Diarrhea in children
Synonyms and keywords: Diarrhea in kids

# Overview
Diarrhea defines as an increase in frequency or change in consistency of stool to become more liquid; which is different than normal for that person is called diarrhea. Causes include infections, diet intolerance, malnutrition, etc. Diarrhea is usually self-limited. Severe cases of dehydration may require treatment.

# Historical Perspective
- Hippocrates first coined the term diarrhea which was derived from the Greek word "diarrhoia", which translates into "flowing through".
- It was described as a symptom of a lot of conditions such as intestinal parasites, cholera, and in relation to improper water and food handling.

# Classification
- Chronic diarrhea in children may be classified according to the following subtypes/groups:
- Osmotic: due to unabsorbed nutrients
- Secretory: due to imbalances in ion secretion
- Mixed: stool osmotic gap (50-100 mOsm)

# Pathophysiology

# Causes
- Diarrhea in children can be divided into acute and chronic causes:   
- Acute:
Use of antibiotics
Gastroenteritis
Allergies
Food poisoning
- Use of antibiotics
- Gastroenteritis
- Allergies
- Food poisoning
- Chronic:
Diet-related
Infectious causes
Autoimmune such as celiac disease
Inflammatory bowel disease
- Diet-related
- Infectious causes
- Autoimmune such as celiac disease
- Inflammatory bowel disease
- Few other causes of chronic diarrhea in children are:
Lactose intolerance
Iirritable bowel syndrome
Non-specific: from consumption of artificially sweetened drinks in a large amount, eg: sports drinks, juice, etc.
- Lactose intolerance
- Iirritable bowel syndrome
- Non-specific: from consumption of artificially sweetened drinks in a large amount, eg: sports drinks, juice, etc.
- Covid-19

# Differentiating Diarrhea in children from other Diseases
For further information about the differential diagnosis, click here.

# Epidemiology and Demographics
- In 2017, 8% of all deaths in children all over the world were due to diarrhea.  
- 2-3 million deaths per year occur every year due to acute diarrhea especially in developing countries.
- 9% of all hospitalizations in the United States under the age of 5 are due to diarrhea.
- In the age group of fewer than 3 years, the incidence of diarrhea is noted to be 1.3-2.3 episodes per child annually.

## Age
- In one study conducted in Hanoi, Vietnam on children <5 years of age with diarrhea; it was found that 40.9% were 1 year and below and 71.0% were 2 years and below.

## Gender
- Female gender has a lower risk of diarrheal disease. 

# Risk Factors
- Travel to countries with poor sanitary conditions, swimming, daycare, sick contacts at home and school, antibiotics usage. Autoimmune conditions such as celiac and inflammatory bowel disease. 

# Natural History, Complications and Prognosis
- Moderate to severe diarrhea can cause dehydration in children. Severe dehydration can cause seizures, dizziness, lack of energy, dry skin, etc. 
- Usually prognosis is good, and most cases resolve in a few days.

# Diagnosis

## Diagnostic Criteria
- The diagnosis of diarrhea is made when either the frequency of bowel movements increases or the consistency of stools becomes looser than what is normal for that child. 

## Symptoms
Signs and symptoms that indicate severe disease: 
- Altered mental status
- Vomiting with bile or blood in it
- Cyanosis
- Increased irritability and/or crying
- Rash
- Fast breathing
- Temperature of 104 F (40C) or more
- Age less than six months or baby with low body weight

## Physical Examination
- Patients with severe diarrhea usually appear toxic.
- Physical examination may be remarkable for:  
- tenderness
- low blood pressure
- dry skin
- history of constipation which may be leading to overflow diarrhea.
- right lower abdominal quadrant tenderness caused by pseudoappendicitis can also be caused by causes like Yersinia enterocolitica, intussusception, hemolytic uremic syndrome, etc.

## Laboratory Findings
- Measurement of serum bicarbonate concentration of more than 15mEq per L is the laboratory finding used to evaluate 5% or less dehydration. Hypernatremic dehydration can be confirmed by serum sodium levels.  
- If there is evidence of blood or mucus in stool, or if the patient is immunocompromised, then stool microbiological tests can be done. They are, however, not required in suspected viral cases.
- Stool culture results can sometimes become available only after 3-5 days, in some infectious causes, the organism is not visible even on stool testing.

## Electrocardiogram
There are no ECG findings associated with diarrhea.

## X-ray
- Usually not indicated but may be done to rule out structural anomalies of the digestive tract. 

## Echocardiography or Ultrasound
- Severe dehydration in children caused by acute diarrhea can be measured by ultrasound evaluation of the ratio of aorta/inferior vena cava. 

## CT scan
There are no CT scan findings associated with diarrhea in children.

## MRI
There are no MRI findings associated with diarrhea in children.

## Other Imaging Findings
There are no other imaging findings associated with diarrhea.

## Other Diagnostic Studies
- Upper gastrointestinal endoscopy or colonoscopy may be done. 

# Treatment

## Medical Therapy
- Fluids to prevent dehydration, especially in babies under six months of age. Artificially sweetened drinks like fruit juices should be avoided as these can make it worse.
- Slow initiation of rehydration drinks which have a perfect mix of water and electrolytes. Feed normally, medications are usually not required. 

## Prevention
- Mainstay is the maintenance of sanitary conditions. Caregivers should wash their own hands and encourage children to do so after changing diapers, before and after handling food, after having contact with pets, after spending time in the garden/ soil.