Terminal ileal photography or biopsy to verify total colonoscopy: does the endoscope agree with the microscope?

Various modalities exist to document the extent of colonoscopy, including a terminal ileum (TI) biopsy, which is considered the criterion standard by some authorities. A TI biopsy adds to procedure costs, is potentially hazardous, and the detection of pathology in routinely acquired biopsy specimens of a macroscopically normal TI is limited. A safer, less costly alternative for documenting total colonoscopy is desirable.

To evaluate the effectiveness of TI photography as a means of documenting total colonoscopy. We also assessed the diagnostic yield of TI biopsies in patients with a macroscopically normal TI.

Prospective, observational study.

District general hospital in the United Kingdom.

A total of 232 unselected patients undergoing colonoscopy, TI intubation, photography, and biopsy.

Independent, experienced endoscopists were asked to state whether villi (and, therefore, TI entry) were "definitely," "probably," or "definitely not" depicted in TI photographs. This was compared with TI histology as a means of verifying total colonoscopy. The diagnostic yield of biopsy specimens from a macroscopically normal TI was determined.

Reviewers agreed that villi were "definitely present" in 93.8%, "probably present" in 5.9%, and "definitely not" present in 0.3% of cases, with excellent interobserver agreement (kappa value = 0.778, P < .0001). TI photographs "definitely" depicting villi (93.8%) did not differ significantly from histology confirming TI mucosa (96.1%, P = .285). Microscopic evidence of pathology was only detectable in 2.3% of patients with an endoscopically normal TI.

TI photography is an effective, safe, and cost-effective means of documenting total colonoscopy. Routine biopsy of a "normal" TI has a low diagnostic yield.