Severs M, Mangen MJ, van der Valk ME, Fidder HH, Dijkstra G, van der Have M, van Bodegraven AA, de Jong DJ, van der Woude CJ, Romberg-Camps MJ, Clemens CH, Jansen JM, van de Meeberg PC, Mahmmod N, Ponsioen CY, Vermeijden JR, van der Meulen-de Jong AE, Pierik M, Siersema PD, Oldenburg B; COIN study group and the Dutch Initiative on Crohn and Colitis. J Crohns Colitis. 2017 Mar 1; 11(3):342-252