What is diarrhea?

Diarrhea is when your stools are loose and watery. You may also need to go to the bathroom more often. Diarrhea is a common problem. It may last 1 or 2 days and go away on its own. If it lasts more than 2 days, it may mean you have a more serious problem.

Diarrhea may be either:

  • Short-term (acute). This type lasts 1 or 2 days and then goes away. It may be caused by having food or water that was made unsafe by a bacterial infection. Or it may happen if you get sick from a virus or a food toxin.
  • Long-term (chronic). This type lasts several weeks. It may be caused by another health problem such as irritable bowel syndrome. It can also be caused by an intestinal disease such as Crohn’s disease or celiac disease. Some infections, such as parasites, can cause chronic diarrhea.

What causes diarrhea?

Diarrhea may be caused by many things, including:

  • A bacterial infection
  • A virus
  • Food poisoning
  • Trouble digesting certain things (food intolerance)
  • Food allergy such as celiac disease or gluten allergy
  • Parasites that enter the body through food or water
  • A reaction to medicines
  • An intestinal disease, such as inflammatory bowel disease
  • A problem with how your stomach and bowels work (functional bowel disorder), such as irritable bowel syndrome
  • A result of surgery on the stomach or gallbladder
  • Recent antibiotic use
  • Metabolic problems such as thyroid conditions
  • Other less common reasons such as damage from radiation treatments or tumors that make too many hormones

Many people get traveler's diarrhea. This happens when you have food or water that is not safe because of bacteria, parasites, and even food poisoning.

Severe diarrhea may mean you have a serious disease. See your healthcare provider if your symptoms don’t go away or if they keep you from doing your daily activities. It may be hard to find out what is causing your diarrhea.

What are the symptoms of diarrhea?

Each person’s symptoms may vary. Symptoms of diarrhea may include:

  • Belly (abdominal) cramps
  • Stomach pain
  • Swelling (bloating)
  • Upset stomach (nausea or vomiting)
  • Urgent need to go to the bathroom
  • Fever
  • Bloody stools
  • Loss of body fluids (dehydration)
  • Leaking stool and not being able to control your bowels (incontinence)

Dehydration is a serious side effect of diarrhea. Symptoms include:

  • Feeling thirsty
  • Not urinating as often
  • Having dry skin as well as a dry mouth and nostrils (mucous membranes)
  • Feeling very tired
  • Feeling that you may pass out or faint (lightheaded)
  • Headaches
  • Fast heart rate

Diarrhea symptoms may look like other health problems. Bloody diarrhea is always a concern. Always see your healthcare provider to be sure. Tell the healthcare provider about any bleeding, fever, or vomiting.

How is diarrhea diagnosed?

To see if you have diarrhea, your healthcare provider will give you a physical exam and ask about your past health. You may also have lab tests to check your blood and urine.

Other tests may include:

  • Stool studies including culture and other tests. This test checks for any abnormal bacteria or parasites in your digestive tract that may cause diarrhea and other problems. To do this test, a small stool sample is taken and sent to a lab.
  • Sigmoidoscopy. This test lets your healthcare provider check the inside of part of your large intestine. It helps tell what is causing diarrhea. A short, flexible, lighted tube (sigmoidoscope) is put into your intestine through the rectum. This tube blows air into your intestine to make it swell. This makes it easier to see inside. A biopsy can be taken if needed.
  • Colonoscopy. This test looks at the full length of your large intestine. It can help check for any abnormal growths, tissue that is red or swollen, sores (ulcers), or bleeding. A long, flexible, lighted tube (colonoscope) is put into your rectum up into the colon. This tube lets your healthcare provider see the lining of your colon and take out a tissue sample (biopsy) to test it. They can also treat some problems that may be found.
  • Imaging tests. These tests can see if there are any problems with the way your organs are formed (structural abnormalities).
  • Fasting tests. These tests show if you are unable to digest certain foods (food intolerance). They can also tell if certain foods bring on an immune system reaction (food allergy).
  • Blood tests. These can look for metabolic problems like thyroid disease, anemia (low blood count), low vitamin levels that can mean poor absorption, and celiac disease, among other things.

How is diarrhea treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

In most cases, you will need to replace the fluids you have lost. If dehydration is severe, the best replacement is called an oral rehydration solution instead of fruit juice or sports drinks. You may also need a medicine that fights infection (antibiotic) if a bacterial infection is causing your diarrhea. Antidiarrhea medicines are commonly used, but they should not be used if you have bloody diarrhea or diarrhea with a fever.

What are possible complications of diarrhea?

If your diarrhea is not treated, you are at risk for dehydration. Severe dehydration can lead to organ damage, shock, and fainting (loss of consciousness) or coma, and even death.

What can I do to prevent diarrhea?

Having good personal habits can keep you from getting diarrhea caused by bacteria or a virus. It is important to:

  • Wash your hands often.
  • Use alcohol-based sanitizers.
  • Eat foods that have been cleaned and cooked in a safe way.
  • Not take any foods or liquids that may have been infected with a bacteria or virus.

When you are traveling, make sure anything you eat and drink is safe. This is even more important if you travel to developing countries.

Travel safety tips for water and other liquids include:

  • Not drinking tap water or using it to brush your teeth
  • Not using ice made from tap water
  • Not drinking milk or milk items that have not gone through a process to kill certain bacteria (pasteurization)

Travel safety tips for food include:

  • Not eating any fresh or raw fruits and vegetables unless you wash and peel them yourself
  • Making sure all meat and fish have been cooked to at least medium doneness
  • Not eating raw or rare-cooked meat or fish
  • Making sure meat and shellfish such as shrimp, crab, and scallops are hot when served
  • Not eating food from street vendors or food trucks

Living with diarrhea

In most cases, diarrhea is a short-term problem. Often it only lasts for a few days. Be sure to take plenty of liquids when you’re having a bout of diarrhea.

Some health problems can make diarrhea last longer or keep coming back. These include inflammatory bowel disease and irritable bowel syndrome. If another health problem is causing your diarrhea, follow your healthcare provider’s advice for treating that problem.

When should I call my healthcare provider?

Call your healthcare provider if:

  • You have diarrhea more often.
  • You have a greater amount of diarrhea.
  • You have symptoms of dehydration. You may feel thirsty, tired, or dizzy. You may also have less urine or a dry mouth.
  • You have diarrhea with rectal bleeding or black and tarry stools, a fever, or are vomiting.

Key points about diarrhea

  • Diarrhea is when your stools are loose and watery.
  • You may also need to go to the bathroom more often.
  • Short-term (acute) diarrhea lasts 1 or 2 days.
  • Long-term (chronic) diarrhea lasts several weeks.
  • Diarrhea symptoms may include belly cramps and an urgent need to go to the bathroom.
  • Loss of fluids (dehydration) is one of the more serious side effects.
  • Treatment usually involves replacing lost fluids.
  • You may need an antibiotic medicine if a bacterial infection is the cause.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.
Medical Reviewer: Jen Lehrer MD
Medical Reviewer: Ronald Karlin MD
Medical Reviewer: Raymond Kent Turley BSN MSN RN
© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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