We’ve all been there: sitting on the commode and you literally can’t get up for fear of not being able to make it back in time. We get it. Everyone gets it. However, when a patient presents with similar symptoms, it can be difficult to remember and differentiate between different types of infectious diarrhea, let alone how to manage it definitively. This guide aims to ease that process!
There are many different etiologies of diarrhea, even infectious diarrhea, but this will focus on bacterial diarrhea. This is because we can employ more treatment for bacterial etiologies, and bacterial infectious diarrheas are often more severe than non-bacterial cases. Common pathogens include Clostridioides, Salmonella, Shigella, E. Coli, and Campylobacter. Let’s break down some of the characteristics of each infecting pathogens and how a patient infected with such a pathogen would present.
Clostridioides spp. (C. diff)
-Diarrhea: Watery
-Risk Factors: Antibiotic usage, recent hospitalization
-Incubation Period: N/A
-Specific Treatment: Fidaxomycin PO >> Vancomycin PO, Metronidazole PO/IV (dose/frequency/duration of each treatment is patient-specific)
Enterohemorrhagic E. Coli
-Diarrhea: Watery, may progress to bloody
-Risk Factors: Meats, fresh fruits/veggies, unpasteurized milk and juices
-Incubation Period: 1-7 days
-Specific Treatment: No antibiotics >> azithromycin 1000mg PO x 1 dose, Ciprofloxacin 500mg PO BID x 6 doses
Enterotoxigenic E. Coli (Traveler’s Diarrhea)
-Diarrhea: Watery
-Risk Factors: Recent travel (especially to less-developed countries), food/water contaminated with feces
-Incubation: 1-3 days
-Specific Treatment: No antibiotics >> Azithromycin 1000mg PO x 1 dose, Ciprofloxacin 500mg PO BID x 6 doses
Campylobacter
-Diarrhea: Watery, may progress to bloody
-Risk Factors: Recent travel (especially to less-developed countries), animal contacts (usually cattle/poultry close to dwellings)
-Incubation: 1-3 days
-Specific Treatment: Azithromycin 500mg PO daily x 3 doses, Ciprofloxacin 500mg PO daily for 3 doses
Shigella
-Diarrhea: Watery, may progress to bloody
-Risk Factors: Recent travel (especially to less-developed countries), daycares, crowded living spaces, raw vegetable consumption
-Incubation: 1-3 days
-Specific Treatment: Ciprofloxacin 500mg PO BID for 6 doses >> Ceftriaxone 1000mg-2000mg IV daily for 5 days
Vibrio cholera (Cholera)
-Diarrhea: Watery, flecked with mucous (RICE-WATER STOOLS)
-Risk Factors: Recent travel (especially to less-developed countries)
-Incubation: 1-3 days
-Specific Treatment: Doxcycline 300mg PO x 1 dose >> Azithromycin 1000mg PO x 1 dose or Ciprofloxacin 500mg PO BID for 6 doses
Non-typhoidal Salmonella --> Note: (Typhoidal salmonella may manifest as constipation or diarrhea, not discussed here)
-Diarrhea: Watery or may contain blood/mucous
-Risk Factors: Animal contact, recent travel (especially to less-developed countries)
-Incubation: 1-3 days
-Specific Treatment: Azithromycin 1000mg PO x 1 dose, Ciprofloxacin 500mg PO BID x 6 doses
As with treatment of any etiology of diarrhea, fluid and electrolyte replacement is paramount. Oral rehydration with solutions equivalent to pedialyte (which contains a more balanced formula of electrolyte than things like Gatorade/Powerade) is preferred, but for patients with severe symptoms/disease or who cannot take oral fluids, IV solutions and electrolyte replacement based on lab work is also acceptable.
Additionally, antimotility agents such as loperamide, or even opioids, should generally be avoided in cases outside of mild-moderate traveler’s diarrhea. This is because inflammatory etiologies of diarrhea, especially caused by toxin-producing bacteria can become much more harmful if the toxins are retained using antimotility agents, instead of being frequently excreted.
With this, I will leave you, dear reader, with a general summary of what to do with your patients who have infectious bacterial diarrhea:
1. FLUIDS AND ELECTROLYTES FOR EVERYBODY
2. No loperamide/antimotility agents for anybody except mild-moderate traveler’s diarrhea
3. Ciprofloxacin 500mg PO BID for 6 doses will treat every etiology that needs antibiotic treatment except for C. Diff
4. C. Diff is special and requires treatment/dose/duration tailored to each patient anyways
5. Generally don’t treat diarrhea caused by E. Coli. It’s usually self-limiting and antibiotic use will increase the risk of Hemolytic Uremic Syndrome (HUS) which can cause sudden death