their stools.

When symptoms do happen, foul-smelling and watery diarrhea is the most obvious symptom, along with gas, bloating, and stomach cramps.

Other Causes

Infectious diseases are the most common cause of watery diarrhea, but some non-infectious health conditions can lead to frequent bouts with diarrhea as well.

They include:

• Lactose intolerance
• Celiac disease
• Crohn’s disease
• Irritable bowel syndrome (IBS)

Some medications and, in particular, long-term use of antibiotics can also cause watery diarrhea.

Diagnosis

Few people need a healthcare provider to diagnose them with watery diarrhea. The liquid stools are often quite enough for a person to know they have this condition.

However, if the condition doesn’t get better after a couple of days—or you or your child are exhibiting signs of dehydration—your healthcare provider may want to run some tests. This will help to figure out the exact cause of the diarrhea so that it can be treated effectively.

Physical Exam

Before running tests, your healthcare provider will likely do a physical exam. They will check your blood pressure and pulse, and take your temperature to rule out any signs of serious dehydration.

Then, they might use a stethoscope to listen to your abdomen for specific sounds. They may also check your abdomen for any tenderness or pain.

It's not routine, but your healthcare provider might also check your rectal area to check for blood in your stool. They would do this by inserting a gloved finger into your anus.

Your healthcare provider will ask questions to get more information about your symptoms. They'll want to know:

• How long you’ve been having watery diarrhea
• How often you need to use the bathroom
• The color, consistency, and any odor of your stool
• If you're having other symptoms, like nausea or fever

Additionally, your healthcare provider will ask if you have had recent travels or taken any antibiotics in the past month or two.

Diagnostic Tests

The most common tool used to find the cause of watery diarrhea is a stool test. Blood tests, a hydrogen breath test, fasting tests, or an endoscopy might also be used to make a diagnosis.

Stool Test

These tests examine stool samples to see if they show the presence of germs. A stool test may reveal bacteria or parasites in the sample, along with any blood or signs of other health conditions.

Blood Tests

Blood samples can be tested for a range of diseases or disorders that can lead to watery diarrhea. This type of test could find celiac disease or another health condition is related to the diarrhea.

Hydrogen Breath Test

A hydrogen breath test is most often used to diagnose an intolerance to lactose, the sugar found in milk. It looks for unusually high levels of hydrogen in the breath. This is linked to undigested lactose reacting with certain bacteria in the colon.

This test is completed by first drinking something containing lactose and then breathing into a device that measures hydrogen levels. A high level indicates lactose intolerance.

Fasting Tests

Watery diarrhea may be caused by a food allergy or intolerance. Fasting tests can help you to find out what specific food may be causing the issue. You can then try to avoid these foods to see if the diarrhea goes away.

In some cases, your healthcare provider might recommend an elimination diet, where you cut out a list of foods, such as lactose or wheat. You can then slowly reintroduce these foods into your diet to see how your body responds.

Endoscopy

A healthcare provider may use a lighted instrument with a camera, called an endoscope, to look inside the body to spot potential causes of diarrhea.

They may do an upper endoscopy, in which they thread this tool down into the body through the mouth to see the esophagus, stomach, and part of the small intestine.

They may also do a colonoscopy, in which the endoscope is instead threaded into the body through the anus so that they can see inside the colon.

Treatment

Watery diarrhea treatment is focused on the root cause of the illness, often with medication to ease the severity of diarrhea. Imodium (loperamide) is one example that is available over the counter.

If the illness is caused by bacteria, antibiotics are sometimes used to treat the infection. This is especially true if diarrhea doesn’t go away on its own. If the symptoms are caused by a parasite infection, then anti-parasite drugs may be given.

It's important to replace lost fluids while waiting for symptoms to resolve in order to avoid dehydration. Keep in mind that not everyone with watery diarrhea will need treatment. Many cases clear up on their own within a few days.

Even without treatment, it’s important to prevent complications like dehydration until the watery diarrhea goes away.

If you have nausea or vomiting, taking tiny, frequent sips rather than big gulps can help the fluids stay down.

Water should be your primary drink, but you should also address a potential electrolyte imbalance caused by watery diarrhea.

Electrolytes are charged particles, like sodium and potassium, that are key to your body's health. They are found in a wide variety of sources, but if you’re not feeling well, the easiest place to get them is through drinking beverages with a small amount of salt.

Sports drinks and special hydration fluids like Pedialyte work well, or you can make your own. Just add a pinch of salt and a small amount of sugar to lemon water.

Caffeinated and alcoholic beverages should be avoided. These can block your body from absorbing fluids, making you urinate more often than you normally would and speeding up fluid loss.

Prevention

The vast majority of watery diarrhea cases can be avoided by taking precautions. These include handwashing and proper food care, clean water and sanitation, and getting vaccinated.

Sanitation

Most germs that cause watery diarrhea are spread through contaminated food and water. This is often because of unsanitary conditions or practices.

Safe Food Practices

• Some infections that cause watery diarrhea are caused by food that hasn’t been prepared properly. Be sure to wash your hands before handling food.
• Keep your fresh produce away from raw meats.
• Cook meats thoroughly.
• Store any prepared foods at proper temperatures and out of the reach of pests such as house flies.

Vaccination

Two common causes of diarrhea, rotavirus and cholera, can be prevented through vaccination.

Rotavirus Vaccine

Rotavirus vaccination is part of the routine childhood vaccinations recommended by the CDC. It’s given orally in two or three doses (depending on the brand) beginning at 2 months of age. While the vaccine is recommended by healthcare providers, it’s rarely required for childcare enrollment.

This may, in part, be why rates of rotavirus vaccination in the U.S. tend to lag behind those of other vaccines given at the same age. In 2017, only about 73% of kids ages 19 to 35 months got a rotavirus vaccine, compared to 91.5% who were vaccinated against measles.

Cholera Vaccine

The Food and Drug Administration (FDA) approved a cholera vaccine in 2016. It has been shown to lower the chances of getting severe diarrhea in adults by 80% to 90%.

However, it is currently only recommended for adults ages 18 to 64 who are planning to travel to places where cholera is common or there are active outbreaks. Most travelers do not need one.

Summary

If you or your child have watery diarrhea, there are a number of possible reasons for why. Viral infections, exposure to bacteria, tiny parasites, or even an underlying health condition, like Crohn's disease, could be to blame.

Dehydration and malabsorption are main concerns with watery diarrhea. Be sure to replace the lost fluids, even if you don't need medical attention. If you have other symptoms with the diarrhea, let your healthcare provider know. Don't wait more than 24 hours to call your healthcare provider if your child has watery diarrhea.

Proper treatment depends on the cause of the diarrhea, but many infections will get better on their own. Prevention also is key. This means handling and storing food safely, and washing your hands often. You also may wish to consider vaccines available for rotavirus and cholera infections.