
Long Covid and Digestive Health
While many people have started travelling, visiting public spaces, and entertaining once again, the effects of the COVID-19 pandemic linger. Although COVID-19 has been widely known to impact the respiratory system, the impact on the gastrointestinal tract is still being reported and explored. If you’re experiencing GI difficulties after contracting COVID-19, you may have heard of the term “long COVID” and are wondering if it applies to you. Long COVID also goes by several different names including post covid-19 condition/syndrome, or long-haul covid – but they all refer to the same thing. Research is still on going in this area, but we have gathered the latest information on long covid and digestive health below!
What is long COVID?
While we are still learning a lot about what long COVID is, and how it manifests in different people, the World Health Organization (WHO) defines long COVID as “as the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection (aka Covid-19), with these symptoms lasting for at least 2 months with no other explanation.1. This means that the symptoms cannot be explained by any other diagnosis, so ruling out other possible causes of symptoms is important to do first. It’s important to note that long COVID can affect anyone who has had COVD-19, regardless of age and severity of symptoms from your initial infection.
The latest data from the Centers for Disease Control and Prevention (CDC) in the United States showed that 1 in 13 adults in the U.S. (7.5%) have long COVID symptoms, defined as symptoms lasting three or more months after first contracting the virus, that they didn’t have prior to their COVID-19 infection 2. That data also showed that younger adults were more likely to have long COVID than older adults, as three times as many adults aged 50-59 had long COVID than those age 80 and older, and women were more likely than men2. It’s important to keep in mind that the data from these numbers are people who are self-reporting.
What are the symptoms?
First things first, long COVID is not COVID-19. The symptoms outlined below can continue for weeks or months after your initial COVID-19 infection, and you can also develop new symptoms 3. Symptoms will vary for everyone differently, but the most common symptoms in adults include: 3
- Shortness of breath
- Fatigue
- Trouble sleeping
- General pain and discomfort
- Cognitive dysfunction that can significantly impact one’s day-to-day life
- Memory loss
- Difficulty thinking or concentrating
- Mental health symptoms such as:
- Anxiety
- Depression

New research into long COVID and digestive health presents symptoms that impact the GI tract, including 1,2
- Abdominal pain
- Constipation
- Diarrhea (loose, watery stools more frequently than normal)
- Nausea/Vomiting
- Heartburn
A study published in March of 2023 found that those who contracted COVID and survived the first 30 days were more likely to develop GERD, Irritable Bowel Syndrome, functional dyspepsia, and cholangitis than people in non-COVID groups. 4 The impact on day-to-day life has been shown to be significant. As found by the Canadian COVID-19 Antibody Health Survey, 47.3% of adults who experienced longer-term COVID-19 symptoms experienced them for at least one year. 21.3% reported that their symptoms limited their daily activities, and 74.1% of people missed school or work because of their symptoms. 5 Another study reported that the degree of the initial infection may influence the symptoms that develop later. 51% of patients who were hospitalized with COVID-19 reported suffering from GI issues, versus 26% in non-hospitalized patients. 6
Can I test for long COVID?
As of now, there is no test that determines if your long-term symptoms are a result of contracting COVID-19. Your healthcare provider may examine your health history and symptoms to determine the best treatment options for you. 7
What GI Issues can occur post COVID-19?
Recent research from the Washington School of Medicine found that people who had had COVID-19 were at a “62% increased risk of developing ulcers in the lining of the stomach or small intestine; a 35% heightened risk of suffering from acid reflux disease; and a 46% increased risk of experiencing acute pancreatitis.” 8 The study also found that those who contracted COVID-19 were 54% more likely to suffer from IBS, 47% more likely to experience inflammation of the stomach lining, and 36% more likely to experience stomach upset with no definite cause.9
We know that chronic digestive conditions such as irritable bowel syndrome (IBS) can sometimes occur after an infection or stomach flu (gastroenteritis) which is otherwise known as post-infectious IBS, so although more research is needed in this area, this is one explanation of why chronic gut symptoms might occur after a COVID-19 infection.
Can I prevent long COVID?
As of now, there is no definite research as to why some people experience long COVID while others don’t. According to Health Canada, evidence suggests that having two or more vaccinations before infection helps to reduce the risk of developing long COVID. 3
Nutrition
More research is needed into specific diets such as the low histamine diet, and the mediterranean diet when it comes to the management of long COVID. The mediterranean diet includes eating a lot of vegetables, fruit, nuts, whole grains, fish and healthy oils. It is high in vitamins, minerals, and dietary fibre, and researchers have suggested that it may be beneficial in reducing the severity of long COVID. 10
The low histamine diet involves restricting foods and drinks that are considered high in histamine for several weeks and then adding them back into the diet gradually to test tolerance. Foods that are high in histamine include dairy products, shellfish, alcohol, and processed meats, however it has been proven challenging to truly know which foods are high in histamine 11 and because of this it can be hard to implement. More evidence is required to recommend the low histamine for long COVID. It’s important to speak with your doctor or registered dietitian to ensure you are getting the nutrients you need in your diet, tailored specifically to you and what you are experiencing. 12
If you are experiencing long COVID and digestive health issues, talk to your doctor about how to manage your symptoms. What Canada is doing to learn more about long COVID , and how to prevent, and treat the condition can be found here.
References
1. World Health Organization. (2022, December). Post covid-19 condition (long covid). World Health Organization. Retrieved April 11, 2023, from https://www.who.int/europe/news-room/fact-sheets/item/post-covid-19-condition
2. Centers for Disease Control and Prevention. (2022, June 22). Nearly one in five American adults who have had COVID-19 still have “long covid”. Centers for Disease Control and Prevention. Retrieved April 11, 2023, from https://www.cdc.gov/nchs/pressroom/nchs_press_releases/2022/20220622.htm
3. Government of Canada. (2023, March 9). Post COVID-19 condition (long COVID). Post-COVID-19 condition (long COVID) – Canada.ca. Retrieved April 11, 2023, from https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/symptoms/post-covid-19-condition.html
4.Xu, E., Xie, Y. & Al-Aly, Z. (2023, March). Long-term gastrointestinal outcomes of COVID-19. Nat Commun 14, 983. https://doi.org/10.1038/s41467-023-36223-7
5. Government of Canada. (2023, March 24). Covid-19: Longer-term symptoms among Canadian adults. Retrieved April 11, 2023, from https://health-infobase.canada.ca/covid-19/post-covid-condition/
6. Blackett, J. W., Wainberg, M., Elkind, M. S. V., & Freedberg, D. E. (2022). Potential long coronavirus disease 2019 gastrointestinal symptoms 6 months after coronavirus infection are associated with mental health symptoms. Gastroenterology, 162(2). https://doi.org/10.1053/j.gastro.2021.10.040
7. Centers for Disease Control and Prevention. (2022). Long Covid or post-covid conditions. Centers for Disease Control and Prevention. Retrieved April 11, 2023, from https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html
8. Sauerwein, K. (2023, March 6). Covid-19 infections raise risk of long-term gastrointestinal problems. Washington University School of Medicine in St. Louis. Retrieved April 11, 2023, from https://medicine.wustl.edu/news/covid-19-infections-raise-risk-of-long-term-gastrointestinal-problems/
9. Understanding the post covid-19 condition (long covid) in adults and the expected burden for Ontario. Ontario COVID-19 Science Advisory Table. (2022, September 15). Retrieved April 11, 2023, from https://covid19-sciencetable.ca/sciencebrief/understanding-the-post-covid-19-condition-long-covid-in-adults-and-the-expected-burden-for-ontario/
10. Angelidi, A. M., Kokkinos, A., Katechaki, E., Ros, E., & Mantzoros, C. S. (2021, January). Mediterranean diet as a nutritional approach for COVID-19. Metabolism: clinical and experimental. Retrieved April 11, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7833284/
11. Comas-Basté, O., Sánchez-Pérez, S., Veciana-Nogués, M. T., Latorre-Moratalla, M., & Vidal-Carou, M. del. (2020). Histamine intolerance: The current state of the art. Biomolecules, 10(8), 1181. https://doi.org/10.3390/biom10081181
12. Barrea, L., Grant, W. B., Frias-Toral, E., Vetrani, C., Verde, L., de Alteriis, G., Docimo, A., Savastano, S., Colao, A., & Muscogiuri, G. (2022). Dietary Recommendations for Post-COVID-19 Syndrome. Nutrients, 14(6), 1305. https://doi.org/10.3390/nu14061305