Symptoms & 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:
- an urgent need to use the bathroom
- loss of control of bowel movements
- pain in the abdomen
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
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.
Symptoms of dehydration in adults may include:
- 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
- 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
Symptoms of malabsorption in adults may include
Symptoms of malabsorption in infants, toddlers, and young children may include
- changes in appetite
- 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.
Three types of infections that cause diarrhea include
Bacterial infections. Several types of bacteria can enter your body through contaminated food or water and cause diarrhea. Common bacteria that cause diarrhea include Campylobacter, Escherichia coli (E. coli), Salmonella, and Shigella.
- Parasitic infections. Parasites can enter your body through food or water and settle in your digestive tract. Parasites that cause diarrhea include Cryptosporidium enteritis, Entamoeba histolytica, and Giardia lamblia.
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 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.
Side effects of medicines
Some infections, food allergies and intolerances, digestive tract problems, abdominal surgery, and long-term use of medicines can cause chronic diarrhea.
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
- celiac disease
- Crohn’s disease
- irritable bowel syndrome and other functional gastrointestinal (GI) disorders
- small intestinal bacterial overgrowth
- ulcerative colitis
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 Clostridioides difficile, a bacterium that can cause chronic diarrhea.
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. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.