Submitted on: 08 March 2000.
Revised on: 28 March 2000.
Accepted on: 09 April 2000.
United European Gastroenterology Journal
Submitted on: 06 October 2001.
Revised on: 04 November 2001.
Accepted on: 22 November 2001.
United European Gastroenterology Journal
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Submitted on: 09 March 2003.
Revised on: 14 April 2003.
Accepted on: 07 May 2003.
United European Gastroenterology Journal