BACKGROUND: We aimed to assess the gastrointestinal (GI) manifestations of patients with severe acute respiratory syndrome coronavirus 2 infection and determine factors predicting disease prognosis and severity among patients with GI symptoms. METHODS: In this retrospective study, we evaluated laboratory confirmed (by real-time polymerase chain reaction) inpatient cases of coronavirus-associated disease 2019 (COVID-19), referred to Sina hospital, a tertiary educational hospital of Tehran University of Medical Sciences, from March 10 to May 20, 2020. Demographic and clinical characteristics, laboratory data, outcomes and treatment data were extracted and analyzed using SPSS version 20. RESULTS: A total of 611 patients (234 women and 377 men) were included with 155 patients having GI symptoms. The most prevalent reported GI symptom was nausea/vomiting in 115 (18.8%) of patients. A total of 20 patients (3.2%) only had GI symptoms (without respiratory symptoms). There was no statistically significant difference in the clinical outcomes, disease severity, intensive care unit (ICU) admission and mortality between patients with and without GI symptoms. Aspartate Aminotransferase level was associated with 446% increased risk of disease severity (adjusted odds ratio: 5.46, 95% CI: 2.01 to 14.81) (=0.040) among patients with GI symptoms. Additionally, we found that treatment with antibiotics in addition to mechanical ventilation was associated with increased survival among patients with GI symptoms (Pearson Chi square: 6.22; value: 0.013). CONCLUSION: More attention should be paid to patients with only GI symptoms for early patient detection and isolation. Moreover, patients with GI manifestations are not exposed to higher rates of disease severity or mortality.