European evidence-based Consensus on the prevention, diagnosis and management of opportunistic infections in inflammatory bowel disease. by Rahier, J, Ben-Horin, S, Chowers, Y, Conlon, C, De Munter, P, D'Haens, G, Domènech, E, Eliakim, R, Eser, A, Frater, J, Gassull, M, Giladi, M, Kaser, A, Lémann, M, Moreels, T, Moschen, A, Pollok, R, Reinisch, W, Schunter, M, Stange, E, Tilg, H, Van Assche, G, Viget, N, Vucelic, B, Walsh, A