Diarrhea is loose or watery stools. It is usually not harmful, but if it lasts more than 3 days it may cause dehydration or be a sign of a more serious condition.

Diarrhea Overview

Reviewed: May 21, 2014

Diarrhea means that you have loose, watery stools more often than you normally have regular bowel movements. You may also have cramps, bloating, nausea, and an urgent need to have a bowel movement. Causes of diarrhea include bacteria, viruses, or parasites, certain medicines, food intolerances. and diseases that affect the stomach, small intestine, or colon. In many cases, no cause can be found.

Although usually not harmful, diarrhea can become dangerous or signal a more serious problem if it does not resolve within a few days. You should talk to your doctor if you have a strong pain in your abdomen or rectum, a fever, blood in your stools, severe diarrhea for more than 3 days, or symptoms of dehydration.

Diarrhea Symptoms

Signs and symptoms associated with diarrhea may include:

  • frequent, loose, watery stools
  • abdominal cramps
  • abdominal pain
  • fever
  • blood in the stool
  • bloating

Diarrhea can cause dehydration. Loss of electrolytes through dehydration affects the amount of water in the body, muscle activity, and other important functions.

Dehydration is particularly dangerous in children, older adults, and people with weakened immune systems. Dehydration must be treated promptly to avoid serious health problems, such as organ damage, shock, or coma.

Signs of dehydration include:

  • thirst
  • less frequent urination than usual
  • dark-colored urine
  • dry skin
  • fatigue
  • dizziness
  • light-headedness

Anyone with signs of dehydration should see a health care provider immediately. Severe dehydration may require hospitalization.

Although drinking plenty of water is important in preventing dehydration, water does not contain electrolytes. Adults can prevent dehydration by also drinking liquids that contain electrolytes, such as fruit juices, sports drinks, caffeine-free soft drinks, and broths. Children with diarrhea should be given oral rehydration solutions such as Pedialyte, Naturalyte, Infalyte, and CeraLyte to prevent dehydration.

Diarrhea Causes

Acute diarrhea may be caused by a bacterial, viral, or parasitic infection. Chronic diarrhea is usually related to a functional disorder such as irritable bowel syndrome or an intestinal disease such as Crohn’s disease.

Diarrhea occurs when the food and fluids you ingest pass too quickly or in too large an amount — or both — through your colon. Normally, your colon absorbs liquids from the food you eat, leaving a semisolid stool. But if the liquids from the foods you eat are not absorbed, the result is a watery bowel movement.

A number of diseases and conditions can cause diarrhea. Common causes of diarrhea include:

  • Viruses. Viruses that can cause diarrhea include Norwalk virus, cytomegalovirus, and viral hepatitis. Rotavirus is a common cause of acute childhood diarrhea.
  • Bacteria and parasites. Contaminated food or water can transmit bacteria and parasites to your body. Parasites such as Giardia lamblia and cryptosporidium can cause diarrhea. Common bacterial causes of diarrhea include campylobacter, salmonella, shigella, and Escherichia coli. Diarrhea caused by bacteria and parasites can be common when traveling in developing countries and is often called traveler's diarrhea.
  • Medications. Many medications can cause diarrhea. The most common are antibiotics. Antibiotics destroy both good and bad bacteria, which can disturb the natural balance of bacteria in your intestines. This disturbance sometimes leads to an infection with bacteria called Clostridium difficile, which also can cause diarrhea. Cancer drugs and antacids containing magnesium can all cause diarrhea.
  • Lactose intolerance. Lactose is a sugar found in milk and other dairy products. Many people have difficulty digesting lactose and experience diarrhea after eating dairy products.Your body makes an enzyme that helps digest lactose, but for most people, the levels of this enzyme drop off rapidly after childhood. This causes an increased risk of lactose intolerance as you age.
  • Fructose. Fructose, a sugar found naturally in fruits and honey and added as a sweetener to some beverages, can cause diarrhea in people who have trouble digesting it.
  • Artificial sweeteners. Sorbitol and mannitol, artificial sweeteners found in chewing gum and other sugar-free products, can cause diarrhea in some otherwise healthy people.
  • Surgery. Some people may experience diarrhea after undergoing abdominal surgery or gallbladder removal surgery.
  • Other digestive disorders. Chronic diarrhea has a number of other causes, such as Crohn's disease, ulcerative colitis, celiac disease, microscopic colitis and irritable bowel syndrome.
In many cases, the cause of diarrhea cannot be found. As long as diarrhea goes away on its own within 1 to 2 days, finding the cause is not usually necessary.

Diarrhea Diagnosis

Tests and procedures used to determine what is causing your diarrhea may include:

  • Physical exam. You will have your temperature measured to check for a fever. Your blood pressure and pulse may also be measured to check for signs of dehydration. Your doctor may also examine your abdomen for abdominal pain.
  • Review of your medications. Your doctor may ask about any medications you are taking, including over-the-counter drugs. Also, tell your doctor about any supplements you take.
  • Blood test. A complete blood count test may help determine what is causing your diarrhea.
  • Stool test. Your doctor may recommend a stool test to determine whether a bacterium or parasite is causing your diarrhea.

Living With Diarrhea

Until diarrhea subsides, avoiding caffeine and foods that are greasy, high in fiber, or sweet may lessen symptoms. These foods can aggravate diarrhea. Some people also have problems digesting lactose during or after a bout of diarrhea. Yogurt, which has less lactose than milk, is often better tolerated. Yogurt with active, live bacterial cultures may even help people recover from diarrhea more quickly.

As symptoms improve, soft, bland foods can be added to the diet, including bananas, plain rice, boiled potatoes, toast, crackers, cooked carrots, and baked chicken without the skin or fat. Once the diarrhea stops, you can usually return to a normal and healthy diet if it can be tolerated.

Diarrhea Treatments

Most diarrhea cases clear up on their own within a few days. To help you cope with your signs and symptoms until the diarrhea goes away, try to:

  • Drink plenty of clear liquids, including water, broths and juices, every day. Avoid caffeine and alcohol.
  • Add semisolid and low-fiber foods gradually as your bowel movements return to normal. Try soda crackers, toast, eggs, rice or chicken.
  • Avoid certain foods such as dairy products, fatty foods, high-fiber foods or highly seasoned foods for a few days.
  • Ask about anti-diarrheal medications. Over-the-counter anti-diarrheal medications, such as loperamide (Imodium A-D) and bismuth subsalicylate (Pepto-Bismol), may help reduce the number of watery bowel movements you experience.
  • Consider probiotics. Probiotics contain strains of living bacteria that are similar to the healthy bacteria normally found in your digestive system. Probiotics may boost the number of healthy bacteria present to fight germs in your digestive tract. Probiotic supplements are available. Beneficial bacteria may also be found in yogurt and cheese.

Diarrhea Prognosis