Association Between COVID-19 Vaccination and Gastrointestinal Manifestations: A Cross-Sectional Study

To investigate a possible association between COVID-19 vaccines and gastrointestinal manifestations.

A cross-sectional study employing convenience sampling was used to collect data using an online survey developed by the research team in Amman, Jordan. The study was web-based and designed with Google Forms and was carried out between October 1, 2022, and February 1, 2023. Nine hundred eighty-seven responses were included, aged 18 and above and had taken the COVID-19 vaccine with their complete agreement to participate in the study, using the Chi-square test and binary logistic regression models with (95%) confidence interval performed using SPSS version 25.0 (IBM Corp, Armonk, NY, USA). Statistical significance was set at p < 0.05.

Participants were 987 individuals; nearly half were between 18 and 25 years old, 65% were female, and 75% had bachelor's degrees. Seventy percent received two doses, with 37.5% reporting side effects. Females reported significantly more side effects than males (41.3% vs. 30.5%, p = 0.001); those with previous COVID-19 infection reported higher side effects (41.6% vs. 34.7%, p = 0.028); and hospitalized individuals due to side effects had higher side effect rates (72.4% vs. 36.4%, p < 0.001). The second dose correlated with fewer side effects, with specific symptoms (indigestion, anorexia, flatulence, and abdominal pain) exhibiting significant differences (p < 0.05).

This study found a positive association between COVID-19 vaccines and gastrointestinal side effects, including significant heartburn, anorexia, and bloating.