Diarrhea

Patient Population: Adult
Diagnosis Common Pathogens Drug(s) of First Choice Alternative Drug(s) Comments Expected Duration
C. difficile Clostridioides difficile

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. 

Azithromycin 500mg PO daily x 3 days OR 

Ciprofloxacin

(avoid antibiotic treatment in cases of E. coli O157:H7 as it may increase the risk of hemolytic-uremic syndrome)
 

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

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.

3 days
Nondysenteric diarrhea (other than C. difficile)

Viruses

Giardia

Enterotoxigenic E. coli

Enterotoxin-producing bacteria

Clostridium difficile

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.

No antibiotic therapy indicated except for C. difficile
Traveler's diarrhea

Toxigenic E. coli

Salmonella

Shigella

Campylobacter

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

Azithromycin  OR

Ciprofloxacin OR

Rifaximin 200 mg PO TID x 3 days

 

EITHER WITH or WITHOUT

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

MAX 16 mg/day

0-3 days

Clinical Infectious Diseases, Volume 65, Issue 12, 29 November 2017, Pages e45–e80, https://doi.org/10.1093/cid/cix669