Symptoms and Causes of Diarrhea

What are the symptoms of diarrhea?

The main symptom of diarrhea is passing loose, watery stools three or more times a day.

People with diarrhea may also have one or more of the following symptoms:

People with diarrhea caused by some infections may also have one or more of the following symptoms:

  • bloody stools
  • fever and chills
  • light-headedness and dizziness
  • vomiting

Diarrhea may cause dehydration and malabsorption.

What are the symptoms of dehydration and malabsorption?

Dehydration and malabsorption can be serious complications of diarrhea. Their symptoms in adults, infants, toddlers, and young children are as follows.

Dehydration

Symptoms of dehydration in adults may include:

  • thirst
  • urinating less than usual
  • feeling tired
  • dark-colored urine
  • dry mouth
  • decreased skin turgor, meaning that when your skin is pinched and released, the skin does not flatten back to normal right away
  • sunken eyes or cheeks
  • light-headedness or fainting

Signs of dehydration in infants, toddlers, and young children may include

  • thirst
  • urinating less than usual, or no wet diapers for 3 hours or more
  • lack of energy
  • dry mouth
  • no tears when crying
  • decreased skin turgor
  • sunken eyes, cheeks, or soft spot in the skull

Malabsorption

Symptoms of malabsorption in adults may include

  • bloating
  • changes in appetite
  • gas
  • loose, greasy, foul-smelling bowel movements
  • weight loss

Symptoms of malabsorption in infants, toddlers, and young children may include

  • bloating
  • changes in appetite
  • gas
  • loose, greasy, foul-smelling bowel movements
  • weight loss or poor weight gain

What causes diarrhea?

Acute and persistent diarrhea may have causes that are different from those of chronic diarrhea. In many cases, doctors do not find the cause of diarrhea. Most diarrhea goes away on its own within 4 days, and finding the cause is not necessary.

Acute and persistent diarrhea

The most common causes of acute and persistent diarrhea are infections, travelers’ diarrhea, and side effects of medicines.

Infections

Three types of infections that cause diarrhea include

Infections in the digestive tract that spread through foods or drinks are called foodborne illnesses.

Infections lasting more than 2 weeks and less than 4 weeks can cause persistent diarrhea.

Travelers’ diarrhea

Travelers’ diarrhea is caused by eating food or drinking water contaminated with bacteria, viruses, or parasites. Travelers’ diarrhea is most often acute. However, some parasites cause diarrhea that lasts longer. Travelers’ diarrhea can be a problem for people traveling to developing countries.

Man and woman having picnic lunch outside
Travelers’ diarrhea can be a problem for people traveling to developing countries.

Side effects of medicines

Many medicines may cause diarrhea. Medicines that may cause diarrhea include antibiotics, antacids containing magnesium, and medicines used to treat cancer.

Chronic diarrhea

Some infections, food allergies and intolerances, digestive tract problems, abdominal surgery, and long-term use of medicines can cause chronic diarrhea.

Infections

Some infections from bacteria and parasites that cause diarrhea do not go away quickly without treatment. Also, after an infection, people may have problems digesting carbohydrates such as lactose or proteins in foods such as cow’s milk, milk products, or soy. Problems digesting carbohydrates or proteins can prolong diarrhea.

Food allergies and intolerances

Allergies to foods such as cow’s milk, soy, cereal grains, eggs, and seafood may cause chronic diarrhea.

Lactose intolerance is a common condition that may cause diarrhea after eating foods or drinking liquids that contain milk or milk products.

Fructose intolerance is a condition that may cause diarrhea after eating foods or drinking liquids that contain fructose, a sugar found in fruits, fruit juices, and honey. Fructose is added to many foods and soft drinks as a sweetener called high-fructose corn syrup.

Sugar alcohols such as sorbitol, mannitol, and xylitol may cause diarrhea in some people. Sugar-free candies and gum often include these sugar alcohols.

Digestive tract problems

Digestive tract problems that may cause chronic diarrhea include

Abdominal surgery

You may develop chronic diarrhea after abdominal surgery. Abdominal surgery is an operation on the appendix, gallbladder, large intestine, liver, pancreas, small intestine, spleen, or stomach.

Long-term use of medicines

Medicines that must be taken for a long time may cause chronic diarrhea. Some medicines, such as antibiotics, can change the normal gut flora and increase your chances of infection with Clostridium difficile, a bacterium that can cause chronic diarrhea.

November 2016
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This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.