Footnotes

• Competing interests None.

• Study background and organisation RK is a registrar in general surgery with a special interest in colorectal disease. DCW is a consultant laparoscopic colorectal surgeon in a university teaching hospital. This article originated from a discussion following a multidisciplinary meeting in our hospital. DCW noted that international guidelines were quoted by all interest groups and we wanted to satisfy ourselves that the literature supported this uniform acceptance. Analysis of the literature was performed by RK and both authors contributed to drafting and editing. DCW is guarantor.

• Provenance and Peer review Not commissioned; externally peer reviewed.