Gastrointestinal Infections

See site-specific guidelines:

UCSF

ZSFG

VASF

Dysenteric diarrhea (other than C. difficile)

Shigella

Salmonella

Campylobacter

Yersinia

E. coli 0157:H7

Most outpatients do not warrant empiric antibiotics.

Empiric therapy is generally indicated if patient is toxic appearing, elderly or immunocompromised. 

Avoid antibiotic treatment in cases of E. coli O157:H7 and all shiga-like toxin producing E. coli (STEC) as it may increase the risk of hemolytic-uremic syndrome

Azithromycin 500mg PO daily x 3 days 

OR 

Ciprofloxacin

Frequent, sometimes bloody, small-volume diarrhea associated with abdominal pain and cramping.

Patient may be febrile and toxic

Fluoroquinolone resistance may be present, particularly with Shigella and Campylobacter.

Antimicrobial treatment may worsen outcomes in patients with E. coli 0157:H7 and shiga-like toxin producing E. coli (STEC)

Antimotility drugs improve symptoms and can be used if patient is not toxic.  Antimotility drugs should not be used in C.difficile.

Strict handwashing is mandatory in all food preparation.

Viruses

Giardia

Enterotoxigenic E. coli

Enterotoxin-producing bacteria

General Care: Observation

Oral rehydration

Antimotility agents (do not use in C. difficile infection)

Large volume, nonbloody, watery diarrhea.

Patient may have nausea, vomiting, and abdominal cramping but fever often absent

Generally, empiric therapy and stool cultures are not indicated. Most disease is self-limiting and can be treated with antimotility agents.

If patient does not improve, cultures are negative, and symptoms persist, consider stool for parasite PCR

Check C. difficile toxin, especially if recent history of antibiotic use or hospitalization.

Toxigenic E. coli

Salmonella

Shigella

Campylobacter

Mild, self-limited cases can be treated with fluid and electrolyte repletion +/- bismuth subsalicylate.

Azithromycin  OR

Ciprofloxacin OR

EITHER WITH or WITHOUT

Loperamide 4 mg PO x1; then 2 mg after each loose stool,

MAX 16 mg/day

Helicobacter pylori infection, initial treatment, susceptibilities unknown 

Refer to ESPGHAN/ NASPGHAN guidelines (linked below) for treatment based on susceptibilities if they are available  

Helicobacter pylori 

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Options for proton pump inhibitor (PPI): 

Omeprazole (Prilosec)  

OR  

Esomeprazole (Nexium)  

Weight 15-24 kg: 20 mg enterally bid 

Weight 25-34 kg: 30 mg enterally bid 

Weight > 35 kg: 40 mg enterally bid 

OR 

Lansoprazole 

Weight 15-24 kg: 15 mg enterally bid 

Weight 25-34 kg: 30 mg enterally bid 

Weight > 35 kg: 30 mg enterally bid or tid 

PPI dose equivalents (follow link for options) 

PPI (from second column)  

AND 

Amoxicillin 

Weight 15-24 kg: 750 mg enterally bid  

Weight 25-34 kg: 1000 mg enterally bid  

Weight > 35 kg: 1500 mg enterally bid  

AND  

Metronidazole  

Weight 15-24 kg: 250 mg enterally bid  

Weight 25-34 kg: 500 mg AM and 250 mg enterally PM 

Weight > 35 kg: 500 mg enterally bid  

Penicillin allergy with higher risk for allergic reaction: 

Refer to guidelines below for alternative treatment based on susceptibilities or consult ID/ASP for guidance 

Bismuth-based or quadruple therapy are alternatives included in ESPGHAN/NASPGHAN guidelines (see below reference). 

Treatment failure should be addressed with individualized rescue therapy considering antibiotic susceptibility, the age of the child, and available antimicrobial options; patients with treatment failure should be managed in consultation with GI 

GI consult recommended for patients with positive H. pylori testing to consider next steps in diagnosis and treatment  

Duration: 14 days 

Patient and family should be counseled about the importance of adherence to the anti – H. pylori therapy to enhance successful eradication 

Clostridioides difficile infection - initial episode, non-severe 

Non-severe disease defined by lack of the following:  

WBC ≥ 15,000 cells/mL 

Creatinine > 1.5x pre-disease baseline 

Hypotension or shock, ileus, or megacolon  

Metronidazole  
7.5 mg/kg/dose (max 500 mg/dose) enterally  4 times daily  

OR 

Vancomycin 
10 mg/kg/dose (max 125 mg/dose) enterally 4 times daily  

Note: IV Metronidazole is suboptimal for C. difficile treatment compared to enteral metronidazole 

If failure to respond to Metronidazole in 5-7 days, switch to above Vancomycin regimen 

Discontinue inciting antimicrobials as soon as possible 

Avoid re-testing unless symptoms of C. difficile infection recur 

Oral vancomycin is usually preferred in pediatric oncology patients or stem cell transplant recipients 

Duration: 10 days 

Clostridioides difficile infection - initial episode, severe or fulminant  

Severe disease defined by: 

WBC ≥ 15,000 cells/mL 

OR 

Creatinine > 1.5x pre-disease baseline  

Fulminant disease defined by:  

Hypotension or shock, ileus or  megacolon 

Vancomycin
10  mg/kg/dose (max 500 mg/dose) enterally 4 times daily 

ADD 

Metronidazole
10 mg/kg/dose (max 500 mg/dose) IV q8h for fulminant disease (see 1st column for definition) 

Alternative administration for Vancomycin, consider when ileus is present:  

Vancomycin rectal enema 
500mg in 100mL normal saline with volume based on age:  
1-3 years old: 50 ml 
4-9 years old: 75 ml 
>10 years old: 100ml 
Administer 4 times daily 

Consider ID consult, particularly if not improving with initial therapy 

Discontinue inciting antimicrobials as soon as possible 

Avoid re-testing unless symptoms of C. difficile infection recur 

Duration: 10 days 

Clostridioides difficile infection - first recurrence, non-severe 

Definition: Re-appearance of symptoms and positive assay  within 2-8 weeks after completion of therapy for prior episode for which symptoms and signs had resolved 

Metronidazole
7.5 mg/kg/dose (max 500 mg/dose) enterally 4 times daily 

OR 

Vancomycin
10 mg/kg/dose (max 125 mg/dose) enterally 4 times daily 

Clostridioides difficile infection - second or subsequent recurrence 

Definition: Re-appearance of symptoms and positive assay  within 2-8 weeks after completion of therapy for prior episode for which symptoms and signs had resolved 

Vancomycin taper and pulse per the following regimen:  

10 mg/kg/dose (max 125 mg/dose) enterally 4 times daily x 10 days 

THEN bid x 7 days 

THEN daily x 7 days 

THEN every other day x 8 days (4 doses)  

THEN every 3 days x 2 weeks 

Consider Fidaxomicin in consultation with ID for recurrence in pediatric oncology patients or stem cell transplant recipients 

Consider evaluation for fecal microbiota transplantation in clinically appropriate situations 

ID and GI consults recommended for second recurrence 

Duration: per taper schedule 

Bacterial gastroenteritis, community-onset 

Characterized by frequent, sometimes bloody, small-volume diarrhea associated with abdominal pain and cramping 

Escherichia coli 

Salmonella species 

Shigella species 

Campylobacter jejuni 

Yersinia enterocolitica 

Supportive care is the primary therapy for most patients 

Antibiotics can predispose to complications such as hemolytic uremic syndrome with Shiga-toxin producing E. coli infection 

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Consider empiric therapy in toxic-appearing patients, young infants*, or immunocompromised hosts, or if recent international travel with diarrhea & fever:        

Azithromycin
10  mg/kg/dose (max 500 mg/dose) enterally daily  

OR 

Ceftriaxone*
50 mg/kg/dose (max 1000 mg/dose) IV q24h  

*For infants 1-3 months of age and if needed for infections with other sites involved e.g. Salmonella gastroenteritis with bloodstream infection. For infant <1 month of age refer to Fever Without a Source - Young Infant section for initial empiric therapy 

Avoid empiric treatment if persistent diarrhea has lasted 14 days or more  

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For traveler's diarrhea (enterotoxigenic E. coli): 

Azithromycin 10 mg/kg/dose (max 500 mg/dose) enterally daily x 3 days - provide un-reconstituted powder for suspension to infants and children traveling in high-risk areas 

Send stool culture (BCH OAK) or bacterial panel (BCH SF) for diagnosis 

Consider testing for Clostridioides difficile if patient has recent hospital or antibiotic exposure 

Blood cultures should also be sent for patients who are hospitalized and/or toxic-appearing  with suspected bacterial gastroenteritis. If antibiotic therapy is given for Salmonella gastroenteritis, blood culture should be obtained prior to initiation of antibiotic.  

Directed therapy may be indicated early in the course for specific pathogens (such as Campylobacter, Shigella, Yersinia) but in most cases should be deferred until a positive stool culture result is obtained. For recommended therapies, refer to IDSA guidelines linked below or consult ID. 

Duration of therapy (if given) depends on the specific diagnosis