Hyponatremia is common; hypernatremia is less common. Metabolic acidosis results from losses of bicarbonate in stool, lactic acidosis results from shock, and phosphate retention results from transient prerenal-renal insufficiency. Traditionally therapy for 24 hours with oral rehydration solutions alone is effective for viral diarrhea. Therapy for severe fluid and electrolyte losses involves IV hydration. Less severe degrees of dehydration (<10%) in the absence of excessive vomiting or shock may be managed with oral rehydration solutions containing glucose and electrolytes. Ondansetron may be administered to reduce emesis when persistent.
Antibiotic therapy is necessary only for patients with S. typhi(typhoid fever) and sepsis or bacteremia with signs of systemic toxicity, those with metastatic foci, or infants younger than 3 months with nontyphoidal salmonella. Antibiotic treatment of Shigella produces a bacteriologic cure in 80% of patients after 48 hours, reducing the spread of the disease. Many Shigella sonnei isolates, the predominant strain affecting children, are resistant to amoxicillin and trimethoprim-sulfamethoxazole. Recommended treatment for children is an oral third-generation cephalosporin or a fluoroquinolone for patients 18 years and older.
Treatment of C. difficile (pseudomembranous colitis) includesdiscontinuation of the antibiotic and, if diarrhea is severe, oral metronidazole or vancomycin. E. histolytica dysentery is treatedwith metronidazole followed by a luminal agent, such as iodoquinol. The treatment of G. lamblia is with albendazole, metronidazole, furazolidone, or quinacrine. Nitazoxanide can be usedin children younger than 12 months of age for the treatment ofCryptosporidium.
The major complication of gastroenteritis is dehydration and hypovolemic shock. Seizures may occur with high fever, especially with Shigella. Intestinal abscesses can form with Shigella and Salmonella infections, especially typhoid fever, leading to intestinal perforation, a life-threatening complication. Severe vomiting associated with gastroenteritis can cause esophageal tears or aspiration pneumonia.
Deaths resulting from diarrhea reflect the principal problem of disruption of fluid and electrolyte homeostasis, which leads to dehydration, electrolyte imbalance, vascular instability, and shock. In the United States, approximately 75 to 150 deaths occur annually from diarrheal disease, primarily in children under 1 year of age. These deaths occur in a seasonal pattern between October and February, concurrent with the rotavirus season.
At least 10% of patients who have typhoid fever shed S. typhifor about 3 months, and 4% become chronic carriers. The risk of becoming a chronic carrier is low in children. Ciprofloxacin is recommended for adult carriers with persistent Salmonella excretion.
The most important means of preventing childhood diarrhea is the provision of clean, uncontaminated water and proper hygiene in growing, collecting, and preparing foods. Good hygienic measures, especially good hand washing with soap and water, are the best means of controlling person-to-person spread of most organisms causing gastroenteritis. Similarly poultry products should be considered potentially contaminated with Salmonella and should be handled and cooked appropriately.