RT Journal Article SR Electronic T1 Mycobacterium avium subspecies paratuberculosis is a cause of Crohn's disease JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 757 OP 760 DO 10.1136/gut.49.6.757 VO 49 IS 6 A1 P Quirke YR 2001 UL http://gut.bmj.com/content/49/6/757.abstract AB