We performed a systematic literature search to identify published and unpublished studies using OVID Medline and preprint servers (medRxiv, LitCovid, and SSRN) up until April 5, 2020; major journal sites were monitored for US publications until April 19, 2020. We pooled the prevalence of diarrhea, nausea, vomiting, and abdominal pain, as well as liver function tests abnormalities, using a fixed-effect model and assessed the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework.