RT Journal Article SR Electronic T1 Understanding the delayed onset of action of azathioprine in IBD: are we there yet? JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 325 OP 326 DO 10.1136/gut.2008.163485 VO 58 IS 3 A1 Imke Atreya A1 Markus F Neurath YR 2009 UL http://gut.bmj.com/content/58/3/325.abstract AB