RT Journal Article SR Electronic T1 Rare cause of chronic abdominal pain JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 340 OP 340 DO 10.1136/gut.2009.185603 VO 60 IS 3 A1 Maqsood Ahmed Khan A1 Sonu Dhillon YR 2011 UL http://gut.bmj.com/content/60/3/340.abstract AB