Gastroenteritis in children: principles of diagnosis and treatment.

Gastroenteritis in children is a common reason for visits to family physicians. Most cases of gastroenteritis have a viral etiology and are self-limited. However, more severe or prolonged cases of gastroenteritis can result in dehydration with significant morbidity and mortality. This is often the scenario in third-world countries, where gastroenteritis results in 3 million deaths annually. A proper clinical evaluation will allow the physician to estimate the percentage of dehydration and determine appropriate therapy. In some situations, laboratory studies such as determination of blood urea nitrogen and serum electrolytes may be helpful. Stool studies are indicated if a child is having bloody diarrhea or if an unusual etiology is suspected, such as Escherichia coli O157:H7 or Cryptosporidium. Most children with gastroenteritis can be treated with physiologically balanced oral rehydration solutions. In children who are hypovolemic, lethargic and estimated to be more than 5 percent dehydrated, initial treatment with intravenous boluses of isotonic saline or Ringer's lactate may be required. Children with severe diarrhea need nutrition to restore digestive function and, generally, food should not be withheld.