What is diarrhea?

Diarrhea is defined as watery stool, increased frequency of bowel movement or both. In most cases, diarrhea in children lasts no more than a few days and goes away on its own. These short-term (or acute) cases of diarrhea are usually related to bacterial or viral infections.

In other cases, diarrhea may last for weeks at a time — this is called chronic diarrhea. Chronic diarrhea may also be caused by infections such as giardia, but is more likely to be caused by a chronic medical condition, such as irritable bowel syndrome, or an inflammatory condition such as ulcerative colitisCrohn’s disease, or celiac disease

Chronic diarrhea in children may indicate a larger health problem. If your child has diarrhea for more than a few days, consult your doctor. For mild diarrhea, you can typically wait for your child to get better and use home care remedies.

According to the National Institutes of Health, you should call your doctor if your newborn (under 3 months old) has diarrhea. Also call your physician if your child has:

  • blood, mucus, or pus in the stool
  • more than eight stools in eight hours
  • vomiting that continues for more than 24 hours
  • fever and diarrhea lasting more than two to three days
  • stomach pain or abdominal cramping
  • diarrhea that develops within one week of travel outside of the United States or after a camping trip (the diarrhea may be due to bacteria or parasites that require treatment)
  • diarrhea that keeps returning, or if your child is losing weight
  • much less activity than normal (not sitting up at all or not looking around)

Severe or chronic diarrhea may indicate a serious disease, and it is important to consult your child's health care provider if the symptoms persist or affect daily activities. Identifying the cause of the problem may be difficult. 

Seek medical help immediately if your child shows signs of dehydration:

  • dry and sticky mouth
  • no urine for six hours
  • no tears when crying
  • sunken eyes

What are the symptoms of diarrhea?

The following are the most common symptoms of diarrhea. However, each child may experience symptoms differently. Severe or chronic diarrhea may indicate a serious disease, making it important to consult your child's health care provider if any or all of the following symptoms persist:

  • cramping
  • abdominal pain
  • bloating
  • nausea
  • urgent need to use the restroom
  • fever
  • bloody stools
  • dehydration
  • incontinence

The symptoms of diarrhea may resemble other conditions or medical problems. Always consult your child's health care provider for a diagnosis.

What are the causes of diarrhea in children?

Diarrhea in children may be caused by a number of conditions, including the following:

  • bacterial infection
  • viral infection
  • food intolerances or allergies
  • parasites
  • reaction to medications
  • intestinal disease, such as inflammatory bowel disease
  • functional bowel disorder, such as irritable bowel syndrome
  • result of surgery on the stomach or gallbladder

Many people suffer "traveler's diarrhea" caused by a bacterial infection or a parasite, or even food poisoning.

How we care for diarrhea

The Boston Children’s Hospital Division of Gastroenterology, Hepatology and Nutrition is part of the #1-ranked children's hospital by U.S. News & World Report. Our team includes the best doctors and clinicians for children, who can help with the diagnosis and treatment of different gastrointestinal diseases, including problematic or chronic diarrhea. For children who have chronic diarrhea with a genetic cause — also called congenital enteropathy — the skilled clinicians in our Congenital Enteropathy Program can offer comprehensive evaluation and treatment.