https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-35 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-42 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-33 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-41 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-45 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-40 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-38 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-44 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-37 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-39 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-43 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-34 https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-11-36