GI Symptoms May Signal Milder COVID-19 Infection

The SARS-CoV-2 virus responsible for COVID-19 can take root in the digestive tract and trigger gastrointestinal (GI) issues such as diarrhea, nausea, vomiting, and abdominal pain, mounting evidence shows, though this may be indicative of a more mild infection. 

These symptoms, which occur in about 10% of COVID-19 patients, tend to appear later and last longer, leaving physical imprints across the digestive system in the form of fissures, polyps, hemorrhoids, and more.

Why GI Symptoms Sometimes Occur

To enter our cells, the SARS-CoV-2 pathogen latches on to angiotensin-converting enzyme 2 (ACE2) receptors. Typically, this occurs in the lungs, but the virus can also take hold in the ACE2 receptors located in the digestive system, specifically in the colon and ileum. Once there, the virus has the ability to spread throughout the entire GI system, upsetting the body’s balance of bacteria. 

In a study published in the journal Gastroenterology in May, researchers at the Chinese University of Hong Kong examined the gut microbiomes of 15 COVID-19 patients and 15 control patients without COVID-19. They discovered many differences in the gut bacteria of those with COVID-19, including an increase in the pathogens that lead to bacteremia, a condition caused by bacteria spilling into the bloodstream.

Researchers also discovered that healthy gut microbes, such as Lachnospiraceae bacterium and Ruminococcus obeum, were not present in COVID-19 patients. 

Reem Sharaiha, MD, MSc, a gastroenterologist based in New York City, shed light on the effects of an unbalanced gut during a live Zoom session as part of the Pulmonary Wellness Foundation’s COVID Rehab & Recovery Series.

“Normally you have good bacteria that line your stomach, colon, and intestines,” she said during the July 22 session. “What happens with COVID-19 and other viruses is it wipes all of that, so you're left with either bad bacteria, or just bacteria that are not your usual ones. That’s when you can start having symptoms like intolerances to normal things like lactose, or you feel bloated and have a lot more irritation and cramping. That might last for three months down the line.”

Sharaiha authored a retrospective review that looked at GI incidents in 1,059 patients admitted to two hospitals in Manhattan for COVID-19. Sharaiha and her team analyzed patients’ lab work and medical records to look for GI manifestations, which they defined as the occurrence of diarrhea, abdominal pain, nausea, or vomiting. The results showed that 33% of the patients displayed GI symptoms, with diarrhea present in 22% of patients, nausea in 16%, vomiting in 9%, and abdominal pain in 7%. 

Sharaiha says that the prevalence of GI symptoms isn't necessarily correlated with a worse prognosis. 

“We found that people with GI symptoms were more likely to be admitted to the hospital, but less likely to be admitted to the ICU or die of COVID-19, which is a good thing," Sharaiha says. "Maybe that means if you have the GI symptoms, you would have a less of a severe course."

Diagnosis of GI Symptoms

If you have pervasive GI symptoms despite recovering from the SARS-CoV-2 virus, Sharaiha recommends seeing specialist to screen for other conditions.

“As a GI doctor, you need to rule out that it’s not some sort of infection—it’s not norovirus, it's not food poisoning—so if you have symptoms that last more than 24 to 48 hours, we would need to know about it,” she says.

Physical manifestations of GI symptoms, like polyps, can get worse if left untreated.

“If you leave a polyp for a very long time, that could turn into cancer, so those are things that you want to make sure that you are watching for when you are seeing your doctor,” Sharaiha says.

She recommends standard lab work for patients with GI issues include a stool test, a liver test, and a full blood count that looks for the inflammatory markers of infection. It's also important to screen for proper kidney function, because long-term diarrhea leads to dehydration that could damage kidneys.

Treatment Is Based On Specific Symptoms

Sharaiha says a combination of home remedies and medications can be appropriate for treating GI issues, depending on what you're experiencing.

• Persistent nausea: Prescription anti-nausea medication
• Diarrhea lasting over a week: Antidiarrheal medicines
• Acid reflux: Over-the-counter medications, such as Tums
• Vomiting: Hydration with electrolyte-filled fluids such as Gatorade and Smart Water

Dietary Modifications

If you have mild to moderate GI symptoms that you’re nursing at home, or if you have persistent symptoms that linger long after infection, Sharaiha recommends a simple diet consisting of clean ingredients: no processed foods and sugar, which can trigger more inflammation. 

“Going back to the basics definitely helps,” she says. “Avoid things like onions, broccoli, garlic, and things that are going to give you more gas...eat something that will calm your stomach—nothing too spicy or heavy.” 

She also recommends looking into the Low-FODMAP diet, which is typically used to manage irritable bowel syndrome (IBS). This stomach-friendly diet restricts certain foods that cause abdominal pain, bloating, and gas. It is divided into three phases:

1. A restriction phase where you avoid all FODMAP-foods
2. A reintroduction phase where you slowly reincorporate high-FODMAP foods to see what you can tolerate
3. A personalization phase where you adjust your diet based on the discoveries made in the second phase

Sharaiha also says green and mint tea can help minimize digestive symptoms. 

Use Blood Thinners Cautiously

Some patients hospitalized with COVID-19 are put on blood thinners to help mitigate their symptoms. However, according to Sharaiha, blood-thinning medications such as Advil, Ibuprofen, and Aspirin increase the risk of GI bleeds. 

“If you can avoid taking anything that could thin the blood, then you should do that," she says. "If you [take blood thinners] too much you could increase the risk of GI bleeding."

However, she says blood-thinning medications are sometimes a necessary treatment in an in-patient setting. To counteract their potentially damaging effects in the GI tract, Sharaiha says it’s important to be put on antacids. 

"You can take something as simple as Tums, but there are over-the-counter medications that you can buy such as Nexium or Omeprazole. Those are the ones that help prevent GI bleeds," she says. “If you need to take antacids to reduce the risk of bleeding, then you should take them, despite any side effects."

She states that over-the-counter medications should be taken for seven to 14 days. If you’re on a long-term blood thinner, you should see your primary care doctor or gastroenterologist for a long-term antacid prescription.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.