The SARS-CoV-2 virus, which causes COVID-19, is primarily known for affecting the respiratory system, leading to symptoms like cough and shortness of breath. However, the virus is now understood to be a systemic infection that can affect multiple organ systems throughout the body. The varied presentation of the disease means that symptoms can extend far beyond the lungs. This article clarifies the connection between SARS-CoV-2 infection and the gastrointestinal tract, focusing on digestive issues like diarrhea.
Diarrhea as a Recognized COVID-19 Symptom
Diarrhea is a recognized manifestation of COVID-19, with reports indicating it affects 10% to 20% of patients. Unlike the more common fever or cough, digestive symptoms can sometimes be the first indication of the infection. Diarrhea may even appear as the sole presenting symptom, although this is less frequent.
When present, COVID-related diarrhea is generally described as mild to moderate and is usually non-bloody. The consistency is often watery, and patients report loose or mushy stools. The duration of this symptom is typically short-lived, often lasting an average of about five days, though it can persist for up to two weeks in more severe cases.
Other digestive complaints often occur alongside or independently of diarrhea, including nausea, vomiting, and abdominal pain. The presence of gastrointestinal symptoms, especially when severe, has sometimes been linked to a potentially more serious course of the overall infection. Recognizing these digestive signs is helpful for early identification and appropriate management.
How the Virus Affects the Digestive Tract
The mechanism by which SARS-CoV-2 causes diarrhea is linked to how the virus enters human cells. The virus utilizes a protein receptor called Angiotensin-Converting Enzyme 2 (ACE2) to gain access. While ACE2 is present in the respiratory tract, it is also highly abundant on the surface of enterocytes, which are the cells lining the small intestine.
The virus binds to these ACE2 receptors in the gut, allowing it to invade and replicate within the intestinal lining cells. This direct viral invasion leads to inflammation and disruption of the protective barrier of the gut. When the intestinal lining is damaged, it impairs the ability of the enterocytes to properly absorb water and nutrients, which results in loose, watery stool.
Beyond direct cell damage, the infection can also contribute to changes in the gut microbiome, a condition known as dysbiosis. The imbalance between beneficial and harmful bacteria in the intestine can further compromise digestive function and contribute to persistent symptoms. This combination of direct viral attack and secondary inflammation explains why a respiratory virus can produce such distinct digestive symptoms.
Managing COVID-Related Gastrointestinal Issues
Managing diarrhea during a COVID-19 infection centers on preventing dehydration and supporting the digestive system. Because diarrhea causes a significant loss of fluids and electrolytes, maintaining adequate hydration is the most important step. Drinking water, clear broths, and oral rehydration solutions is advised to replenish lost salts and minerals.
Dietary adjustments can help reduce irritation on the inflamed gut lining. Eating bland, easy-to-digest foods, such as bananas, rice, applesauce, and toast, can be helpful. It is recommended to temporarily avoid foods that can aggravate the digestive system, including dairy products, spicy dishes, fatty foods, and caffeine.
Over-the-counter anti-diarrheal medications, such as loperamide, may be used for symptomatic relief, but caution is advised. Experts advise against the immediate use of these medications, as they can slow the movement of waste and potentially delay the clearance of the virus from the digestive system. Consulting a healthcare provider before taking anti-diarrheal drugs is necessary.
When to Seek Medical Attention
Certain “red flag” symptoms warrant immediate medical attention to prevent complications. These include signs of significant dehydration, such as dizziness, a rapid heart rate, or a lack of urination. If the diarrhea is accompanied by severe abdominal pain, bloody or black stools, or if symptoms last longer than two days, contact a doctor immediately.