Recent studies have reported that some gastrointestinal symptoms, such as diarrhea, vomiting, nausea, and abdominal pain, can be found in patients with COVID-19, as a less common manifestation [6, 8, 9]. However, hitherto, gastrointestinal bleeding has not been reported in COVID-19 patients. Our study showed that gastrointestinal bleeding can be found in a proportion of patients with severe COVID-19. Gastrointestinal bleeding in patients with severe COVID-19 occurred usually during the course of disease, suggesting that gastrointestinal bleeding may also be a manifestation of COVID-19, although not one of the initial symptoms. In our study, the presentations of gastrointestinal bleeding were not obvious, and in most patients, gastrointestinal bleeding was found only by fecal occult blood test. Our findings imply that frequent fecal occult blood test is essential for timely detection of gastrointestinal bleeding in patients with COVID-19, especially in severe patients, to prevent acute aggravation.
Some previous studies discovered that COVID-19 acts on angiotensin-converting enzyme 2 (ACE2) [10, 11]. ACE2 is expressed not only in the lungs, but also in the small-intestine enterocytes, crypt cells, and the colon, which may cause inflammation susceptibility of the gastrointestinal tract [12, 13]. In addition, anticoagulants, antiplatelet drugs, and glucocorticoids are often used in severe forms of COVID-19, which puts the patients to a higher risk of gastrointestinal bleeding. Although most of the gastrointestinal bleeding was mild in our study, it is important for first-line clinicians to take measures in advance to prevent massive gastrointestinal bleeding.
Gastrointestinal bleeding encompasses various forms of bleeding from the oral cavity to the rectum. A small amount of bleeding can only be detected by a fecal occult blood test. When a large amount of blood is lost in a short period of time, symptoms may include vomiting red blood, vomiting black blood, bloody stools, or black stools, which may be life-threatening. In our cases, patients with black stool and bloody stools were given blood transfusion.
We compared the characteristics between mild bleeding patients and severe bleeding patients, and tracked their final outcomes. The outcome was mainly survival or death. No statistical analysis was performed because of the small sample size. We found that the proportion of patients using anticoagulants drugs and antiplatelet drugs was slightly higher in the severe bleeding group. This reminds us that great attention to gastrointestinal bleeding is needed when using anticoagulants and/or antiplatelet drugs in patients with COVID-19. In contrast, the use of glucocorticoids and history of gastrointestinal bleeding were similar in both groups. In terms of prognosis, all of the patients in the severe bleeding group recovered, while the patients who died were in the mild bleeding group. Our research suggested that blood transfusion support therapy prevented mortality of patients with severe gastrointestinal bleeding. However, the sample size is limited and more data is needed.
This study had several limitations. The sample size was small and there may be bias, so a larger, multi-center clinical study is needed. In this study, patients did not undergo endoscopy to determine the cause of bleeding. Endoscopy is generally used to diagnose and treat hospitalized gastrointestinal bleeding patients; however, the endoscopy in COVID-19 patients with gastrointestinal bleeding puts the endoscopy staff and anesthesia staff at a high exposure to the virus [14, 15]. In the early stage of the pandemic, protection of staff was limited, and gastrointestinal examination could not be performed. It is recommended that, in the future, COVID-19 patients with obvious gastrointestinal bleeding should undergo gastrointestinal examination to determine the cause of gastrointestinal bleeding if body condition can tolerate it.