https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-10-142
https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-10-144
https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-10-141
https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-10-143
https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-10-145
https://bmcgastroenterol.biomedcentral.com/articles/10.1186/1471-230X-10-146