What is Diarrhea

People suffering from diarrhea experience frequent, loose, watery stools. This disorder can affect people of all ages but is particularly worrisome in the young and old because of the threat of dehydration. Diarrhea lasting for more than 2 days may be a sign of a more serious problem.

Acute diarrhea

Physicians talk about two types of diarrhea. Acute diarrhea can be caused by bacterial, viral, or parasitic infections, food intolerance, or reactions to medicine and lasts a short time.

Chronic diarrhea

Chronic diarrhea is usually related to other digestive disorders such as irritable bowel syndrome or inflammatory bowel disease and may last for the duration of the illness. Diarrhea can be a symptom of intestinal infection, celiac disease or lactose intolerance.

Traveler's diarrhea

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's diarrhea can be a problem for people visiting developing countries

Is diarrhea common?

Research funding for diarrhea is very low in spite of the high mortality rates. Each year, 4.5 billion people contract diarrhea worldwide. In Canada, 86% of acute gastrointestinal illnesses involve diarrhea and approximately 25% of people taking antibiotic medicines develop diarrhea. Over-the-counter retail sales for diarrhea remedies doubled between 2003 and 2008 to equal $50 million in 2008.

What causes diarrhea?

Food intolerances or allergies may be the cause of your diarrhea. Your doctor may ask you to avoid lactose, carbohydrates, wheat, or other foods. If you diarrhea stops when these items are removed from your diet, curing your diarrhea may involve changing your diet.

If the cause of your diarrhea is not easily determined and it does not resolve itself, your doctor may send you for a sigmoidoscopy, colonoscopy or imaging tests to have a look at your digestive tract from the inside.

Can I prevent diarrhea?

Trying a bulking agent such as psyllium may be helpful. Bulking agents help hold water in the stool and add bulk which may slow your bowel movements down. Don't be confused by labels that say bulking agents are for constipation. These products can be helpful for both diarrhea and constipation.

You may also try to avoid foods that have a tendency to aggravate your diarrhea. These include caffeine, milk products, and foods that are greasy, high in fibre and/or very sweet.

Living Positively

Managing diarrhea

Treatment of diarrhea involves replacing lost fluid and electrolytes. Depending on the cause of the problem, a person might also need medication to stop the diarrhea or treat an infection. Children may need an oral rehydration solution to replace lost fluid and electrolytes.

Keep a food diary if diarrhea occurs intermittently

Monitor the foods you eat and the reactions your body has. This may help identify a food intolerance or celiac disease which would explain your diarrhea and allow you to make a decision to change your diet and relieve your diarrhea.

It is important to remember that if you have diarrhea for several days or develop a new onset of diarrhea, fever or severe abdominal pain, you should see your doctor.


  • There are about 2 billion cases of diarrheal disease worldwide every year. (World Gastroenterology Organisation 2012)
  • Chronic diarrhea is usually related to other digestive disorders such as inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS). Diarrhea can also be a symptom of intestinal infection, celiac disease or lactose intolerance.
  • In the Western population, the estimated prevalence of chronic diarrhea is 4 to 5%. (Arasaradnam et al. 2018)
  • Acute diarrhea is the second most common reason travellers returning from developing countries seek medical attention. (Hatchette et al. 2011)
  • The incidence of travellers’ diarrhea ranges from 20 to 90% among those travelling up to two weeks in high risk regions (low and middle income countries). (The Committee to Advise on Tropical Medicine and Travel 2015)
  • A 2017 study in the US demonstrated that on average, each patient with IBS with diarrhea spent US$2,268 more per year, of which 78% were from medical costs and 22% were from prescription costs. (Buono et al. 2017)
  • In 2008, Canadians spent $50 million on diarrheal remedies. (Fedorak et al. 2012) 


Arasaradnam RP et al. Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition. Gut. 2018 Aug;67(8):1380-99.

Buono JL et al. Economic burden of irritable bowel syndrome with diarrhea: Retrospective analysis of a U.S. commercially insured population. J Manag Care Spec Pharm. 2017 Apr;23(4):453-60.

Fedorak RN et al. Canadian Digestive Health Foundation Public Impact Series 3: Irritable bowel syndrome in Canada. Incidence, prevalence, and direct and indirect economic impact. Can J Gastroenterol. 2012 May;26(5):252-6.

Hatchette TF and Farina D. Infectious diarrhea: When to test and when to treat. CMAJ. 2011 Feb 22; 183(3):339-44.

The Committee to Advise on Tropical Medicine and Travel. 2015. An Advisory Committee Statement Committee to Advise on Tropical Medicine and Travel. https://www.canada.ca/en/public-health/services/travel-health/about-catmat/statement-travellers-diarrhea.html [accessed 3 September 2018]

World Gastroenterology Organisation. 2012. World Gastroenterology Organisation Global Guidelines. Acute diarrhea in adults and children: A global perspective. http://www.nghd.pt/nghd/images/Acute_Diarrhea.pdf [accessed 3 September 2018]

Signs and Symptoms

Diarrhea may be accompanied by cramping, abdominal pain, bloating, nausea, or an urgent need to use the bathroom. Sometimes diarrhea may be accompanied by fever or bloody stools and/or severe pain in the abdominal or rectum. If you experience these symptoms or dehydration, you need to see your doctor.

Signs of dehydration that accompany diarrhea may include:

  • thirst,
  • infrequent urination,
  • dark-colored urine,
  • dry skin,
  • fatigue,
  • light-headedness.

If you have a child with diarrhea, watch carefully for additional indicators of dehydration which may include:

  • dry mouth,
  • tearless crying,
  • dry diapers,
  • sunken abdomen, eyes, or cheeks

A child can die from dehydration within a few days so it is very important to contact your doctor immediately if you child has diarrhea for more than a day.

Diarrhea as a symptom of the Coronavirus (COVID-19)

Diarrhea. You know if you have THIS digestive condition. People who suffer from diarrhea experience loose, watery stools more frequently than normal and often experience a sense of urgency to go. Generally, there are two types of diarrhea, acute and chronic. Acute diarrhea lasts a short time, about three to 5 days. Chronic diarrhea is usually related to other digestive disorders such as irritable bowel syndrome or inflammatory bowel disease and may last for as long as you have the illness. Most recently, diarrhea has been added as a symptom of the coronavirus (COVID-19).

According to the World Health Organization, the most common symptoms of COVID-19 are:

  • Fever
  • Tiredness
  • Dry cough
  • Difficulty breathing

With some patients experiencing the following:

  • Aches and pains
  • Nasal congestion
  • Runny nose
  • Sore throat
  • Diarrhea

Some people become infected but don’t develop any symptoms or feel unwell at all!

We’ve seen the most common list of COVID-19 symptoms repeatedly on the TV, in news articles, and from our friends and family. However, as doctors learn more about COVID-19, a new study has shown that digestive symptoms, in particular diarrhea, could be a symptom for people who have a mild form of COVID-19 (without difficulty breathing or low blood oxygen levels).  In this study published in the American Journal of Gastroenterology, patients in this unique sub-group showed that diarrhea can be the initial presentation of COVID-19, and patients may only later or never present respiratory symptoms or a fever.

In more detail, this study showed that 23% of patients were admitted with digestive symptoms, 43% with respiratory symptoms only, and 33% with both respiratory and gastrointestinal (gastro) symptoms. Among the patients with gastro symptoms, 67% of them had diarrhea, and 20% experienced diarrhea as the first symptom of their illness. Diarrhea lasted an average of 5 days, and about one-third of patients with gastro symptoms never experienced a fever. The study also found that those with gastrointestinal symptoms were much more likely to have the coronavirus (SARS-CoV-2) detected in their stool samples, with about 73% of patients testing positively compared with 14% of those with respiratory symptoms only. 

The authors of this study note that because gastro problems are so common, having diarrhea doesn’t necessarily mean that a person has COVID-19.  But this study does tell us that diarrhea can be a vital warning-sign. If patients experience new-onset gastrointestinal symptoms after possibly coming into contact with someone who has COVID-19, they should be suspected for the illness, EVEN in the absence of cough, shortness of breath, sore throat, or fever.

This study came about after previous research, also published in the American Journal of Gastroenterology found that 50% of a group of 200 patients with COVID-19 in Wuhan, China reported at least one gastro symptom, with 18% reporting diarrhea, vomiting, or abdominal pain. This study focused on patients with severe COVID-19, rather than a mild form.

It’s important to note that both studies were relatively small, so larger studies are needed to describe digestive symptoms in patients with COVID-19. We will update this article as new information becomes available.

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Tests and Treatment

Testing for diarrhea

Often diagnosis is based on questions your doctor asks about your eating habits, recent use of medications, recent travel experiences and physical examination.

  • Stool cultures can be analyzed in a laboratory to check for bacteria, parasites, or other signs of disease and infection.
  • Blood tests help rule out certain diseases.
  • Allergy tests and determining food intolerances: Often times, diarrhea is caused due to an intolerance or allergy to certain types of foods. Talk to your doctor about working on an elimination diet to determine of the things you are eating are causing your diarrhea. Things like lactose, wheat, and carbohydrates are often the culprits.

Treating diarrhea

In most cases of diarrhea, replacing lost fluid to prevent dehydration is the only treatment necessary.

Fluid and electrolytes that help our bodies function are lost when we have diarrhea. These need to be replaced quickly. Water does not contain electrolytes. Broth and soups that contain sodium, and fruit juices, soft fruits, or vegetables that contain potassium, help restore electrolyte levels. Over-the-counter rehydration solutions such as Pedialyte, Ceralyte, and Infalyte are also good electrolyte sources, especially for children.


Medicines that stop diarrhea may be helpful, but they are unlikely to resolve the problem if your diarrhea is caused by a bacterial infection or parasite. In these cases, doctors usually prescribe antibiotics. If a viral infection is the cause of your diarrhea, you may or may not be treated with medication depending on the severity of the infection and type of virus.


I am travelling to a developing country and am afraid of developing traveller’s diarrhea. What can I do to protect myself?

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. Although there are antibiotic prophylaxis available, they are not recommended in most cases. While you are travelling, wash your hands with warm, soapy water, drink bottled water and eat food that are served warm and cooked thoroughly. Try to avoid tap water (including ice), dairy products, raw vegetables, uncooked meats, and seafood. Foods that are usually safe to drink include hot coffee and tea, beer, wine and carbonated beverages. Fruits and vegetables that can be peeled are generally safe to eat.

Can you die from diarrhea?

Fluid and electrolytes help our bodies function. If we are dehydrated, water and electrolytes are lost and need to be replaced. If a person is severely dehydrated because of diarrhea, they can die. This is why it is important – particularly for children and the elderly – to seek medical attention if they have diarrhea that stretched over into a second day, have severe abdominal pain or cramping, fever or show signs of dehydration.

My symptoms are frequent diarrhea with undigested food in stool. What would cause this?

Diarrhea is a symptom that can result from many different causes. You would be wise to see your doctor. Below are some questions you may be asked by your doctor are:

  • How long have you had this problem?
  • Where you have traveled in the recent past?
  • Were you taking antibiotics before the onset of the diarrhea?
  • Has a new medication been prescribed for you? If so, what and when?
  • What other symptoms are you experiencing? (ie. bleeding, weight loss)

The answers to these questions will help your doctor decide whether you need to be referred to a specialist for further investigation. You may need to have routine blood work done as well as stool tests for bacterial cultures looking for parasites and a special bacterial infection called Clostridium difficile.