What is the workup for a 5-year-old female with recurrent episodes of bloody diarrhea?

Workup for a 5-Year-Old Female with Recurrent Bloody Diarrhea

Immediately obtain stool culture and assess for dehydration severity, while avoiding empiric antibiotics unless the child has documented fever with signs of sepsis or bacillary dysentery. 1, 2

Initial Clinical Assessment

Assess dehydration severity by examining:

• Skin turgor, capillary refill time, mental status, mucous membrane moisture, and perfusion of extremities 2, 3
• Rapid deep breathing, which suggests acidosis and correlates with significant dehydration 2
• Body weight to establish baseline fluid deficit 3

Categorize dehydration as mild (3-5% fluid deficit), moderate (6-9% fluid deficit), or severe (≥10% fluid deficit with shock) 2, 3

Essential Laboratory Workup

Obtain stool culture immediately for all children with bloody diarrhea 2, 4

If E. coli O157:H7 or other Shiga toxin-producing E. coli (STEC) is suspected or confirmed:

• Measure complete blood count, blood urea nitrogen, and creatinine to detect early manifestations of hemolytic uremic syndrome (HUS) 1
• Examine peripheral blood smear for red blood cell fragments when HUS is suspected 1

Additional stool workup should include evaluation for:

• Fecal leukocytes, C. difficile, Salmonella, E. coli, Campylobacter, and infectious colitis 1

Critical Decision Point: Antibiotic Use

Do NOT give empiric antibiotics to this immunocompetent 5-year-old with bloody diarrhea 1, 2

The 2017 IDSA guidelines provide strong evidence against routine empiric antibiotics because they significantly increase the risk of HUS when STEC is the cause 1, 2

Exceptions where empiric antibiotics ARE indicated:

• Documented fever in a medical setting PLUS abdominal pain PLUS bacillary dysentery pattern (frequent scant bloody stools, fever, abdominal cramps, tenesmus) presumptively due to Shigella 1
• Recent international travel with body temperature ≥38.5°C and/or signs of sepsis 1

If antibiotics are indicated, use azithromycin as preferred empiric therapy for children based on local susceptibility patterns and travel history 1, 2

Rehydration Protocol

For mild dehydration (3-5% fluid deficit):

• Administer 50 mL/kg oral rehydration solution (ORS) containing 50-90 mEq/L sodium over 2-4 hours 2, 3

For moderate dehydration (6-9% fluid deficit):

• Administer 100 mL/kg ORS over 2-4 hours 2, 3

For severe dehydration (≥10% fluid deficit with shock):

• Initiate immediate intravenous rehydration; oral therapy is insufficient 1, 2

Replace ongoing losses with 10 mL/kg ORS for each diarrheal stool and 2 mL/kg ORS for each vomiting episode 2, 3

Nutritional Management

Resume age-appropriate usual diet immediately after rehydration is completed 1

Continue normal feeding throughout the illness; do not withhold food 1

Oral zinc supplementation reduces diarrhea duration in children 6 months to 5 years of age who reside in countries with high prevalence of zinc deficiency or who have signs of malnutrition 1

Medications to AVOID

Do NOT give antimotility drugs (loperamide) to children <18 years of age with acute diarrhea 1

Antimotility drugs should be avoided at any age when toxic megacolon may result in inflammatory diarrhea or diarrhea with fever 1

When to Consider Non-Infectious Causes

If symptoms persist ≥14 days despite appropriate management:

• Reassess for non-infectious conditions including inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and lactose intolerance 1, 2
• Consider endoscopy or proctoscopic examination for persistent, unexplained diarrhea 1

Follow-Up and Public Health Considerations

Collaborate with local public health authorities regarding return to childcare settings 1, 2

Follow-up testing using culture-dependent methods may be required by local health authorities before return to childcare 1

Key Pitfalls to Avoid

The most critical error is administering antibiotics when STEC O157:H7 or other Shiga toxin-producing E. coli is suspected, as this significantly increases HUS risk 1, 2

Do not allow ad libitum drinking in vomiting patients—administer small volumes (5-10 mL) every 1-2 minutes via spoon or syringe with gradual increases 1, 2

Do not delay stool culture collection; obtain it immediately before considering any antimicrobial therapy 2, 4