Lack of knowledge about the type and prevalence of gastrointestinal symptoms as a clinical manifestation is one of the reasons for delayed diagnosis and treatment of COVID-19 patients. This review study aimed to systematically review the type and prevalence of gastrointestinal symptoms in COVID-19 patients. To study the gastrointestinal manifestations of COVID-19, we used the 06- PRISMA registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. PubMed, Embase, Web of Science, Google Scholar, and Scopus databases were searched for publications on the gastrointestinal manifestations of COVID-19 with no publication time frame. Articles were found using the following terms and search strategy: [“COVID-19, Coronavirus, 2019-nCoV, Clinical SymptomsGastrointestinal or gastric or intestinal manifestations”]. Out of 27652 papers, 35 papers on a total of 6730 COVID-19 patients up to 2022 met the inclusion criteria. Remarkably, most articles (28 papers, 77.8%) were from China (77.8%). The most common gastrointestinal manifestations were nausea or vomiting (13.1%), diarrhea (11.05%), anorexia (8.7%), and abdominal pain (2.4%), respectively. The findings of the present review revealed that contrary to what was initially assumed in the COVID-19 outbreak, this infection does not manifest only as respiratory symptoms but also as gastrointestinal symptoms. Therefore, clinicians and gastroenterologists must be alert to these unusual cases and fecal–oral transmission during the COVID-19 pandemic and implement preventive strategies.