RT Journal Article SR Electronic T1 Guidance on large bowel surveillance for people with two first degree relatives with colorectal cancer or one first degree relative diagnosed with colorectal cancer under 45 years JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP v17 OP v20 DO 10.1136/gut.51.suppl_5.v17 VO 51 IS suppl 5 A1 M G Dunlop YR 2002 UL http://gut.bmj.com/content/51/suppl_5/v17.abstract AB