RT Journal Article SR Electronic T1 Reply JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 861 OP 861 DO 10.1136/gut.34.6.861-c VO 34 IS 6 A1 Spencer, J YR 1993 UL http://gut.bmj.com/content/34/6/861.4.abstract AB