Can COVID-19 cause diarrhea?

COVID-19 Can Cause Diarrhea

Yes, COVID-19 can definitely cause diarrhea, with prevalence rates ranging from 7.7% to 20% of infected patients. 1 Diarrhea is one of the most common gastrointestinal manifestations of COVID-19 infection, alongside nausea and vomiting.

Prevalence and Characteristics of COVID-19-Related Diarrhea

• Overall prevalence: 7.7% (95% CI, 7.2-8.2%) across all patients, but higher (18.3%) in studies outside China 1

• Timing:

  • Can occur at disease onset or during the course of illness
  • May precede respiratory symptoms by a few days 1
  • Average onset is 3.0 days (IQR 0.0-5.0) from illness onset 2
  • Average duration is 5.0 days (IQR 2.0-9.3) 2

• Characteristics:

  • Usually mild to moderate and non-bloody 3
  • Primarily watery (64%) or mushy (28%) 2
  • Defecation frequency: 37% of patients defecate more than 3 times daily 2
  • Maximum reported bowel movements: up to 20 per day 4
  • Stool occult blood detected in 6.8% of cases 4

Pathophysiology

COVID-19 causes diarrhea through several mechanisms:

1. Direct viral infection: SARS-CoV-2 enters intestinal cells via the ACE2 receptor, which is highly expressed in the GI tract, particularly in the stomach and small intestine 3

2. Viral shedding in stool: Patients with diarrhea show higher rates of positive viral RNA in stool (80.0% vs. 52.4%) compared to those with both diarrhea and respiratory symptoms 5

3. Gut microbiome dysbiosis: COVID-19 infection can disrupt normal gut flora 6

4. Medication effects: Treatment with antibiotics or antivirals may contribute to diarrhea 6

Clinical Significance and Management

• Presentation patterns:

  • Diarrhea as the only presenting symptom: 6.1% of cases 4
  • Diarrhea as initial symptom: 4.3-9% of cases 2, 4
  • Diarrhea with other GI symptoms: 31.9% reported additional GI symptoms 1

• Associated symptoms:

  • Nausea (24%)
  • Vomiting (17%)
  • Poor appetite (24%) 2
  • Patients with diarrhea are more likely to experience headache, nausea, vomiting, and abdominal pain 4

• Management approach:

  1. Consider COVID-19 testing in patients with new-onset diarrhea, especially in high-prevalence settings 1
  2. Obtain thorough history of GI symptoms (onset, characteristics, duration, severity) 1
  3. Monitor for development of respiratory symptoms 1
  4. Provide symptomatic treatment:
     • Intravenous fluid and electrolyte replacement as needed
     • Antidiarrheal medications (loperamide, kaolin-pectin) 3
  5. Rule out other causes of diarrhea, particularly C. difficile infection 1, 3

Prognostic Implications

• Patients with both diarrhea and respiratory symptoms have:

  • Higher levels of inflammatory activity
  • Longer hospital stays (27.5 vs. 23.0 vs. 22.0 days)
  • Higher mortality (3.2 times higher odds ratio) compared to those with diarrhea only or respiratory symptoms only 5

• Patients with diarrhea only:

  • Generally have milder illness
  • Tend to delay seeking medical care (14.5 days vs. 11.0 days to admission) 5

Important Considerations

• During the COVID-19 pandemic, acute nausea, vomiting, or diarrhea should be considered COVID-related until proven otherwise 1

• GI symptoms may be the only initial presentation in some patients, with respiratory symptoms developing later 1

• Viral RNA can persist in stool even after respiratory samples become negative, raising concerns about potential fecal-oral transmission 2

• Patients with COVID-19-related diarrhea require adequate hydration and nutritional support during hospitalization 2

By recognizing diarrhea as a potential manifestation of COVID-19, clinicians can improve early detection, implement appropriate isolation measures, and provide timely supportive care to affected patients.