IDSA Clinical Practice Guidelines for Infectious Diarrhea
A pediatrician's quick reference to the Infectious Diseases Society of America (IDSA) 2017 evidence-based guidelines for diagnosing and managing acute and persistent infectious diarrhea in infants, children, and adolescents. This summary covers when to obtain stool testing, which clinical features signal bacterial enteropathogens like Salmonella, Shigella, Campylobacter, and STEC, and the role of oral rehydration, targeted antimicrobials, and outbreak reporting in pediatric practice.
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IDSA Clinical Practice Guidelines for Infectious Diarrhea
A practical summary of the 2017 IDSA guidelines for the diagnosis and management of infectious diarrhea — covering clinical features, laboratory diagnostics, antimicrobial therapy, supportive care, and prevention.
1 Overview & U.S. Burden
Practice guidelines are systematically developed statements to help clinicians and patients make decisions about appropriate care for specific clinical circumstances. The 2017 update applies GRADE methodology to rate evidence quality and the strength of each recommendation.
Diarrheal illness can be classified by duration: acute (0–13 days), persistent (14–29 days), and chronic (≥30 days). The burden in the United States remains substantial.
2 Evaluating the Patient
Several host and exposure factors shape the differential diagnosis and the decision to test or treat. Consider each of the following when assessing a patient with diarrhea:
- Foodborne or waterborne exposure — outbreaks, untreated water, raw products
- International travel — to resource-limited regions
- Antimicrobial use — recent therapy raising concern for C. difficile
- Immunocompromised host — broadens differential and severity
- Animal exposure — reptiles, amphibians, young poultry, farm/petting-zoo contact
- Care settings — child care, long-term care, hospitalization
- Certain sexual practices — anal-genital, oral-anal, digital-anal contact
When to pursue laboratory investigation
- Bloody diarrhea or suspicion of a Shiga toxin–producing organism (HUS risk)
- Immunocompromised host or extraintestinal manifestations
- Epidemiologic concern (child care, nursing home, suspected outbreak)
- Recent travel, or any scenario where results would change management
3 Exposures & Associated Pathogens
Specific exposures point toward particular organisms. The table below condenses the guideline's exposure-to-pathogen associations.
| Exposure or condition | Likely pathogen(s) |
|---|---|
| Foodborne | |
| Outbreaks (hotels, cruise ships, resorts, catered events) | Norovirus, nontyphoidal Salmonella, C. perfringens, B. cereus, S. aureus, Campylobacter, ETEC, STEC, Listeria, Shigella, Cyclospora, Cryptosporidium |
| Unpasteurized milk / dairy | Salmonella, Campylobacter, Yersinia enterocolitica, S. aureus toxin, Cryptosporidium, STEC; Brucella (goat-milk cheese) |
| Raw / undercooked meat or poultry | STEC (beef), C. perfringens, Salmonella, Campylobacter, Yersinia (pork), Trichinella (pork, wild game) |
| Raw shellfish | Vibrio species, norovirus, hepatitis A, Plesiomonas |
| Exposure or contact | |
| Untreated fresh water (swimming/drinking) | Campylobacter, Cryptosporidium, Giardia, Shigella, Salmonella, STEC, Plesiomonas shigelloides |
| Child care attendance / employment | Rotavirus, Cryptosporidium, Giardia, Shigella, STEC |
| Recent antimicrobial therapy | C. difficile, multidrug-resistant Salmonella |
| Travel to resource-challenged countries | E. coli (ETEC/EAEC/EIEC), Shigella, Salmonella Typhi & nontyphoidal, Campylobacter, V. cholerae, E. histolytica, Giardia, Cyclospora |
| Young poultry or reptile contact | Nontyphoidal Salmonella |
| Farm or petting-zoo visit | STEC, Cryptosporidium, Campylobacter |
4 Clinical Presentations & Likely Etiologies
| Finding | Likely pathogens |
|---|---|
| Persistent or chronic diarrhea | Cryptosporidium, Giardia lamblia, Cyclospora cayetanensis, Cystoisospora belli, Entamoeba histolytica |
| Visible blood in stool | STEC, Shigella, Salmonella, Campylobacter, E. histolytica, noncholera Vibrio, Yersinia, Balantidium coli, Plesiomonas |
| Fever | Not highly discriminatory — viral, bacterial, and parasitic causes all possible. Higher temperatures suggest bacterial etiology or E. histolytica; STEC patients are often afebrile at presentation. |
| Severe abdominal pain, often grossly bloody stools, minimal/no fever | STEC, Salmonella, Shigella, Campylobacter, Yersinia enterocolitica |
| Persistent abdominal pain + fever (may mimic appendicitis) | Y. enterocolitica and Y. pseudotuberculosis |
| Nausea & vomiting ≤24 hours | S. aureus enterotoxin or B. cereus (short-incubation emetic syndrome) |
| Vomiting + nonbloody diarrhea, 2–3 days | Norovirus (low-grade fever in ~40% during first 24h) |
5 Post-Infectious Manifestations
Enteric infections can trigger significant sequelae well after the acute illness resolves.
| Manifestation | Organism(s) |
|---|---|
| Guillain-Barré syndrome | Campylobacter |
| Hemolytic uremic syndrome (HUS) | STEC, Shigella dysenteriae serotype 1 |
| Reactive arthritis (incl. Reiter syndrome) | Salmonella, Shigella, Campylobacter, Yersinia; rarely Giardia, Cyclospora |
| Erythema nodosum | Yersinia, Campylobacter, Salmonella, Shigella |
| Meningitis (infants ≤3 months at high risk) | Listeria, Salmonella |
| Intestinal perforation | Salmonella (incl. Typhi), Shigella, Campylobacter, Yersinia, E. histolytica |
| Ekiri syndrome (lethal toxic encephalopathy / seizure) | Shigella |
| Aortitis, osteomyelitis, extravascular deep-tissue focus | Salmonella, Yersinia |
| Post-infectious irritable bowel syndrome | Campylobacter, Salmonella, Shigella, STEC, Giardia |
6 Laboratory Diagnosis
Diagnosis is matched to the suspected agent and optimal specimen. Culture-independent diagnostic tests (CIDTs) — multiplex GI panels — rapidly detect a wide range of bacterial, viral, and parasitic organisms, and can detect pathogens unsuspected by the clinician.
| Etiologic agent | Diagnostic procedure | Optimal specimen |
|---|---|---|
| Clostridium difficile | NAAT; or GDH antigen with/without toxin detection, followed by cytotoxin or toxigenic culture | Stool |
| Salmonella, Shigella, Campylobacter | Routine stool enteric pathogen culture or NAAT | Stool |
| Salmonella Typhi / Paratyphi (enteric fever) | Routine culture | Stool, blood, bone marrow, duodenal fluid |
| Shiga toxin–producing E. coli | Culture for E. coli O157:H7 plus Shiga toxin immunoassay or NAAT for toxin genes | Stool |
| E. histolytica | Species-specific immunoassay or NAAT | Stool |
| Giardia lamblia | EIA or NAAT | Stool |
| Cryptosporidium spp. | Direct fluorescent immunoassay, EIA, or NAAT | Stool |
| Norovirus / sapovirus, enteric adenovirus, rotavirus | NAAT | Stool |
Tests generally not recommended
- Fecal leukocytes / stool lactoferrin — not recommended
- Serologic tests — not recommended (exception: post-diarrheal HUS)
- Serial stool specimens — generally only for public-health reasons (e.g., return to child care/work) or culture-dependent susceptibility testing
7 Antimicrobial Therapy by Pathogen
| Pathogen | First choice | Alternative |
|---|---|---|
| Bacteria | ||
| Campylobacter | Azithromycin | Ciprofloxacin |
| C. difficile | Oral vancomycin | Fidaxomicin (not currently recommended <18 yrs; metronidazole acceptable in children & as 2nd-line in adults) |
| Nontyphoidal Salmonella | Usually not indicated for uncomplicated infection | Consider for groups at increased risk of invasive disease |
| Salmonella Typhi / Paratyphi | Ceftriaxone or ciprofloxacin | Ampicillin, TMP-SMX, or azithromycin |
| Shigella | Azithromycin, ciprofloxacin, or ceftriaxone | TMP-SMX or ampicillin (if susceptible) |
| Vibrio cholerae | Doxycycline | Ciprofloxacin, azithromycin, or ceftriaxone |
| Yersinia enterocolitica | TMP-SMX | Cefotaxime or ciprofloxacin |
| Parasites | ||
| Cryptosporidium spp. | Nitazoxanide (+ effective cART if HIV-infected) | — |
| Cyclospora cayetanensis | TMP-SMX | Nitazoxanide (limited data) |
| Giardia lamblia | Tinidazole or nitazoxanide | Metronidazole |
| Cystoisospora belli | TMP-SMX | Pyrimethamine; ciprofloxacin or nitazoxanide |
8 Supportive & Ancillary Care
Rehydration is the cornerstone of management. Oral rehydration solution (ORS) is appropriate for all age groups and is safe in both hypernatremia and hyponatremia (except when edema is present).
| Degree of dehydration | Rehydration therapy | Replacement during maintenance |
|---|---|---|
| Mild to moderate | Infants & children: ORS 50–100 mL/kg over 3–4 h. Adolescents & adults (≥30 kg): ORS 2–4 L. | <10 kg: 60–120 mL ORS per stool/vomit (up to ~500 mL/day). >10 kg: 120–240 mL per episode (up to ~1 L/day). Adults: ad libitum, up to ~2 L/day. |
| Severe | Children, adolescents & adults: IV isotonic crystalloid boluses per current resuscitation guidelines until pulse, perfusion, and mental status normalize (up to 20 mL/kg). | As above; if unable to drink, give via nasogastric tube, or 5% dextrose / 0.25 normal saline with 20 mEq/L potassium chloride IV. |
Directed & ancillary measures
- Human milk — breastfed infants should continue nursing throughout the illness
- Diet — resume an age-appropriate normal diet after rehydration; diluted formula confers no benefit
- Antimotility drugs — generally not recommended
- Antiemetics — occasionally appropriate
- Probiotics & oral zinc supplementation — may be considered
9 Prevention & Vaccines
Prevention rests on hand hygiene, infection control, food-safety practices, patient education, and reporting of nationally notifiable diseases.
Vaccines that prevent diarrhea
- Rotavirus — routinely recommended for infants
- Typhoid — oral and injectable vaccines available in the U.S.; not routinely recommended
- Cholera — live-attenuated single-dose oral vaccine for adults 18–64 traveling to cholera-affected areas
This page is an educational summary for healthcare professionals and does not replace the full guideline or individual clinical judgment. Refer to the complete IDSA guideline and current product labeling for dosing, susceptibility, and population-specific recommendations.