Diarrhea: Types, Symptoms, Causes, Complications, Diagnosis, Treatment and Prevention



Everyone has suffered from diarrhea at least once in their lifetime. However, diarrhea can be a symptom of an underlying health condition. In fact, it is one of the most common reasons for people to seek medical attention. Diarrhea can range from mild to severe,
with some considered as life-threatening.

Across the globe, there are an estimated 2 billion cases of diarrheal disease every year. About 1.9 million children under the age of 5 years old, mostly living in developing countries, die from diarrhea. Though the condition can be mild and resolve on its own, people from vulnerable groups like infants, children, older adults, and those with weakened immune systems may suffer from potentially-fatal complications of diarrhea.

Diarrhea is described as the increase in the frequency of bowel movements and an increase in the looseness of stool. It is usually caused by the increased secretion of fluid into the intestine, rapid passage of stool in the intestine and decreased absorption of fluid from the intestine.

2Types of Diarrhea

Absolute Diarrhea

This is the type of diarrhea defined as more than five bowel movements in a day.

Relative Diarrhea

This type of diarrhea means that there is an increase in the number of bowel movements in a day or increase the stool’s looseness of stools.

Acute Diarrhea

This type of diarrhea means that diarrhea happened abruptly and lasted only a few days.

Chronic Diarrhea

Chronic diarrhea means a long-standing condition that lasts for weeks or even months.
The most common causes of chronic diarrhea are Crohn disease, ulcerative colitis, inflammatory bowel syndrome and malabsorption syndromes.

Who gets diarrhea?

People of all ages can get diarrhea. In the United States, adults have acute diarrhea at least once a year while younger children may have it twice a year, on average.
However, people in the developing countries may suffer from diarrhea more frequently as a result of contaminated food and water.


Diarrhea has common signs and symptoms including:

  • Abdominal cramps
  • Bloating in the stomach area
  • Loose stools
  • Watery stools
  • Nausea and vomiting
  • Urgent feeling that you need to defecate

More serious symptoms of diarrhea include:

  • Weight loss
  • Fever
  • Blood in the stool
  • Mucus in the stool

When to see a doctor:

In adults, you need to see a doctor if:

  • Diarrhea persists for more than two days
  • Signs of dehydration have emerged
  • You have blood or mucus in your stool
  • You have black stools
  • You have a fever of more than 102 F or 39 C

Diarrhea can be life-threatening for babies and infants. Diarrhea can quickly lead to dehydration. Bring your child to the doctor or hospital if:

  • Dehydration emerges
  • They have fever of more than 102 F or 39 C
  • Has bloody or black stools


Since diarrhea is a very common symptom of various diseases, there are many factors that may cause this condition, including:


Pathogens, which are disease-causing microorganisms, may cause diarrhea.
The viruses that can cause diarrhea include hepatitis A virus, Norwalk virus, and cytomegalovirus. Another common cause of childhood diarrhea is the rotavirus.

On the other hand, bacteria and parasites may also cause diarrhea. The common bacteria that cause diarrhea include salmonella, shigella, and Escherichia coli.  The parasites that may cause diarrhea include the Giardia lamblia and cryptosporidium. These pathogens are commonly found in contaminated food and water.

Irritable Bowel Syndrome (IBS)

This condition is used to describe two diseases namely ulcerative colitis or Crohn’s disease. The common signs and symptoms of this condition include abdominal pain and altered bowel habits – constipation, diarrhea or both.

Lactose Intolerance

Lactose intolerance is a common hypersensitivity condition that may cause diarrhea. Lactose is sugar commonly found in milk and other dairy products. Some people can’t digest this sugar, leading to diarrhea.

Some Medications

Some medications like antibiotics may cause diarrhea. These antibacterial drugs damage both the bad and good bacteria in the abdominal area, disturbing the natural balance of bacteria in the intestines.


When a person undergoes surgical treatments of the abdominal area or gall bladder, diarrhea is a common postoperative complication.


This sugar, which is found in fruits, can cause diarrhea for people with the condition that prevents the breakdown or digestion of fructose.

Digestive Problems

There are other digestive problems that may cause diarrhea like celiac disease and microscopic colitis.

Other Causes:

  • Alcohol abuse
  • Diabetes
  • Allergies to some foods
  • Eating foods that may upset the digestive system
  • Laxative abuse
  • Medications
  • Hyperthyroidism
  • Some cancers
  • Radiation therapy
  • Malabsorption


One of the most common complications of diarrhea is dehydration. Sometimes, especially among vulnerable age groups, this is life-threatening. Dehydration is potentially-fatal in children, older adults and those with weakened immune systems.

Adults and children may manifest varying symptoms of dehydration.

Dehydration in adults may include symptoms like:

  • Excessive thirst
  • Little or no urination
  • Dry mouth or skin
  • Fatigue
  • Body weakness
  • Dizziness
  • Dark-colored urine

Young children may show the symptoms of dehydration such as:

  • Dry diaper in three or more hours
  • Dry mouth and tongue
  • Crying without tears
  • Fever of more than 102 F or 39 C\
  • Irritability
  • Drowsiness
  • Unresponsiveness
  • Sunken eyes, cheeks, and abdomen


To diagnose diarrhea and its possible cause, the doctor may conduct a physical examination and a medical history interview.

The doctor may also ask about the medications you’re taking, your diet, the food you recently consumed and a history of gastrointestinal conditions or surgeries. Other diagnostic tests include:

Stool Exam

 Fecalysis or stool exam may look for the presence of bacteria, parasites and other signs of infection in the stool.

Blood Test

A complete blood count may help test the cause of diarrhea. Moreover, other tests may determine signs of certain diseases.


A colonoscopy is recommended to check on the intestinal linings of the colon.
This is usually done for people with persistent diarrhea.


Most cases of diarrhea can clear on their own within a few days without treatment. However, for mild and acute cases of diarrhea, replacement of fluids is important.

Treatment to replace fluids

The doctor will advise drinking more water and fluids. For most adults, drinking water, broth or juice may help replace lost fluids and electrolytes in the body. If the drinking of fluids can’t be tolerated because of abdominal problems, the fluids may be introduced intravenously.

Children and older people are more susceptible to dehydration and its accompanying complications. Hence, fluid replacement is important. The use of oral rehydration salts or solutions is recommended. According to the World Health Organization (WHO), the use of ORS can effectively treat more than 90 percent of mild to moderate diarrhea cases.


There are some nutritional tips to treat diarrhea including:

  • Sip on clear liquids without sugar to replace lost water.
  • Drink fluids between meals, not during meals
  • Consume high-sodium foods like soups, sports drinks, and broths.
  • Consume high-potassium foods like bananas and skinless potatoes
  • Stay away from certain foods that may make diarrhea worse like fried, sugary and creamy foods. Avoid sugar-free gums, mints, prunes, caffeinated drinks, nuts, grapes, dates, honey and dairy products.

Use of Probiotics

There are various studies that show the role of probiotics in the treatment of diarrhea. In kids, some doctors recommend the use of probiotics to reduce diarrheal illness by one day.


Diarrhea can be accompanied by abdominal discomfort, pain and even dehydration.
Since most cases of diarrhea are caused by bacteria, viruses, and parasites, there are many ways to help prevent it, including:

  • Practice good hygiene
  • Always wash your hands before and after you use the bathroom
  • Wash your hands before eating
  • Wash your hands when you handle your pets or come into contact with their waste
  • Practice proper hand washing by using soap and water
  • If you can’t wash your hands, use a hand sanitizer to kill pathogens on your hands
  • Prevent kids from putting toys into their mouths.
  • Drink only bottled water, even for tooth brushing.
  • When you travel, do not eat street foods and make sure the food you’re eating is safe. Choose established restaurants over those without the proper permits.
  • Avoid eating food from street vendors.
  • Avoid ice made with tap water.
  • Be sure all the meat you consume are well cooked
  • Avoid eating raw meat or seafood
  • Be vaccinated against rotavirus and the hepatitis A virus.

If you prepare foods, make sure they are well-cooked and clean.

  • Keep all potentially contaminated foods away from other foods.
  • Store all perishable food properly. Refrigerate or freeze them.
  • Make sure the meat is cooked properly.
  • Wash all fruits and vegetables properly.
  • Never eat undercooked eggs.
  • Keep all countertops and utensils clean
  • Never handle or cook food when you have diarrhea.

Probiotics can also help prevent diarrhea. Probiotics are live bacteria and yeasts found in some food supplements, drinks, and yogurts. There are studies that show the link between probiotics and a reduced risk of having diarrhea, but the evidence is not strong enough for doctors to recommend taking probiotics.

Before you take these probiotics, make sure that the doctor has recommended them to you. Sometimes, probiotics are given to patients after a long-course of antibiotics, to help restore the stomach’s normal flora and reduce the risk of diarrheal illness.