Stolper CF, Van Bokhoven MA, Houben PHH, Van Royen P, Van de Wiel M, Van der Weijden T et al. The diagnostic role of gut feelings in general practice. A focus group study of the concept and its determinants. BMC Fam Pract 2009; 10(17). http://www.biomedcentral.com/1471-2296/10/17