RT Journal Article SR Electronic T1 Reply JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1741 OP 1741 DO 10.1136/gut.34.12.1741 VO 34 IS 12 A1 A Ferguson A1 E Arranz YR 1993 UL http://gut.bmj.com/content/34/12/1741.1.abstract AB