Anemia and iron deficiency in inflammatory bowel disease patients in a referral center in brazil: Prevalence and risk factors - Parra, Rogério Serafim; Feitosa, Marley Ribeiro; Ferreira, Sandro da Costa; Rocha, José Joaquim Ribeiro da; Troncon, Luiz Ernesto de Almeida; Féres, Omar (Arquivos de Gastroenterologia, 2020)