COVID-19 is primarily known as a respiratory illness, but the virus, SARS-CoV-2, can affect multiple body systems. While cough and fever are common, the gastrointestinal (GI) tract is also a target. Nausea and vomiting are possible during a COVID-19 infection, so it is important to understand how these issues arise and how to manage them.
How Common Are Vomiting and Nausea
Vomiting and nausea are less frequent than typical respiratory symptoms, but they are a recognized part of the COVID-19 symptom spectrum. Studies show that the overall incidence of any gastrointestinal symptom, including diarrhea and abdominal pain, ranges between 12% and 61% of patients.
Nausea is reported more often than vomiting, with a median incidence around 10.5% (ranging from 1% to 30%). Vomiting is less common, with a median incidence of about 7% (ranging from 1% to 12.5%). For some individuals, these digestive issues can even be the first symptoms to appear before any respiratory signs.
Variations in symptom presentation occur across different age groups and viral variants. For example, vomiting was seen more frequently in children aged 5 to 11 during the Omicron era compared to earlier variants.
The Biological Reason for Digestive Symptoms
The SARS-CoV-2 virus causes vomiting and other GI issues because of the specific cell entry point it uses. The virus gains access to human cells by binding to the Angiotensin-Converting Enzyme 2 (ACE2) receptor. This receptor is highly abundant in the lungs and in the absorptive enterocytes lining the small intestine and colon.
When the virus binds to the ACE2 receptor in the digestive tract, it directly infects and damages these intestinal cells. This viral activity disrupts normal gut function, leading to inflammation and symptoms like nausea and vomiting. The resulting infection can also change the balance of bacteria in the gut, a condition called dysbiosis, which contributes to digestive distress.
A systemic inflammatory response triggered by the infection also plays a role. The immune system releases signaling molecules that activate the vomiting center in the brain. This dual mechanism—direct viral invasion of the gut and generalized inflammatory reaction—explains why digestive symptoms occur.
Strategies for Managing GI Distress
Managing vomiting and nausea associated with COVID-19 focuses on preventing dehydration. Replacing lost fluids and electrolytes is a priority, achieved by drinking small, frequent sips of water, clear broths, or oral rehydration solutions. Avoiding large amounts of liquid at once helps prevent further vomiting.
When the stomach can tolerate food, stick to a bland diet that is easy to digest. Gentle options include bananas, rice, applesauce, and toast. Avoid spicy, fatty foods, caffeine, or alcohol, as they can irritate the digestive tract.
Over-the-counter antiemetics or anti-diarrheal medications may provide relief, but consult a healthcare provider before using them. Seek prompt medical attention if you experience warning signs, such as:
- Inability to keep fluids down for 24 hours.
- Signs of severe dehydration (dark urine, dizziness, or extreme weakness).
- Intense or worsening abdominal pain.
- Fever over 102°F.
- Blood in your vomit or stool.