RT Journal Article SR Electronic T1 Current gastroenterology JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 414 OP 415 DO 10.1136/gut.29.3.414-a VO 29 IS 3 A1 Michael N Marsh YR 1988 UL http://gut.bmj.com/content/29/3/414.2.abstract AB