Objectives: Flexible sigmoidoscopy (flex sig) is an easily administered method of screening for colorectal polyps and cancer. In some patients, the depth of insertion is incomplete, which may result in missed polyps and cancers. To address the question of prospective patient selection for this procedure, we analyzed the factors affecting depth of insertion of sigmoidoscopies performed in outpatients over a 3-year period.Study Design: The study involved retrospective chart review of procedures performed by one endoscopist over a 3-year period.Outcomes Conclusions: Our study showed a relationship between incomplete examination and increasing age, female sex (more than 75% of the incomplete examinations were in women), poor bowel preparation (in women), hysterectomy, abdominal surgery (in men) and weight loss (in men). Further research is necessary to determine whether a predictive model can be developed that would be useful to select patients most appropriate for flex sig. In those patients in whom difficulty is anticipated, the choice can be made in to perform flex sig under sedation, analgesia, with the help of distraction techniques, or offer primary colonoscopy. Most colorectal cancers arise from adenomatous polyps.1 Their long asymptomatic phase allows for timely screening and adequate treatment of these premalignant lesions. Although screening colonoscopy is regarded as the ideal mechanism of detecting polyps because of its completeness and therapeutic potential, significant logistic barriers prevent its widespread implementation. Studies evaluating colonoscopy have suggested that screening flexible sigmoidoscopy (flex sig) using the 60-cm instrument has the capability of detecting 65% to 75% of polyps and 40% to 65% of colorectal cancers.
2-4The procedure can be performed by many physicians and physician extenders with relatively less investment in training and equipment. Hence, flex sig remains an important means of screening a major segment of the population at risk for colorectal cancer.Incomplete examination is an unfortunate drawback of flex sig, because the procedure is routinely offered without sedation or analgesia for simplicity and ease of administration. Olynyk et al 5 noted that 30% of patients had a depth of insertion of less than 50 cm. Stewart et al 6 suggest a 25% incomplete examination rate and technical difficulty in up to one third of the cases. Painter et al 7 found that in up to a quarter of the patients, the descending colon was not intubated. Using radiopaque clips, Lehman et al 8 noted that a 60-cm examination reached the splenic flexure in only 33% of patients, a 50-to 55-cm examination reached the sigmoid/ descending colon junction in most instances, a 40-