Diarrhea is a medical term used to describe a condition in which a child’s bowel movements increase in frequency, liquidity and volume. Diarrhea is usually described as loose, watery stools, and patients may also experience abdominal pain, abdominal cramping, fever, nausea or blood in the stool.

Diarrhea is extremely common in children, particularly before the age of 3 or 4. Only colds and other respiratory infections are conditions that strike children more often. Diarrhea usually lasts a few days and does not typically require treatment. However, diarrhea can become life-threatening when it causes severe dehydration, especially in the very young.

Different processes in the body may promote diarrhea. These include a failure of the intestines to absorb adequate nutrients and fluids during digestion, the release of too much fluid into the digestive tract or complications as the result of intestinal disorders.

Diarrhea can be short-term (acute) or long-term (chronic), and both types can range in severity. Acute diarrhea lasts less than four weeks. The most common cause of acute diarrhea is a viral infection (e.g., stomach flu) or bacteria or parasites consumed through contaminated food or water (e.g., food poisoning, traveler’s diarrhea).

Chronic diarrhea lasts for more than four weeks and may indicate a more serious problem, such as malabsorption of nutrients, inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS).

Because diarrhea is a symptom of other problems, treatment options will depend on the cause of the diarrhea. In children with a viral infection, the diarrhea is usually left untreated and resolves on its own within a few days. When the diarrhea is caused by certain foodborne bacteria or parasites (e.g., certain forms of Escherichia coli and salmonella), antibiotics may be required to treat the infection. For chronic conditions, such as IBD, specific medical treatment may be required.

If a child is dehydrated as a result of diarrhea, lost fluids and electrolytes will need to be replaced. For most children, this means drinking more fluids or an oral rehydration solution until the diarrhea resolves. Intravenous (into a vein) hydration may be necessary for some infants. Parents should check with a physician before using rehydration solutions or diarrhea medications in children.

Diarrhea is an increase in the liquidity and/or volume of stool or the frequency of bowel movements. It may be mild, moderate or severe and can have an impact on normal activities. Diarrhea is extremely common in children, particularly before the age of 3 or 4.

The average frequency of bowel movements and firmness of stool can vary greatly from child to child. Thus, it is important to note any significant changes in what is normal for a particular child. Children with diarrhea have stool that ranges from soft to liquid in texture and brown to clear in color. During bouts of diarrhea, they typically have bowel movements more than three times a day.

Diarrhea is caused by a disruption of the normal process of digestion. Normal digestion involves food traveling from the stomach to the small intestine, where most nutrients are absorbed. By the time it gets to the colon, only waste material remains. The colon absorbs most of the water from the waste and passes the stool along via muscle contractions (peristalsis) to the rectum at the end of the digestive tract. Diarrhea occurs when too much fluid remains in the intestines as stool travels through the digestive tract. When this occurs, the stool that eventually is passed is loose and watery.

Younger children with diarrhea tend to have stools that are more watery than older children. The color of diarrhea also varies from child to child and may include light brown, yellow or green stools.

Too much fluid in the intestines can be caused by several different types of digestive dysfunction, including:

• The small intestine and colon may fail to absorb enough nutrients and fluids from stool, making the stool loose and watery.
  
  
• The intestines may be stimulated to secrete water, salt or other fluids into the digestive tract, making stool runny. This stimulation can occur as the result of infection, disease or the presence of certain other substances (e.g., castor oil, excess bile acids).
  
  
• Food may pass through the intestines too quickly or in too large an amount to be properly absorbed. The rapid transit of stool through the digestive tract is a common cause of diarrhea.

Most cases of diarrhea in children are the result of an infection with a gastrointestinal virus. Children often are infected with these viruses when they are exposed to the virus in childcare centers, playgrounds, school classrooms or children’s hospitals.

Acute diarrhea (lasting less than four weeks) is the most common type of diarrhea. Most cases of acute diarrhea are caused by infection or antibiotic treatment, and resolve spontaneously. However, frequent, explosive episodes of diarrhea can lead to dehydration, particularly in small children. This is a potentially dangerous situation that demands prompt medical attention.

Diarrhea is a common symptom of many different problems. It often appears with other symptoms, which may help physicians determine the underlying cause. For example, children with diarrhea due to infection may also experience abdominal pain, abdominal cramping, fever and blood in the stool as a result of damage in the lining of the bowel. Nausea and vomiting may also occur with gastrointestinal infections.

Specific combinations of symptoms and possible causes include:

• Chronic diarrhea. This may be a symptom of lactose or sorbitol intolerance, infection or irritable bowel syndrome (IBS). Symptoms of abdominal bloating and excessive gas after consuming dairy products may indicate lactose intolerance. When diarrhea is accompanied by alternating episodes of constipation, as well as abdominal pain and frequent bowel movements, it may indicate IBS.
  
  
• Chronic bloody diarrhea. This may be a symptom of inflammatory bowel disease (IBD), especially if accompanied by abdominal pain, cramping and unintentional weight loss.
  
  
• Chronic oily or fatty diarrhea (stool often appears bulky, greasy or foul smelling). This may indicate absorption problems or other digestive problems. It may also indicate bile duct or liver diseases, celiac sprue (damage to the small intestine caused by eating gluten) or complications of intestinal surgery.

In some cases, children may pass large volumes of diarrhea. This can lead to dehydration as the body loses significant amounts of water and salt. Dehydration can be life-threatening for very young children and children with weakened immune systems. Infants can become dehydrated after just one or two days of severe diarrhea.

Signs of dehydration in children include:

• Darkened urine
  
  
• Dry mouth or tongue
  
  
• High fever
  
  
• Lack of tears when crying
  
  
• No wet diapers for three hours or more
  
  
• Poor appetite (anorexia)
  
  
• Rapid heartbeat
  
  
• Restlessness, irritability
  
  
• Skin that does not flatten after being pinched and released
  
  
• Sunken abdomen, eyes, cheeks, “soft spot” or fontanel (in babies younger than 18 months)
  
  
• Thirst
  
  
• Weight loss

Some signs that children need immediate medical attention include black stool, presence of blood or pus in stool, temperature of 101.4 degrees Fahrenheit (38.6 degrees Celsius) or higher, diminished responsiveness or a lack of improvement after 24 hours.

Diarrhea can be either short-term (acute) or long-term (chronic). Virtually all children experience the severe and sudden development of acute diarrhea at some point. It is usually short-lived (a few days) and runs its course without need for medication. Acute diarrhea is most often caused by infection (infectious diarrhea), but may also be a side effect of many different prescription or over-the-counter medications.

Chronic diarrhea, on the other hand, lasts for four weeks or more and may indicate a more serious problem requiring treatment. Irritable bowel syndrome (IBS) can cause chronic diarrhea and can affect children. Malabsorption of certain foods is a common cause of chronic diarrhea in children.  

Diarrhea can be categorized into different types, depending on the processes that drive them. Food that passes too quickly through the intestines or in too large an amount to be properly absorbed is a common cause of diarrhea. Additional types of diarrhea by process include:

• Osmotic diarrhea. Occurs when sugars (e.g., lactose, fructose), sugar alcohols (e.g., sorbitol) and some minerals (e.g., magnesium, sulfate, phosphate) in the intestines fail to be absorbed into the body. These unabsorbed substances draw water into the intestines, causing watery stool. Diarrhea caused by lactose intolerance is an example of osmotic diarrhea. Sorbitol is also a common cause of this type of diarrhea. Typically, osmotic diarrhea goes away when foods containing these elements are removed from a patient’s diet.
  
  
• Secretory diarrhea. Occurs when the intestines release water and salt into the stool, making it runny. This can be due to numerous causes, the most common being infections that release toxins. The toxic substances interfere with the intestines, causing them to secrete water and salt. Secretory diarrhea can be due to poor absorption of bile acids and fatty acids by the intestines. This may occur in people with certain medical conditions, such as celiac sprue and inflammatory bowel disease (IBD). Cancerous tumors can also stimulate secretions that lead to secretory diarrhea.
  
  Children with digestive systems that move digestive products too quickly are also prone to secretory diarrhea, because the intestines do not have enough time to absorb fluid.
  
  
• Exudative diarrhea. Occurs when inflammation or irritation of the lining of the colon causes the release of blood, mucus or other fluids. This type of diarrhea can be caused by a number of conditions (e.g., IBD, tuberculosis, some cancers).  

It is important to note that different types of diarrhea may occur at the same time. For example, it is rare that children who see a physician about their diarrhea have solely osmotic or solely secretory diarrhea. Some viral or inflammatory conditions can cause both to occur simultaneously.

Diarrhea can be a symptom of many different illnesses and medical conditions, or a side effect of certain medications. It most often is the result of gastrointestinal infections caused by viruses, bacteria or parasites. Diarrhea may also be the result of a reaction to specific dietary choices or unfamiliar foods, especially in children.

Potential causes of diarrhea include:

• Viral infection. Viruses are the most common cause of infectious diarrhea. A virus may damage the lining of the small intestine, interfering with normal fluid and nutrient absorption, causing diarrhea. A group of viruses called rotavirus is the most common cause of severe diarrhea in children – an estimated 55,000 children are hospitalized for it each year in the United States, according to the Centers for Disease Control and Prevention (CDC). Virtually all children have been infected with rotavirus (most often in the winter or early spring) by the time they are 4 or 5 years old, even if they do not experience symptoms. Another form of viral infection called enterovirus (especially group A and B coxsackie viruses) tends to cause outbreaks of diarrhea in children during the summer months. Viral infections are easily spread, because the viruses can survive for significant periods of time on toys and play-area surfaces. Another group of related viruses, known collectively as noroviruses, cause gastroenteritis and intestinal flu, which include diarrhea as a primary symptom.
  
  
• Bacteria/parasites. Bacteria (e.g., Escherichia coli, salmonella) and parasites (e.g., Giardia, cryptosporidia) are commonly ingested through contaminated food or water. Parasites such as Giardia also can be transmitted in water parks, pools and children’s “touch tanks” in aquariums. Some bacteria and parasites release toxins that cause the intestines to secrete water and salt, adding to the liquidity of stool. Certain types of bacterial infections are likely to cause blood to appear in the stool. These include Campylobacter jejuni, salmonella, various strains of Escherichia coli and shigella.
  
  Traveler’s diarrhea is a form of diarrhea related to bacteria or parasites that often affects children. It occurs when a child ingests contaminated food or water while in a foreign country. Children under the age of 2 are especially vulnerable to traveler’s diarrhea because their immune systems are not yet fully developed, and because of their tendency to put things in their mouths. Traveler’s diarrhea can cause extreme dehydration in children very quickly. However, it is usually only a problem when visiting developing countries. Visitors to developed nations, such as the United States, Canada, Japan, Australia, New Zealand and most of Europe, are less likely to contract traveler’s diarrhea.
  
  
• Flu. Although influenza (the flu) is an upper respiratory tract disorder, it may cause diarrhea in some children, in addition to more common symptoms such as fever, a runny nose and fatigue.
  
  
• Intestinal disorders. If the colon is inflamed or diseased, it may be unable to absorb fluid from food products traveling through the intestines, resulting in diarrhea. Examples of intestinal disorders that can cause diarrhea include inflammatory bowel disease (IBD), celiac sprue (intestinal problem that results from eating gluten found in foods such as wheat, rye, barley and oats) and dysentery (bacterial or parasite infection of the intestines marked by severe, bloody diarrhea).
  
  
• Motility disorders. When stool moves too quickly through the intestines, not enough fluids are absorbed from the stool, leading to watery, unformed bowel movements. If stool moves too slowly, it can lead to bacteria overgrowth and loose, greasy bowels. Causes of motility disorders include an overactive thyroid gland (hyperthyroidism) and irritable bowel syndrome (IBS). Stress and anxiety can also cause increased movement of stool through the digestive tract, causing diarrhea.
  
  
• Surgical procedures. Various types of surgery may cause changes within the digestive tract that can lead to diarrhea. Bowel resections decrease surface area of the intestines, which limits fluid absorption and may cause diarrhea. Bacterial overgrowth as a result of exposure during intestinal surgery can cause inflammation and diarrhea.
  
  
• Medication. There are hundreds of prescription and over-the-counter medications that can cause diarrhea. Antibiotics are the most common culprit – they can disrupt the natural balance of bacteria in the intestines. Diarrhea is a common side effect of other medications such as those used to treat depression and cancer. Habitual use of laxatives can also cause diarrhea. Cancer treatments, including radiation, sometimes injure the lining of the bowels, triggering severe diarrhea. In most cases, diarrhea resolves once the antibiotic or other aggravating agent is discontinued.
  
  
• Artificial sweeteners and caffeine. Products used as sugar substitutes, such as sorbitol and mannitol, are sometimes not absorbed into the bloodstream and remain in the intestines, leading to loose, watery stool. Caffeine (found in many sodas) stimulates the passage of stool, which can cause it to move too quickly through the intestines, disrupting normal fluid absorption and resulting in watery stool.
  
  
• Food allergies or intolerances. Certain foods may cause children to have bouts of diarrhea. For example, children who lack the enzyme lactase are unable to digest milk products. The undigested lactose in the intestines causes an osmotic diarrhea (diarrhea caused by problems with the absorption of carbohydrates). Children who are allergic to the protein (casein) in milk also may experience diarrhea when eating certain foods.
  
  
• Ingestion of toxins. The inadvertent ingestion of environmental toxins (e.g., insecticides, arsenic) can lead to diarrhea. Eating poisonous mushrooms may also cause diarrhea.

Other, rare causes of diarrhea in children include:

• Cystic fibrosis (disease that causes thick mucus buildup in the lungs and digestive tract)
  
  
• HIV/AIDS infection
  
  
• Immune deficiency
  
  
• Tumor

A condition known as toddler’s diarrhea is not caused by any infection or illness, but is more likely caused by dietary issues, such as drinking too much fruit juice. This form of diarrhea affects toddlers and preschool children and can cause diarrhea that lasts for months or even years, if fruit juice intake is not adjusted.

In addition, researchers have recently identified a rare genetic disorder that causes chronic diarrhea and intestinal failure in children. Babies born with enteric anendocrinosis have a gene mutation or malfunction that results in an abnormally low number of endocrine cells – which facilitate the absorption of nutrients – in the intestine. The condition can lead to malnutrition and failure to thrive in children. Patients with enteric anendocrinosis also eventually develop type 1 diabetes. There is no cure for the condition, which is worsened by eating. Treatment options for enteric anendocrinosis include specialized baby formulas and intravenous (into a vein) feeding to alleviate diarrhea and promote growth.

Physicians often rely on a child’s or the parent’s report of symptoms when diagnosing and determining the treatment for diarrhea. A medical history will include questions about the duration and severity of symptoms, eating habits and current medications. A physical examination will allow a physician to look for signs of illness that may be causing the diarrhea.

Most children with diarrhea will not need extensive testing. When diarrhea goes away by itself, it is usually not necessary to submit to various tests to determine the cause of diarrhea. When tests are used, they may include:

• Stool tests. Stool (feces) is tested for bacteria, parasites or other signs of infection that may be causing the diarrhea.
  
  
• Blood tests. Blood is drawn and tested for evidence of disease (e.g., bacterial infection) that may be causing the diarrhea.
  
  
• Fasting tests. Under the guidance of a physician the child is asked to avoid certain products to determine whether an allergy or food intolerance may be responsible for the diarrhea. Bowel habits are observed to identify whether a change in diet affects the diarrhea. Physicians commonly ask children to avoid dairy products, carbohydrates and wheat, although other foods may be included. Milk may be purchased with added lactase, and yogurt is usually well-tolerated.
  
  
• Endoscopy. A flexible tube (with attached light and camera) is inserted into a child’s digestive tract to identify any abnormalities that may be causing the diarrhea. Biopsies (tissue samples) and color photographs may be taken during this procedure. In a colonoscopy, the tube is inserted via the anus and usually through the entire colon. A sigmoidoscopy is similar, but only goes as far as the lower part of the colon (the sigmoid colon).

Dehydration is a serious consequence of diarrhea that should be addressed immediately. Replacement of fluids and electrolytes is required for children who suffer from dehydration. Infants and small children need more than water for adequate rehydration, because they require an influx of sodium, potassium, sugar and other elements. Parents who suspect dehydration should consult a physician about the best way to rehydrate a child. Sports drinks, which include sodium and potassium, can help restore fluid balance and cardiovascular functioning in the body. Other fluids used to replenish the body after dehydration include fruit juices, broth and carbonated beverages that have gone flat (contain no fizz). Caffeinated beverages should not be used, as they deprive the body of both salt and water.

In some cases, a physician may recommend that a child use an over-the-counter pediatric oral rehydration solution to replenish lost nutrients. These solutions contain water and salts that help replenish electrolyte and salt balances. In addition, they contain glucose and another carbohydrate (such as rice powder) that help enhance absorption in the intestinal tract. The physician will explain how this solution is to be given to the child. It usually can be given safely in generous amounts.

Generally, women who are breastfeeding or are using formula are urged to continue their routine. In some cases, formula-fed babies and children eating solid foods may go through a short period where a rehydrating solution replaces or supplements other foods.

Intravenous (into a vein) rehydration given in a hospital emergency room over the course of several hours may be necessary for infants who are profoundly dehydrated.

In general, treatment for diarrhea will depend on its cause. Diarrhea caused by a viral infection will not respond to antibiotics and will most likely resolve itself within 24 to 48 hours, depending on the severity of the diarrhea. Bacterial infections causing diarrhea may be treated with antibiotics.

Children with diarrhea should avoid dairy products for three to seven days. In addition, they may benefit from eating bland foods for the first 24 hours, including bananas, rice, applesauce, toast and unsweetened cereals. Other foods can gradually be added over the next 48 hours. Most children resume a normal diet about three days after diarrhea ceases. 

If diarrhea is the result of invasive bacteria, such as salmonella, antibiotics are sometimes used – especially in very young children or children with compromised immune systems or cardiovascular problems. For chronic diarrhea that is the result of intestinal disorders, specific medical treatment of those disorders may be required.

Many cases of diarrhea can be resolved through changes to diet. Removing caffeine products from the diet, for example, may relieve some forms of chronic diarrhea. Dairy products, foods high in simple sugars (e.g., sweetened cereals) and foods high in fat are other foods that, if removed or limited in a patient’s diet, can help relieve diarrhea. Bananas, pears, and boiled or mashed potatoes are good sources of potassium, which may be depleted in a person with diarrhea. Adding these food products to a patient’s diet can help restore the balance of nutrients.

Any changes in diet should not involve reducing a child’s overall food intake if the child is at a healthy weight. Although eating may increase a child’s diarrhea, it is an important part of maintaining a child’s weight and helping the child to recover more quickly.

Prevention of diarrhea begins early in a baby’s life. Breastfeeding can reduce the future risk of diarrhea because breast milk contains ingredients that help lower the risk of infections and food allergies in babies. Older children can be taught to wash their hands frequently, especially before meals and after going to the bathroom. This can reduce the risk of becoming infected with certain types of bacteria or viruses. Parents are also urged to remind other caregivers to wash their hands before they prepare food for the child or after changing the child’s diaper.

A change in diet is one of the easiest ways to prevent diarrhea. Certain food products can aggravate or cause diarrhea, while others can help prevent it. Paying attention to what is consumed, limiting some choices while seeking out others, can help prevent diarrhea.

The first step is to avoid those foods or drinks that can cause diarrhea, such as:

• Fatty foods. A diet high in fats (e.g., fried foods, pastries, potato chips) can lead to absorption problems in the intestines, making stool soft and greasy.
  
  
• High-fiber foods. Fiber in foods such as bran, beans, fresh fruits and vegetables can add bulk and softness to stool, aggravating diarrhea.
  
  
• Caffeine. Products containing caffeine (e.g., soda) can stimulate the passage of stool through the intestines, causing insufficient fluid absorption and diarrhea.
  
  
• Dairy products. An inability to digest lactose in dairy products can increase the wateriness of stool and lead to diarrhea.
  
  
• Unpasteurized products. Products that are not pasteurized may contain bacteria that, once consumed, may cause diarrhea.

Parents of children will also want to gradually add foods or drinks to the child’s diet that can help prevent diarrhea. This includes soft, easily digested foods (e.g., soup, crackers) as well as low-fiber foods (e.g., rice, noodles, white bread, lean meats). The American Dietetic Association recommends the BRAT (banana, rice, applesauce, toast) diet to help prevent overstimulation of the intestines and to help reduce the frequency of bowel movements.

For chronic diarrhea caused by an underlying intestinal disorder, such as irritable bowel syndrome (IBS), specific dietary changes may be recommended.

Practicing good hygiene is another way to prevent diarrhea caused by bacterial or viral infection. Children who touch surfaces contaminated with infectious germs can become contaminated when biting their nails or inserting any part of their hands into their mouths. Therefore, it is crucial that children wash their hands with soap and water before eating, when preparing food and after using the bathroom.

Proper handling and storing of foods also can reduce the risk of infectious contamination that can lead to diarrhea. Parents are urged to wash a child’s fruits and vegetables before they are consumed, to wash kitchen counters and cooking utensils exposed to raw meat (particularly poultry) and to store meat in a refrigerated setting immediately after they are purchased. Cooking meat until it is no longer pink also helps kill germs.   

Parents are also urged to keep the feeding areas of pets separate from family eating areas, and to avoid washing the bowls or cages of pets in any sink that is used to prepare food for children.

Parents can also take steps to lower a child’s risk of infectious diarrhea when traveling, a condition known as traveler’s diarrhea. Children may receive antibiotics in advance from their physician, depending on the location and duration of travel. In addition, traveler’s diarrhea can be avoided by taking the following actions:

• Eat only hot, well-cooked foods. Avoid food that has been left at room temperature for long periods of time. Meat or shellfish should be hot when served and consumed – do not consume raw or rare meat or fish. Avoid food sold by street vendors.
  
  
• Avoid accidental exposure to contaminated water. Use bottled water when traveling. Avoid ice and tap water, even when brushing teeth, to avoid possible contaminants in the water. Do not let shower water get into the ears or mouth.
  
  
• Choose hot drinks or those in sealed containers. Bottled water, carbonated soft drinks, as well as boiled water drinks are safe.
  
  
• Avoid raw fruits or vegetables, unless they can be peeled. Fruits or vegetables may have been rinsed with contaminated water.
  
  
• Avoid unpasteurized products. Milk, orange juice or other products that have not been pasteurized (heated during processing to eliminate bacteria), may cause diarrhea.

Parents should call a physician if their child has diarrhea and is younger than 6 months old, or older than 6 months old and has a fever of 101.4 degrees Fahrenheit (38.6 degrees Celsius).

Parents are urged to call a physician if their child experiences severe diarrhea or diarrhea that lasts longer than 48 hours. Blood or mucus in stools, severe abdominal pain or abdominal pain lasting more than two hours, skin rash and jaundice, and excessive fever or vomiting are other symptoms that require a physician’s attention.

Diarrhea associated with abdominal pain that begins in the navel and moves to the lower right abdomen may indicate appendicitis, which requires emergency medical attention.

Preparing questions in advance can help patients and parents have more meaningful discussions with their physicians regarding their or their child’s treatment options. The following questions related to diarrhea may be helpful:

1. Is it normal for my child to have diarrhea? How often is normal?
   
   
2. Should I be concerned about the frequency of my child’s bowel movements?
   
   
3. Is watery stool the only way to tell if my child has diarrhea?
   
   
4. When should I seek treatment for my child’s diarrhea?
   
   
5. What do you think is the cause of my child’s diarrhea?
   
   
6. Should my child be screened for any conditions or potential causes?
   
   
7. Should my child receive an oral rehydration solution?
   
   
8. Are there certain foods my child should avoid?
   
   
9. Are there medications or home remedies you can recommend to help with the other symptoms associated with my child’s diarrhea (e.g., stomach pain)?
   
   
10. What diet or lifestyle changes can my child make to help prevent diarrhea?
    
    
11. During treatment, are there any side effects or changes that you want me to report to you immediately?