Diarrhea in Children - Acute

Evaluation of the Child with Diarrhea

Diarrhea is a common childhood complaint and is characterized by loose, watery stools. The differential diagnosis for diarrhea is initially broad, including infectious, dietary and malabsorbtive processes, and a thorough history and physical is an important first step in its evaluation. 

A proper history should ask for recent travel history, known exposures or sick contacts including daycare attendance, recent medication changes or antibiotic use, and a complete past medical history, including previous episodes of diarrhea. If available, a weight can be compared to a recent weight in order to help gague dehydration though this value is often unabailable. Dehydration can be assessed as follows: 

  1. Mild dehydration( 3-5%)- mucous membranes are slightly dry but vital signs are normal and there is normal capillary refill and skin turgor. Tears are usually present and child is alert.
  2. Moderate dehydration (6-9%)- increased heart and respiratory rate and slightly prolonged capillary refill, and tenting of the skin. Lack of tears and the child isbecoming listless.
  3. Severe dehydration(>10%)- blood pressure is decreased and the child is very lethargic. Mucous membranes are very dry. Skin is cold and clammy.

Differential Diagnosis

  1. Malabsorptive - Lactase deficiency, increased intake of hyperosmolar fluids.
  2. Medication side effect - common with Amoxicillin and other antibiotics. 
  3. Viral- usually watery diarrhea without blood. Often have accompanying vomiting and fever. Common culprits are Rotovirus, Norwalk Virus, and Adenovirus. 
  4. Bacterial- either invasive or produce toxins
  • Salmonella- invasive. Causes short-lived illness with fever, vomiting, sometimes bloody stools. Usually doesn't require treatment
  • Shigella- invasive. Causes bloody, mucousy stools. Usually requires antibiotic treatment. May be associated with seizures
  • Campylobacteria- usually watery but also may cause bloody stools. May require antibiotic treatment in severe prolonged cases with Erythromycin
  • Yersinia- 10% bloody diarrhea and often with accompanying systemic symptoms. No treatment necessary in most cases.
  • E. Coli- usually watery, but may be bloody in the case of O157:H7 strain. Also associated with Hemolytic Uremic Syndrome (HUS)
  • Staphylococcal-responsible for food poisoning. Toxin is in the food and symptoms frequently appear 6-12 hours after ingestion. Often with vomiting. Short lived. 
  • Cryptosporidium- watery stools usually without blood. Common in immunocompromised population.
  • Giardia- often from contaminated water in certain areas. Bloating and abdominal pain is present, bulky greasy stools. Usually not bloody.
  • Protozoan


Most cases of acute diarrhea do not require any laboratory investigations. If the child has bloody stools, cultures may be indicated and if there is severe dehydration, electrolytes should be checked.

Most cases can be treated with oral rehydration solutions. Exceptions are for severely dehyrated children, if there is persistent vomiting, or the child refuses to drink. Oral rehydration solutions should contain 75-90 meq of sodium, glucose, and potassium. The closest over-the -counter solution availabe are Pedialyte and Infalyte. The child's losses and maintenance requirements should be calculated and small amounts at a time should be offered to meet these requirements. If you give too much at one time you may induce vomiting. Only giving Soft drinks, juices, sport drinks, water and tea should be avoided because they lack electrolytes and are hyperosmolar. They may induce more diarrhea, and can cause hyponatremia due to increased free water load. It is important to emphasize to the parents that this mode of treatment will not decrease the amount of stool initially. [The child in the case has a deficit of 500cc (50cc/kg.). Maintenance requirement of 40cc/hr., and to correct the deficit after 6 hours, needs about 125cc./hr. 2 tbs./15 minutes will provide the child's needs. Ongoing losses should be corrected with 10cc/kg per stool.]

If the mother is nursing, breastfeeding shouldn't be interupted and if formula feeding may be continued. It has been shown that starving may lead to villous atrophy so feeding is recommended. The BRAT (bananas, rice, applesauce, tea/toast) diet and other foods high in carbohydrates are recommended to enhance fluid and sodium absorption. but should not be given alone given inadequate nutritional value.

Any medication that slows intestinal motility and allow overgrowth of organisms should be avoided. Imodium and Lomotil can also cause ileus, bloating, respiratory depression, and drowsiness.


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