RT Journal Article SR Electronic T1 Colorectal JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP S64 OP S66 DO 10.1136/gut.33.1_Suppl.S64 VO 33 IS 1 Suppl YR 1992 UL http://gut.bmj.com/content/33/1_Suppl/S64.abstract AB