P.07.13 FOUR-YEAR EFFICACY AND SAFETY OF AZATHIOPRINE TREATMENT IN THE MAINTAINANCE OF STEROID-FREE REMISSION IN INFLAMMATORY BOWEL DISEASE PATIENTS. (24th February 2016) - Cassieri, C.; Pica, R.; Avallone, E.V.; Brandimarte, G.; Zippi, M.; Crispino, P.; De Nitto, D.; Corrado, C.; Vernia, P.; Paoluzi, P.; Corazziari, E.S.