The characteristics of gastrointestinal symptoms in patients with severe COVID-19: a systematic review and meta-analysis

Although primarily a respiratory illness, several studies have shown that COVID-19 causes elevation of liver enzymes and various gastrointestinal (GI) symptoms. The aim of this study was to undertake a systematic review and meta-analysis to determine whether the presence of gastrointestinal (GI) symptoms contributed toward COVID-19 severity, and identify the GI symptoms characteristic of severe COVID-19. We conducted a literature search of PubMed from December 1, 2019, to June 30, 2020, and identified all reports with GI symptoms reported. A meta-analysis comparing the severity of COVID-19 with the presence of liver enzyme elevation and GI symptoms was performed using RevMan version 5.4. Pooled data from 15,305 unique reverse transcriptase–polymerase chain reaction positive COVID-19 patients from 44 studies were analyzed. We found that the severe COVID-19 patients significantly had abdominal pain compared to the non-severe COVID-19 patients (OR = 2.70, 95% CI 1.17–6.27, Z = 2.32, p = 0.02, I(2) = 0%) by analyzed 609 patients of 4 studies who reported both abdominal pain and COVID-19 severity. However, there was no significant difference in the incidence of diarrhea, nausea, or vomiting between the two groups. Thus, this systematic review and meta-analysis demonstrated that abdominal pain could be characteristic of severe COVID-19 infections. Compared with other viral infections that primarily infect the respiratory system, patients with COVID-19 have a slightly lower frequency of diarrheal symptoms with abdominal pain. However, to confirm this, further studies with COVID-19 patients across various countries and ethnicities are required. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00535-021-01778-z.