Rigid sigmoidoscopy: an evaluation of three parameters regarding diagnostic accuracy.

Rigid sigmoidoscopy is the method employed for examining the rectum and sigmoid colon in most general surgical clinics. Commonly, this is performed without any prior preparation of the bowel and with the patient in the left lateral (Sims') position. This study was designed to assess three factors relating to this method: preparation of the bowel; position of the patient; and the experience of the operator. The study shows that diagnostic accuracy without preparation is adequate in only 50 per cent of cases but, by employing a preliminary disposable (Fletcher's) enema, this can be improved to 80 per cent. Employing the knee-elbow position gave only slight advantage over the usual Sims' position and operator experience did not improve diagnostic accuracy once familiarity with the use of the sigmoidoscope had been achieved. The study underlines the importance of preparation as an essential prelude to sigmoidoscopy.