Diarrea

• The mainstay of management of infectious diarrheal illness in children remains supportive care with oral or intravenous rehydration
• In the postvaccine era, norovirus has supplanted rotavirus as the leading cause of gastroenteritis presenting to medical facilities in the United States
• After reading the article, the reader should be able to:

  • Recognize common pathogens associated with infectious diarrhea and develop a management plan
  • Identify key differences between infectious and noninfectious causes of diarrhea
  • Effectively treat a child with cow milk protein intolerance
  • Understand that antidiarrheal and antimotility agents are not indicated in the treatment of infectious diarrhea
  • Understand the changing epidemiology of infectious diarrhea in the postvaccine era
• Diarrhea is the second leading cause of death in children under 5 years old, accounting for 760,000 deaths per year in this age group
• Stools that are more frequent or looser in consistency than an individual’s regular stools are generally regarded as diarrhea
• Classifying diarrhea based on timing and content is clinically useful:

  • Acute watery diarrhea lasting several hours to days
  • Acute bloody diarrhea or dysentery
  • Prolonged diarrhea lasting 7 to 14 days and persistent diarrhea lasting 14 days or longer
  • Diarrhea with severe malnutrition, which places the child at high risk for complications
• Acute watery diarrhea is generally viral- or toxin-mediated, requiring replacement of ongoing fluid losses and reassurance
• Acute bloody diarrhea is an urgent issue that requires quick action and necessitates collection of a stool sample for culture
• Diarrhea that persists longer than 14 days may be infectious, represent the unmasking of a chronic illness, or be a complication of acute gastroenteritis
• Chronic illnesses that may present as acute and persistent diarrhea include celiac disease and inflammatory bowel disease
• Diarrhea in the setting of severe malnutrition, especially vitamin A deficiency and zinc deficiency, is deserving of its own category due to the increased risk of severe complications and even death
• Viral gastroenteritis:

  • Common viral pathogens in the US are norovirus and rotavirus
  • Norovirus has overtaken rotavirus as the leading cause of medical visits related to viral gastroenteritis in the US
  • Rotavirus is a key pathogen in global childhood morbidity and mortality related to diarrheal illness
• Bacterial gastroenteritis:

  • Bacterial infections are an important cause of acute diarrheal disease in children
  • Clinical findings suggesting a bacterial pathogen include high temperature, bloody stools, severe abdominal pain, and central nervous system involvement
• Salmonella gastroenteritis treatment:

  • Optimal duration not defined, but expert opinions suggest a 5- to 7-day course of antibiotics
• Shigella species:

  • Most common cause of bloody diarrhea in children
  • Only 10 to 100 organisms needed for person-to-person transmission
  • Symptoms: fever, malaise, watery diarrhea, tenesmus, crampy abdominal pain
  • Blood and mucus in stools by the second day of illness
  • Infection usually self-limited, resolves in 48 to 72 hours after symptom onset
  • Treatment with antibiotics reserved for severe cases or hospitalization
• Campylobacter jejuni:

  • Common cause of bacterial gastroenteritis worldwide
  • Peaks in children under 2 years and young adults in developed countries
  • Symptoms: mild diarrhea to frank dysentery, fever, malaise, nausea, abdominal pain
  • Stool culture for diagnosis
  • Most children recover in 1 week without specific antimicrobial treatment
  • Severe cases or outbreaks in child care settings treated with a 5-day course of erythromycin
• Escherichia coli:

  • Diarrheagenic strains have virulence factors producing distinct clinical presentations
  • E coli O157:H7 infection presents with bloody diarrhea, can lead to HUS in up to 20% of affected individuals
  • Hospitalization recommended for volume expansion with IV fluids
  • Avoid antimicrobials due to risk of developing HUS
  • Infection control measures crucial
• Clostridium difficile:

  • Increasingly prevalent cause of diarrhea in children
  • Discontinuation of antimicrobial agents often first step in treatment
  • Oral metronidazole for 10 to 14 days recommended as initial treatment
  • Recurrent infections may require repeated courses of metronidazole or oral vancomycin
  • Fecal microbiota transplant (FMT) used in refractory cases
• Noninfectious causes of diarrhea in children:

  • Carbohydrate malabsorption, functional diarrhea, inflammatory bowel disease, pancreatic insufficiency, immunodeficiency syndromes, motility disorders, neuroendocrine tumors, hyperthyroidism, congenital diarrhea, drug-related causes
• Diagnostic considerations for persistent diarrhea:

  • Stepwise approach based on history and child's age
  • Evaluation for infections, celiac disease, intractable diarrhea of infancy, pancreatic insufficiency, inflammatory bowel disease in children not gaining weight
• Evaluation for a child not gaining weight might include:

  • Persistent infections
  • Celiac disease
  • Intractable diarrhea of infancy
  • Pancreatic insufficiency
  • Inflammatory bowel disease
• Evaluation for acute diarrhea in infants and toddlers should be considered if:

  • Moderate-to-severe illness in a child younger than 3 months
  • Severe underlying disease such as diabetes or renal failure
  • Persistent vomiting
• Assessment of dehydration in children with acute gastroenteritis includes:

  • Comparing pre-illness bodyweight to current weight to calculate the percentage of weight loss
  • Using a global assessment method like skin turgor, sunken eyes, general appearance, capillary refill time, mucous membranes, or a validated scoring tool like the Clinical Dehydration Scale
• Categories of dehydration severity are:

  • No or minimal dehydration
  • Mild-to-moderate dehydration
  • Severe dehydration
• Laboratory tests are not recommended in the routine assessment of dehydration
• Episodes of acute gastroenteritis in children generally do not require a specific diagnostic evaluation
• Vaccinations have significantly reduced diarrhea-associated healthcare use and medical expenditures since the introduction of rotavirus vaccine in the United States in 2006
• Oral rehydration with reduced-osmolarity oral rehydration solution (ORS) is the first-line treatment for children with acute gastroenteritis
• Parenteral rehydration should be limited to select circumstances, including shock, severe dehydration with altered level of consciousness, or persistent vomiting that compromises oral or nasogastric tube hydration
• The two pillars of management in acute gastroenteritis are immediate oral rehydration and rapid reintroduction of regular feeding following initial fluid rehydration
• Indications for hospitalization in children with acute gastroenteritis include shock, severe dehydration, neurologic abnormalities, intractable or bilious vomiting, failure of oral rehydration, and concern for a surgical abdomen
• The routine use of antiemetics in the treatment of acute gastroenteritis in children is controversial
• Ondansetron therapy has been shown to decrease the risk for persistent vomiting, the need for IV fluids, and the risk of immediate hospital admission in children with vomiting related to acute gastroenteritis
• Increased diarrhea frequency is one of the most common adverse effects of ondansetron
• Safety considerations must be taken into account when prescribing ondansetron, considering the FDA's "black box" alert recommending electrocardiographic monitoring in patients with electrolyte abnormalities who are receiving ondansetron
• FDA recommends electrocardiographic monitoring in patients with electrolyte abnormalities who are receiving ondansetron due to the risk of developing prolongation of the QT interval that can lead to a potentially fatal ventricular tachydysrhythmia
• Antimotility agents like loperamide are usually contraindicated in the treatment of childhood Acute Gastroenteritis (AGE)
• Most guidelines state that antimotility agents are not indicated in children with AGE, especially those younger than age 3 years
• Probiotics in children with acute and persistent diarrhea are associated with reduced severity and duration of illness
• Prebiotics have failed to show a significant decrease in diarrheal severity or length of illness in children and are not routinely recommended