PT - JOURNAL ARTICLE ED - , TI - ANSWER AID - 10.1136/gut.2008.164939a DP - 2009 Apr 01 TA - Gut PG - 544--544 VI - 58 IP - 4 4099 - http://gut.bmj.com/content/58/4/544.short 4100 - http://gut.bmj.com/content/58/4/544.full SO - Gut2009 Apr 01; 58