Prospective evaluation of a small caliber upper endoscope for colonoscopy after unsuccessful standard examination.

Colonoscopy is unsuccessful in some patients because of a fixed sigmoid loop or anatomical stenoses. We prospectively evaluated 1600 patients undergoing colonoscopy at Virginia Mason Medical Center from December 1, 1986 to November 31, 1987. Thirty-one procedures (1.9%) failed to reach the splenic flexure because of functional or anatomic stenoses. Attempt at pancolonoscopy with a 9.8-mm diameter, 102-cm length endoscope (Olympus XQ) was successful to the right colon in 73% and cecum in 60% of these patients. Two thirds of the successfully intubated patients had clarification of radiographic abnormalities or delineation of additional colon pathology. There were no complications or instrument damages, but limitations included short scope length and small suction channel. We conclude that small diameter upper endoscopes can be used safely and effectively for colonoscopy in a subset of patients in whom conventional colonoscopy is unsuccessful.