Acute Diarrhea

What is acute diarrhea?

Diarrhea is one of the most common illnesses in children and is a common reason for doctor visits. If diarrhea lasts less than one week, it is considered acute; diarrhea that lasts longer than one week is considered chronic.

Diarrhea is an increase in the number of stools per day and/or an increase in their looseness. It is a common problem that generally lasts only a few days. Diarrhea that lasts less than one week is considered “acute”.

How common is diarrhea?

Acute diarrhea is one of the most common illnesses in children and is a common reason for doctor visits. Often it can occur in several members of a family or a classroom at the same time.

The average child younger than 3 years of age will have 1–3 episodes of diarrhea every year. Acute diarrhea accounts for almost 10% of all childhood hospital admissions.

Although diarrhea occurs year-round, it is more common during winter months.

What causes acute diarrhea?

The most common causes of acute diarrhea are:

  • Viruses, bacteria, and parasites
  • Food poisoning
  • Medications, especially antibiotics
  • Food allergies
  • Toxic substances

How does the doctor/nurse determine the cause of my child’s diarrhea?

Your description of the problem often provides the most useful clues to help determine the possible cause of your child’s diarrhea. For example, has your child come in contact with other people with similar symptoms? Has he/she eaten food that was not properly cooked? Did he/she use antibiotics recently? When this description clearly suggests a cause, tests for viruses and bacteria are often not needed.

Exceptions include children with bloody diarrhea or severe diarrhea. Children with bloody diarrhea, severe weight loss, or signs of dehydration (lack of energy, dry mouth/lips, lack of tears when crying, significant decrease in urine per day) should be evaluated promptly by a healthcare professional. In these situations, your doctor may order testing of your child’s blood and stool.

How is diarrhea treated?

Acute diarrhea stops when the body clears the infection or toxin causing the problem. Diarrhea is often caused by viruses, and in these cases antibiotics will not help. In fact, sometimes antibiotics can worsen diarrhea.

Some infections (for example, a bacterium called Shigella, or certain parasites) can be treated, so getting a stool sample to check for these infections may be helpful.

Children with acute diarrhea should continue to eat a regular diet, unless the diarrhea is severe or accompanied by vomiting. Sometimes, restriction of milk and dairy products might be helpful, but is not necessary.

Excessive fluid loss can result in dehydration. This can be avoided by making sure your child is drinking enough fluids to urinate normally. Infants younger than 3 months of age and children who are vomiting are at the highest risk for dehydration. High fever increases the loss of body fluids, so fever should be controlled.

A decrease in the number of wet diapers, lack of tears when crying, and excessive sleepiness are signs of dehydration and require medical attention. When diarrhea is severe or your child is vomiting, replacement fluid mineral drinks such as Pedialyte, Infalyte, Cerealyte, Naturalyte, and Rehydralyte are recommended. These are also available in popsicles.

If your child cannot keep enough fluids in the body, hospitalization and intravenous fluid are recommended to prevent serious dehydration and to allow “bowel rest” until the infection clears. Feedings by mouth will be started as soon as the condition improves and while the child’s response can be watched closely.

The most important way to prevent spread of acute diarrhea is to focus on good hygiene, particularly strict handwashing and prompt cleaning of soiled laundry and surfaces.

Quick Facts:

  • Acute diarrhea is an increase in the daily number and/or looseness of stools that lasts 7 days or less.
  • Most cases of acute diarrhea are caused by infections, including those caused by viruses, bacteria, and parasites.
  • Most cases of acute diarrhea do not require antibiotic treatment and may get worse if antibiotics are used.
  • Treatment of acute diarrhea should focus on maintaining nutrition and identifying and treating dehydration.


Reviewed April 2019
Author: Vincent Mukkada MD

North American Society for Pediatric Gastroenterology, Hepatology and Nutrition
The Association of Pediatric Gastroenterology and Nutrition Nurses
North American Society for Pediatric Gastroenterology, Hepatology and Nutrition Foundation
The NASPGHAN Council For Pediatric Nutrition Professionals
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