Diarrhea

Diarrhea is loose, watery stools. A person with diarrhea typically passes stool more than three times a day. People with diarrhea may pass more than a quart of stool a day. Acute diarrhea is a common problem that usually lasts one or two days and goes away on its own without special treatment. Prolonged diarrhea persisting for more than two days may be a sign of a more serious problem and poses the risk of dehydration. Chronic diarrhea may be a feature of a chronic disease.

Diarrhea can cause dehydration, which means the body lacks enough fluid to function properly. Dehydration is particularly dangerous in children and older people. It must be treated promptly to avoid serious health problems.

People of all ages can get diarrhea. The average adult has a bout of acute diarrhea about four times a year. In the United States, on average each child will have had seven to fifteen episodes of diarrhea by age five.

Other Names

Diarrhea has many informal names, such as the trots, the runs, etc. It is often associated with gastroenteritis and enteritis. When associated with travel it is called traveler's diarrhea.

Causes

Acute diarrhea is usually related to a bacterial, viral, or parasitic infection. Chronic diarrhea is usually related to functional disorders such as irritable bowel syndrome or inflammatory bowel disease.

A few of the more common causes of diarrhea include the following:

• Bacterial infections. Several types of bacteria consumed through contaminated food or water can cause diarrhea. Common culprits include Campylobacter, Salmonella, Shigella]], and Escherichia coli (E. coli).
• Viral infections. Many viruses cause diarrhea, including rotavirus, Norwalk virus]], cytomegalovirus, herpes simplex virus]], and viral hepatitis.
• Food intolerances. Some people are unable to digest food components such as artificial sweeteners and lactose—the sugar found in milk.
• Parasites. Parasites can enter the body through food or water and settle in the digestive system. Parasites that cause diarrhea include Giardia lamblia, Entamoeba histolytica (amoebiasis), and Cryptosporidium.
• Reaction to medicines. Antibiotics, blood pressure medications, cancer drugs, and antacids containing magnesium can all cause diarrhea.
• Intestinal diseases. Inflammatory bowel disease, colitis, Crohn's disease, and celiac disease often lead to diarrhea.
• Functional bowel disorders. Diarrhea can be a symptom of irritable bowel syndrome.

Some people develop diarrhea after stomach surgery or removal of the gallbladder. The reason may be a change in how quickly food moves through the digestive system after stomach surgery or an increase in bile in the colon after gallbladder surgery.

People who visit foreign countries are at risk for traveler's diarrhea, which is caused by eating food or drinking water contaminated with bacteria, viruses, or parasites. Traveler' diarrhea can be a problem for people visiting developing countries. Visitors to the United States, Canada, most European countries, Japan, Australia, and New Zealand do not face much risk for traveler' diarrhea.

In many cases, the cause of diarrhea cannot be found. As long as diarrhea goes away on its own, an extensive search for the cause is not usually necessary.

Diarrhea may be accompanied by cramping, abdominal pain, bloating, nausea, or an urgent need to use the bathroom. Depending on the cause, a person may have a fever or bloody stools.

Infectious causes of diarrhea and associated symptoms ^[1]

Diagnosis

Diagnostic tests to find the cause of diarrhea may include the following^[2]

• Medical history and physical examination. The doctor will ask about eating habits and medication use and will do an examination to look for signs of illness.
• Stool culture. A sample of stool is analyzed in a laboratory to check for bacteria, parasites, or other signs of disease and infection.
• Blood tests. Blood tests can be helpful in ruling out certain diseases.
• Fasting tests. To find out if a food intolerance or allergy is causing the diarrhea, the doctor may advise avoiding lactose, carbohydrates, wheat, or other foods to see whether the diarrhea responds to a change in diet.
• Sigmoidoscopy. For this test, the doctor uses a special instrument to look at the inside of the rectum and lower part of the colon.
• Colonoscopy. This test is similar to a sigmoidoscopy, but it allows the doctor to view the entire colon.
• Imaging tests. These tests can rule out structural abnormalities as the cause of diarrhea.

Diarrhea in children

Children can have acute and chronic forms of diarrhea. Causes include bacteria, viruses, parasites, medications, functional bowel disorders, and food sensitivities. Infection with the rotavirus is the most common cause of acute childhood diarrhea. Rotavirus diarrhea usually resolves in three to nine days. Children who are 6 to 32 weeks old can be vaccinated against the virus with a vaccine called Rotateq.^[2]

Diarrhea is especially dangerous in newborns and infants, and can lead to dehydration in just a day or two. A child can die from dehydration within a few days. The main treatment for diarrhea in children is rehydration to replace lost fluid quickly.^[2]

The following symptoms indicate an especially dangerous situation in children:

• Stools containing blood or pus
• Black stools
• Fever above 102 degrees Fahrenheit
• Signs of dehydration (see below)

Dehydration

Diarrhea can cause dehydration, which means the body has lost too much fluid, too many electrolytes (salts in the blood), and can't function properly. Dehydration is particularly dangerous in children and in older adults, and must be treated promptly to avoid serious health problems.

Signs of dehydration include:

• Thirst
• Less frequent urination
• Dry skin
• Fatigue
• Light-headedness
• Dark-colored urine

Signs of dehydration in children include

• Dry mouth and tongue
• No tears when crying
• No wet diapers for 3 hours or more
• Sunken abdomen, eyes, or cheeks
• High fever
• Listlessness or irritability
• Skin that does not flatten back down when pinched and released

Severe dehydration may require hospitalization.

Treatment

In most cases of diarrhea, replacing lost fluid to prevent dehydration is the only treatment necessary. Medicines that stop diarrhea may be helpful, but they are not recommended for people whose diarrhea is caused by a bacterial infection or parasite. Stopping the diarrhea before having purged the bacteria or parasite will trap the organism in the intestines and prolong the problem. Antibiotics can be used for cases like these. Viral infections are usually left to run their course, depending on the severity and type of virus. This is because antibiotics do not kill viruses.

Self-care

In addition to preventing dehydration, diet is an important tool in warding off diarrhea. The BRAT diet^[3] (Bananas, White Rice, unsweetened Applesauce and plain, dry Toast) is well known to be help alleviate diarrhea. All are easy on the stomach and the intestines.

Here is how the BRAT diet works:

• Eliminate all solid food from the diet.
• Sip room temperature water for hydrating purposes. At least 2 cups per hour and be certain to sip - not gulp all at once.
• Slowly introduce bananas, rice, applesauce and dry toast into the diet.

Preventing dehydration

The fluid and electrolytes lost during diarrhea need to be replaced promptly because the body cannot function without them. Electrolytes are the salts and minerals that affect the amount of water in the body, muscle activity, and other important functions.

Although water is extremely important in preventing dehydration, it does not contain electrolytes. Broth and soups that contain sodium, and soft fruits, or vegetables that contain potassium, help restore electrolyte levels. Sugary sodas and juices may worsen the diarrhea because the high sugar content in these foods can cause excess water to enter the intestines. Over-the-counter rehydration solutions such as Pedialyte, Ceralyte, and Infalyte are also good electrolyte sources and are especially recommended for use in children.

Preventing Traveler's Diarrhea

Traveler's diarrhea happens when a person consumes food or water contaminated with bacteria, viruses, or parasites. The following precautions can be taken to prevent traveler's diarrhea when traveling outside of the United States:

• Not drinking tap water or using it to brush your teeth.
• Not drinking unpasteurized milk or dairy products.
• Not using ice made from tap water.
• Avoiding all raw fruits and vegetables, including lettuce and fruit salads, unless they can be peeled. The traveler should peel these foods himself.
• Not eating raw or rare meat and fish.
• Not eating meat or shellfish that is not hot when served.
• Not eating food from street vendors.

Research

The Division of Digestive Diseases and Nutrition at the National Institute of Diabetes and Digestive and Kidney Diseases supports basic and clinical research into gastrointestinal conditions, including diarrhea. Among other areas, researchers are studying how the processes of absorption and secretion in the digestive tract affect the content and consistency of stool, the relationship between diarrhea and Helicobacter pylori, motility in chronic diarrhea, and chemical compounds that may be useful in treating diarrhea.

References

1. ↑ D Amarapurkar, R. Baijal. Infections of colon and rectum including AIDS-related infections. Bombay Hospital Journal. 2000 Apr; 42(2): 264-75. Full Text
2. ↑ ^{2.0 2.1 2.2} Petri WA Jr, Miller M, Binder HJ, Levine MM, Dillingham R, Guerrant RL. Enteric infections, diarrhea, and their impact on function and development. J Clin Invest. 2008 Apr;118(4):1277-90. Abstract | Full Text
3. ↑ C.S. Mott Children's Hospital, University of Michigan, What is the Brat Diet?

External Links

Food and Drug Administration: Center for Food Safety and Applied Nutrition

Federal, State, and local government information

World Health Organization