There has been a deluge of scientific data since coronavirus disease 2019 (COVID-19) was first reported. The effects of COVID-19 on the digestive system are now increasingly well understood. This article aims to review the current data on the effects of COVID-19 on the digestive system with particular emphasis on preexisting digestive diseases and its implications on nutrition practices.Evidence has shown that Severe acute respiratory syndrome coronavirus 2 virus affects the gastrointestinal (GI) tract, pancreas and hepatobiliary system resulting in different GI manifestations. Several preexisting digestive diseases have been investigated. These studies have revealed that these special patient population groups are generally not at an increased risk to contract COVID-19, but are susceptible to develop increasing severity of disease. Aside from medical therapy, optimizing nutritional care has a beneficial role in this group of patients.GI manifestations of COVID-19 in addition to preexisting digestive diseases have an impact on patient's nutrition. Digestion, absorption and transport of nutrients may be impaired. To date, there are no existing guidelines on the nutritional management of patients for this particular at-risk group. Most nutrition practices are based only on observations and clinical experience. Basic prepandemic nutrition care principles are primarily followed but often individualized based on clinical judgment.
