Rectal retroflexion: an essential part of lower gastrointestinal endoscopic examination

Retroflexion of the endoscope during rectal examination may increase diagnostic yield but is not routinely performed because of concerns about safety and a lack of appreciation of its importance. The purpose of this study was to examine the yield, safety, and tolerance of endoscopic rectal retroflexion.

Prospective cohorts of subjects undergoing unsedated screening flexible sigmoidoscopy were examined with and without routine retroflexion. Pain scores were recorded.

A total of 526 subjects (mean age 60 (range, 55-66) years) underwent flexible sigmoidoscopy in the first period when the endoscope was not routinely retroflexed. Of these, 480 (mean age 60 (range, 55-66) years) were subsequently examined with routine retroflexion. Retroflexion was impossible in 17 subjects (3.5 percent) because of discomfort. In the second group, 12 subjects (2.5 percent) had polyps in the lower rectum seen only on retroflexion. Of these, eight had metaplastic and four had adenomatous polyps (3 tubular <5 mm, 1 tubulovillous 15 mm). There was no difference in mean pain scores between the groups (no retroflexion = 2.13, retroflexion = 2.18).

With an adenoma pick-up rate of 8 to 12 percent for screening flexible sigmoidoscopy, retroflexion increases adenoma detection by approximately 1 percent without adverse effects and should be an integral part of flexible sigmoidoscopy.