Management of Gastroenteritis with Hematochezia in Infants

Diagnostic Approach

The Centers for Disease Control and Prevention recommends assessing dehydration severity as this increases risk of life-threatening illness and death, especially in infants 1
Look for specific signs by severity level:
Obtain accurate body weight and check for adequate bowel sounds before initiating oral therapy 2
Visual examination of stool to confirm blood presence 2
The American Academy of Pediatrics suggests obtaining stool testing for Shiga toxin-producing organisms (STEC), Salmonella, Shigella, Campylobacter, and Yersinia in infants with bloody diarrhea 1
STEC testing should use tests that detect Shiga toxin or genes encoding them, distinguishing O157:H7 from non-O157 strains 1

The World Health Organization recommends oral rehydration solution (ORS) as the primary treatment for most infants with gastroenteritis and dehydration 2
For severe dehydration (>5% dehydrated, lethargic, hypovolemic): initiate IV boluses of isotonic saline or Ringer's lactate 4
Goal is normalization of blood pressure and heart rate 4
Do NOT use antidiarrheal agents (loperamide, kaolin-pectin, antimotility drugs) in infants with gastroenteritis 2
Hold antibiotics until pathogen identification in most cases, except for confirmed Salmonella, Shigella, or Campylobacter after susceptibility testing 1
NEVER give antibiotics if STEC is suspected or confirmed, as this increases risk of hemolytic uremic syndrome (HUS) 1

Hemodynamic instability despite fluid resuscitation requires urgent intervention 4
Signs of sepsis, altered mental status or severe lethargy, and persistent or worsening bloody diarrhea are red flags 1, 2
Monitor for hemolytic uremic syndrome development, especially if STEC is identified 1
STEC, particularly those producing Shiga toxin 2, carry higher HUS risk 1
Shigella dysenteriae type 1 can also cause HUS 1