Context: Within only 30 days after the first announcement of infection with "SARS-CoV-2" in Wuhan, it spread to more than 20 countries and become a pandemic by WHO as a "high alarming level of infection" with 136,343 involved cases all over the world. Methods: To uncover more about the probable gastrointestinal transmission and its clinical manifestations, we reviewed all research publications with keywords including: "COVID-19", "SARS-CoV-2", "Coronavirus", "outbreak", "ARAS-CoV" in Medline, Scopus, Google Scholar as well as all news in social media about "novel COVID-19 pandemic". Out of 40 recent publications, 10 articles were studied by 2 authors. Results: Although the SARS-CoV-2 tends to infect respiratory epithelial cells through the respiratory tracts, recent investigations detected the virus in the stool specimen, raising the question of the fecal-oral transmission route. Different studies showed that almost all gastrointestinal signs and symptoms were seen in elderly patients (more than 65 years old). including anorexia (40%), nonspecific abdominal pains (8%), diarrhea (10%) and nausea and Vomiting in about 8% of patients. Anorexia and generalized abdominal pain suffer many treated cases even 10-20 days after negative blood tests (like CRP, lymphopenia) and negative PCR of respiratory samples. The main reason for this prolonged anorexia and abdominal pain may be due to the long persistence of COVID-19 in the gastrointestinal tracts after primary treatment. Conclusions: Comparing to SARS, patients with COVID-19 showed less diarrhea, nausea, vomiting and/or abdominal discomfort before respiratory symptoms. Feces as a potential contagious source of Viral RNA can last even after viral clearance in the respiratory tract. We strongly recommend all cured patients of COVID-19 to disinfect and clean their toilets until 17-20 days after negative blood tests and solving their respiratory disorders. Gastrointestinal manifestations have seen in all men while no women referred with GI signs.